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 equally between rangeland sites in the oak savannah of the Edwards Plateau (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 were grazed on rangeland typical of the respective regions and were given typical management that included shearing in February and July or August of each year. Shorn goats were weighed and individual fleeces were measured for grease weight (GFW), clean yield (CMFP), average fiber diameter (AFD), and proportion of medullated fibers, med (MFP) and kemp (KFP). Rainfall and maximum and minimum temperatures were recorded daily at each site. The AFD (P = .01) and its associated SD (P < .001) and kemp levels (P = .03) were all higher at the STP than at the EP site (39.4 vs 37.9 micrometers, 10.4 vs 11.1 micrometers, and .80 vs .68%, respectively). Angora 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 micrometers, 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 or in mohair production or quality were apparent at STP. The proportions 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 fibers. The effects of rainfall accumulation within specific 6-mo growing periods were positive for BW, GFW, CFW, AFD, SD of AFD and MFP and negative for CMFP and KFP. Only the rainfall effects on SD of AFD and medullated fibers were significant (P < .05). The effects of age were positive 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 body weight, mohair production, and fiber characteristics.