Effect of supplementary feeding to ewes and suckling lambs on ewe and lamb live weights while grazing wheat stubble

摘要

A trial was conducted to determine the effects on the performance of creep feeding suckling lambs and supplementing ewes that were grazing wheat stubble. Eight experimental units of South African Mutton Merino (SAMM) ewes and lambs were used in a 2 (supplementing ewes or not) x 2 (creep feeding lambs or not) factorial design. Two groups, consisting of 68 and 100 ewes, grazed 12.9 ha and 18 ha paddocks, respectively. Each group was then divided into four sub-groups, of which two sub-groups received supplementation and two were not supplemented. Within each ewe group, two groups of lambs received creep feeding and two groups did not. Ewe groups were rotated between these camps each week to eliminate the effect of camps. Supplementation at 200 g/day took place from February 2000 to May 2000, after which it was increased to 300 g/day until August 2000. The liveweight change (LWC) of ewes during the total experimental period from 22 November to 31 August, as well as during the feeding period from 22 February to 31 August, was not affected significantly by supplementation, although ewes that received supplementary feed maintained higher live weights for a large part of the experimental period. The average daily gain (ADG) of lambs from ewes that received supplementary feed tended (9%) to be higher compared to the lambs of ewes that did not received any supplementary feed. There was no significant difference in the LWC of ewes during the total experimental period or during the feeding period due to the creep feeding of their lambs. The ADG of the lambs that received creep feeding from 24 May to 28 August was 25% higher than that of lambs that did not receive it, and the creep-fed lambs maintained higher live weights for most of the experimental period.