1Deligeorgis SG,English PR,Lodge GA,et al. Interrelationship be- tween the growth gonadotrophin secretion and sexual maturation in gilts in reared in different litter size[J]. Anim. Prod,1985,41:393-401.
2Almeida F R C L,Kirkwood R N,Aherne F X,et al. Effect of different patterns of feed intake during the luteal phase on reproductive metabolic and endocrine parameters in cyclic gilts [J]. Anim.Sci,2000,78: 1556-1563.
3Ronnekleiv OK,Ojeda S R,McCan S M. Undemutrition,puperty and development of estrogen of positive feedback in the female rat [J]. Journal of biological reprod,1978,19:414-424.
4YWH,Kimura M,Walczewska A,et al. Role of leptin in hypotha- lamie-pituitory function[J]. Proc.Acad.Sci,1997,94:1023-1028.
5Hughes P E,Cole D J A,Foxcroft G R. Factors affecting natural attainment of puberty in the gilt [J].In Cotrol of pig reproduction . Lon- don Chp,1982,34: 161-177.
6Beltranena E,Aherne F X, Foxcroft GR, et al. Effect of pre-and post pubertal feeding on production traits at first and second estrus in gilt [J]. Anim.Sci, 1991,69:886-893.
7Patterson A M,Cole DJA and Foxcroft G R The controlled in- duduction of puberty Control pig of reproduction[J]. Butterworth' s,Lon- don,1982,23:130-160.
8Kirkwood R N,Aheme F X. Energy intake,body composition and reproductive performance of the gilt [J]. Anim.Sci,1985,60:1518- 1529.
9Aheme F X. Nutritional management to optimize breeding per- formance. Advance in pork production[J]. Anim. Sci,1996,7:143-155.
10Aheme FX. Foxcroft G R,Pettigrew J E [J]. Anita. Sci,1999,88: 1029-1044.
