Effect of the age of rams on reproductive performance of ewe hoggets

References

• Allison , AJ . 1975 a . Flock mating in sheep. I. Effect of number of ewes joined per ram on mating behaviour and fertility . New Zealand Journal of Agricultural Research , 18 : 1 – 8 .
   Web of Science ®Google Scholar
• Allison , AJ . 1975 b . Ewe and ram fertility in commercial flocks mated with differing numbers of ewes per ram . New Zealand Journal of Experimental Agriculture , 3 : 161 – 167 .
   Google Scholar
• Allison , AJ . 1978 . Flock mating in sheep. IV. Effect of number of ewes per ram on ejaculate characteristics and libido during the mating period . New Zealand Journal of Agricultural Research , 21 : 187 – 195 .
   Web of Science ®Google Scholar
• Clarke , JN , Roberts , EM , Carter , AH and Kirton , AH . 1966 . Hormonal synchronisation of oestrus in Romney ewes during the breeding season . Proceedings of the New Zealand Society of Animal Production , 29 : 107 – 121 .
   Google Scholar
• Courot , M . 1979 . “ Semen quality and quantity in the ram ” . In Sheep Breeding , Edited by: Tomes , GL , Robertson , DE and Lightfoot , RJ . 495 – 503 . London, , UK : Butterworths .
   Google Scholar
• Dyrmundsson , OR . 1973 a . Puberty and early reproductive performance in sheep. I. Ewe lambs . Animal Breeding Abstracts , 41 : 273 – 289 .
   Google Scholar
• Dyrmundsson , OR . 1973 b . Puberty and early reproductive performance in sheep. II. Ram lambs . Animal Breeding Abstracts , 41 : 419 – 427 .
   Google Scholar
• Dyrmundsson , OR . 1981 . Natural factors affecting puberty and reproductive performance in ewe lambs: a review . Livestock Production Science , 8 : 55 – 65 .
   Google Scholar
• Dyrmundsson , OR . 1987 . “ Advancement of puberty in male and female sheep ” . In New Techniques in Sheep Production , Edited by: Fayez , I , Marai , M and Owen , JB . 65 – 76 . London, , UK : Butterworths & Co .
   Google Scholar
• Dyrmundsson , OR and Lees , JL . 1973 . Effect of rams on the onset of breeding activity in Clun-Forest ewe lambs . Journal of Agricultural Science , 79 : 269 – 271 .
   Google Scholar
• Edey , TN , Kilgour , R and Bremner , K . 1978 . Sexual behaviour and reproductive performance of ewe lambs at and after puberty . Journal of Agricultural Science , 90 : 83 – 91 .
   Web of Science ®Google Scholar
• Hight , GK . 1982 . “ Improving the efficiency of breeding schemes ” . In Sheep Production. Volume 1: Breeding and Reproduction , Edited by: Wickham , GA and McDonald , MF . 169 – 197 . Wellington, , NZ : New Zealand Institute of Agricultural Science .
   Google Scholar
• Hudgens , RE , Martin , TG , Diekman , MA and Waller , SL . 1987 . Reproductive performance of Suffolk and Suffolk-cross ewes and ewe lambs exposed to vasectomised rams before breeding . Journal of Animal Science , 65 : 1173 – 1179 .
   PubMed Web of Science ®Google Scholar
• Kenyon , PR , Perkins , NR , Pinchbeck , GL , Morris , ST and West , DM . 2004 . Identifying factors which maximise the lambing performance of hoggets: a cross sectional study . New Zealand Veterinary Journal , 52 : 371 – 377 .
   PubMed Web of Science ®Google Scholar
• Kenyon , PR , Morel , PCH , Morris , ST and West , DM . 2005 . The effect of individual liveweight and use of teaser rams prior to mating on the reproductive performance of ewe hoggets . New Zealand Veterinary Journal , 53 : 340 – 343 .
   PubMed Web of Science ®Google Scholar
• Kenyon , PR , Morel , PCH , Morris , ST , Burnham , DL and West , DM . 2006 a . The effect of length of use of teaser rams prior to mating and individual liveweight on the reproductive performance of ewe hoggets . New Zealand Veterinary Journal , 54 : 91 – 95 .
   PubMed Web of Science ®Google Scholar
• Kenyon , PR , Morel , PCH , West , DM and Morris , ST . 2006 b . Effect of liveweight and teasing of ewe hoggets prior to breeding on lambing pattern and weight of singleton lambs . New Zealand Journal of Agricultural Research , 49 : 341 – 347 .
   Web of Science ®Google Scholar
• Lightfoot , RJ . 1968 . Studies on the number of ewes joined per ram for flock matings under paddock conditions. II. The effect of mating on semen characteristics . Australian Journal of Agricultural Research , 19 : 1043 – 1057 .
   Google Scholar
• Lightfoot , RJ and Smith , JAC . 1968 . Studies on the number of ewes joined per ram for flock matings under paddock conditions. I. Mating behaviour and fertility . Australian Journal of Agricultural Research , 19 : 1029 – 1042 .
   Google Scholar
• Lindsay , DR . 1979 . “ Mating behaviour in sheep ” . In Sheep Breeding , Edited by: Tomes , GL , Robertson , DE and Lightfoot , RJ . 473 – 479 . London, , UK : Butterworths .
   Google Scholar
• Price , EO , Estep , DQ , Wallach , SJR and Dally , MR . 1991 . Sexual performance of rams as determined by maturation and sexual experience . Journal of Animal Science , 69 : 1047 – 1052 .
   PubMed Web of Science ®Google Scholar
• Rosciszewska , ZE . 1985 . The influence of earlier mating experience of ewes on their subsequent mating behaviour and reproductive performance . Animal Reproduction Science , 9 : 223 – 229 .
   Google Scholar
• Schinckel , PG . 1954 . The effect of the ram on the incidence and occurrence of oestrus in ewes . Australian Veterinary Journal , 30 : 189 – 195 .
   Google Scholar