• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.566-572
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• 1998

The present study examined the effects of excessive dietary protein and energy on growth response to clenbuterol in broilers. The chicks were allocated into 6 groups at 14d old, and used for a $3{\times}2$ factorial experiment. Birds were fed six diets, the control diet containing 21% crude protein (CP) and 3,100 kcal of metabolizable energy ME/kg, a high protein (30% CP) or a high energy (3,500 kcal/ ME/kg) diet, with or without 1 ppm clenbuterol, for 18 d. Clenbuterol feeding markedly decreased (p < 0.05) body weight gain by 23% in the high energy group. Feed intake was also decreased (p < 0.05) by clenbuterol administration across diet treatments. Abdominal fat weight was reduced (p < 0.05) by clenbuterol only when chickens were fed the high energy diet. Clenbuterol increased (p < 0.05) leg muscle weight in the control diet group, but decreased (p < 0.05) it in the high energy group. Muscle protein concentration was increased by 11 % in leg muscle only of the birds at the high energy level. In leg muscle, clenbuterol enhanced the protein/DNA ratio by 18%, except for the high protein group. These results indicate that feeding a diet containing excessive amounts of protein and more energy than normal did not necessarily improve growth response to clenbuterol.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.628-637
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• 2020

In poultry diets, a requirement of crude protein is one of the most important factors in poultry productivity. Besides, the Pekin duck requirement of crude protein is still not clear. This experiment was conducted to determine the crude protein requirement of Pekin duck on diet formulation by investigation of growth performance, carcass trait, and analysis of blood parameter for a hatch to 21-day (d) of age. A total of 432 male White Pekin ducks were randomly allocated to six levels of crude protein (i.e., 15%, 17%, 19%, 21%, 23%, and 25%) to give six replicate pens per treatment with 12 ducklings per each pen. Body weight and feed intake were measured weekly by calculating feed conversion ratio and protein intake. Two ducklings each pen was euthanized via cervical dislocation for analysis of carcass trait and plasma blood on 21-d of age. Data were applied on both prediction linear-plateau and quadratic-plateau models by estimation of the crude protein requirements. Data were applied on both prediction linear-plateau and quadratic-plateau models by estimation of the crude protein requirements. The level of crude protein requirements of Pekin ducks for 21 days after the hatch was estimated to be 20.63% and 23.25% diet for maximum daily gain, and minimum feed conversion ratio, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.865-870
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• 2009

In this study, we have attempted to understand the effects of taurine on serum and liver concentrations of cholesterol and triglycerides in broiler chickens and mice in the post-absorptive state, and on in vitro protein synthesis in the livers of broiler chickens and laying hens, as well as the effects of taurine on in vivo protein synthesis in the liver of mice. The experimental animals were subjected to 24 h of starvation in order to perpetuate a post-absorptive state. Serum concentrations of high density lipoprotein cholesterol and triglycerides were significantly (p<0.05) higher in the taurine groups than in the controls in both the broilers and the mice. However, taurine resulted in a significant (p<0.05) reduction in liver concentrations of total cholesterol and triglycerides, relative to what was seen in the control groups of both animals. Taurine stimulated the in vitro synthesis of 57-kDa, 40-kDa and 23-kDa proteins in the liver of broilers, but inhibited the in vitro synthesis of 54-kDa, 37-kDa and 24-kDa proteins. Taurine in the liver of laying hens exerted effects on in vitro protein synthesis, with the exception of the 26-kDa protein which was not detected in broiler liver, but was inhibited by taurine in the liver of laying hens. Unlike the findings regarding in vitro protein synthesis in the liver of broilers or laying hens, taurine appeared to stimulate the synthesis of only two proteins, a 47-kDa and a 40-kDa protein, in the liver of mice. Overall, theses findings indicate that taurine treatment results in a reduction in cholesterol and triglyceride concentrations, and also affects protein synthesis in the livers of broilers, laying hens, and mice.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.2
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• pp.170-175
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• 2016

The objective of this study was to assess variance components and genetic parameters for fat and protein content in Tsigai sheep using multivariate animal models in which fat and protein content in individual months of lactation were treated as different traits, and univariate models in which fat and protein content were treated as repeated measures of the same traits. Test day measurements were taken between the second and the seventh month of lactation. The fixed effects were lactation number, litter size and days in milk. The random effects were animal genetic effect and permanent environmental effect of ewe. The effect of flock-year-month of test day measurement was fitted either as a fixed (FYM) or random (fym) effect. Heritabilities for fat content were estimated between 0.06 and 0.17 (FYM fitted) and between 0.06 and 0.11 (fym fitted). Heritabilities for protein content were estimated between 0.15 and 0.23 (FYM fitted) and between 0.10 and 0.18 (fym fitted). For fat content, variance ratios of permanent environmental effect of ewe were estimated between 0.04 and 0.11 (FYM fitted) and between 0.02 and 0.06 (fym fitted). For protein content, variance ratios of permanent environmental effect of ewe were estimated between 0.13 and 0.20 (FYM fitted) and between 0.08 and 0.12 (fym fitted). The proportion of phenotypic variance explained by fym effect ranged from 0.39 to 0.43 for fat content and from 0.25 to 0.36 for protein content. Genetic correlations between individual months of lactation ranged from 0.74 to 0.99 (fat content) and from 0.64 to 0.99 (protein content). Fat content heritabilities estimated with univariate animal models roughly corresponded with heritability estimates from multivariate models: 0.13 (FYM fitted) and 0.07 (fym fitted). Protein content heritabilities estimated with univariate animal models also corresponded with heritability estimates from multivariate models: 0.18 (FYM fitted) and 0.13 (fym fitted).

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.9
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• pp.1267-1278
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• 2009

Three beef steers fitted with permanent cannulae in the rumen and duodenum were used to determine the effects of protein supply from soyhulls (SH) and wheat bran (WB) on ruminal metabolism, blood metabolites, nitrogen metabolism, nutrient digestion and concentrations of soluble non-ammonia nitrogen (SNAN) in ruminal (RD) and omasal digesta (OD). In a 3${\times}$3 Latin square design, steers were offered rice straw and concentrates formulated either without (control) or with two brans to increase crude protein (CP) level (9 vs. 11% dietary DM for control and bran-based diets, respectively). The brans used were SH and WB that had similar CP contents but different ruminal CP degradability (52 vs. 80% CP for SH and WB, respectively) for evaluating the effects of protein degradability. Ruminal ammonia concentrations were higher for bran diets (p<0.01) than for the control, and for WB (p<0.001) compared to the SH diet. Similarly, microbial nitrogen and blood urea nitrogen were significantly increased (p<0.05) by bran and WB diets, respectively. Retained nitrogen tended (p<0.082) to be increased by SH compared with the WB diet. Intestinal and total tract CP digestion was enhanced by bran diets. In addition, bran diets tended (p<0.085) to increase intestinal starch digestion. Concentrations of SNAN fractions in RD and OD were higher (p<0.05) for bran diets than for the control, and for WB than for the SH diet. More rumendegraded protein supply resulting from a higher level and degradability of CP released from SH and WB enhanced ruminal microbial nitrogen synthesis and ruminal protein degradation. Thus, free amino acids, peptides and soluble proteins from microbial cells as well as degraded dietary protein may have contributed to increased SNAN concentrations in the rumen and, consequently, the omasum. These results indicate that protein supply from SH and WB, having a low level of protein (13 and 16%, respectively), could affect ruminal metabolism and nutrient digestion if inclusion level is relatively high (>20%).

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.257-259
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• 1992

Three tropical legumes, very different in growth form, but believed to be of potential value for animal production were evaluated by substituting the leaf meal made from each for lucerne at the level used in a standard diet for growing rabbits (50%). Each leaf meal had a nitrogen content of close to 3.5% and contributed about 60% of the crude protein in the diet. Albizia lebbeck and Clitoria ternatea showed no evidence of toxic or antinutrient effects. The protein digestibility of the complete diets were 66 and 61% respectively, implying a protein digestibility of the leaf of at least 50%. Both species would be suitable for practical production diets for rabbits and should be excellent for ruminants. In contrast, the diet containing Desmanthus virgatus had a protein digestibility of only 40%, implying that only about 15% of the leaf protein was available. The leaves showed marked non-enzymic browning on drying. When dried this species is clearly unsuitable as a feed for rabbits and possibly also for ruminants. However, it may well be valuable as fresh forage.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.4
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• pp.399-405
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• 1991

The interaction of 4 dietary crude protein (13, 16, 19 or 22%) and 4 metabolizable energy (2600, 2800, 3000 or 3100 kcal ME/kg) levels on egg quality performances of Starcross layers were assessed between 245 and 275 days of age. The egg weight increased significantly with the increasing dietary protein and energy levels. But egg shape index, albumen index, yolk index, yolk dry matter, yolk protein, yolk fat, albumen protein and shell tickness were similar at all dietary protein and/or energy levels. The egg specific gravity and albumen weight increased but the yolk, weight, Haugh unit and albumen drymatter decreased with the increase of dietary protein levels and showed irregular trend with energy levels. The albumen dry matter and egg shell weight, however, were not affected by energy and protein levels. Simultaneous increase of protein and energy increased specific gravity, albumen index and shell thickness at a greater rate than that increased by the increase of protein or energy alone.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.123-128
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• 1992

In Experiment 1, when fasted chicks were fed diets containing various sources of protein for 3 days, the activities of lipogenic enzymes (acetyl-CoA carboxylase, fatty acid synthetase, citrate cleavage enzyme and malic enzyme) in the liver of growing chicks were significantly lower in the soybean protein or gluten diet than in the casein or fish protein diet. Triglycride contents of the liver and plasma of chicks fed the casein or fish protein diet were significantly lower than that of those fed soybean protein or gluten diet. In Experiment 2, the effects of dietary amino acid mixture simulating casein or protein on the activities of hepatic lipogenic enzymes were examined. The activities of acetyl-CoA carboxylase and fatty acid synthetase in the liver of chicks fed the casein diet were significantly higher than that of those fed the soybean protein diet or two diets of amino acid mixtures. Furthermore, there were no significant differences between the two diets of amino acid mixture based on casein or soybean protein. However, the activities of malic enzyme and citrate cleavage enzyme tended to be lower in the soybean-type amino acid diet than in the casein-type amino acid diet. Thus, some effects can be ascribed to the protein itself and some to the amino acid composition of the protein sources.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.329-330
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• 1989

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.235-236
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• 1989