Effects of the standardized ileal digestible lysine to metabolizable energy ratio on performance and carcass characteristics of growing-finishing pigs

• Published in: Journal of animal science and biotechnology Vol. 3; no. 1; pp. 42 - 50
• Main Authors: Li, Pengfei, Zeng, Zhikai, Wang, Ding, Xue, Lingfeng, Zhang, Rongfei, Piao, Xiangshu
• Format: Journal Article
• Language: English
• Published: England Springer-Verlag 01-03-2012; BioMed Central; Ministry of Agriculture Feed Industry Centre,State Key Laboratory of Animal Nutrition,China Agricultural University,Beijing 100193,China; BioMed Central Ltd; BMC
• Subjects: Amino acids; backfat; Body weight gain; carcass characteristics; Carcasses; Corn; Diet; Duroc; Energy; Energy levels; Experiments; fat thickness; Feed conversion; Feed efficiency; feed intake; Finishing; growing-finishing pigs; Hogs; ileum; Laboratories; landraces; Large White; Lysine; metabolizable energy; Physical growth; Ratios; Small intestine; Soybeans; standardized ileal digestible lysine; Swine; Thickness; Vegetable oils; Vitamin A; Vitamin E; weight gain; 代谢能; 回肠; 标准化; 消化; 生产性能; 生长肥育猪; 胴体特性; 赖氨酸; China; metabolizable energy; growing-finishing pigs; carcass characteristics; performance; standardized ileal digestible lysine
• DOI: 10.1186/2049-1891-3-9
• EISSN: 2049-1891
• ISSN: 1674-9782; 2049-1891

A total of 2,121 growing-finishing pigs （Duroc × Landrace ×Large White） were utilized in six experiments conducted to determine the effects of different ratios of standardized ileal digestible lysine （SID-Lys） to metabolizable energy （ME） on the performance and carcass characteristics of growing-finishing pigs. Exps. 1 （30 to 50 kg）, 2 （52 to 70 kg） and 3 （81 to 104 kg） were conducted to find an optimum ME level and then this level was used in Exps. 4 （29 to 47 kg）, 5 （54 to 76 kg） and 6 （84 to 109 kg） to test the response of pigs to different ratios of SID-Lys：ME. In Exps.1 to 3, four treatments were used consisting of diets with a formulated ME content of 3.1, 3.2, 3.3 or 3.4 in Exps. I and 2 while Exp. 3 used 3.05, 3.1 S, 3.25 or 3.35 Mcal/kg. A constant SID-Lys：ME ratio of 2.6, 2.3 or 2.0 g/Mcal was used in Exps. 1, 2 and 3, respectively. Weight gain was significantly increased with increasing energy level in Exp.1 while weight gain was unaltered in Exps. 2 and 3. For all three experiments, feed intake was decreased （P 〈 0.05） and feed efficiency was improved （P 〈 0.05） with increasing energy level. Tenth rib back fat thickness linearly increased （P 〈 0.05） with increasing energy level, in Exps. 4 to 6, five treatments were used consisting of diets with a SID-Lys：ME ratio of 2.4, 2.6, 2.8, 3.0 or 3.2 in Exp. 1, 2.1, 2.3, 2.5, 2.7, 2.9 or 3.2 in Exp. 2 and 1.8, 2.0, 2.2, 2.4, or 2.6 in Exp. 3. A constant ME level 3.2, 3.2 and 3.05 Mcal/kg was used in Exps. 1, 2 and 3, respectively （selected based on the results of weight gain）. For all three experiments, weight gain increased （P 〈 0.05） and feed efficiency improved linearly （P 〈 0.05） as the SID-Lys：ME ratio increased. Tenth rib back fat thickness linearly decreased （P 〈 0.0,5） as the SID-Lys：ME ratio increased. Based on a straight broken-line model, the estimated SID-Lys：ME ratio to maximize weight gain was 3.0, 2.43 and 2.2 for 29 to 47, 54 to76 and 84 to 109 kg of pigs, respectively.