ANIMAL PERFORMANCE AND FLEECE CHARACTERISTICS OF ANGORA-GOATS MAINTAINED ON WESTERN AND SOUTHERN TEXAS RANGELAND

Two hundred castrated male Angora goats (18 mo of age) were divided eq ually between rangeland sites in the oak savannah of the Edwards Plate au (EP) and the mixed-brush shrublands of the South Texas Plains (STP) for 5 yr to study influence of environment and age on body weight (BW ), mohair production, and mohair fiber characteristics. Goats mere gra zed on rangeland typical of the respective regions and were given typi cal management that included shearing in February and July or August o f each year. Shorn goats were weighed and individual fleeces were meas ured for grease weight (GFW), clean yield (CMFP), average fiber diamet er (AFD), and proportion of medullated fibers, med (MFP) and kemp (KFP ). Rainfall and maximum and minimum temperatures were recorded daily a t each site. The AFD (P = .01) and its associated SD (P < .001) and ke mp levels (P = .03) were all higher at the STP than at the EP site (39 .4 vs 37.9 mu m, 10.4 vs 11.1 mu m, and .80 vs .68%, respectively). An gora goats at EP weighed less (38.1 vs 41.7 kg, P = .03), and sheared less (1.90 vs 2.22 kg, P = .01), finer (36.4 vs 39.3 mu m, P < .001), and less kempy (.52 vs .84%, P < .001) mohair at the February shearing than at the August shearing. No seasonal differences in body weight o r in mohair production or quality were apparent at STP. The proportion s of total variation in grease mohair production (30.6%), CMFP (22.2%) , and AFD (15.7%) due to year effects were two to three times greater at STP than at EP. In contrast, year effects were responsible for only a small proportion (2.2 to 4.6%) of the variation in medullated fiber s. The effects of rainfall accumulation within specific 6-mo growing p eriods were positive for BW, GFW, CFW, AFD, SD of AFD and MFP and nega tive for CMFP and KFP. Only the rainfall effects on SD of AFD and medu llated fibers were significant (P < .05). The effects of age were posi tive for BW(P < .001), CMFP (P = .046), AFD (P < .001), MFP(P = .014), and KFP (P = .084) and negative for GFW (P = .046) and CFW (P = .107) . This study documents influence of environment and age of goats on bo dy weight, mohair production, and fiber characteristics.