Effects of increasing palm kernel cake inclusion in supplements fed to grazing lambs on growth performance, carcass characteristics, and fatty acid profile

The aim of this study was to evaluate the effects of the inclusion of palm kernel cake (PKC) in the supplement composition for grazing lambs on intake, digestibility, growth performance, carcass characteristics and fatty acid profile of the meat. Thirty-one non-castrated Santa Inês-crossed male lambs (age = 120 ± 15 d; initial body weight = 20 ± 3.9 kg) were divided into 4 groups, following a completely randomized design. Treatments were 0%, 10%, 20%, and 30% PKC substitution for ground corn and wheat bran in the supplement. Animals were stratified to equalize body weight: 8 animals in treatment 0%; 8 in treatment 10%; 6 in treatment 20%; and 9 in treatment 30%. Lambs were fed for 84 d and grazed a predominantly braquiarão grass (Urochloa brizantha cv. Marandu) and Tifton 85 (Cynodon dactylon) grass pasture. The remainder of the supplement contained soybean meal, wheat bran, ground corn, urea, and mineral salt. The level of supplementation was 1.6% BW per animal/d. There was a linear decrease (P < 0.01) for total DM intake and pasture intake as the inclusion of PKC in the supplement was increased. Feeding increasing PKC in the supplement did not affect (P ≥ 0.35) lamb growth performance nor did it affect most carcass characteristics (P ≥ 0.16). However, it did lower conformation (P = 0.02) and carcass shrink (P = 0.03). Palmitic fatty acid decreased (linear; P = 0.04) as PKC fed to lambs increased in the supplement. No other fatty acids were affected (P ≥ 0.10). Feeding up to 30% PKC in a supplement for grazing lambs reduced DMI without altering average daily gain or economic traits of carcass characteristic.