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Sixty growing 3/4 Boer x 1/4 Spanish (BS) and Spanish (SP) wethers were used to determine influences of diet and breed on growth and body composition. A pelleted 50% concentrate diet (CD) and a diet based on grass hay (HD) were fed for ad libitum intake. Six wethers of each breed were slaughtered at 0 wk (total of 12). Six wethers of each diet-breed combination were slaughtered at 14 and 28 wk (24 per time) after consumption of the CD or HD. Initial BW of fed wethers were 21.6 and 18.8 kg for BS and SP, respectively (SEM = 0.7). Average daily gain during the entire experiment was influenced by an interaction (P < 0.05) between breed and diet (199, 142, 44, and 50 g/d for BS:CD, SP:CD, BS:HD, and SP:HD, respectively). Carcass mass was greater (P < 0.05) for CD vs. HD (56.2, 56.2, 53.2, and 54.0% of empty BW for BS:CD, SP:CD, BS:HD, and SP:HD, respectively). Mass of the liver (2.11, 1.92, 2.00, and 1.98% of empty BW; SEM = 0.05) and gastrointestinal tract (5.50, 4.83, 8.43, and 8.36% of empty BW for BS:CD, SP:CD, BS:HD, and SP:HD, respectively; SEM = 0.16) tended (P < 0.07) to be influenced by an interaction between breed and diet. Mass of internal fat (12.2, 12.1, 3.4, and 3.4% empty BW for BS:CD, SP:CD, BS:HD, and SP:HD, respectively; SEM = 0.3) differed (P < 0.05) between diets. Energy in the carcass (320, 236, 87, and 79 MJ), noncarcass tissues (318, 237, 77, and 72 MJ), and empty body (638, 472, 164, and 150 MJ) ranked (P < 0.05) BS:CD > SP:CD > BS:HD and SP:HD. Empty body concentration of protein was 18.3, 17.5, 18.3, and 19.7% (SEM = 0.3) and of fat was 24.0, 23.4, 10.8, and 10.3% for BS:CD, SP:CD, BS:HD, and SP:HD, respectively (SEM = 0.6). Energy concentration in accreted tissue was 17.0, 18.7, 16.3, and 6.4 MJ/kg for CD:wk 1 to 14, CD:wk 15 to 28, HD:wk 1 to 14, and HD:wk 15 to 28, respectively (SEM = 1.4). In conclusion, relatively high growth potential of growing Boer crossbred goats with a moderate to high nutritional plane does not entail a penalty in realized growth when the nutritional plane is low. Body composition of growing Boer and Spanish goats is fairly similar regardless of growth rate. For growing meat goats other than with a prolonged limited nutritional plane, an average energy concentration in accreted tissue is 17.3 MJ/kg.

Dairy goat herds in the United States generally are small, widely scattered, and distant from processing facilities. Unlike the situation for cow milk, it is not cost-effective to collect goat milk everyday or every other day. In some areas, goat milk is collected only once each week, which is in violation of regulations specified in the Pasteurized Milk Ordinance for grade A milk. This study was conducted to determine the effect of up to 7 days of refrigerated bulk tank storage on composition, somatic cell count (SCC), pH, and microbiological quality of goat milk. Duplicate farm bulk tank samples were taken daily after the morning milking for seven consecutive days each month during the lactation season. Samples were analyzed immediately for all variables except free fatty acids. There were no significant changes (P > 0.05) detected in milk fat, protein, lactose, nonfat solids, SCC, or pH during extended storage, although significant effects of stage of lactation (P < 0.05) were observed. The mean standard plate count (SPC) increased to 1.8 x 10(5) CFU/ml after 6 days of storage, exceeding the grade A limit (i.e., 1.0 x 10(5) CFU/ml). The mean psychrotrophic bacteria count increased steadily to 1.5 x 10(4) CFU/ml after 6 days of storage, whereas the mean coliform count was approximately 500 CFU/ml for the first 3 days and less than 2500 CFU/ml throughout the 7 days of storage. No significant changes (P > 0.05) in the concentrations of free fatty acids, except for butyric and caprylic acids, were observed during milk storage. When stored under refrigerated and sanitary conditions, goat milk in farm bulk tanks met the grade A criteria for both SPC and SCC during 5 days of storage but was of low quality thereafter because of the growth of psychrotrophic bacteria.

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