The aim of this study was to compare the area production and grazing behavior of single- and twin-rearing ewes kept on a mixed Italian ryegrass/white clover pasture. The herbage allowance was maintained at 12 kg DM/10...The aim of this study was to compare the area production and grazing behavior of single- and twin-rearing ewes kept on a mixed Italian ryegrass/white clover pasture. The herbage allowance was maintained at 12 kg DM/100kg live weight during the experiment, by continuous variable stocking management for 112 days (4 periods of 28 days). We measure the live weight gains, the area production and the body condition score of ewes and lambs. Animal behavior was observed on four occasions during which we evaluated whether the lambs were grazing near to or far from their mother. Live-weight output from the ewes and lambs, and net output (ewes and lambs) were calculated. Results showed that being irrespective of birth type, ewes had similar mean daily weight gains, although ewes with twin lambs presented a mean lower body condition score. Ewes live weight output/ha did not differ significantly among birth types, but twin lambs produced 98.2 kg (45%) more live weight gain/ha. Total net live-weight output (ewes + lambs) was 121.5 kg greater for twins than for singles. Ewes with twin lambs spent more time grazing and ruminating. Lambs increased the time they spent grazing in each successive period. Single lambs spent significantly longer time grazing within 12 m of their dams (near grazing). Analysis of far grazing times by the broken line method showed that growing lambs rapidly increase the time spent far grazing up to a live weight of 20.3 kg in both birth types, which occurs at 95.3 and 115.9 days of age for single and twins, respectively. The results indicate that twin lambs are more productive than singles, when evaluated per area unit of pasture.展开更多
本文旨在研究内蒙古牧区冬春季低质粗料供给条件下,补饲不同能氮比精料对羔羊生长性能及血清指标的影响。采取单因子试验设计选取(61±2)日龄健康、体重为(20.56±1.43)kg断奶的羔羊128只,公母各占1/2,分成4组,每组32个重复,每...本文旨在研究内蒙古牧区冬春季低质粗料供给条件下,补饲不同能氮比精料对羔羊生长性能及血清指标的影响。采取单因子试验设计选取(61±2)日龄健康、体重为(20.56±1.43)kg断奶的羔羊128只,公母各占1/2,分成4组,每组32个重复,每个重复1只羊,分别补饲消化能(DE)水平相近、粗蛋白质(CP)水平逐渐升高的4种颗粒精料,其能氮比(采用DE/CP)分别为90.03(Ⅰ组)、82.55(Ⅱ组)、73.25(Ⅲ组)、67.87 M J/kg(Ⅳ组)。试验期40 d。结果表明:1)Ⅲ组平均日增重分别高于Ⅳ组7.75%(P<0.01)、Ⅰ组4.94%(P<0.05)和Ⅱ组3.41%(P>0.05),且该组料重比最优。2)Ⅰ组羔羊末体高极显著低于其他组(P<0.01),其中Ⅱ、Ⅲ、Ⅳ组母羔末体高分别比Ⅰ组高3.68%、4.12%、4.44%(P<0.05);不同能氮比精料对不同性别羔羊的胸围增长、胸围增长率无显著影响(P>0.05)。3)血清尿素氮含量随着精料蛋白质水平增加而升高,Ⅳ组极显著高于Ⅰ、Ⅱ组(P<0.01);Ⅲ组羔羊血清中白细胞介素-6含量显著高于Ⅱ、Ⅳ组(P<0.05),免疫球蛋白M含量显著高于其他各组(P<0.05)。结果提示,牧区冬春季枯草期对羔羊及时补饲精料能够取得较好的生长效果,不同能氮比精料对牧区羔羊部分血清指标产生显著影响,补饲精料最适能氮比为73.25 MJ/kg。展开更多
文摘The aim of this study was to compare the area production and grazing behavior of single- and twin-rearing ewes kept on a mixed Italian ryegrass/white clover pasture. The herbage allowance was maintained at 12 kg DM/100kg live weight during the experiment, by continuous variable stocking management for 112 days (4 periods of 28 days). We measure the live weight gains, the area production and the body condition score of ewes and lambs. Animal behavior was observed on four occasions during which we evaluated whether the lambs were grazing near to or far from their mother. Live-weight output from the ewes and lambs, and net output (ewes and lambs) were calculated. Results showed that being irrespective of birth type, ewes had similar mean daily weight gains, although ewes with twin lambs presented a mean lower body condition score. Ewes live weight output/ha did not differ significantly among birth types, but twin lambs produced 98.2 kg (45%) more live weight gain/ha. Total net live-weight output (ewes + lambs) was 121.5 kg greater for twins than for singles. Ewes with twin lambs spent more time grazing and ruminating. Lambs increased the time they spent grazing in each successive period. Single lambs spent significantly longer time grazing within 12 m of their dams (near grazing). Analysis of far grazing times by the broken line method showed that growing lambs rapidly increase the time spent far grazing up to a live weight of 20.3 kg in both birth types, which occurs at 95.3 and 115.9 days of age for single and twins, respectively. The results indicate that twin lambs are more productive than singles, when evaluated per area unit of pasture.
文摘本文旨在研究内蒙古牧区冬春季低质粗料供给条件下,补饲不同能氮比精料对羔羊生长性能及血清指标的影响。采取单因子试验设计选取(61±2)日龄健康、体重为(20.56±1.43)kg断奶的羔羊128只,公母各占1/2,分成4组,每组32个重复,每个重复1只羊,分别补饲消化能(DE)水平相近、粗蛋白质(CP)水平逐渐升高的4种颗粒精料,其能氮比(采用DE/CP)分别为90.03(Ⅰ组)、82.55(Ⅱ组)、73.25(Ⅲ组)、67.87 M J/kg(Ⅳ组)。试验期40 d。结果表明:1)Ⅲ组平均日增重分别高于Ⅳ组7.75%(P<0.01)、Ⅰ组4.94%(P<0.05)和Ⅱ组3.41%(P>0.05),且该组料重比最优。2)Ⅰ组羔羊末体高极显著低于其他组(P<0.01),其中Ⅱ、Ⅲ、Ⅳ组母羔末体高分别比Ⅰ组高3.68%、4.12%、4.44%(P<0.05);不同能氮比精料对不同性别羔羊的胸围增长、胸围增长率无显著影响(P>0.05)。3)血清尿素氮含量随着精料蛋白质水平增加而升高,Ⅳ组极显著高于Ⅰ、Ⅱ组(P<0.01);Ⅲ组羔羊血清中白细胞介素-6含量显著高于Ⅱ、Ⅳ组(P<0.05),免疫球蛋白M含量显著高于其他各组(P<0.05)。结果提示,牧区冬春季枯草期对羔羊及时补饲精料能够取得较好的生长效果,不同能氮比精料对牧区羔羊部分血清指标产生显著影响,补饲精料最适能氮比为73.25 MJ/kg。
