Abstract
Abstract
Background
This study was conducted to determine the effects of different dietary protein levels and amino acids supplementation patterns in low protein diets on the growth performance, carcass characteristics and nitrogen excretion in growing-finishing pigs.
Forty-two barrows (25.00 ± 0.39 kg) were randomly assigned to 7 diets. Diet 1: the high crude protein diet with balanced for 10 essential amino acids (EAAs). Diet 2: the medium crude protein diet with 2% (approx) decreased protein level of Diet 1 and balanced 10 EAAs. Diet 3: the low crude protein diet with 4% decreased protein level of Diet 1 and balanced 10 EAAs. The protein levels of Diet 4, 5, 6 and 7 were the same as that of Diet 3. Diet 4 was only balanced for lysine (Lys), methionine (Met), threonine (Thr) and tryptophan (Trp); Diet 5 and 6 were further supplemented with extra isoleucine (Ile) or valine (Val), respectively; Diet 7 was further supplemented with extra Ile + Val.
Results
Over the 112 days trial, the reduction of dietary protein by 2% or 4% with balanced10 EAAs significantly decreased nitrogen excretion (P < 0.05), but had no effects on growth performance and carcass characteristics (P > 0.05). In low protein diet, Val supplementation significantly increased body weight gain at 25–50 kg phase (P < 0.05), while Ile supplementation at 75–100 kg phase and 100–125 kg phase significantly reduced the ratio of feed to gain (P < 0.05). No effect of different dietary protein levels and amino acids supplementation patterns in low protein diets on carcass characteristics was observed (P > 0.05). The total N excretion of pigs supplemented with only Lys, Met, Thr and Trp was numerically higher than that of pigs fed with extra Ile, or Val, or Ile + Val diets.
Conclusion
In low protein diet, Val is more required than Ile in the early growing phage (25–50 kg), while Ile becomes more required in the late growing and finishing phage (75–125 kg).
Funder
Science and Technology Support Program of Sichuan Province
National Key R&D Program of China
Publisher
Springer Science and Business Media LLC
Subject
Animal Science and Zoology,Biochemistry,Food Science,Biotechnology
Reference42 articles.
1. Kendall DC, Gaines AM, Kerr BJ, Allee GL. True ileal digestible tryptophan to lysine ratios in ninety- to one hundred twenty-five-kilogram barrows. J Anim Sci. 2007;85(11):3004–12.
https://doi.org/10.2527/jas.2007-0013
.
2. Chen HY, Yi XW, Zhang GJ, Lu N, Chu LC, Thacker PA, et al. Studies on reducing nitrogen excretion: I. net energy requirement of finishing pigs maximizing performance and carcass quality fed low crude protein diets supplemented with crystalline amino acids. J Anim Sci Biotechnol. 2011;02(2):84–93.
3. Kerr BJ. Dietary manipulation to reduce environmental impact. In: Page139-158 in 9th international symposium on digestive physiology in pigs. Banff, Alberta: Canadap; 2003. p. 14–7.
4. Kerr BJ, Mckeith FK, Easter RA. Effect on performance and carcass characteristics of nursery to finisher pigs fed reduced crude protein, amino acid-supplemented diets. J Anim Sci. 1995;73(2):433–40.
https://doi.org/10.2527/1995.732433x
.
5. Jin CF, Kim JH, Han IK, Bea SH. Effects of supplemental synthetic amino acids to the low protein diets on the performance of growing pigs. Asian Australas J Anim Sci. 1998;11(1):1–7.
https://doi.org/10.5713/ajas.1998.1
.
Cited by
32 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献