不同日粮能量水平对蛋鸡血液FSH、LH、P_4和产蛋率的影响

Effects of Diet Energy on FSH,LH,P_4 in Plasma and Laying Rates of Layers

采用放射免疫分析方法（RIA）测定蛋鸡性成熟过程中和产蛋期血液中FSH、LH和P4的含量,研究不同日粮能量水平对蛋鸡血液FSH、LH、P4和产蛋率的影响,进而研究这些激素与产蛋率的关系。结果表明,高能使见蛋日龄提前,但见蛋后,高能I和低能Ⅱ组产蛋率上升较慢。随着能量的降低,到达产蛋率峰值的时间推迟,峰值以对照组最高,低能组居中,高能组最低。峰值后,高能组产蛋率迅速下降,而其它各组在37周龄前产蛋率维持较高水平的70%左右,到46周龄仍维持在41%以上。在性成熟过程中,血清FSH含量上升,到22周龄时极显著升高,高能组FSH水平显著高于低能组;LH水平也随着周龄的增大而升高;高能I组LH水平显著高于低能组。28周龄高能I组FSH达到峰值,其它各组在33-40周龄达到峰值。高能I、高能Ⅱ和对照组LH水平分别在27、34、30周龄达峰值,低能I和低能Ⅱ组分别在30和42周龄达峰值。在产蛋期,对照组LH水平高于低能组,低于高能组,而对照组产蛋率无一例外地高于其它各组。FSH峰值与平均产蛋率呈显著正相关,产蛋期FSH均值与平均产蛋率呈显著正相关。在性成熟过程中P4含量上升,但18周龄前血清P4含量较低,到22周龄极显著升高;高能组血清中P4水平显著高于低能组。产蛋期,对照和低能组平均P4水平和平均产蛋率均比高能组高。P4峰值和峰后平均值和平均产蛋率呈显著正相关,产蛋期血浆中P4水平与平均产蛋率呈显著正相关。

The objectives of this study were to investigate the effects of diet energy on plasma follicle-stimulating hormone （FSH）, luteinizing hormone （LH）, progesterone （P4） and laying rates of layers and to relate these hormone levels with the laying performance. Radiation immunity analysis was used to determine the plasma hormone concentration during prepubertal development and laying period. The results demonstrated that high energy level led to ahead of the day to first egg. Laying rates of high energy Ⅰ and low energy Ⅱ increased slowly after first egg. With the decrease of energy level, the time to laying peak was delayed. The order of laying peak value from high to low was control group, low energy group and high energy group. Compared with other groups, laying rates in high energy groups descended rapidly. During sexual maturity, plasma FSH concentration increased with age, FSH concentrations were higher in high energy groups than that in low energy groups, plasma LH concentration increased with age, LH concentration was higher in high energy group than that in low energy groups. High energy Ⅰ reached FSH level peak at 28 weeks, whereas other groups reached the peaks at 33-40 weeks. High energy Ⅰ,high energy Ⅱ and control groups reached LH level peak at 27,34 and 30 weeks, respectively, whereas low energy Ⅰ and low energy Ⅱ reached the peaks at 30 and 42 weeks; During laying period, control group had higher FSH level than other groups and higher LH level than low energy groups. Control group had higher laying rate than other groups. When FSH concentrations at peaks and during laying period were related to mean laying rates, a significant positive correlation and a significant positive correlation were obtained respectively. During sexual maturity, P4 concentration increased with age in all groups, P4 concentration was low before 18 weeks and increased at 22 weeks sharply, P4 concentrations in high energy groups were higher than that of low energy groups. During laying period, P4 concentrations and mean laying rates were higher in control and low energy groups than that in high energy groups. Significant positive correlations of P4 concentration at peak, after peak and during laying period with mean laying rate were obtained, respectively.