McDonald et al. (2002) also stated that though energy and protein are of primary importance to any animals, optimal animal performance is possible only if there is an adequate supply of minerals and vitamins. In the Central Rift valley, Ca and P concentrations of the major feedstuffs except for some fodder trees and barley straw were low (Zewdi Wondatir, 2010) as compared to the recommendations. To this end, it is important to know the possible sources of essential minerals. The existing animal feed processing firms and dairy producers add limestone and common salt (NaCl) in concentrate mixtures as mineral source depending on availability (Nega et al., 2006). A number of mineral soils that can be obtained from different parts of Ethiopian Rift Valley lakes and other areas contain adequate amount of most of the essential minerals with the exception of phosphorus (Adugna Tolera, 2008). These include Bole (Lake Abaya, Abijata, Zeway and Shala), Addo or Megadua (L. Abaya) and Red Soil. From these, Bole is abundantly and locally available in the Central Rift Valley than the other kinds of mineral soil and is used by local farmers as a mineral source for their cattle. Previous work showed that bole soil improves milkyield and feed intake of dairy cows (Nega et al., 2006), however, there was no documented information on the level of intake and corresponding productivity. Therefore, this study was conducted with the objective to evaluate the effect of different levels of Bole (lake soil) on feed intake, milkyield and milkcomposition of Holstein Friesian cows.
The present study was designed to assess the impact of husbandry, stage of lactation and parity number on milkyield and chemical composition of camel milk within three different camel farms at Khartoum State, Sudan. Camel milk samples (n=220) were collected from 43 healthy she-camels at different lactation stages (early, mid, late and latest stages of lactation) and parity number (1-7 parities). The overall means of daily milkyield and composition of fat, protein, lactose, solids not fat (SNF), acidity and density were 2.73±1.16 L/day, 3.69±1.31%, 3.32±0.33%, 4.59±0.45, 8.49±0.86%, 0.19±0.03% and 1.030±0.017g/cm3, respectively. Camel milkyield and composition were significantly (P<0.05) affected by husbandry, stage of lactation and parity number. The highest milkyield (3.49±0.89 L/day) was recorded for she-camels kept in the intensive farming system during early stage of lactation (2.96±1.28 L/day). The result showed that the she-camels in the second parity gave the highest milkyield (4.06±1.85 L/day), while the lower milkyield was found at the subsequent parities. The highest means of fat (4.05±1.5%), SNF (8.78±0.74%), protein (3.41±0.3%) and lactose (4.67±0.42%) were recorded for the milk of she camels in the semi-intensive farming. The highest means of fat, protein, lactose and SNF (4.46±1.62%, 3.5±0.27%, 4.75±0.42% and 8.88±0.89%, respectively) were found in camel milk during the early stage of lactation. Moreover the highest means of protein, lactose and SNF (3.42±0.33%, 4.71±0.52% and 8.83±0.86%, respectively) were recorded in milk for the she camels at parity number five. This study concluded that husbandry systems, stage of lactation and parity number have impact on milkyield and chemical composition of camel milk. Therefore, factors that cause variations in milkyield and composition should be considered for the nutritional and technological uses of camel milk.
Statistically signiﬁcant diﬀerences caused by the season of kidding (s) in the three traits were found with model 2 and 3. Similar results were found by other authors (Pedauye, 1989; Gipson and Grossman, 1990; Pacheco et al., 1998). The eﬀect of the season of kidding on milkyield and composition (according to model 3) is shown in Table 7. The most of the kidding took place in February and March, 32.6 and 38.2%, respectively. Goats kidding in March and April had the highest milk yields. Probably, the low- er milk yields of the goats kidding in the ﬁrst two seasons (December–January and February) were caused by the poor quality feed and the change of the winter to the summer ration when they reached the lactation peak (between 40–80 days in milk). A
The aim of our experiment was to assess changes in milkyield, composition and renneting parameters (pH, titratable acidity, coagulation time and curd quality) of sheep milk in the course of lactation and their relationships in the Lacaune ewes (n = 8), reared under intensive nutrition. The stage of lactation (SL) had a conclusive effect on the daily milkyield (DMY) and contents of all basic milk compounds. The DMY and fat content were relatively high during whole lactation. In our opinion these trends were influenced by the quite intensive nutrition. The SL had inconclusive effect on pH. In contrast, the SL had a conclusive effect on titratable acidity (TA) of milk. The correlations between the pH and all other indicators, with the exception of the coagulation time (CT), were inconclusive. Also most correlations between the TA and all other indicators monitored were inconclusive. The SL had inconclusive effect on the CT and curd quality (CQ). In our opinion, relatively balanced values of the CT and CQ during lactation indicate on the good health state and correct nutrition of ewes.
Evaluation of the eﬀ ect of parity, stage of lactation and interaction of PA x SL on daily milkyield, composition (contents of total solids, fat, total protein and lactose) and quality (somatic cell and bacteria counts) of organic milk of East Friesian sheep was carried out on organic farm in Habří in 2009. Ten ewes were on the second lactation and other ten ewes were on the third parity. All ewes were reared, till the end of our study, on permanent pasture and a er weaning all ewes began to be machine-milked once a day. Samples for microbiological determination were milked by hand and were collected in sterile plastic containers. During the experiment, the daily feed ration of ewes consisted of permanent pasture (ad libitum), organic mineral lick (ad libitum) and organic oat (0.5kg/ewe/day). The milk records and samplings were carried out three times in the period from May to September, speciﬁ cally on the average 75 th , 132 th and 190 th day of lactation. The milk analysis were carried out
Evaluation of eﬀ ect of chosen factor (stage of lactation, parity, litter size and month of kidding) on daily milkyield, basic composition (contents of total solids, fat, total protein, casein and lactose) and somatic cell count of organic goat milk was carried out on an organic farm in Olešenka during the year 2011. Thirtytwo goats of Brown short-haired breed were involved in the experiment, while 15 goats were on the ﬁ rst lactation (PA1), 10 goats on the second (PA2) and 7 goats on the third lactation (PA3). With regard to litter size, 15 goats gave birth to singles and 17 to twins, while the kidding occurred in January (n = 5), February (n = 13) and March (n = 8). The weaning was carried out at the age of kids from 45 to 50 days, a er that all goats began to be machine milked twice a day. During the lactation, the daily feed ration of goats consisted of permanent pasture (ad libitum), meadow hay (ad libitum), organic oat (0.5 kg/head), organic feed mixture for milking goats (VK DRCMAN/CZE, 0.5kg/head) and organic mineral lick (ad libitum). The milk records and samplings for each goat were carried out seven times in the period from April to October. The milk analysis were carried out using standard methods. The stage of lactation had a signiﬁ cant eﬀ ect on all monitored parameters except somatic cell count (SCC) and the parity had a signiﬁ cant eﬀ ect on all monitored parameters. On the other hand, systematic factors of litter size and month of kidding had a signiﬁ cant eﬀ ect only on daily milkyield (DMY) and SCC. With regard to the particular basic components of milk, the milk fat was the most variable component; on the other hand, the lactose content was during lactation very well-balanced. SCCs were relatively low, except the 260 th day of lactation, which indicates good health status of mammary
Growth rate of daily milk production (parameter b) had the lowest value (0.011 kg) from cows that calved in summer and 0,023 kg in autumn calved cows. The value of this parameter is obtained from cows that have calved in spring, ie 0.101 kg. The values of the parameter b describing the rate of increase of the quantity of milk until reaching lactation curve peak, the cow calved in winter (0.089 kg) and which the spring calving (0.101 kg) had similar values.
The content of chosen components in cows’ co- lostrum is showed in Tab. III. There were no statis- tically significant differences between the groups. The highest content of dry matter (263.2 g/l) and lac- tose (19.13 g/l) was noted in colostrum of cows from group III, however, the content of fat (51.28 g/l) was the highest in group II. The increased fat content in colostrum in this group could possibly be explained by the formation of so-called chylomicrons. They are synthesised from precursors of glucose and af- ter their release into milk they increase the amount of detectable milk fat (Jelínek and Koudela, 2003). The smallest content of α-lactoglobulines and β-lactoglo- bulines was stated in cows’ colostrum from group II. The largest content of β-lactoglobulines was found in group III (109.59 g/l). The content of colostrum com- ponents for all the cows was similar to the results ob- tained by others authors (Zachwieja, 1991 and 1995; Blum and Hammon, 2000). Taking of colostrum by the calves directly after the birth in the right amount is very important with respect to gaining the immunity and because of the content of hydroxycarbons, lipids, proteins, mineral elements and vitamins (Zachwieja, 1991; Blum and Hammon, 2000). Despite of the lack of statistic differences, the more profitable composi- tion of colostrum was stated in group III receiving the highest dose of propylene glycol. There are no works concerning the influence of propylene glycol used in cows’ feeding before parturition onto colostrum com- position, thus it is difficult to compare the results.
fed during the first four weeks of lactation to cows of the CLA-group. Group arrangement was based on how well cows accepted the fat supplement. Cows that con- sumed the fat concentrate during five successive test days before milk stasis (56 days before expected calving date) immediately after submission were arranged to CLA-treatment group. Due to the well known feed intake depression at the beginning of lactation, espe- cially related to the mealy and powdery supplement, a good acceptance of the supplement by each cow of treatment group was required. The study was performed with primiparous cows exclusively to avoid lactation number as a confounding factor and due to the fact that the overall effects of CLA on milk synthesis do not depend on the lactation number . All cows were housed in free stall barns fitted with rubber mats and fed the same basal diet (corn silage 43%, grass silage 25%, hay 32%; NE L 1.36 Mcal/kg, Table 1) during the
ABSTRACT: The objective of this study was to determine rumen degradability and total digestibility of flavonolignans from a milk thistle fruit expeller in dairy cows considering milk production and changes in plasma flavonolignans. The experiment was carried out on three lactating Holstein cows and was divided into three periods as follows: preliminary period (Pr, 3 days) was used for the diet stabilization followed by the adaptation period (A, 6 days) in which the treatment was applied and by the balance period (B, 4 days). Cows were fed individually twice a day (6:40 and 16:40 h) ad libitum the diet based on maize silage, lucerne hay and supplemental mixture. In the periods A and B the diet was supplemented with 150 g/day of milk thistle fruit expeller applied in two equal portions at each feeding. Average daily intake of dry matter and basic nutrients was similar in all periods (P > 0.05). Milkyield and composition were not affected by the treatment (P > 0.05). The milk thistle fruit expeller used in this experiment contained 4.10 ± 0.10 mass percentage of the silymarin complex. Digestibility of silybin A and silybin B was 40.0 and 45.5%, respectively. Digestibility of other components of the silymarin complex was 100%. The highest value of the effective degradation was found for taxifolin (59.11%), while the effective degradation of the other flavonolignans ranged from 23.28 to 35.19%. Animals receiving the milk thistle fruit expeller had a higher content of plasma conjugated silybin (P < 0.001) than those without its supplementation.
 Grisart B, Coppieters W, Farnir F, Karim L, Ford C, Berzi P, Cambisano N, Mni M, Reid S, Simon P, Spelman R, Georges M, Snell R. Positional candidate cloning of a QTL in dairy cattle: Identification of a missense mutation in the bovine DGAT1 gene with major effect on milkyield and composition. Genome Research. 2002; 12, 222-231.
higher yields would be achieved if the BCS of cows allows energy mobilization but excessive lipid mobilization may induce metabolic and reproductive disord- ers . Supplementation with energy concentrates may improve the productive response of cows  reducing the loss of body reserves . Milk production in pasture based systems may be also limited by imbalances at ruminal level be- tween availability of fermentable energy and the excess of rumen degradable protein (RDP) as suggested by . Pasture RDP utilization can be improved by feeding starch-rich concentrates  but when high levels of cereal-based sup- plements are fed, ruminal pH and pasture NDF digestion can be affected  leading to reductions in forage intake and milk fat content. The aim of this study was to determine the effect of feeding three levels of energy concentrate on milkyield and composition, DM and energy intake, plasma metabolite and hormone concentrations and ruminal pasture NDF digestion in grazing dairy cows.
mers are motivated to renovate or reseed grasslands. This reduced performance is often associated with the botanical composition where the desirable species of the sward has decreased, e.g. proportion of perennial ryegrass (Lolium perenne L.) is less than 50% (Søega- ard et al., 2007). The sown species is preferred due to its greater nutritional value and therefore potential for increasing production and decreasing the negati- ve unintended consequences (nutrients loss to water contamination or greenhouse gas (GHG) emissions) through improving nutrient use efficiency, particularly N use efficiency (NUE). In grazing systems, NUE can be improved by increasing the water-soluble carbohydra- te (WSC) content of forage with an expected increase in milkyield per cow and simultaneously reduced release of labile-N (urine) to the environment (Lee et al., 2018). For this purpose, high sugar grass (HSG) cultivars of L. perenne have been developed in the UK as an approach to increase efficiency of grazing systems. However, ma- king the decision to reseed is a balance between poten- tial future benefits of improved animal performance, driven by improved DM yield and pasture quality, and loss of grazing area plus potential risk of poor yields during first year after establishment. Therefore, the ob- jective of this study was to assess the effect of replacing permanent pasture with HSG reseed on pasture per- formance, dairy cows productivity and product quality in the first year after establishment with the grazing management based on commercial decisions at a farm system level.
2.4 MilkComposition and Production Responses to Fat Supplementation Bobe et al.  fed mid-lactating dairy cows with tallow at 4.2% of dry matter (DM) and found that both fat and protein contents of milk were increased. Chilliard et al.  obtained similar results when they fed ruminally inert tallow at 1.48kg/d to cows. Chichlowski et al.  fed ground canola seed to lactating Holstein cows and reported no change in milkyield, somatic cell count (SCC) and lactose percentage; however, protein and fat percentages were lowered. Feeding multiparous Holstein-Friesians with encapsulated fat containing 40.8% flaxseed oil (E-FLAX) had no effect on their milk production, but encapsulated fat containing 40.8% sunflower oil (E-SUN) decreased milk production . In the same study, milk fat percentage was higher in the E-FLAX group than in the E-SUN group (P < 0.02), although fat yield remained the same across treatment groups. The group of cows receiving E-FLAX produced less protein and had a lower protein percentage in their milk compared to the E-SUN and the control group. The E-FLAX and control groups produced milk with a higher lactose percentage but lower lactose yield than the E-SUN group. In another study by Caroprese et al. , feeding whole flaxseed (FS) at 2.2kg/d and microencapsulated fish oil at 200g/d (FO) to Italian Friesian cows did not affect milkyield, although higher numerical milkyield was obtained from the FS cows. In the same study, fat yield and fat percentage were significantly higher in the group receiving FS. However, no observable differences were seen between lactose, protein and SCC compositions across the different treatment groups. This result was also supported by the study of He and Armentano , who found no change in milk protein yield of multiparous Holstein cows supplemented with palm oil, corn oil, linseed oil, high oleic and linoleic safflower oil. However, the overall milk protein concentration was significantly lower for the cows on linseed, palm, high oleic safflower oil and the control group. Corn and high linoleic safflower oil significantly lowered fat concentration and yield, while palm oil increased milkyield, fat yield and fat concentration. High linoleic safflower oil greatly decreased milkyield compared with linseed oil.
ME intakes were similar for both S and D pastures (190 vs. 176 MJ ME/kg DM respectively). However, despite this, milkyield (L/cow/day) tended to be higher for the S pasture (14.9 vs. 14.0 L respectively) with this reflected in lactose yield (0.72 vs. 0.66 kg/cow/day respectively). There were no statistical differences in milkcomposition for either fat, protein or lactose %. However, with cows on the S pasture tending to have a higher milkyield, this resulted in greater yields for both fat and protein (kg/cow/day), and hence a tendency for higher MS production on the S pasture was seen of 1.52 and 1.36 kg MS/cow/day and NE produced in milk (60.3 vs. 54.6 MJ NE/cow/day) for S and D pastures respectively. These findings are in line with the work where MS production was similar when ME intakes were comparable on S or D diets (Edwards et al., 2015; Totty et al., 2013; Woodward et al., 2013) . ME intakes in this trial were considered to be sufficient for cows with this level of milk production in late lactation (Nicol & Brookes, 2007). CP intake was also considered sufficient (>20% of DM) to support lactation (Waghorn et al., 2007). The tendency for higher MS production on the S pasture possibly suggests an undersupply of AA for milk production for cows grazing the D pasture. This may have been due CT reducing the supply of bacterial CP to the animals grazing the D pasture. This CP considered to be a high quality source of protein supplying the essential amino acids
The negative perception of milk fat associated products is a major concern of the dairy sector and there is a growing interest on the milk fat composition of bovine milk around the world (Nantapo et al., 2014). The FA composition could be changed through either dietary manipulation or genetic selection. The use of pasture (fresh leafy grass) to change the FA profile in a desirable direction is an important option, although the influence of pasture and forages in changing FA composition is significantly smaller compared to feeding concentrates (Dewhurst et al., 2006). Presently, there is no genetic selection program in animal breeding anywhere in the world which considers the proportion of FA as genetic traits. In recent years, the dairy sector has become more focused on improving health aspects of milk products, especially changing bovine milk fat composition by increasing the content of MUFA and PUFA and decreasing the proportions of undesirable SFA and trans fatty acids in milk. Stoop et al. (2008) further indicated that the marked demand for healthy milk and dairy products at large has increased in recent years and this may result in large adaptations to the present dairy production and breeding programs if it aims to breed cows for changes in FA composition rather than increased milkyield.