Comparative study of PMSG treatment and different levels of concentrate supplements prior to mating on twinning rate of horro ewes

An investigation was made to compare different levels of concentrate supplements vis a vis PMSG injection prior to mating on twining rate of Horro ewes. Sixty seven Horro ewes were randomly allotted to 5 feeding plus hormonal treatment groups (12 ewes/group) based on their body weight, condition score (score range, 0 to 5), age, parity and type of birth (single, twins or purchased). The 5 treatment groups were; grazing only (Control), grazing + 300 g/head/day concentrate (T1), grazing + 450 g/head/day concentrate (T2), grazing + 600 g/head/day concentrate (T3) and grazing + 300 i.u. PMSG (T4). Oestrus and ovulation were synchronised in all ewes using 2 dosages of prostaglandin F2 alpha 12 days apart. At the second prostaglandin injection one group of ewes (T4) were injected with 300 i. u. PMSG also. The results indicated that more uniform exhibition of oestrus was observed in PMSG treated group vis a vis control. (p<0.05). PMSG treatment increased twinning rate and therefore total number of Iambs born. However, the difference did not reach the level of significance (p>0.05) for groups supplemented with 300,450 and 600 g concentrate/head/day. Based on this investigation it can be concluded that concentrate supplementation above 300 g/head/day may not be of much significance. PMSG administration on the other hand resulted in production of significantly more Iambs per ewe.