Effect of dietary protein content on growth and body composition of fast and slow feathering broiler chickens

The relationship between dietary protein, essential amino acids (EM) and energy was examined in two experiments using male broiler chicks fed practical diets to eight weeks of age. All diets contained a balanced proportion of ten EAA which was maintained over various treatments. Growth of birds was closely related to the EAA content of the diet and poorly related to dietary protein content. When the dietary concentration of ten EAA was treated as a combined unit and expressed as proportion of diet, 7.6 per cent EAA in an 18 per cent protein starter diet and 5.8 per cent EAA in a 16 per cent protein finisher diet were adequate to support maximal growth of male birds to eight weeks of age. Feed intakes were reduced as energy concentrations increased in diets regardless of protein content of diets.

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The influence of nutrition in early life on growth and development of the pig 1. Effects of protein nutrition prior and subsequent to 6·5 kg on growth and development to 45 kg

Animal Science ◽

10.1017/s0003356100010461 ◽

1983 ◽

Vol 36 (3) ◽

pp. 415-423 ◽

Cited By ~ 6

Author(s):

R. G. Campbell ◽

A. C. Dunkin

Keyword(s):

Body Composition ◽

Growth Performance ◽

Protein Content ◽

Dietary Protein ◽

Growth And Development ◽

Crude Protein ◽

Live Weight ◽

Body Protein ◽

Protein Diets ◽

Protein Treatment

ABSTRACTForty-five piglets were used to study the effects of feeding diets containing 153, 239 or 321 g crude protein per kg dry matter between 1·8 and 6·5 kg live weight, and low and high protein diets subsequent to 6·5 kg live weight on growth performance, body composition and the cellularity of skeletal muscle to 45 kg live weight.Reducing dietary crude protein between 1·8 and 6·5 kg live weight depressed growth performance and at 6·5 kg live weight increased body fat content but reduced body protein, body water and the weight and DNA content of the adductor muscle. The effects of dietary protein content before 6·5 kg live weight on body composition at the latter weight were still evident in pigs killed at 11·5 kg live weight whilst the differences in muscle DNA persisted to 45 kg live weight.On the lower protein treatment subsequent to 6·5 kg live weight there was a tendency for pigs given the lowest protein diet before 6-5 kg live weight to exhibit better growth performance and deposit protein at a faster rate than those given the higher protein diets. However, these responses were reversed on the higher protein treatment subsequent to 6·5 kg live weight.The effects of dietary protein content subsequent to 6·5 kg live weight on growth performance, body composition and the cellularity of muscle tissue were qualitatively the same as those for the live-weight phase 1·8 to 6·5 kg.

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Effects of dietary protein content on IGF-I, testosterone, and body composition during 8 days of severe energy deficit and arduous physical activity

Journal of Applied Physiology ◽

10.1152/japplphysiol.00005.2008 ◽

2008 ◽

Vol 105 (1) ◽

pp. 58-64 ◽

Cited By ~ 48

Author(s):

Joseph A. Alemany ◽

Bradley C. Nindl ◽

Mark D. Kellogg ◽

William J. Tharion ◽

Andrew J. Young ◽

...

Keyword(s):

Body Composition ◽

Energy Expenditure ◽

Protein Content ◽

Energy Intake ◽

Dietary Protein ◽

High Energy ◽

Low Energy ◽

Fat Free Mass ◽

Energy Deficit ◽

Igf I

Energy restriction coupled with high energy expenditure from arduous work is associated with an altered insulin-like growth factor-I (IGF-I) system and androgens that are coincident with losses of fat-free mass. The aim of this study was to determine the effects of two levels of dietary protein content and its effects on IGF-I, androgens, and losses of fat-free mass accompanying energy deficit. We hypothesized that higher dietary protein content would attenuate the decline of anabolic hormones and, thus, prevent losses of fat-free mass. Thirty-four men [24 (SD 0.3) yr, 180.1 (SD 1.1) cm, and 83.0 (SD 1.4) kg] participated in an 8-day military exercise characterized by high energy expenditure (16.5 MJ/day), low energy intake (6.5 MJ/day), and sleep deprivation (4 h/24 h) and were randomly divided into two dietary groups: 0.9 and 0.5 g/kg dietary protein intake. IGF-I system analytes, androgens, and body composition were assessed before and on days 4 and 8 of the intervention. Total, free, and nonternary IGF-I and testosterone declined 50%, 64%, 55%, and 45%, respectively, with similar reductions in both groups. There was, however, a diet × time interaction on day 8 for total IGF-I and sex hormone-binding globulin. Decreases in body mass (3.2 kg), fat-free mass (1.2 kg), fat mass (2.0 kg), and percent body fat (1.5%) were similar in both groups ( P = 0.01). Dietary protein content of 0.5 and 0.9 g/kg minimally attenuated the decline of IGF-I, the androgenic system, and fat-free mass during 8 days of negative energy balance associated with high energy expenditure and low energy intake.

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Effects of dietary protein content and 2-hydroxy-4-methylthiobutanoic acid ordl-methionine supplementation on performance and oxidative status of broiler chickens

British Journal Of Nutrition ◽

10.1017/s0007114511002558 ◽

2011 ◽

Vol 106 (12) ◽

pp. 1845-1854 ◽

Cited By ~ 43

Author(s):

Quirine Swennen ◽

Pierre-André Geraert ◽

Yves Mercier ◽

Nadia Everaert ◽

Anneleen Stinckens ◽

...

Keyword(s):

Lipid Peroxidation ◽

Protein Content ◽

Dietary Protein ◽

Broiler Chickens ◽

Antioxidant Status ◽

Body Weight Gain ◽

Oxidative Status ◽

High Protein ◽

Methionine Sulfoxide Reductase ◽

Low Protein

Besides its typical role as an amino acid in protein synthesis, methionine is an important intermediate in methylation reactions. In addition, it can also be converted to cysteine and hence plays a role in the defence against oxidative stress. The present study was conducted to investigate further the role ofdl-methionine (DLM) and its hydroxy analogue,dl-2-hydroxy-4-methylthiobutanoic acid (DL-HMTBA), on zootechnical performance and oxidative status of broiler chickens. Male broiler chickens were reared on two diets differing in crude protein (CP) content (low-protein, 18·3 %v.high-protein, 23·2 % CP) and were supplemented either with 0·25 % DLM or 0·25 % DL-HMTBA. Reducing the dietary protein content resulted in an impaired body weight gain (P < 0·0001). However, supplementation of DL-HMTBA to the low-protein diet partially alleviated these negative effects (P = 0·0003). This latter phenomenon could be explained by the fact that chickens fed DL-HMTBA-supplemented diets displayed a better antioxidant status as reflected in lower lipid peroxidation probably as a consequence of their higher hepatic concentrations of total and reduced glutathione compared with their DLM counterparts. On the other hand, within the high protein levels, uric acid might be an important antioxidant to explain the lower lipid peroxidation of high-protein DL-HMTBA-supplemented chickens. Hepatic methionine sulfoxide reductase-A gene expression was not significantly affected by the dietary treatments. In conclusion, the present study indicates that there are interactions between dietary protein content and supplementation of methionine analogues with respect to broiler performance and antioxidant status, also suggesting a causal link between these traits.

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Growth performance, nutrient utilisation and carcass composition respond to dietary protein concentrations in broiler chickens but responses are modified by dietary lipid levels

British Journal Of Nutrition ◽

10.1017/s0007114517002070 ◽

2017 ◽

Vol 118 (4) ◽

pp. 250-262 ◽

Cited By ~ 7

Author(s):

Sonia Y. Liu ◽

Peter H. Selle ◽

David Raubenheimer ◽

Rob M. Gous ◽

Peter V. Chrystal ◽

...

Keyword(s):

Weight Gain ◽

Protein Content ◽

Lipid Content ◽

Dietary Protein ◽

Broiler Chickens ◽

Dietary Lipid ◽

Lipid Levels ◽

Maximum Weight ◽

High Lipid ◽

Nutrient Utilisation

AbstractA total of ten experimental diets with protein concentrations ranging from 154 to 400 g/kg and two lipid levels (46 and 85 g/kg) with identical energy densities were offered to 240 male Ross 308 broilers from 7 to 28 d post-hatch. Growth performance was monitored and nutrient utilisation (apparent metabolisable energy (AME), N-corrected AME (AMEn), AME daily intake, AME:gross energy ratios, N retention) was determined. The weight gain response of broiler chickens to dietary protein concentrations in diets containing high and low lipid levels was diverse, with the relevant quadratic regressions being significantly different (P<0·05). With low lipid levels, the predicted maximum weight gain of 1809 g/bird equated to 342 g/kg dietary protein, whereas, for high lipid levels the predicted maximum weight gain of 1694 g/bird equated to 281 g/kg dietary protein. AME was linearly correlated with dietary protein concentration but regressions in diets with different lipid content were not significantly different (P>0·05). AMEn was also linearly (P<0·0001) increased with dietary protein concentrations but regressions in diets with low and high lipid content were significantly different (P<0·03). Carcass protein content increased linearly with dietary protein content in diets containing high lipid concentrations (r 0·933, P<0·0001); by contrast, this relationship was quadratic (R2=0·93, P<0·0001) in diets with low lipid levels. In conclusion, predictably, the effects of dietary protein concentrations on broiler performance were profound; however, the impact of dietary protein on performance in broiler chickens was modified by dietary lipid concentrations.

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