我国肉鸽养殖业常采用 1 对种鸽哺乳多只乳鸽的生产模式,然而过多的带仔数可能会对种鸽的繁殖性能造成不利影响,特别是冬季气温较低,更容易引起种鸽生殖激素紊乱.为明确不同带仔数对冬季哺乳期种鸽生殖激素的影响,本研究选取 144 对 14 月龄欧洲Mimas肉种鸽,随机分为 3 组,每组 48 对,分别在哺乳期带 2、3、4 只乳鸽("2+2"、"2+3"和"2+4"),检测雌鸽哺乳期 0、7、14、21d的空腹血浆生殖激素含量.结果表明:雌鸽的雌二醇和孕酮含量随着带仔数的增加而升高(P<0.05),促黄体生成素、促卵泡激素、催乳素和睾酮含量随乳鸽数增多而下降(P<0.05).相关性分析发现,雌鸽在哺乳期第 7 天的体重损失与孕酮含量呈极显著正相关;哺乳期第14天血浆促黄体生成素水平与产蛋间隔呈显著负相关.以上结果表明,带仔数增加会显著影响雌鸽哺乳期血浆生殖激素含量,并可能进一步引起种鸽哺乳期体损失增加和产蛋间隔延长,造成种鸽繁殖性能下降.
Breeding pigeons are the fundamental source of profitability in pigeon breeding,and in order to achieve higher economic benefits,the breeding industry in China usually employs a high-rearing pattern.However,too many squabs consume more energy of breeding pigeons,especially in winter when the temperature is low,which may cause reproductive hormone disorders in breeding pigeons and adversely affect their reproductive performance.To determine the effect of different numbers of litters on the reproductive hormones of breeders during winter lactation,144 pairs of 14-month-old European Mimas breeders were randomly divided into 3 groups of 48 pairs each with 2,3 and 4 squabs during lactation("2+2","2+3"and"2+4"),and fasting plasma reproductive hormones were measured on days 0,7,14 and 28 of lactation.The results showed that the levels of estradiol and progesterone in female pigeons increased significantly(P<0.05)with the number of litters carried,while the levels of luteinizing hormone,follicle stimulating hormone,prolactin and testosterone tended to decrease significantly(P<0.05)with the number of litters.Correlation analysis revealed that body weight loss on day 7 of lactation was significantly positively correlated with testosterone levels and highly significantly negatively correlated with progesterone levels in hens;body weight loss on day 21 of lactation was significantly negatively correlated with follicle stimulating hormone.Plasma luteinizing hormone levels on day 14 of lactation were significantly and negatively correlated with egg production interval.The above studies suggest that an increase in the number of litters significantly affects the plasma reproductive hormone levels of hens during lactation and may further increase the body weight loss and prolong the egg-laying interval during lactation,resulting in a decrease in breeding performance.