This Is AuburnElectronic Theses and Dissertations

Evaluation of Sustainable Forage Systems for Meat Goat Production in the Southern US

Date

2006-08-15

Author

Hopkins, Carla

Type of Degree

Dissertation

Department

Animal Sciences

Abstract

The effect of production systems on growth, carcass traits and carcass quality of 45 Boer wether goat kids was determined and the development of prediction equations for carcass composition was examined using carcasses from 89 goat kids of varying weights and feeding regimes. Forty-five Boer crossbred goat kids were randomly assigned to 1 of 3 production systems. Concentrate diet (CONC), bahiagrass pasture (BG) or mimosa browse (MB). Growth was measured by weighing goats every two weeks for 14 weeks. Goats receiving CONC had higher (P = 0.001) average daily gains, heavier (P > 0.05) carcass weights, higher dressing and shrinkage percentages, greater body wall fat and more kilograms of total carcass lean than BG or MB goats. Moisture and ash percentages were higher (P < 0.05) while fat percentages were lower (P < 0.05) in goats grazing BG and browsing MB carcasses than goats receiving CONC. Total fatty acid concentrations were higher (P = 0.01) in CONC goats and fatty acid profiles indicated that goats receiving CONC contained higher (P = 0.05) amounts of C18:2 n-6, while goats browsing MB contained higher (P = 0.001) amounts of C18:3 n-3, with a lower n-6:n-3 ratio. Retail data indicated that surface discoloration occurs at d 4 of display regardless of production system. Cook loss and sensory attributes were not affected (P > 0.05) by production system and WBSF values were within acceptable values for tender meat products. Whole body fat percentages were predicted from the 9-10-11th rib cut and carcass traits with an R2 value of 0.81 and 0.74, respectively. These results indicated that goat kids receiving a concentrate-based diet produced heavier carcasses with higher fat percentage and more total carcass lean than goat kids receiving a primarily forage-based diet. Managing goats on forage-based systems improved the fatty acid profile and lowered total fatty acid content with no adverse effects on meat quality or palatability traits. These data also indicated that fat percentages in goat carcasses can be predicted accurately utilizing the 9-10-11th rib cut and carcass traits.