摘要
进行两个试验,研究了初情期前不同日龄的枫泾和长白母猪LRH-A_2诱导的LH水平和不同剂量的LRH-A_2对LH水平的影响。结果表明,77日龄枫泾猪,85和202日龄长白猪在诱导前血清中LH含量分别为1.70±0.17、0.74±0.10和1.40±0.14ng/ml,前二者和后二者间的差异极为明显(P<0.001)。除枫泾猪的5μg和10μg剂量外,其余各剂量在注射5分钟后血清中LH含量均显著高于注射前的LH值(P<0.005～0.001)。枫泾猪诱导的LH峰值与LRH-A_2的剂量无关,而长白猪的峰值出现时间和峰值高低均因剂量而异。诱导的LH值随初情期前的小母猪日龄而变化。枫泾猪和长白猪诱导的LH峰值出现的日龄分别为30和60天,峰值分别为5.55±0.63和16.14±2.74ng/ml,差异极明显(P<0.005)。枫泾猪在30～60和75～90日龄时诱导的LH值分别显著低于长白猪在60和95日龄的诱导值,但接近初情期时,两猪种间的差异则变得不明显。可结论如下:甾体激素的负反馈机制,枫泾和长白猪分别在30和60日龄开始建立,并在初情期时达到完善。
The effects of age and breeds on serum LH levels after administr-action of LRH-A2 was studied in Fengjing ( F) and Landrace ( L ) pre-pubertal gilts, Two experiments were coducted, The resting LH concentrations ( + SE ) in F at 77, L at 85 and 202 days of age were 1.70 ±0.70, 0.74 ± 0.10 and 1.40± 0.14ng/ml respectively, differences between the first 2 and the last 2 were highly significant(P<0.001).All groups treated with LRH-A2 showed significant ( P<0.005-0.001 ) elevation in serum LH at first (5 min ) post-treatment samples,except
5 μg and 10μg of F gilts. After treatment peak values were noted at 25 min in F gilts, but there was no significant difference at 25 and 5 -20 min. The peak values of induced LH in 85 days old L gilts appeared at 15-20 min, which were increased with increased doses of LR-H-A2,. As effect of age on LRH-A2 induced LH levels, the peak values were noted at 30 and 60 days of age in F(5.55 ± 0.63ng/ml ) and L
( 16.14±2.74ng/ml ) , which were highly different ( P<0.005 ). Afterwards, induced LH levels reduced to a minimum at 90 and 200 days of age in F and L gilts respectively. Both experiments indicated that induced LH contents at 30-60 and 60-90 days of age of F gilts were significantly lower than that at 60 and 95 days of age of L gilts respectively. With approaching puberty the difference became nonsignificant. It was concluded that the LRH-A, induced LH values fluctuated with age in prepubertal gilts of both pig breeds; steroid feedback mechanism was established at about 30 days of age in F, and at about 60 days of age in L gilts;These differences may be due to the differences in development of the hypothalamic-pituitary-ovarian circuit.
出处
《畜牧兽医学报》
CAS
CSCD
北大核心
1991年第2期122-126,共5页
ACTA VETERINARIA ET ZOOTECHNICA SINICA
