獣医科学と技術

Carcass Characteristics of Menz Ram Lambs Fed Grass Hay Basal Diet and Supplemented Wheat Bran and Lentil Broken Screening

Abstract

Wude Tsega, Berhan Tamir and Girma Abebe

An experiment was conducted to evaluate carcass characteristics of Menz ram lambs fed grass hay basal diet and supplemented different combination of wheat bran and lentil broken screening. The treatments were T₁ (30 g wheat bran 133 g lentil broken screening), T₂ (235 g lentil broken screening only), T₃ (285 g wheat bran only), and T₄ (227 g wheat bran and 120 lentil broken screening). Twenty-four Menz ram lambs of 8 to 10 months of age were grouped into six blocks based on their initial body weight and treatments were randomly distributed to each block of four animals. Six animals per treatment were used for feed intake and body weight change evaluation. Five lambs from each treatment were randomly picked and slaughtered for carcass evaluation. Wheat bran and lentil screening combination affected (P ≤ 0.01) the daily total dry matter intake (TDMI), final body weight, total weight gain and average daily weight gain (P ≤ 0.001) of lambs with the highest value recorded from T₄ diet categories. The experimental lambs showed lower (P ≤ 0.01) feed conversion efficiency (0.06) for the diet containing 30 g wheat bran and 133 g lentil screening (T₁) than the values recorded from T₂, T₃ and T₄ groups. The slaughter body weight was lower (P ≤ 0.001) for those lambs were assigned in T₁ than in T₂, T₃ and T₄. The higher (P ≤ 0.001) empty body weight (19.56 g) was recorded for lambs assigned to T₄ diet than T₁ followed by T₂ and T₃ diet. The carcass yield of lambs was increased (P ≤ 0.01) at T₄ supplemented groups than at T₁ and T₂ diets. The concentrate combination effect was non-significant (P ≥ 0.05) on dressing percentage, and proportions of carcass lean, fat and bone. Lambs assigned to T₄ diet had higher weight of kidney fat and ureo-genital tract (P ≤ 0.01) as well as respiratory tract and blood (P ≤ 0.05) than seen for other treatment categories. Except the dry matter percent of carcass fat (P ≤ 0.001), all carcass quality parameters were not affected (P ≥ 0.05) by the concentrate diet combinations. Carcass yield and quality of Menz ram lambs was better at feeding plan of grass hay basal diet and 227 g wheat bran and 120 g lentil broken screening concentrate mixture supplementation.