This study was conducted to investigate the effect of weaning age on growth performance, nutrient digestion and metabolism, and serological indicators, and to obtain an optimal weaning age in Hu lambs.Forty-eight newb...This study was conducted to investigate the effect of weaning age on growth performance, nutrient digestion and metabolism, and serological indicators, and to obtain an optimal weaning age in Hu lambs.Forty-eight newborn Hu lambs(birth weight, 2.53 ± 0.14 kg) were randomly divided into 4 groups. The lambs in control group(ER) suckled their dams. The lambs in other three experimental groups were weaned on milk replacer at 10.20, and 30 days of age(EW10, EW20, and EW30 groups),respectively. The results were as follows: 1) lambs in EW10 and EW30 groups had a lower(P < 0.05) ADG than those in ER group within 10 days post-weaning; the weaned lambs began to show a higher(P < 0.05) ADG than those in ER group after 20 days post-weaning. 2) EW10 and EW20 groups had a higher(P < 0.05) creep feed intake than EW30 and ER groups from 15 to 60 days of age. 3) The apparent digestibility of dry matter, organic matter, gross energy, nitrogen, ether extract and phosphorus, and the deposition of nitrogen and phosphorus did not differ(P > 0.05) among groups; however, the apparent digestibility and deposition of calcium in early weaned lambs were lower(P < 0.05) than those in ewe-reared lambs. 4)The albumin content in EW30 group was lower(P < 0.05) than that in ER group; the globulin content in EW30 group was higher(P < 0.05) than that in other groups; the content of serum insulin-like growth factor-1 in weaned lambs tended to increase compared with lambs in ER group. Finally, the growth rate of lambs decreased within 10 days post-weaning, but early weaning boosted creep feed intake, leading to better growth and health later in life. The Hu lambs can be weaned on milk replacer and creep feed at 10 days of age.展开更多
This study evaluated the effects of dietary energy levels on growth performance,carcass traits,meat quality,and serum biochemical of female Hu lambs.Seventy female Hu lambs(aged 4 months)were randomly allotted to 5 di...This study evaluated the effects of dietary energy levels on growth performance,carcass traits,meat quality,and serum biochemical of female Hu lambs.Seventy female Hu lambs(aged 4 months)were randomly allotted to 5 dietary treatments.Lambs were fed diets with 5 levels of metabolizable energy(ME):9.17(E1),9.59(E2),10.00(E3),10.41(E4),and 10.82 MJ/kg(E5).The lambs were adapted to the experimental diets for 10 d and the experiment period lasted for 60 d.Dry matter intake and feed conversion ratio linearly(P<0.001)increased and decreased(P<0.001),respectively,with increasing dietary ME levels.Average daily gain(ADG)linearly(P<0.001)increased with increasing dietary ME levels,with the highest final body weight(P=0.041)observed in E4 group.Moreover,dietary energy level was associated with linear increases in serum total protein(TP)(P<0.001),albumin(ALB)(P=0.017),glucose(GLU)(P=0.004),and low-density lipoprotein cholesterol(LDLC)(P=0.006)concentrations,and it was associated with a quadratic decrease in serum triglyceride(TG)concentration(P=0.002).Serum ammonia concentration,which was firstly decreased and then increased,was quadratically affected by dietary ME levels(P=0.013).Compared with E1 group,lambs in E4 group had higher(P<0.05)live weights,carcass weights,mesenteric fat ratio,non-carcass fat ratio,and larger loin muscle area,but lower(P<0.05)meat colour a*and b*values,and lesser(P<0.05)C17:0,C20:0,C18:1 n-9 t,C18:3 n-3,and n-3 polyunsaturated fatty acids(PUFA),but greater(P<0.05)C18:3 n-6 and n-6:n-3 ratios in longissimus dorsi(LD)muscle tissue,and lesser(P<0.05)C17:0,C18:3 n-3,C22:6 n-3,and n-3 PUFA in the biceps femoris(BF)muscle tissue.The results demonstrated that increasing dietary energy level improved the growth performance and affected carcass traits,serum biochemical indexes,and fatty acid profiles in different muscles of female Hu lambs.For 4-month-old female Hu lambs,the recommended fattening energy level is 10.41 MJ/kg.展开更多
基金supported by the Special Fund for Agro-scientific Research in the Public Interest(201303143)China Scholarship Council Fund(201403250010)
文摘This study was conducted to investigate the effect of weaning age on growth performance, nutrient digestion and metabolism, and serological indicators, and to obtain an optimal weaning age in Hu lambs.Forty-eight newborn Hu lambs(birth weight, 2.53 ± 0.14 kg) were randomly divided into 4 groups. The lambs in control group(ER) suckled their dams. The lambs in other three experimental groups were weaned on milk replacer at 10.20, and 30 days of age(EW10, EW20, and EW30 groups),respectively. The results were as follows: 1) lambs in EW10 and EW30 groups had a lower(P < 0.05) ADG than those in ER group within 10 days post-weaning; the weaned lambs began to show a higher(P < 0.05) ADG than those in ER group after 20 days post-weaning. 2) EW10 and EW20 groups had a higher(P < 0.05) creep feed intake than EW30 and ER groups from 15 to 60 days of age. 3) The apparent digestibility of dry matter, organic matter, gross energy, nitrogen, ether extract and phosphorus, and the deposition of nitrogen and phosphorus did not differ(P > 0.05) among groups; however, the apparent digestibility and deposition of calcium in early weaned lambs were lower(P < 0.05) than those in ewe-reared lambs. 4)The albumin content in EW30 group was lower(P < 0.05) than that in ER group; the globulin content in EW30 group was higher(P < 0.05) than that in other groups; the content of serum insulin-like growth factor-1 in weaned lambs tended to increase compared with lambs in ER group. Finally, the growth rate of lambs decreased within 10 days post-weaning, but early weaning boosted creep feed intake, leading to better growth and health later in life. The Hu lambs can be weaned on milk replacer and creep feed at 10 days of age.
基金supported by Natural Science Foundation of Hunan Province(2017JJ1020,2018JJ3340)Young Elite Scientists Sponsorship Program by CAST(YESS20160086)+1 种基金Hunan Province’s Strategic and Emerging Industrial Projects(2018GK4035)Hunan Province’s Changsha-Zhuzhou-Xiangtan National Independent Innovation Demonstration Zone projects(2017XK2058)
文摘This study evaluated the effects of dietary energy levels on growth performance,carcass traits,meat quality,and serum biochemical of female Hu lambs.Seventy female Hu lambs(aged 4 months)were randomly allotted to 5 dietary treatments.Lambs were fed diets with 5 levels of metabolizable energy(ME):9.17(E1),9.59(E2),10.00(E3),10.41(E4),and 10.82 MJ/kg(E5).The lambs were adapted to the experimental diets for 10 d and the experiment period lasted for 60 d.Dry matter intake and feed conversion ratio linearly(P<0.001)increased and decreased(P<0.001),respectively,with increasing dietary ME levels.Average daily gain(ADG)linearly(P<0.001)increased with increasing dietary ME levels,with the highest final body weight(P=0.041)observed in E4 group.Moreover,dietary energy level was associated with linear increases in serum total protein(TP)(P<0.001),albumin(ALB)(P=0.017),glucose(GLU)(P=0.004),and low-density lipoprotein cholesterol(LDLC)(P=0.006)concentrations,and it was associated with a quadratic decrease in serum triglyceride(TG)concentration(P=0.002).Serum ammonia concentration,which was firstly decreased and then increased,was quadratically affected by dietary ME levels(P=0.013).Compared with E1 group,lambs in E4 group had higher(P<0.05)live weights,carcass weights,mesenteric fat ratio,non-carcass fat ratio,and larger loin muscle area,but lower(P<0.05)meat colour a*and b*values,and lesser(P<0.05)C17:0,C20:0,C18:1 n-9 t,C18:3 n-3,and n-3 polyunsaturated fatty acids(PUFA),but greater(P<0.05)C18:3 n-6 and n-6:n-3 ratios in longissimus dorsi(LD)muscle tissue,and lesser(P<0.05)C17:0,C18:3 n-3,C22:6 n-3,and n-3 PUFA in the biceps femoris(BF)muscle tissue.The results demonstrated that increasing dietary energy level improved the growth performance and affected carcass traits,serum biochemical indexes,and fatty acid profiles in different muscles of female Hu lambs.For 4-month-old female Hu lambs,the recommended fattening energy level is 10.41 MJ/kg.
