- Volume 18 Issue 8
DOI QR Code
Growth Performance, Carcass Characteristics, Nutrient Digestibility and Serum Biochemical Parameters of Broilers Fed Low-protein Diets Supplemented with Various Ratios of Threonine to Lysine
Gong, L.M.;Lai, C.H.;Qiao, Shiyan;Li, Defa;Ma, Y.X.;Liu, Y.L.
- Received : 2004.09.26
- Accepted : 2005.03.07
- Published : 2005.08.01
This study was conducted to evaluate performance, breast (thigh) muscle yield, nutrient digestibility and serum biochemical parameters of broilers fed low-protein diets supplemented with various threonine to lysine ratios (Thr/Lys). Three hundred and twenty four day-old male Arbor Acres broilers were randomly allotted to six dietary treatments with six replicates per treatment and nine broilers per replicate. Six treatments included one control diet [formulated according to NRC (1994)], and five experimental diets (treatments 1-5). In treatments 1-5, the crude protein level was 2% lower than that of the NRC control diet. The Thr/Lys in treatments 1-5 was 0.65, 0.70, 0.75, 0.80 and 0.85 during the starter and grower phases and 0.70, 0.75, 0.80, 0.85 and 0.90 during the finisher phase with other nutrient levels kept consistent. The results showed that: (1) With increasing Thr/Lys, ADG of treatments 1, 3 and 4 were lower (p<0.05) than those of the NRC control diet during the starter phase; ADG of treatments 1-5 were lower (p<0.05) than those of the NRC control during the grower phase, and ADG of treatment 1 was lower (p<0.05) than that of the NRC control during the finisher phase. Average daily feed intake in treatments 1 and 4 were lower (p<0.05) than that of broilers on the NRC control diet during the grower phase. Feed/gain (F/G) of the NRC control diet was lowest (p<0.05) during the starter phase. F/G in treatments 2 and 5 were higher (p<0.05) than that of NRC during the grower phase. (2) Breast muscle proportion on d 21 increased linearly (p<0.05) in response to graded levels of Thr/Lys. (3) No differences were detected for dry matter, energy and crude protein digestibility among all seven treatments. (4) On d 21, serum triglyceride of broilers on dietary treatments 3 and 5 was higher (p<0.05) than that of broilers in control. The results indicate that the low-protein diets supplemented with an appropriate Thr/Lys could not support the same performance that was achieved by the broilers fed the NRC control diet.
Ratio of Threonine to Lysine;Broilers;Low-protein Diets
- Dozier, W. A., E. T. Jr. Moran and W. T. Kidd. 2000. Response of fast- and slow- feathering male broilers to dietary threonine during 42 to 56 days of age. J. Applied Poul. Res. 9:460-467.
- Feng, J. and Z. R. Xu. 2003. Effects of different ratios of threonine to lysine on performance and carcass composition of pigs. J. Zhejiang University (Agriculture and life science). 29:14-17.
- Kidd, M. T., B. J. Kerr, J. A. England and P. W. Waldroup. 1997. Performance and carcass composition of large white toms as affected by dietary crude protein and threonine supplements. Poult. Sci. 76:1392-1397.
- Li, Y. L. and Y. M. Guo. 2000. Threonine and tryptophan requirement of 3-6 week broilers. China J. Anim. Sci. 5:3-5.
- Sell, J. L. 1993. Influence of metabolizable feeding sequence and dietary protein on performance and selected carcass traits of tom turkeys. Poult. Sci. 72:521-534. https://doi.org/10.3382/ps.0720521
- Pinchasov, Y., C. X. Mendonca and L. S. Jensen. 1990. Broiler chick response to low protein diets supplemented with synthetic amino acids. Poult. Sci. 69:1950-1955.
- Lu, W. D., Y. L. Zhu, J. Sha and H. B. Zhu. 2000. SPSS for windows. Publishing House of Electronics Industry, Beijing.
- Sell, J. L., P. R. Ferket, C. R.Angel, S. E. Scheideler, F. Escribano and I. Zatari. 1989. Performance and carcass characteristics of turkey toms as influenced by dietary protein and metabolizable energy. Nutr. Rep. Int. 40:979-992.
- Spencer, G. K. 1984. Minimum protein requirements of turkeys fed adequate levels of lysine and methionine. M.S. Thesis, University of Arkansas, Fayetteville, AR.
- NRC. 1994. Feeding Standards of poultry. 8th rev. ed. National Academy Press, Washington, DC.
- Holsheimer, J. P., P. F. Vereijken and J. B. Schutte. 1994. Response of broiler chicks to threonine-supplemented diets to 4 weeks of age. Br. Poult. Sci. 35:551-562.
- Dai, J. G. 2002. Characteristics of dipeptide transport in small intestinal brush border membrane vesicles of weaned piglets. Ph.D. Dissertation, China Agricultural University, Beijing, China.
- Deschepper, K. and G. De Groote. 1995. Effect of dietary protein, essential and non-essential amino acids on the performance and carcass composition of male broiler chickens. Br. Poult. Sci. 36:229-245.
- Alleman, F., J. Michel, A. M. Chagneau and B. Leclercq. 2000. The effects of dietary protein independent of essential amino acids on growth and body composition in genetically lean and fat chickens. Br. Poult. Sci. 41:214-218.
- Feng, J., C. H. Hu, H. Chang and B. Zhou. 2001. The effects of different ratios of threonine to lysine on performance and carcass composition of growing-finishing pigs. Feed Industry, 11:40-41.
- Ciftci, I. and N. Ceylan. 2004. Effects of dietary threonine and crude protein on growth performance, carcass and meat composition of broiler chickens. Br. Poult. Sci. 45:280-289.
- Dozier, W. A., E. T. Jr. Moran and W. T. Kidd. 2001. Male and female responses to low and adequate dietary threonine on nitrogen and energy balance. Poult. Sci. 80:926-930.
- AOAC. 1995. Official Methods of Analysis. 16th ed. Association of Official Analytical Chemists, Washington, DC.