Effects of Birth Weight and Feeding System on Fattening Performance and Feeding Behaviour of Karayaka Male Lambs

Abstract

To determine effects of birth weight (BtW) and feeding system on fattening performance and behavioural responses of lambs, after birth 28 Karayaka male lambs were divided into two BtW groups, namely a low BtW (4.1±0.06 kg) and high BtW (5.0±0.09 kg). After weaning (90 days of age), seven lambs in each of these groups were fed individually ad libitum with total mixed ratio (TMR), consisted of 80% of a compound feed and 20% of roughage based on a dry matter basis (140 g crude protein and 2550 kcal ME/kg) and the other seven lambs were fed on the same ingredients as that of TMR but each ingredient was put in separate troughs (free choice feeding, FCF). Therefore the lambs were distributed into four groups according to 2 (low vs high BtW) × 2 (TMR vs FCF) factorial design. Live weight gains and intakes of dry matter, feedstuffs and nutrients of the lambs were affected by the FCF, but not by the BtW and their interaction. The daily weight gain (P<0.01), intakes of soybean meal and corn (P<0.01), dry matter (P<0.05), protein and energy (P<0.01) of FCF-fed lambs were higher than those of TMR-fed lambs. FCF-fed lambs consumed less alfalfa hay, wheat bran and barley than TMR-fed lambs (P<0.01). The FCF increased rumination (P<0.01) and tend to rest more (P<0.05) compared to the TMR. The study suggests that FCF system can assist in enhancing the live weight gain by promoting the protein and energy intakes and by improving the welfare of lambs.