放养条件下密度和补饲量对蛋鸡生产性能及蛋黄胆固醇含量的影响

Effects of density and feed supplement on layer production and yolk cholesterol under grazing conditions

  • 摘要: 选择45周龄体重接近的健康本地鸡441只, 随机分为7组, 在山西省太谷县生态养鸡场进行2(补饲量)×3(密度)两因子放养试验, 研究林下种植苜蓿不同放养密度与补饲量对蛋鸡生产性能和蛋黄胆固醇含量的影响。补饲量设自由采食量50%、70%两个处理, 密度为每667m2 100只、250只、400只3个处理, 以笼养全程自由采食为对照, 每组3个重复, 每重复3个小区用于轮牧, 小区面积为62 m2; 预试期7 d, 正试期70 d。结果表明: 补饲量和放养密度互作对平均产蛋率影响极显著(P<0.01), 对蛋重和料蛋比影响不显著(P>0.05)。笼养+自由采食组(CK)与补饲量70%、100只·667m-2组蛋重、平均产蛋率及料蛋比差异不显著(P>0.05), 但产蛋率显著高于其他各组(P<0.05), 蛋重显著高于补饲量50%、100只·667m-2组(P<0.05), 料蛋比显著低于补饲量50%组(P<0.05)。补饲量和放养密度互作对蛋黄重、蛋黄胆固醇含量和全蛋胆固醇含量影响不显著(P>0.05); 放养密度对全蛋胆固醇含量影响极显著(P<0.01)。笼养+自由采食组蛋黄重极显著高于补饲量50%、100只·667m-2组(P<0.01), 蛋黄胆固醇含量和全蛋胆固醇含量显著高于100只·667m-2组(P<0.05)。补饲量70%下, 100 只·667m-2放养密度对牧草的破坏性小于其他放养密度。结合产蛋性能、蛋黄胆固醇含量以及草地保护, 以70%补饲量+100 只·667m-2组养殖模式较好, 效果较佳。

     

    Abstract: Although the birth of ecological chicken industry was greeted with great enthusiasm, unreasonable feeding density has largely killed plant cover, exposed hill slopes bare and damaged the ecology. How to use the land resource and shade environment under trees has become a major problem requiring an urgent solution. A total of 441 healthy 45-week-old layer hens were randomly divided into 7 groups to study the effects of density and feed supplement rate on layer production and yolk cholesterol content under grazing conditions. Hens of groups 1?6 were reared under jujube/alfalfa wood. Treatments were set at feed supplement rates of 50% and 70% of free ingestion and at densities of 100, 250 and 400 hens per 667 m2. The 7th group of hens was reared in cages with free ingestion. Each plot area was 62 m2, 3 replicas set up for each group and 3 plots of each group used for rotation grazing. Preliminary trial period was 7 days while normal trial period was 70 days. The results showed that while density and feed supplement interaction had significant effects on egg laying rate (P < 0.01), it had no significant effect on egg weight and feed/egg ratio. Egg weight, egg laying rate and feed/egg ratio were not significantly different between cage-reared hens with free ingestion and 70% feed supplement with density of 100 hens per 667 m2 (P > 0.05). However, in cage-reared hens with free ingestion, egg laying rate was significantly higher than in other treatments (P > 0.05), egg weight significantly higher than in 50% feed supplement with density of 100 hens per 667 m2 (P > 0.05), and feed/egg ratio significantly lower than in 50% feed supplement with density of 100 hens per 667 m2(P < 0.05). The interaction between feed supplement and density had no significant effect on yolk weight, yolk cholesterol content and egg cholesterol content (P > 0.05). However, hen density had significant effect on egg cholesterol content (P < 0.01). Yolk weight of cage-reared hens with free ingestion was significantly higher than that of hens reared under 50% feed supplement and density of 100 hens per 667 m2 (P < 0.01). Yolk cholesterol content and egg cholesterol content of cage-reared hens with free ingestion were significantly higher than those of hens reared under 50% and 70% feed supplements and density of 100 hens per 667 m2 (P< 0.05). Pasture cover was highest for treatment with 70% feed supplement and density of 100 hens per 667 m2. Thus the culture mode with 70% feed supplement and density of 100 hens per 667 m2 was better for layer production, yolk cholesterol content and pasture protection.

     

/

返回文章
返回