GOAT RAISING
The demand for goat meat is ethnic based. However, there is an emerging demand for goat meat as a gourmet item. In addition, health concerns regarding red meat does not apply to goat meat, which compares favorably with chicken in terms of calories and protein, but is lower in total and saturated fat (see table below).
Comparison of Goat Meat to Other Meats (3 oz roasted) Animal
Specie Calories
Total
Fat SaturatedFat Protein grams Goat 122 2.58 .79 23 Beef 245 16.00 6.80 23 Pork 310 24.00 8.70 21 Lamb 235 16.00 7.30 22 Chicken 12 0 3.50 1.10 21
suggesting that beef pastures could support between a half and one million goats. The complementary effects of grazing cattle and goats on the same farm provide an opportunity to enhance and augment North Carolina existing beef cattle industry by improving pasture condition and feed quality. North Carolina farmers are searching for new sources of farm income and for ways to diversify their operations, and develop sound and cost effective environmental practices to stay competitive in a global economy. Goat farming seems to be independent of scale. Small, part-time farmers with only a few acres can raise enough animals to provide an income supplement. On the other hand very large farms can
efficiently integrate a meat goat enterprise to aid in diversification of the farm.
National Sustainable Agriculture Information Service
www.attra.ncat.org
ATTRA is the national sustainable agriculture information service operated by the National Center for Appropriate Technology, through a grant from the Rural Business-Cooperative Service, U.S. Department of Agriculture. These organizations do not recommend or endorse products, companies, or individuals. NCAT has offices in Fayetteville, Arkansas (P.O. Box 3657, Fayetteville, AR 72702), Butte, Montana, and Davis, California.
TIPS ON GOAT RAISING
I. INTRODUCTION
The optimum potential of goat as one of the main sources of milk and meat has not been fully tapped in the Philippines. The goat is popularly known as the poor man's cow because children and old folks who can not afford cow's milk prefer drinking goat's milk. Aside from being cheap, goat's milk is more digestible compared to cow's milk.
The goat is a clean animal and its male odor is only present during the breeding season. Female goat does not smell. Contrary to myth, goats do not I eat trash. They do, however, lick the labels of tin cans to taste the glue on the label's back.
Goat raising is undertaken commonly by small farmers or backyard raisers. A farmer raises an average of one to two head goats. Only a handful of commercial-scale goat farms can be found in the country.
As of 1998, goat population is estimated to be 3,083,262 compared to the 1988 population of 2,120,110 that shows an average annual increase 4.54 percent.
In a study conducted by a government agency, it was found out that goats are multi-purpose ruminants producing 58.4% milk, 35.6% meat, 4.3% hide, and 1.7% fiber. According to them, these small ruminants can provide the answer to improve nutritional requirements of the predominantly rural farm families scattered allover the archipelago.
II. BREEDS TO RAISE
There are many breeds of goat worldwide but the available breeds in the Philippines are as follows:
1. Anglo Nubians - basically a tropical breed that was successfully adapted in the western countries. Its distinguishing features include drooping and pendulous ears, and a brown hair or a combination of brown and black. It has a long body that usually weighs 70-90 kilograms at mature age and produces 1-21iters of milk daily.
2. Boer - a meat type breed with distinct white body color and usually black or reddish brown from rear legs to the head. The goat weighs an average of 90 kilograms at mature age.
3. Saanen - originated from Switzerland, is a pure white to off-white in color. It holds the distinction as the highest milk producer (1.8 liters daily), that weighs an average of 70 kilograms-
4. Toggenburg - also from Switzerland, have distinct white markings on the face, legs and tail and an erect ears like the Saanen. Milk production averages 1.5 liters daily.
5. Alpine - also of European breed has a color that ranges from off-white to red, to black. An alert breed of medium to large size, it weighs I 70 kilograms at mature age. It posses an upright ears and a straight face, the breed produces 1.5 liters of milk daily.
6. Native - the breed are small, stocky and low-set. Colors range from red, white or black or a combination of these colors. Milk production is just enough for its kids. It weighs 20 to 30 kilograms at mature age.
SELECTION CTITERIA
A. Does
1. Does should be purchased from a locality or area with similar climatic conditions;
2. Native or graded does should not be less than 25 kilograms; 3. Udder should be palpated for size, detection of lumps, and other
abnormalities;
4. Teats should be uniform at length and large enough for easy milking;
5. It must have a good appetite, possessing alert eyes, and well formed pupils; and
6. Do not buy breeders from markets; B. Bucks
1. One year old breeder or buck that have successfully mated once is desirable;
2. Acquired buck should be accompanied by pedigree records; 3. It must have a good producing line based from farm records; 4. Buck must come from doe with high twinning rate;
5. Buck must be active and ready to breed in-heat doe; 6. Replace buck, preferably, every three years;
III. MANAGEMENT
A. Housing
Whether on range or confined feeding, housing provisions are necessary. A goat house or shed must be built to provide shelter. Goats are afraid of rain and wetness as these make them prone to pneumonia. They also prefer sleeping in elevated platforms like a stair type arrangement. It must be well ventilated and drained, and easy to clean. Feeding racks (silage, water, mineral and concentrate) should be accessible to both animals and caretaker, preferably in the front of the aisle. Flooring should be provided and elevated at least 15 degrees to facilitate cleaning and drainage.
Separate pens should be provided for lactating and dry does, kids, growers and bucks. The buck pen should be visible to breeding does yet far enough to avoid transfer of the typical goat smell especially to lactating does when milk is to be sold.
Space Requirement for Goats:
Flooring Feeding
(Meter2) (Linear Cm. )
Does/Bucks/Adults 0.75-1.50 15.24-25.40
Growing 0.50-0.75 10.16-15.24
Kids 0.20-0.50 7.62-12. 70
A fenced loafing area beside the goat house must be provided (100 to 150 m2/50 hd. ), complete with feeding racks and water troughs, to allow animals to loaf freely. Flooring of the area must be cemented to facilitate drying. Cogon and nipa as roof materials are preferred in hot and humid areas.
Ventilation is of utmost importance. Majority of pneumonia cases can be traced to excessively warm anQ humid interior and sudden changes in temperature. Allow a 0.5 to 1 ft clearance between floor to wall
and wall to beam to create an adequate circulation and to lower draft. It is desirable to maintain an interior temperature of 28 to 30°C. It has been established that above 30°C ruminants are inhibited from eating.
Lighting may also be provided in the barns during the night. Goats consume up to 30% of the day's intake during the night when light is provided.
B. Fencing
Nine-eye hog wire is the cheapest and most effective fencing available locally. Posts must be staked every 2 meters. Goats are fond of pounding their feet and scraping their bodies on the fences so it must be sturdily built. Barbwire fencing requires a minimum of four strands so it becomes more costly besides making goats prone to wounds.
C. Pasturing
A well developed/improved pasture can carry up to 15 head/ha. When a combine grazing confinement method is observed, provision of a developed 3 ha./50 hd. Pasture divided into 9 paddocks will be desirable. Separate pastUre paddocks should be provided for the dry doe, buck kids and growers. Pasturing during the cool times of the day is commonly due. D. Care of Dry and Pregnant Doe
If the doe is being milked, dry (stop milking) at least 1 Y2 to 2 months before kidding date. This will give her enough reserve for the next lactation. Put all dry does in one compartment. One week before kidding, place her in a separate kidding pen. This can be predicted by swelling and discharge from the vulva, engorgement and waxing of the teats and constant lying down of the doe. Avoid any form of noise in the kidding area. Sometimes it is necessary to help the pregnant doe during the kidding, especially to native does bred with pure bucks because the kids are bigger. Dystocia, or difficult delivery, is common in these cases. Be sure that the presentation is right before attempting to pullout the kid. In anterior presentation, both front legs and head are presented and in posterior presentation, both hind limbs come out at the same time. Oversized kids should be pulled out with an even, continuous pressure. In difficult cases, it is best to see a practicing veterinarian.
E. Care of the Lactating Doe and Newborn Kids
Immediately after delivery, wipe the kid's mouth, nose and body with a clean, dry cloth and massage the thoracic area to initiate breathing.
Normally, the mother does this, but sometimes the mother is too weak to do it. Be sure no mucus is clogging the airways. The kids must be able to suck within one hour. For very weak kids, feeding collostrum through a stomach tube usually produces dramatic results.
First time mother sometime are reluctant to suckle their young due to udder pain caused by over engorgement of milk. Restraining the doe for the first suckling will usually relieve udder pain. If colostrum in the udder is not fully consumed by the kid, stripping (manually milking out excess) will be necessary to prevent mastitis. The placenta must come out within 24 hours from expulsion of the fetus.
Tie the umbilical cord with a sterile string and apply disinfectant. Allow the kids to suckle for the first 4 to. S days. If the doe is to be milked, separate the kids from the mother and start feeding using a baby bottle (8 oz. Size), (refer to feeding guide for dosage). If the doe is not to be milked, the doe can be taken out of the pen for feeding and returned to the kid three times a day and the whole night. This method will ensure greater livability to the kid by not exposing it to the elements, and proper feeding of the doe. Does weaned early (4 to 5 days) usually return to heat after 1 to 2 months.
When the doe comes into heat, introduce it to the buck, not vice-versa. Two services a day for two days is an optimum. If the doe does not conceive, heat may return in 8 to 12 days. Higher conception is accomplished in the secondary heat. If breeding is successful, milk production drops after one month and the right side of the abdomen starts to fill up.
Milking
Milking periods must be established and strictly adhered. If milking is done twice a day, e.g. 6 AM and 6 PM, the process should not be delayed or advanced. Possibly, same personnel should be used. Goats can withhold milk, so unnecessary changes in the routine should be avoided.
Milk quickly and continuously
Milk let down can be initiated by washing the udder with lukewarm water and wiping with a clean towel. All milking utensils, especially the milkers' hands, must be thoroughly cleaned.
Feed concentrates during milking
This serves as incentive to the goats for them to enjoy and look forward.
Contrary to popular belief, properly drawn and processed goat milk have no offending smell. During milking, the buck should not be near the doe to avoid transfer of the typical goat smell to the milk.
F. Care of Weanling and Growing Kids 5
Place all weaned kids in a separate pen, and if possible, according to size. If male kids are to be raised for meat, castrate as early as possible, preferably within the first month. If female are to be raised for milking, check for excess teats and have them removed. Horn buds usually appear within the first to third month. De-horn when buds reach the size of a fingernail. Separate males from females at the age of four months. Goats sometimes reach puberty at this age.
Start breeding females at 8 to 10 months. Bucks can start breeding at the same age.
G. Care of the Breeding Buck
The breeding buck must always be confined separately but always visible to the does. The buck is the source of the typical goat smell such that direct contact with the doe must be avoided. Provide a loafing area. One to two years old buck can make 25 to 50 doe services a year, an older buck more.
H. Breeding
Does reach puberty from 4 to 18 months. Best breeding age will be 10 to 12 months, depending on desired weight. Limit yearling buck services to 25 doe services/year. Older bucks can cover up to 75/year. Buck to doe ratio is I :25.
Reproductive Characteristics of Goats
Age of puberty 4- 8 months
Cycle of type Polyestrus
Cycle length 18 -21 days
Duration of heat 2- 3 days (secondary
Heat: 8- 12 days after) Gestation period 150 (+/-) 5 days
Signs of Heat or Estrus:
1. Mucus discharge from the vulva, causing matting of tail hair. 2. Uneasiness, constant urination, lack of appetite and bleating. 3. Seeks out or stays near the buck and lets herself be mounted. When breeding, always introduce the doe to the buck, not to the doe herd. Particularly when bucks have not been used for a long time, it will be dangerous to mix it with a herd of pregnant does for d1ey will breed indiscriminately. Two to four breedings during the heat period will suffice.
It is highly impractical if not economical to raise pure breed goats, unless the main purpose is to sell breeders. The preferred method will be to upgrade local native or grade does with pure bucks. Crossbreeds usually perform better than pure ones under local conditions. Infusion of two or more bloodlines into the native doe will elicit a better product due to hybrid vigor. Three-way crosses between the native, any of three Occidental breeds and the Nubian has produced a greatly superior animal than any of the three under our conditions. Higher milk production should be the main consideration for it will not only mean bigger kid but also more milk for human consumption. A maximum infusion of75% foreign bloodline must be observed to retain the natural resistance of the native. Never practice inbreeding unless fully knowledgeable in breeding techniques. On the otherhand, intensive culling, especially in milking herds, will largely be beneficial.
Dystocia is very common in crossing natives with large pure breeds due to the invariably large size of the unborn kids. Crossbreed birthweights of up to four kilos for multiple births and up to six kilos for single births have been observed while native birthweights reach only 2 and 4 kilos for multiple and single births, respectively. Thus, in crossbreeding, large native does with a minimum weight of25 kilos or more and those that have given birth at least once, should be used. Providing human assistance during birth will also be ofhelp in saving kids, but this should be done only when necessary.
Anestrus, or failure to come in heat, is a common problem most particularly with high-producing does. Vitamin, mineral and other nutrient deficiencies, infections of the genital tract and hormone deficiencies are some of the various causes. Several hormones, like prostaglandin, progesterone sponges and implants and pregnant mare serum (PMS) have been used with varying rates of success. Routine administration of oxytocin right after kidding and before weaning (5 days) aids in faster expulsion of the placenta, uterine fluids and in the rapid regression of the uterus. Routine Vitamin A, D & E injections to breeding herds also contribute to reproductive well being.
Fifty percent of breeding problems can be traced to the buck used. Routine check up of the bucks' health condition, especially of the , genito-urinary tract, should be done. Preputial scraping, blood tests and , sperm motility tests
are some very useful procedures to follow in , successful buck management. Always consult a trained veterinarian to do these tests.
Procedures in Artificial Insemination (AI) *
1. Keep the semen warm - Goat semen is extremely temperature sensitive
and will be irrevocably damaged if improperly handled. Never allow the temperature of semen thawed in 95°F water to drop below 80°F. If at all possible, perform your inseminating in a heated environment. Thoroughly pre-warm the inseminating gun before inserting the straw. If no heated facility is available, use a heating pad or hot water bottle to keep the semen and related equipment at the proper temperature before use.
2. Inseminate at the proper time - Most successful inseminators agree that
conception rates are generally highest when breeding during the later third of standing heat. In our experience, breeding a doe approximately 6-10 hours before she goes out of standing heat has yielded the best results. During the main part of the breeding season and with most does, this means breeding approximately 24-30 hours after the onset of estrous. 3. Deposit semen deep intracervically - Always measure the depth of
penetration of the breeding gun. After passing through several cervical rings, place a clean breeding sheath in the speculum alongside the gun with its tip against the back wall of the does' vagina. Compare the difference between the length of the two breeding sheaths. Ideal depth of penetration is approximately I Y2 inches.
4. Use only one straw per breeding - Recent research in goat production
indicates that sperm cells introduced into the doe's reproductive tract tend to form "colonies" in the mucous present in the folds of the cervix. After undergoing a short maturation process, they migrate in fairly constant numbers from the cervix into the uterus and ultimately on to the oviduct, where union with the egg actually occurs. Quantities of viable sperm cells sufficient for adequate fertilization should remain in the reproductive tract for up to 18 hours after the first insemination. The use of a second straw of semen later in heat can cause a disruption in the orderly migration of mature sperm cells from the colonies already established in the cervix and actually reduces the chance for conception.
5. Avoid attempting to AI does who remain in standing heat longer than 48 hours - For reasons not fully understood, does exhibiting extremely
lengthy standing estrus generally fail to conceive when artificially inseminated. Abnormally long heats are more common early in the breeding season, and occur more frequently in some areas than others. Fortunately, in most cases the condition is transitory, and most does begin
to exhibit more normal estrous behavior as the breeding season progresses.
6. Use of hormones to synchronize does, though successful and useful, may result in lowered conception rates - Many breeders have reported
disappointing AI conception rates after having used hormones to induce estrus in goats. If it is necessary to synchronize a group of does in this way, wait until the first natural heat after the drug induced estrus before artificially inseminating. Be aware that the use of prostaglandins may cause erratic estrous behavior in some animals, which can persist for several months.
7. Deposit semen very slowly -Rapid expulsion of semen from the breeding
gun can damage sperm cells and cause irritation of the doe's reproductive tract. Count to fifteen very slowly while depressing the plunger on the breeding gun.
8. Don’ t haul a doe in heat to have her bred A - If you do not have your
own equipment or storage tank and must transport your does to have them bred, plan to board them for several days before they are due to come into heat. It is probably preferable; if you cannot breed your own does yourself, to have the AI technician come to your farm to perform the insemination. You can do your own inseminating even if you do not own your own tank. Small quantities of semen can be transported and stored for a half day or longer in a stainless steel thermos bottle. Make sure that you do not screw the lid onto the thermos as possible rupture can occur as a result of nitrogen gas pressure.
9. For best conception rates, inseminate only does with regularly occurring heats and no history of breeding or kidding problems - Does that are
difficult to settle by natural service are not good AI candidates. Proper nutritional management also pays a big role in reproductive efficiency. Does that are overly fat or thin are less than ideal prospects for AI breeding. Virgin does should present no problem so long as they weigh at least 75 lbs.
10. Don’t attempt to Al a doe on her first heat cycle of the season - The first
heat cycle of the year is often infertile and is frequently followed by a second heat 5-8 days later. Conception rates will usually be higher if you wait until the second or later heats to do your breeding. Likewise, conception rates may drop off if you attempt AI towards the very end of the normal breeding season.
11. Watch your does carefully 17 - 22 days after breeding them by Al -F or
some reason, some does who conceive by AI experience a false heat three weeks later. Although they may exhibit otherwise typical estrous
behavior, such does will seldom allow a buck to mount them. If in doubt, submit a milk or blood sample to a testing laboratory for a progesterone assay.
12. Keep detailed records of your AI breeding - Note such factors as color
and consistency of cervical mucous, depth and relative difficulty or cervical penetration, length of standing heat both before and after inseminating, weather conditions, time required to complete the insemination, and other pertinent information. These records will often be of great help in explaining why some does settle and others did not.
13. Know your does - Chart the heat cycles of each of your animals on a
calendar. Observe them at least three times daily during the breeding season of signs of estrous behavior. Note the number of hours that each doe remains in standing heat, and the relative intensity of estrous activities such as flagging, fighting and mounting other does.
14. Observe proper sanitary procedures - Specula should be thoroughly
washed and sanitized between use. Scrub the doe's external genitalia with soap and water and dry completely before inserting the speculum. Do not use iodine-based products, as iodine is spermicidal. Take care not to touch the part of the speculum or breeding sheath which is inserted in the doe's vagina.
15. Attend an AI school - Attendance at an AI school taught by a competent
and knowledgeable instructor can increase your chances of success with AI. As with any other acquired skill, hands-on experience is the best way to develop the confidence and correct techniques necessary to use AI effectively.
16. Do your homework - Artificial insemination is only a tool, albeit a powerful
one. To be really successful with AI, you need to do more than just put kids on the ground. Only through intelligent selection of sires compatible with the objectives of a carefully thought out breeding program can AI benefit you, the breeder, or the meat and dairy goat industry.
I. Other Management Practices
1. HoofTrimming - Goats' hooves under confinement are usually overgrown.
Trimming is then required. A rose pruner and a small curved knife are adequate tools. Cut excess hoof until level with the frog (white-centerpart). Untrimmed hooves will cause lameness and make it prone to foot rot. Bucks refuse to mount when having sore feet.
2. Dehoming - Especially in milking herds, dehorning is essential. A
dehorned animal is more docile than a horned one. It will also eliminate unnecessary wounds due to fighting. Dehorn when horn buds appear (2 to
4 mos.) using hot iron cautery. A Y2 inch GI pipe is an effective and cheap material for cauterizing. Chemical cautery is not preferred because kids tend to lick one another and may therefore lead to cauterized or burned tongues.
3. Castration - Castration of unwanted male goats is preferable within the
first month of age. The testicles at this age are still not developed; thus there is lesser bleeding and stress. Castrated males grow faster than uncastrated males and are free of the goaty male odor.
4. Tattooing, Ear Notching and Other Forms of Identification - In order to
keep track of individual animals, a positive identification are needed. No recording is possible without this. Ear notching is done more commonly because of permanence and easy identification. Refrain from using plastic tags. Tattooing causes no deformities but requires special tools that may be costly.
5. Recording - For a good breeding herd program, a proper and well-kept
recording system is necessary. The record reflects all the essential data of individual animals. Below is an example:
INDIVIDUAL RECORD
Goat No./Name ___________________ Date of Birth ________________ Sire ____________________________ Birthweight, Kg ______________ Dam ____________________________ Color ______________________ Sex ____________________________ Littermates -(Single. Twin. Triplet)- Method of Disposal ________________ Wt. At Disposal, Kg. __________
Date Breeding Sir e Date Kidding Kid No. Sex Birth Weight Milk Prod. Lact. Days Ave. Prod. Remarks
Herd Data: Kidding Rate
Kidding Frequencies Productive Pattern
Superior to Doe Combination
Other Data: Forage Production
Forage and Concentrate Intake Health and Treatment Situations
IV. FEEDING
A. Recommended Pasture Grasses and Legumes
Goats, like other livestock require the same nutrients such as protein, carbohydrates, fats, minerals, vitamins, and water but their need for some of these nutrients is not as critical. Bacteria and protozoa in the rumen of the goat have the ability to manufacture and make available many of the nutrients from such feeds as silage, hay-soilage, and other fibrous feedstuffs. Goats are known to relish Paragras, Stargrass, Napier grass, Guinea grass and Centrosema over many improved tropical grasses and legumes. It is also known that goats can browse on leaves of shrubs and bushes for their feed requirements. (See Table I below)
Feedstuffs Dry Matter % (DM) Total Digestible Nutrients % (TDN) Crude Protein % (CP) Digestible Crude Protein % (DCP) Concentrates Copra Meal 89.6 78.5 20.6 14.5
Corn Glutten, Feed 90.1 74.9 20.2 17.1
Corn Grain 88.8 84.2 8.1 7.1
Rice Bran (Cono) 88.0 69.1 12.3 8.3
Rice Bran (Kiskis) 89.0 46.6 6.2 4.5
Feedstuffs Dry Matter % (DM) Total Digestible Nutrients % (TDN) Crude Protein % (CP) Digestible Crude Protein % (DCP) Wheat Pollard 88.2 73.1 17.1 10.4
Soybean Oil Meal 88.4 76.0 44.0 41.0
Molasses, Cane 76.3 53.0 2.0 0.4 Corn Bran 88.0 72.1 10.5 5.6 Green Roughage Napier Grass 21 Days 16.5 9.3 2.4 1.7 42 Days 18.3 10.8 1.9 1.1 84 Days 19.6 10.9 1.0 0.4 105 Days 25.6 13.6 1.2 0.5
Paragrass Dry season 28 Days 22.5 12.9 2.0 1.0 56 Days 24.0 11.0 0.7 0.1 84 Days 39.1 17.6 0.9 0.2 Wet season 28 Days 16.3 9.4 2.4 1.6 56 Days 22.8 12.9 2.8 1.7 84 Days 21.7 12.2 1.7 0.8 Feedstuffs Dry Matter % (DM) Total Digestible Nutrients % (TDN) Crude Protein % (CP) Digestible Crude Protein % (DCP) Guinea Grass Dry season 21 Days 22.5 12.9 2.0 1.0 42 Days 24.0 11.0 0.7 0.1 84 Days 39.1 17.6 0.9 0.2 Wet season 28 Days 16.3 9.4 2.4 1.6 56 Days 22.8 12.9 2.8 1.7 84 Days 21.7 12.2 1.7 0.8 Centrocema 28 Days 24.4 14.0 3.9 2.6
56 Days 29.5 16.8 5.1 3.5
133 Days 32.6 18.9 6.1 4.4
175 Days 30.6 17.3 4.9 3.3
Tree Leaves/Browse Plants
Banana 94.0 - 9.8 5.7 Kakawati 25.3 - 6.52 Ipil-Ipil 13.30 - 27.80 22.50 Santan 27.68 - 4.02 -Feedstuffs Dry Matter % (DM) Total Digestible Nutrients % (TDN) Crude Protein % (CP) Digestible Crude Protein % (DCP) Caimito 48.32 - 4.98 Camachile 34.78 - 9.96 Gumamela 19.10 - 4.14 Bamboo 42.0 - 7.60 3.54 Acacia 43.40 - 9.10 Sources of Ca and P % Ca %P
Dicalcium Phosphate 26.0 18.0
Oyster Shell Flour 33.0 0.0
Source: Gerpacio, A. and L.S. Castillo, 1974. Nutrient Composition of Some Philippine Feedstuffs. Tech. Bul. 21, UPLB-College of Agriculture, College, Laguna p. 117
B. Feed Requirements
A practical feeding program for goats, being ruminants, should be based on the type and quality of roughage available. This is because the quality of roughage available determines both the amount and the quality of concentrates needed to supplement the diet. (See Table 2 below)
Table 2. Feed Requirements
AGE FEEDS AMOUNT PER DAY
Birth – 3 days Colostrum Ad Libitum
(3-5 times feeding) 4 Days – 2 Weeks Whole Milk (Goat/Cow Milk)
Vitamin – Mineral Water
0.5 – 1 Li/Kid divided into 3 time feeding Ad Libitum
Ad Libitum 2 Weeks–16 Weeks Whole Milk of Milk Replacer
Grass-Legume Hay or Qualti Fresh Forage Viatmin-Mineral Mix
0.5 – 1 Li/Kid divided into 2 time feeding Ad Libitum
Ad Libitum Ad Libitum
Water
Starter (22% CP)1 Increasing amountwithout causing
digestive upset 4 Months-Kidding Forage, Vitamin-Mineral Mix
Water Concentrates (18-20%CP)2 Ad Libitum Ad Libitum 0.2-0.7 Kg/Hd Dry, Pregnant,
Bucks Forage, Vitamin-Mineral MixWater Concentrates (16-18%CP)3
Ad Libitum Ad Libitum
Lactating Forage, Vitamin-Mineral Mix Water Concentrates Ad Libitum Ad Libitum 0.3-0.5 Kg/Li of Milk Produced
1 Ground Corn -12; Rice Bran -24; Copra Meal- 40; Soybean Oil Meal -8; Meat &
Bone Meal- 10; Molasses- 5; and Salt-1 Kg.
2 Copra Meal- 50; Wheat Pollard -32; Molasses -15; Bone Meal- 2; and Salt -1
Kg.
3 Copra Meal- 40; Corn -25; Soybean Oil Meal-15; Rice Bran -10; Molasses -8;
Bone Meal- 1; and Salt -1 Kg. 1. Lactating Does
Confined goats should be given good quality forage for free choice,
ad libitum. To increase water consumption, concentrates can be added
at ! the rate of 1 kg./20 liters of drinking water. Provide vitamin-minera1 and salt, ad libitum.
2. Pregnant Dry Does
Pregnant dry does should be adequately fed with quality feeds to build reserves for the coming lactation and to nourish the developing fetuses. Does should be allowed liberal access to good quality forage and roughage, vitamin-mineral plus concentrates at a level of 0.20 to 0.70 kg./ day depending on the body condition of the does.
3. Four Months Old and Above
They should be fed enough for maintenance and for desirable growth, but not for fattening them. Generally, a liberal supply of good quality forage/roughage plus 0.20 to 0.50 kg./day of concentrates is enough to obtain desired growth rate. Under complete confinement, goats may be fed with quality forage plus vitamin-mineral, and salt, ad libidum.
4. Breeding Bucks
Bucks should be maintained on good pasture alone when not used for breeding. Two weeks before and during the breeding season, the ration of the breeding bucks should be supplemented with 0.2 to 0.7 kg. of concentrates. Forage, vitamin-mineral mix, and water should be given ad
libitum.
5. Practical Feeding Guides
The general herd should be pastured most of the time to lower the cost of feeding and maintaining them. Provide enough space for grazing, but be sure that the pasture is rotated frequently, i.e., the herd is moved to another pasture after one pasture lot has been grazed for sometime. This will keep a pasture from being overgrazed and polluted or heavily infested by parasites. Even if the pasture has abundant feed, it may become a breeding place for parasites if the goats are allowed to graze on it for so long.
Breeding goats, as well as the growing and fattening stock, can be raised solely on pasture feeds. Goats enjoy feeding on a large variety of plant growths so that bush land, together with the common pasture grasses, is an ideal combination for raising healthy goats.
Goats are also selective when it comes to grazing. They eat only what seems suitable to them; hence, there is little danger of their eating poisonous weeds. Goats will be able to live on grazing even if only grasses are available on the pasture. However, they can feed better and grow better if there are different species of plants on the pasture. Leguminous plants can also help improve the quality of the pasture.
During the rainy days, keep the goats shut in the barn, well protected from the draft and provided with a clean solid floor. Give them cut grass or hay to eat. Ifthe weather is humid and cold, and especially if there are strong winds, cheap grain feeds, like rice bran, will help maintain body vigor among the animals.
Care of the herd also includes giving them clean water and salt. Place a watering trough in the pen where the goats can drink any time they like. Also, place enough salt in the pen for them to lick whenever they want to.
V. HEALTH MANAGEMENT
Health Management Practices 1. Sanitation
Have pens cleaned daily and washed at least three times a week. Disinfect at least twice a month. Accumulated feces and urine provide a good breeding ground for disease-causing microorganisms. Provide a lagoon or pit to store waste for at least a month before spreading to the pasture. Use as fertilizer for orchards or vegetable garden.
Train personnel to observe sanitary procedures. Provide separate pens for diseased animals.
Limit visitors coming into the farm, including other animals. Quarantine newly arrive stock for at least a month before mixing with the main breeding stock.
2. Deworming
Aside from pneumonia, parasites rank second in causing heavy mortality. From experience, tapeworms are the most debilitating worm problem in all ages of goats, Protozoa-like coccidia and amoeba are also common problems especially in young kids.
Have your goats checked regularly for specific worm load and deworm regularly depending on worm load and seasonal occurrences. Know what kind of internal parasite is affecting your herd before attempting to use a deworming product, or else it will be a waste of money; and effort. I
3. External Parasites
Lice and ticks are common problems. When these are observed, apply acaricide or chemicals against lice and ticks, in powder or dust form. This can be done by mixing the powder-form chemicals with 7 to 10 parts of starch or flour and apply as dusting powder. Refrain from using the liquid or spray form.
Common Infectious Diseases of Goats 1. Bacterial Pneumonia
Mode of transmission: Direct contact from infected or contaminated udder, navel infection, genital or intra uterine infection of dam, contaminated environment Symptoms: Fever, inability to suckle, nasal discharge, coughing
and respiratory distress
Gradual emaciation may terminate as pneumonia-enteritis combination. Death common.
Prevention: Proper nursing in clean, dry environment necessary. Early cases respond to antibiotic treatment.
2. Infectious Arthritis
Mode of Transmission Direct, through mouth, skin, open wounds or via umbilicus
Symptoms: Swollen knees, lameness, pain if pressure is applied on affected joint. Fever may be present. Joints involved are hock, knee, elbow and stifle. Animal prefers recumbency, appetite affected with gradual deterioration.
Prevention / Control: Minimize infection by treating wounds (castration and navel) dressing, hygiene management especially in areas of confinement. Treatment includes wide spectrum anti-biotic and sulfa drugs. 3. Mastitis
Mode of Transmission: Direct or indirect .
Symptoms: Hot, painful and swollen udder. May become red due to inflammation later changing to dark reddish-blue indicating necrosis of udder tissue. Milk may be bloodstained, may contain flakes or clots. Fever, loss of appetite, depression and dehydration; gait or movement of doe is affected.
Treatment: Intramammary infusion of antibiotics. Early and repeated treatment needed to prevent complications such as gangrene and toxemia.
Prevention: Proper treatment of injured teats with antiseptics; disinfecting udders for milking and proper milking technique. Monitor by surveillance to detect early cases for immediate isolation and treatment.
4. Sore MouthlORF/Contagious Ecthyma
Mode of transmission: Contaminated equipment, fences, manure, bedding and feeds
Over crowding
Contaminated vehicles and workers
Infected suckling Iambs, contaminated teats and udders of dams
Symptoms: Characterized by papules, pustules, vesicles and scabs on the skin of the face, genitalia and feet, mucous of the mouth, rumen, nostrils eyelids, gums, tongue, palate and middle ear. Occurs commonly to less than one-year-old sheep/ goat, and feedlot Iambs 3- 7 months of age.
Prevention/Treatment: Vaccinate feedlot Iambs after entering the fattening facilities
Vaccinate suckling Iambs 1-3 days of age
5. HMD
Mode of Transmission: Direct and indirect contact with naturally infected animals, carriers, implements and other infected materials
Blister fluid, saliva and other bodily discharges highly infective.
Symptoms: Fever vesicles, erosion in between hooves, coronary band (junction between skin and hoot), teats and udders, oral mucosa and tongue
Raw ulceration follows, rupture ofvesicles, stingy or foamy salivation, smocking of the lips, difficulty in feed ingestion; staggering gait and lameness. Abortion in pregnant animals.
Prevention: Immediate notification of the authorities
Designation of quarantine areas and restricted movement of animals; disinfecting areas with virucidal agents (commercial disinfectant or lye caustic soda) Animal should be kept on dry ground and lesions treated with mild antiseptic (5% formalin) I , Mass immunization and effective restriction in movement of animals and carriers is necessary
6. Brucellosis
Mode of Transmission: Ingestion of contaminated feed and water. Aborted fetus, fatal membrane, placenta, urine and uterine discharge are main sources of infection Infected males may transfer disease through natural/ artificial breeding
Symptoms: Infertility, abortion, retained placenta, persistent vaginal discharge. In males, swollen and painful testicles with subsequent infertility/sterility
Prevention: Blood tests and removal of infected animals Vaccination may be tried
Antibiotic medication is found to be impractical 7. Hemorrhagic Septicemia
Mode of Transmission: Ingestion or inhalation of infective agent. Maybe normally present in the nasopharyngeal area but predisposition causes flare-up of infection
Symptoms: High fever, loss of appetite
Respiratory distress, salivation, nasal discharges, swelling of the throat and brisket congestion of mucous membrane, diarrhea becoming bloody later.
Prevention: Prophylactic vaccination
Removal of predisposition when possible
Early treatment with parenteral antibiotics and sulfa drugs
8. Anthrax
Mode of Transmission: Direct ingestion of infected material, biting flies
Indirect, through contact with materials and carriers Symptoms: Sudden onset of fever, depression and loss of
appetite
Swelling of chest, head, belly and legs, bloody diarrhea Death common in early stages
Colic, abortion in pregnant animals, blood stained discharges, convulsions
Prevention: Dead animals should be cremated or buried deeply under a layer of lime
Antibiotic treatment is only effective in early and less acute cases
9. Blackleg
Mode of Transmission: Infection initiated by trauma of the body and oral mucosa. Cases in larger ruminants maybe source of infection in the area
Symptoms: Sudden deaths in acute cases
Less acute: depression, fever, rapid respiration and suspended ruminatism
Typically, not painful swelling in thigh and leg muscles. Crackling sensation of palpation of swelling due to gas in tissues
Lameness in affected limb Prevention: Vaccination
Cremation of carcasses
Early isolation and treatment with massive doses of antibiotics
10. Tetanus
Mode of Transmission: Direct infection due to introduction of organism in wounds. Castration, old ulcerating wounds, dehorning complications. Not contagious to other animals
Symptoms: Early stages characterized by rigidity and stiffness of muscles, stilthy gait
Late stages: with tetanic convulsions, prolapse of third eyelid, stiff tail, head and neck thrown back; hyperexcitability
Bloat and other nervous signs.
Prevention: Treat wound with oxidizing antiseptic (hydrogenperoxide ) until completely healed; use clean instrument in castration and dehorning
11. Parasitic Gastroenteritis
Mode of transmission: Commonly through direct infection with parasitic larval stages through herbage, less common through skin penetration and intrauterine infection in some species
Symptoms: Poor body condition, anemia, diarrhea, potbelly and weakness
Prevention: Regular deforming with effective anthelmintics (tetramisole, parbendazole, thiabendazole, pyrantel, etc.)
12. Parasitic Pneumonia
Mode of Transmission: Infection with the parasite in the larval stage through herbage
Symptoms: As in parasitic gastroenteritis for general signs
Specific symptoms includes persistent husky, coughing, respiratory distress
Prevention: Regular deworming with tetramisole, albendazole or oxfendazole
General prevention as parasitic gastroenteritis 13. Tapeworm Infection
Mode of Transmission: Through ingestion of plant mites that are intermediate host
Symptoms: Same as other internal parasitism, passage of tapeworm segment in the feces
Prevention: Regular deworming (albendazole, niclosanide, lead arsenate, and oxfendazole )
14. Liverfluke Disease
Etiology: Four Species of trematodes: a. Fasciola hepatica
b. Fasciola gigantica c. Facioloides magna
d. Dicrocoelium dendriticum Clinical Signs: Post Mortem Lesions
a. Affected animals isolate from the flock b. Decline the feeds
c. Distended abdomen is painful upon manipulation d. Lose weight and become unthrifty, anaemic and
e. Ascites may form
f. The wool looses its flexibility and tensile strength Clinical Forms: Acute Form - traumatic invasion of liver
paranchyma by immature flukes
Chronic Form - billiary fibrosis resulting from prolonged residence of adult flukes
Symptoms: Characterized by unthriftiness, loss ofweight, anemia and edema
Prevention/Treatment: Control of fluke infestations
Prevent the animals from grazing on infected pastures Use flukicide / anthelmintics in treatment
15. Lice Infestation
Mode of Transmission: Direct or indirect contact with infected animals through environment or facilities
Symptoms: Constant scratching and rubbing to relieve itching and rritation.
Scurfy coat ( dandruff) and encrustation of exudate with scabby deposit Loss of hair
Raw skin and bruises in severe infestations
Animals becomes unthrifty, poor thriving, weak and anemic
Prevention: Use insecticide (Asuntol, Ciodrin, Diazinon, Neguvon, Supona, Nankor, etc.) In dust or solution form repeat treatment in 10-14 days to kill nymphs that hatch out. Also spray pens and litter
Isolate treated from untreated animals 16. Mange
Mode of Transmission: Direct and indirect contact with infected animals
Symntoms: Marked itchiness and irritation with animals constantly rubbing or licking affected areas, maybe patchy or generalized
Skin becomes hairless, thickened or scabby Prevention: Periodic examination to detect cases
Regular spraying with effective acaricides such as Malathion, Trichlorfon, Fenthion, Diazinon, Crotoxyphos or Coumaphos
Interval of treatment should be 7 -10 days with 2-3 applications to destroy mites that have hatched after each treatment
17. Bloat
Kinds of Bloat:
a. Green Legume Bloat -results from eating fresh copped green grasses
b. Hay Legume bloat -results from feeding whole, chopped, ground or pellet grasses which is conducive to bloat
c. Free-gas Bloat -result from the inability of the animal to eructate usually associated with systemic disease or due to foreign bodies and abscesses, inflammatory swelling, enlarged thoracic nodes, and also dysfunction such as atrophy of the muscles that interfere with escape of gases and favor its accumulation
d. Grain Concentrate Bloat -results from feeding bloat producing concentrate such as corn, soybean meal and barley
Symptoms: Retention of gas in the rumen, characterized by increased intra-abdominal or intra-thoracic pressure caused by interactions of plants, animals and microbial factors
Distention of the abdomen Animals become uneasy
May alternate between standing and reclining positions
Breathing becomes difficult, rapid and shallow Ruminal movement is prominent
Prevention/Treatment: Good management and medicinal regiment in feeding Avoid grinding the hay and other components too finely
Stomach tube should be passed ill!\) the dorsal part of the rumen to remove any free gas
Administer 0.5 to 1.0 liters of mineral oil or vegetable oil
18. Acute Ingestion of Grain Overload
Mode of Transmission: Non-contagious
Symptoms: Signs appear from 10-36 hours after dietary changes. Depression, loss of appetite, and abdominal distention causing pain and discomfort. Diarrhea develops. Rapid respiration and pulse, incoordination, weakness, coma and death
Prevention: Avoid sudden dietary changes. Treatment is generally unsatisfactory. Early case~ may respond to high antibiotic levels given orally to reduce population of acid-forming bacteria (Acidosis). Indigestion maybe treated with anti-acids like baking soda (sodium bicarbonate), magnesium carbonate or magnesium hydroxide given orally in warm water (Igm/kg body weight) to neutralize rumen acidity. Systematic acidosis requires intravenous injection of acid neutralized like 5% sodium bicarbonate repeatedly given.
THE CONTROL OF INTERNAL PARASITES IN RUMINANTS Table of Contents
General information Life cycle of parasites Role of parasites
Susceptibility and immunity Detection
Preventive measures Herd management Pasture management Soil management
Parasite control methods General information Botanical dewormers Other dewormers Useful addresses Bibliography
By Jean Duval, agronomist, M.Sc. January 1994
I would like to thank Christiane Trudeau of the McGill University Institute of Parasitology, Jean-Marie Boucher of the Centre d'Agriculture Biologique de la Pocatière and consulting agronomist Caroline Morin for their comments on the text.
THE CONTROL OF INTERNAL PARASITES IN RUMINANTS
Internal parasites in ruminants constitute a problem that returns periodically in almost all livestock herds. Recourse to synthetic dewormers is only a short-term solution. Animals that graze are always exposed to parasites and are thus constantly being reinfected; not to mention that routine deworming treatments delay the development of immunity in young animals. Moreover, certain parasites have developed a resistance to such deworming products as
Benzimidazole, Levamisole and even Ivermectin because of too frequent use. Studies in New Zealand and Ireland indicate among other things that dewormers
slow the decomposition of manure.
A serious pest control program in organic farming begins with a good
understanding of parasites and the implementation of preventive measures. The ultimate objective is to develop an animal production system where parasites may be present in small numbers but do not affect the health or performance of herds. Deworming treatments, whether administered using natural products or not, should therefore only be employed in emergency situations or, if using weaker products, as preventive maintenance.
This document provides a description of internal parasites, methods to prevent their infestation and alternatives to conventional dewormers for ruminants. The section on botanical dewormers also includes information on other farm animals (pigs and poultry).
GENERAL INFORMATION LIFE CYCLE OF PARASITES
Knowledge of the life cycle and characteristics of parasitic worms is essential for anyone wishing to reduce their use of dewormers. Figure 1 shows the direct life cycle common to most parasites. Some parasites however have an indirect cycle, which involves a host animal. For example, the liver fluke (Fasciola sp.) spends part of its life in certain snail species before infecting ruminants. Table 1 presents the main classes of internal parasites, whereas Table 2 provides a list of the main internal parasites of ruminants and their characteristics. Internal parasites are most often worms (helminths) but can also be protozoa, which will not be covered here. Worms are generally specific to one organ, such as the abomasum, duodenum, and lungs.
1. Parasite-infested animal harbours adult worms...
2. The eggs produced by the female are deposited in pastures with fecal matter...
3. They develop into various larvae stages.
4. Animal is contaminated by absorbing L3 larvae or infesting larvae with the grass.
5. The larvae make their way to the alimentary canal where they develop and produce a new generation of adult male or female parasites.
Source: Rivard et Huneault (1992)
Table 1 - Major classes of internal parasites ROUNDWORMS or Nemathelminthes Strongyles
Gastrointestinal worms
Abomasum worms: Haemonchus, Trichostrongylus, Ostertagia
Duodenum worms: Trichostrongylus, Nematodirus, Cooperia, Strongyloides Large intestine worms: Oesophagostomum, Trichuris
Small intestine worms or Ancylostomidae (hookworm): Ancylostoma, Necator, Bunostomum
Lungworm or metastrongyles: Dictyocaulus, Metastrongylus, Protostrongylus Ascarids: Ascaris (duodenum)
FLATWORMS or platyhelminthes
Cestodes (tapeworm): Taenia, Echinococcus, Moniezia (duodenum) Trematodes: Fasciola, Dicrocoelium (liver)
Table 2 - Characteristics of main internal parasite genera in cattle, sheep and goats
Parasite Description Infected Organ Life Cycle Symptoms
Haemonchus M: 10-20 mm red F: 18-30 mm red and white Abomasum IS: 4-6 days PP: 3 weeks Anemia, soft swelling under jaw and abdomen, weakness, no weight gain
Ostertagia M: 6-9 mm, brown F: 8-12 mm Abomasum IS: 4-6 days PP: 3 weeks Same as Haemonchus and also lack of appetite, diarrhea
Trichostrongylus M: 4-5.5 mm F: 5-7 mm light brown Abomasum, duodenum IS: 3-4 days PP: 2-3 weeks Same as Haemonchus and also diarrhea and weight loss
Cooperia red M: 5-7 mm F: 6-9 mm Duodenum IS: 5-6 days PP: 15-20 days Same as Haemonchus
Bunostomum 10-30 mm Duodenum IS: ? PP: 30-56 days Edema, anemia, weight loss, diarrhea
Strongyloides (young animals) 4-6 mm Small intestine IS: 1-2 days PP: 8-14 days Anorexia, enteritis, diarrhea
Chabertia M: 13-14 mm F: 17-20 mm Large intestine IS: 5-6 days PP: 42 days Anemia, diarrhea with blood
Oesophagostomum M: 12-17 mm F: 15-22 mm Large intestine IS: 6-7 days PP: 41-45 days Dark green diarrhea edema
Protostrongylus M: 16-28 mm F: 25-35 mm Lungs IS: 12-14 days PP: 30-37 days Pneumonia
Dictyocaulus M: 30-80 mm F: 50-100 mm Lungs IS: 6-7 days PP: 3-4 weeks Sticky nasal discharge, difficulty breathing, cough
Legend: M = Males; F = Females; IS = Infectious stage: minimum number of days for parasite to reach infectious larvae stage (L3) after hatching of eggs; PP = Prepatent stage: period up to appearance of first eggs in dung after host is infected.
ROLE OF PARASITES
One may ask what the role of internal parasites is in nature. Do they reduce populations that are too large for the resources available? Overpopulation is often, if not always, inherent to agriculture. Or do parasites serve to cull the weaker animals, thus reinforcing a species' chances for survival? This is doubtful since it is generally not to the parasite's advantage to kill its host.
Whatever the case, it is normal in nature to find internal parasites in animals. In a natural setting, ruminants, although in herds, are constantly moving from one grazing area to another. It is therefore rare that the soil and grasses they eat are highly contaminated. Since levels of infestation are rarely excessive, animals have a chance to develop immunity.
The levels of infestation in goats and sheep that are raised in fairly natural settings tend to fluctuate with seasonal metabolisms without the animals being treated25. It has been observed in goats and sheep that the highest levels of parasites correspond to periods of change: change in location (e.g. buildings to pasture in the spring); change in diet or use of food (e.g. lactation to
maintenance diet). This would indicate that internal parasites may play a role in helping animals get through periods of change and adaptation.
THE BIODYNAMIC POINT OF VIEW
The point of view of biodynamic practitioners is focused largely on the role parasites play in animal digestion36. They believe that gastrointestinal parasites play a role similar to earthworms in the soil; that they "aerate" the digestive system when it is overloaded by too much silage, grain or green hay. Since the roots of plants have the same effect as earthworms, biodynamic farmers add fodder roots (e.g. beets, carrots) to animal feed to replicate the role of parasites. SUSCEPTIBILITY AND IMMUNITY
An animal without worms is not an ideal to strive for at any cost, at least not in organic farming. An animal that never has worms can not develop resistance and is thus extremely vulnerable when exposed to a parasite. Resistance or immunity is the ability to prevent or limit the establishment or subsequent development of worm infections. Tolerance is the ability to maintain good
productivity despite infection. Contrarily, susceptibility to parasites is defined by how easily the animal becomes infected.
Ideally, grazing animals - especially the youngest ones - should ingest parasites in small quantities so that they may progressively develop immunity. This does not apply, however, to all internal parasite species.
Susceptibility according to species
Most internal parasites are specific to one or two species. When they are found in other animals, it is usually only for a brief period. Certain parasite species common to several types of domestic animals have even developed more specific "breeds".
Although there are just as many parasite species that can infect cattle, sheep or goats, sheep are the most susceptible to internal parasites because they graze close to the ground. Goats and sheep, whose manure is in pellet form, graze directly over their manure, which makes them more susceptible than cattle who do not have access to the grass under their pats. Also, cattle tend to avoid the less appetizing grass near the pats.
Susceptibility according to age
The age as well as the weight of animals determine susceptibility to parasites. Young animals do not have a great deal of immunity to parasites during their first year at pasture. The second year, they have partial immunity and, although they may appear healthy, they excrete many eggs. Adult animals are much less susceptible to most parasites, unless they are in poor living conditions. For example, it has been demonstrated that horses 15 years of age or older are rarely infected by strongyles13. Instead, parasites like Strongyloides are almost exclusively found in young animals.
Other susceptibility
Animals are sometimes kept in conditions that make them highly susceptible to parasites. In the case of a recently dewormed animal, internal parasites no longer exist. There is thus no equilibrium and such an animal put into a
contaminated pasture may be seriously affected. Animals in poor condition (e.g.: recent illness, food shortages) are also highly susceptible.
Genetic resistance
There are breeds or lines of animals that are resistant or more tolerant to internal parasites. In New Zealand, herds of sheep resistant to internal parasites were developed from Romney sheep. The approach adopted by organic farmers in
New Zealand is to over the years develop a herd that is increasingly resistant, using resistant rams only, and not ewes.
DETECTION
The first step in a pest control program is to assess the situation. The two methods used for this purpose are fecal counts and field counts.
FECAL COUNTS
Veterinary offices conduct fecal analyses. These consist in identifying the
species of parasites present in the animal and counting the eggs of the parasites per gram of stool. Results of the analyses are often expressed in qualitative terms: absence of parasites, low, average or high levels. In all cases, it is important to identify the parasite. Two approaches may be used:
Herd analysis
Randomly selected feces are used to determine the general state of the herd. A minimum of three to five pats is required in the case of cattle. Ideally the stools should be collected at midday for the egg production is more uniform at this time8.
Individual analysis
Feces from a single animal are used by isolating the animal and collecting them first thing in the morning and then fresh stools during the day. The purpose of an individual analysis is to confirm that the symptoms observed in the animal are in fact caused by a parasite infection.
Stool analyses have limits as methods for evaluating the situation. Certain species of parasites lay few eggs, others many. Some lay eggs only at certain times of the year or during a particular period in the ruminant's life cycle. The best way to benefit from fecal counts is to always perform them at the same time each year and preferably during critical periods, such as when the animals are put out to pasture or before bringing them in for winter. If the parasite level is high, two to four analyses will provide a better picture of the situation.
Comparison from one year to another of analyses conducted during the same period will indicate if there is an improvement or not.
Other instances where stool analyses are useful are, for example, when there is a change of pasture ground, when new animals arrive, or when there are
animals who appear to be ailing or young animals that are not putting on weight. FIELD COUNT
A field count is more difficult to do. In North America, it is mostly done as part of research programs. Samples that are representative of the grazed pasture must
be collected, taking into account the height of the cut. In New Zealand, where this type of analysis is more common, it is considered with respect to sheep that if there are less than 100 larvae per 100 kg of grass there are neither economic losses nor drops in productivity39.
PREVENTIVE MEASURES
From the ecological perspective, serious problems with internal parasites indicate that changes in feed, field management or soil management are
required. By changing the production method or by using preventive measures, it is not necessary to rely on dewormers too often.
HERD MANAGEMENT
An animal is better able to resist or tolerate internal parasites when its living conditions are good. Links between diet, particularly vitamins and minerals, and susceptibility to internal parasites have been established in certain cases. Vitamins A, D and B complex are the most important vitamins required by
animals to develop resistance to internal parasites23. Nyberg and his coworkers, quoted by Quiquandon31, have established that a lack of cobalt promotes
parasitism, since cobalt is the element used by animals to synthesize vitamin B12. Iron supplements are also very important where animals are affected by worms that drain the blood, like Haemonchus (worms in the abomasum) and Ancylostoma (intestinal worms). According to Lapage23, animals should always have access to mineral blocks to compensate for the mineral deficiencies in pastures. In barns, animals should be fed from feeders rather than directly from the ground to avoid contamination as a result of their mouths coming into contact with manure or bedding.
At the New Zealand Pastoral Agriculture Research Institute, research is currently underway on how different foods affect resistance to parasites. Forage crops that contain condensed tannins, like trefoil, allow animals to better fight parasites than others that do not contain any, like alfalfa.
The age at which young animals are weaned is an important factor in regard to parasite resistance. For example, it has been observed that milk-fed calves are distinctly less contaminated by Haemonchus, Cooperia and Oesophagostomum than weaned calves34. Milk does not have any effect, however, on Ostertagia and Trichostrongylus infections.
Ideally, females should calve during periods when risk of contamination is low, so that young animals are exposed as late as possible to potentially
contaminated pastures. In Northern parts of North America, the winter period seems most appropriate in this respect. All new arrivals to the herd should be quarantined for four to six weeks and dewormed if there is any doubt.
Pasture management that is designed to prevent internal parasites requires long-term planning. It is by varying such factors as the density and age groups of animals and the time and intensity of grazing that serious infections can be avoided.
Animal density
Overpopulation increases the concentrations of parasites. It is generally
estimated that parasite infections increase with the square of the animal load per surface unit. Therefore, for a given parcel of land, parasite infestations are four times greater where animal density is doubled. Density varies depending on whether grazing is intensive or extensive. Where there is extensive grazing, Antoine2 recommends less than 10 lambs/ha (varying according to context).
Pasture rotation, or intensive grazing, consists in dividing the pastures into parcels of land of varying sizes called paddocks and frequently moving the animals from one paddock to another to optimize grass use. From a parasitic point of view, the objective is to not put the animals back into the same field until the risk of infection has diminished. Theoretically this means that parasitism will decrease if the number of parcels of land is increased or the rotation time is increased. Unfortunately, in practice, it appears difficult to diminish the parasitic load with intensive grazing. The lifespan of L3 larvae is in fact always greater than the time required between grazing periods for maximum grass use.
Therefore, if one waits six weeks before returning animals to a lot, the quality of the grass decreases as well as the quantity of grass ingested by the animals, whereas the level of parasites only diminishes slightly.
Grazing height
About 80% of parasites live in the first five centimetres of vegetation. Parasite infection and multiplication are prevented by letting animals graze only 10 cm from the ground in a field where there are parasites. For new pastures, however, New Zealander Vaughan Jones18, an expert on intensive grazing, recommends having animals graze very close to the ground, so that the sun can dry the pats quickly and thus diminish the chances of survival of parasites brought in with the animals. A new pasture is considered a field where animals have not been grazing for a number of years. It may be a pasture seeded in the spring or a hay or silage field that is used as pasture after harvest.
Grazing time
The drier the grass, the more parasites will stay at the base of the plants. It is estimated that in wet grass, larvae can be found over 30 cm away from the pats,
whereas they venture only a few centimetres away when the grass is dry. The risk of infection is greatly lowered by waiting until the dew has lifted or until the grass has dried after rain before putting animals out to pasture.
The larvae of most parasites move to the tops of plants when light levels are low, that is, when the sky is overcast or at sunrise and sunset. They avoid strong light however. Limiting grazing time to when the sun is strong also diminishes the risk of infection.
Since we know that the density of L3 larvae is generally at a maximum in the fall and at a minimum in the summer, it is preferable to limit grazing in highly
contaminated fields to the summer months to reduce levels of ingestion. In the fall, the animals should ideally be put in a new pasture.
Risks of infection from most parasites can be avoided in the spring by waiting until the end of spring to put cattle out to grass, and even later in areas where soil drainage is poor. In practice, this solution is not very satisfactory, both
economically and ecologically, because it implies shortening the grazing season, which is quite short as it is in most northern regions, and feeding the animals more hay.
Harrowing Pastures
With respect to parasites, harrowing pastures is generally not recommended. The parasite eggs and larvae are in fact scattered throughout the pasture. This makes it impossible for the animals to graze selectively, that is, to graze around the pats. Harrowing would be appropriate, however, at the beginning of a dry period in a field that the animals will not be returning to for quite some time. Biodynamic practitioners have a different point of view. They consider that parasites proliferate in an environment that is nitrogen-rich and sheltered from light. They therefore recommend breaking up the pats to let in air and light. Grazing by age group
Since the susceptibility of animals varies with age, it is logical to graze the younger animals in fields where parasite populations are very low.
Organic farmers in New Zealand have established some rules to prevent internal parasites in lambs and ewes. Thus, in intensive grazing, lambs do not have access to paddocks or sections of a pasture already grazed by ewes or other lambs in order to prevent reinfection. Lambs should graze preferably in new pastures, hay or silage fields, or should be greenfed.