Growth and Carcass Characteristics in Goat Kids Fed Grass- and Alfalfa-Hay-Based Diets with Limited Concentrate Supplementation

Two experiments were conducted to evaluate the effect of feeding legume hay (alfalfa; Medicago sativa L.) or mixed-grass hay on ADG and carcass characteristics of growing goats. In Experiment 1, 24 Spanish kids, equally representing female, intact male and wether goats, were pen-fed ad libitum either chopped alfalfa (16.8 percent CP) or mixed grass hay (9.4 percent CP) (3 pens/diet) and a corn/soybean meal supplement (16 percent CP) at 1.5 percent BW for 102 d. Goats were harvested at a commercial abattoir. Average daily gain (62 vs. 37 g/d; P < 0.01), carcass weight (14.8 vs. 12.8 kg; P < 0.05) and dressing percent (52.9 percent vs. 50.4 percent; P < 0.05) were higher in alfalfa than grass-hay-fed goats, respectively. Backfat and percentage kidney/pelvic fat was lower (P < 0.05) in bucks (0.12 cm and 1.8 percent) than in does (0.17 cm and 5.7 percent) and wethers (0.22 cm and 4.0 percent). In Experiment 2, 10-month-old Boer and Boer-cross wethers (n=16) were penfed ad libitum either chopped alfalfa (15.2 percent CP) or grass hay (10.9 percent CP) for 84 days. Forage was supplemented with concentrate (16.3 percent CP) at 1 percent of BW. Carcass characteristics were determined as described for Experiment 1. Wethers fed alfalfa hay had a higher ADG (158 vs. 119 g/d; P < 0.01) and dressing percentage (54.0 percent vs. 52.2 percent, P < 0.05), but did not differ in other carcass characteristics. Alfalfa feeding improved growth rate and dressing percentage, but had no effect on other carcass characteristics, whereas sex class influenced primarily carcass-fat content. Growth and Carcass Characteristics in Goat Kids Fed Grassand Alfalfa-Hay-Based Diets with Limited Concentrate Supplementation