MAFIC郵箱    用戶名:    密碼:         English Version
欄目導航
    當前位置:網站首頁 > 科研進展

    Estimation of the optimum standardized ileal digestible total sulfur amino acid to lysine ratio in late finishing gilts fed low protein diets supplemented with crystalline amino acids
    時間: 2015     來源: 農業部飼料中心

    作者:Ma WF, Zhu JL, Zeng XF, Liu XT, Thacker P and Qiao SY*
    期刊:J Anim Sci.doi: 10.1111/asj.12398
    摘要:Two experiments were conducted to investigate the effects of various standard ileal digestible (SID) lysine (Lys) levels and SID threonine (Thr) to Lys ratios on the performance and carcass characteristics of finishing gilts receiving low crude protein (CP) diets supplemented with crystalline amino acids (CAA). In Exp. 1, 108 gilts (87.8±5.9 kg) were randomly allotted to one of six diets which consisted of a high CP (135 g/kg) diet with 6.1 g/kg SID Lys or five low CP (100 g/kg) diets providing SID Lys levels of 4.9, 5.5, 6.1, 6.7 and 7.3 g/kg,respectively. Gilts were housed in three pigs per pen with six pens per treatment. At the end of the 28 days experiment, 36 gilts (one pig per pen) with average body weight (BW) of 116 kg were killed to evaluate carcass traits. The SID Lys levels required to maximize average daily gain (ADG) and optimize feed conversion ratio (FCR) as well as to minimize serum urea nitrogen (SUN) levels were 5.7, 5.8 and 6.1 g/kg using a linear-break point model and 6.5, 6.5 and 6.6 g/kg using a quadratic model. The fat-free lean gain tended to increase linearly with the increase in dietary SID Lys levels from 4.9 to 7.3 g/kg when gilts receiving a low CP diet (linear effect, P=0.06). In Exp. 2, 90 gilts (90.6±5.7 kg) were utilized in another dose–response study. Based on the Lys requirement estimated in Exp. 1, dietary treatments were formulated to contain 5.1 g/kg SID Lys to ensure the dietary Lys level was marginally deficient for late finishing gilts. Graded levels of crystalline Thr (0, 0.3, 0.6, 0.9 or 1.2 g/kg) were added to the basal diet providing SID Thr to Lys ratios of 0.54, 0.60, 0.66, 0.72 or 0.78,respectively. Each diet was fed to six pens with three gilts per pen. At the end of Exp. 2, 30gilts (one pig per pen) were slaughtered to evaluate carcass traits (average BW= 118 kg).The optimum SID Thr to Lys ratios to maximize ADG and FCR as well as to minimize SUN levels were 0.61, 0.63 and 0.64 using a linear-break point model and 0.70, 0.75 and 0.74 using a quadratic model. With the exception of L* light (linear effect, P<0.05), no effect on carcass characteristics was observed with increasing dietary SID Thr to Lys ratio.

    网络上哪里能买彩票 吉林白城麻将有哪些 上海快3 浙江体彩6十1走势图 网拍接单app 长春麻将微乐真人版 券商融资10万一天利息 辽宁十一选五分布走势一定牛 怏3北京 彩票幸运农场 资产配置的三种基本策略