The influence of R-Salbutamol on feedlot performance, carcass characteristics and meat quality in Dorper ram, wether and ewe lambs

[摘要] ENGLISH ABSTRACT: A study on the effects of different R-salbutamol inclusion levels in a commercial finishing diet, on feedlot performance of three Dorper lamb sexes were carried out. The investigation consisted of two individual feedlot performance testing trials following a 2 x 4 factorial arrangement of treatments. Trial 1 consisted of 28 ram and 28 wether lambs, whilst Trial 2 used the same number of wether and ewe lambs. At the start of the trials, the lambs were randomly allocated to one of four R-salbutamol containing finisher feeds (0mg/kg, 110mg/kg, 135mg/kg and 160mg/kg feed). Live weights, feed intake and ort weights were recorded once a week for four consecutive weeks. Results from Trial 1 show that rams had superior average daily gain (ADG) and feed conversion ratio (FCR) values compared wethers. The comparison of ewes and wethers in Trial 2 showed no differences between these two sexes, for any of the feedlot performance attributes (ADG, FCR and dry matter intake (DMI)). In Trial 1 R-salbutamol had an effect only on the efficiency with which the lambs utilised the feed. The 110mg treatment group had superior FCR values compared to the control group. The 135mg and 160mg inclusion levels did however not differ significantly from either the control or 110mg treatment. No differences between beta-agonist inclusion levels were observed for any of the feedlot performance traits in Trial 2.

[发布机构] Stellenbosch University