Growth in fish is one of the physiological functions that affected by the water salinity, where the metabolic rate and the energy of osmoregulation process were reflect the effect of salinity on growth . The exposure of fish to high levels of salinity leads to an increase in metabolic rate as a result of the increasing need to the necessary energy for iono- osmoregulation to maintain the internal stability (homeostasis) under the new osmotic conditions. The increasing cost of energy needed leads to a reduction in growth rate, which negatively affects the rate and efficiency of feedconversion, protein intake and efficiency of protein utilization in fish, so a little of the energy will be available for growth . The effect of salinity on fish growth is similar to the effect of temperature, this effect mainly depends on fish species and duration of exposure to the salinity . De Silva and Perera  noted a decline in the rate and efficiency of feedconversion and efficiency of protein utilization in grey mullet Mugil cephalus with high salinity, Barman et al.  revealed that the best feedconversion rate and protein utilization of grey mullet were obtained in the salt concentration of 10 g/L, compared with other salt concentrations (0, 15, 25 and 30 g/L).
This study was performed to investigate the effects of feeding rates on growth performance, feedconversion and body composition of juvenile snow trout (Schizothorax zarudnyi). For this purpose, fish with an initial body weight of 2.17±0.1 g were fed a commercial diet (40% protein, 3.8 Kcal g -1 diet) at five ration sizes of 2%, 4%, 6%, 8% and 10% of their body weight per day, for 60 days. The feeding trial was conducted in triplicate. Maximum weight gain, best feedconversion ratio (FCR), best specific growth rate (SGR %), highest energy retention (ERE %) and protein efficiency ratio (PER %) were evident for rations of 4–6% body weight. Second-degree polynomial regression analysis for PER, FCR and ERE indicated the break-points occurred at 4.9, 5.1 and 5.2% BW day −1 , respectively. Maximum body protein content was obtained for 4% and 6% rations. Body moisture, fat and ash content remained unchanged. Based on the above results, it may be concluded that the 4.9-5.2% body weight per day ration is optimal for the growth, conversion efficiencies and body composition of juvenile S. zarudnyi and it entails favorable economic benefits.
general MEm prediction equation may not be suited for sheep, which differ in growth potential. Previous research suggested that high-producing dairy cows had larger in- ternal organs than low-producing dairy cows (Ferrell and Jenkins, 1984), which can lead to a higher MEm require- ment. This is supported by a recent trial in beef cattle, which showed higher FCE (measured as lower residual feed intake) due to a lower weight of the reticulorumen (Fitzsimons et al., 2014). Therefore, different MEm pre- diction equations may be needed to differentiate genetic differences in maintenance cost of animals.
The use of diverse (D) pastures containing multiple species and including herbs, has shown a change in the partitioning of dietary nitrogen (N). Nitrogen use efficiency (NUE) is an important indicator of production efficiency with an increase in NUE linked to an increase in profitability and a reduced environmental footprint (Powell et al., 2010). Reductions in the proportion of N excreted in urine from 43 to 29% have been reported in New Zealand when grazing D pastures (Woodward et al., 2012). This inherently leads to an improvement in NUE with an increase in the proportion of N found in milk. In addition to this, high levels of crude protein (CP) in the diet reduce NUE with an increasing proportion of the ingested N leaving the cow as urine (Kebreab et al., 2001).This imbalance has meant large volumes of N (up to 1000 kg N/ha in urine patches) are excreted by the animal, with urinary N (UN) being easily leached from the system (Di & Cameron, 2002). This loss of N from the system is not only an environmental cost, but also represents a loss in soil fertility. Using alternative species has been shown to improve NUE and reduce the level of N excreted by grazing animals having positive implications both economically and environmentally (Grainger & Goddard, 2004; Totty et al., 2013).
CFU g -1 ) and their effects compared with those of control diet containing no probiotic. Survival in treatments was significantly (P<0.05) higher than control and a slight increasing mortality rate was observed during the first week of experiment. The counts of bacteria associated with trout intestine in all treatments were significantly (P<0.05) higher than controls and Bacillus spp. was not detected in controls. Total bacteria counts were significantly different among treatments and controls; it may suggest that the colonization rate of digestive tracts of rainbow trout fry with bacteria was affected by dietary bacteria level. Specific growth rate, condition factor, protein efficiency ratio were slightly but significantly (P<0.05) higher and feedconversion ratio was lower in groups received probiotic via diets than controls. It may show that probiotic stimulates digestive development and enzymatic activity in fish. Growth performance in treatment received 3.8×10 9 CFU g -1 showed the best results. Therefore, it does not appear that higher levels of probiotics improved results and suitable doze of probiotic should be assessed before application in large scale to prevent any undesired effects. The supplementation of trout starter diet with Bacillus spp. is probably effective for improving rearing conditions.
At the beginning and the end of the feeding trial, all fish were bulk-weighed, counted and their total and fork length were measured for calculation of weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER), feedconversion ratio (FCR), condition factor (CF) and survival. Five fish per tank (fifteen fish per dietary treatment) were collected for whole-body and muscle proximate composition. Analysis of moisture and ash content were performed by the standard procedures (AOAC, 1995). Crude protein was measured by using automatic Kjeltec Analyzer Unit 2300 (FOSS, Sweden) and crude lipid was determined using Soxhlet Extraction System C-SH6 (Korea).
Broiler production has become very popular among small and large scale farmers in Zimbabwe, and like all rational producers, profit maximization is their aim. Field in the Meat Trade News Daily (2010) reported that broiler national production levels stand at 1900 tones per month versus the consumer demand of 3000 tones. The gap between current production and the demand is very wide and provides a challenge to the local producers. Zawe, Chairman of the Poultry Producers Association, in World Poultry.Net (undated) stated that the main causes affecting production include the high cost of the feed, the shortage of feed and the cost of the day old chicks. Broiler research in Zimbabwe has focused on reduction of mortality based on poultry scavenging systems (Pedersen 1998) and use of mash versus pelted feed (Garikayi et al 2006) among many other topics. There appears to be a knowledge gape in terms slaughter age at which return per dollar and feedconversionefficiency are maximized hence the need for the study.
Enzyme supplementation increased the digestive capacity of the birds, improved the feedconversionefficiency, the digestibility of the feed components and reduced sticky droppings (Purushothaman and Natanam 1999) included multi enzymes in the treatments consisting of 0, 30 or 40 per cent raw little millet. They found that the supplementation of multi enzymes, (500g/ton) improved (P<0.05) feedconversionefficiency (FCE) and Phosphorus balance whereas feed intake improved in the 40 per cent little millet diet.(Waldroup et al. 2006) concluded that there were significant interactions in BW and FCR for Arginine and Lysine., (Mathlouthi et al. 2003) concluded that supplementation of diets based on wheat and barley with xylanase and β-glucanase significantly improved body weight gain and feedefficiency, (Sundu et al. 2006; Waldroup et al. 2006) concluded that the inclusion of enzyme significantly increased weight gain, feedconversionefficiency, (Pourreza et al. 2007) Added enzyme (xylanase) improved (P< 0.05) body weight, body weight gain, feed intake and feedconversion ratio. Apparent digestibility of energy and protein were increased (P< 0.05) due to supplemental enzyme. Superior feedefficiency in enzymes supplemented diet over the control was observed in the present experiment. The weekly feedefficiency exposed highly significant effect of DPE at all ages except at 6 th weeks of age.
The present findings concur with a previous report on growth performance of C. gariepinus fed on different CP diets, but not on the feedconversionefficiency . The present observation that growth performances of C. gariepinus were influenced by the CP levels is consistent with several previous reports on hybrid catfish fry , C. nigrodigitatus fingerlings  and in H. longifilis (Babalola & Apata, 2006). More specifically, Diyaware and co-workers  reported that growth rate and weight gain increased progressively with dietary protein level to a maximum of 50%. A high weight gain and SGR was observed in milkfish (C. chanos) fed at 40% protein level . Moreover, catfish fingerlings fed with 40% protein gave the best growth . The highest FCR of 0.06 obtained in this study was better than 1.28 observed in C. gariepinus fed with 40% protein . However, the present study contradicts a previous report, which showed that C. gariepinus raised in hapas and fed on different CP levels had no significant difference in growth performance . The discrepancy between the present and previous outcomes could be related to differences in geographical or environmental conditions. However, the previous reports evaluated high CP levels or utilized fingerlings hence, may not be easily embraced by farmers or formulated from locally available ingredients.
If we analyze the TCS from the point of view of protein content we will clearly see that the best TCS was obtained in the R3 diet containing the highest content of Protein. Siddiqui et al. (1988) report an optimal requirement of 40% for fingerlings of O. niloticus (initial weight 0.838g), and 30% for juveniles (initial weight, 40g). Jauncey (1982), Teshima et al (1992) reported that for rearing fry require 40% protein for normal growth. Kaushik et al. (1995) observed a maximum growth rate and feedefficiency at 35% of dietary protein for the same species. Diyaware et al. (2009) also support our conclusion by revealing that the best growth rates of hybrid catfish, Heterobranchus bidorsalis and Clarias anguillaris fry are obtained with a 40% crude protein content. Sotolu (2010) obtained a better weight gain, a specific growth rate and a feedconversion rate with a 40% dietary protein content in Clarias gariepinus. Adewolu and Adoti (2010) reported that fish fed continuously with 35% protein diets significantly resulted in the best weight gain, specific growth rate
The basal diets of both starter and grower phases were formulated according to the recommendation of National Research Council Nutrient Requirements for Broilers 28 . Performance parameters include the final body weight, feed intake, feedconversion ratio (FCR) 29 and protein efficiency ratio 30 those were determined weekly throughout the experimental period.
The present study was attempted to examine the combined effects of probiotics, Lactobacillus sporogenes (LS), Bacillus subtilis (BS) and yeast, Saccharomyces cerevisiae (SC) on survival, growth, biochemical changes and energy utilization performance of the freshwater prawn M. rosenbergii post larvae. The probiotics, L. sporogenes (4), B. subtilis (3) and S. cerevisiae (4) were taken and mixed. 1%, 2%, 3% and 4% of LS+BS+SC (4+3+4) was incorporated with basal diet. Diet without probiotics served as control. PL-30 of M. rosenbergii was fed with LS+BS+SC (4+3+4) incorporated diet for a period of 90 days. The growth parameters, such as survival, weight gain, specific growth rate, feedconversionefficiency and protein efficiency rate were significantly (P<0.05) higher in 3% LS+BS+SC incorporated diet fed post larvae (PL) followed by other experimental groups when compared with control. Whereas, the feedconversion ratio was significantly (P<0.05) lower in 3% LS+BS+SC incorporated diet fed PL. Similarly the tissues biochemical composition such as protein, amino acid, carbohydrate and lipid content were significantly (P<0.05) higher in 3% LS+BS+SC incorporated diet fed PL. However, insignificant difference was recorded in moisture content between control and experimental groups. The energy utilization parameters, such as feeding rate, absorption rate, conversion rate, NH 3 excretory rate and metabolic rate were significantly (P<0.05) higher in
Only a small portion of that available resource is being reared annually and of those reared, many are being carried through to slaughter at 30 months or older, requiring a second Winter and the poor FeedConversionEfficiency that goes with it. Better utilisation of the findings of the Beef and Lamb, MPI work in this area, would see improvements to Farm systems that create much better returns to Beef Finishers and allow greater throughput of Livestock.
It is suggested that the strategy for dry season livestock feeding programme and research should be directed towards practical solution of providing simple processing and quality feed e.g. the use of UTMS. Although supplementation at 150g of maize bran produced the best result with respect to weight gain, feedconversionefficiency and percentage digestibility, further studies should be conducted using higher levels of urea treatment and above 150g maize bran supplementation to determine the best economy of producing goats in the area for maximum productivity and profitability for the realization of the Millennium Development Goals and vision 2020. as contain in the transformation agenda of the federal government in the livestock sub sector.
The effect of chitosan incorporated into feed formulation on the growth, feed utilization, body composition and histological response of sea bass (Dicentrarchus labrax) was investigated. Final fish weight, feedconversion ratio (FCR), specific growth rate (SGR), protein efficiency ratio (PER), protein productive value (PPV), and energy utilization (EU) of sea bass feed chitosan supple- mented diet and the control diet were determined at the end of experiment. Data presents mean ± SD from triplicate determination (n = 3) for 75 days feeding trial. Different concentrations (0.5, 1.0, 2.0, 3.0 & 4.0) and control without chitosan incorporated with total fish feed in the form of dry di- ets were fed for 75 days. Average final weight (FW) was significantly higher at diet 3 (1 g∙kg −1 chi-
40% protein shows significant growth (Alhafedh, 1999). Diets containing excessive protein will generally be less cost effective and produce excessive nitrogenous wastes. Xic et. al, (2001) worked out that digestible energy content for smaller, rapidly growing fish, large mullaray is consumed relatively more lower energy diet (compared with HE diet), than small fish presumably to meet a greater demand for metabolic energy. However, the greater overall relative feed intake demonstrated by large mullaray was likely compensatory as indicated by the initial body composition. Najia (2003) worked out that crude protein contents in wheat bran used in the present study was comparatively higher (14.52%) than the wheat bran (13.81%) used for Cirrhinus mrigale. Shabir et. Al., (2003) reported that weight gained by hybrids on wheat bran (1.60+-0.14g) was higher than Cirrhinus mrigale which gained 0.19+-0.2g weight on wheat bran. Labeo rohita gained 2.63+-0.45g body weight on sunflower meal which is higher than the weight gained by hybrids (1.62+-0.05) (Ali and Salim, 2004). Diets with excessive lipid content with increase lipid deposition to the visceral cavity liver and muscle tissue of fish. (Nanton 2007) FeedConversionEfficiency: Growth of the fishes depends upon the food supplied to them or present in the natural environment. During the present study fishes had shown good good results of feedconversionefficiency to the diet provided to them. The FCR observed at four control sites were 0.23 gms/day, 0.41 gms/day,and 0.23 gms/day respectively. Where as the results observed at various rearing sites after culturing the fishes on artificial diet were 0.57 gms/day,0.65 gms/day,and 3.03 gms/day respectively This might be because of the fact that the food was rich in nutrients and fishes utilised them
The antibody response and acquired resistance of L. calcarifer to Neobenedenia sp. infections was examined following consecutive experimental infections (Chapter 4). Twenty fish were infected with Neobenedenia sp. oncomiracidia for 10 days with recovery periods (two weeks) between four consecutive exposure events. Before and after each exposure event, each fish was weighed, measured, and blood and mucous samples were collected for ELISA. After each infection the parasites were collected from each fish to analyse infection success, parasite size and reproductive status. Results showed that infected fish had significantly lower feedconversionefficiency than uninfected fish, parasites were significantly smaller on previously exposed fish and Neobenedenia infection success was significantly lower following three exposure events. There was no difference in infection success between the first, second and fourth exposure events. No differences in blood and mucous IgM levels between uninfected and infected fish could be detected by ELISA
Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium longum, Bifidobacterium bifidum and Saccharomyces boulardii was incorporated with basal diet and fed to M. rosenbergii PL for determining its beneficial effects on the survival, growth, nutritional indices (weight gain, specific growth rate, feedconversion ratio, and protein efficiency ratio), activities of digestive enzymes (protease, amylase and lipase), concentrations of biochemical constituents (total protein, carbohydrate and lipid) including profiles of protein, amino acids and fatty acids. In addition to these, biochemical characterization of gut microbial population for understanding the colony establishment, and the molecular characterization of gut bacterial consortium through 16S rDNA analysis to see its genetic diversity were also done.