Lupton C J, Huston J E, Holloway J W, Warrington B G, Waldron D F, Thompson P V, Pfeiffer F A, Qi K
Texas Agricultural Experiment Station, San Angelo 76901, USA.
J Anim Sci. 1996 Mar;74(3):545-50. doi: 10.2527/1996.743545x.
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 microns, 10.4 vs 11.1 microns, 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 microns, 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.
将200只去势的雄性安哥拉山羊（18月龄）平均分配到爱德华兹高原（EP）的橡木稀树草原和南得克萨斯平原（STP）的混合灌丛林地的牧场中，为期5年，以研究环境和年龄对体重（BW）、马海毛产量和马海毛纤维特性的影响。山羊在各自区域典型的牧场上放牧，并接受包括每年2月和7月或8月剪毛在内的常规管理。对剪毛后的山羊进行称重，并测量每只羊的羊毛含脂量（GFW）、净毛率（CMFP）、平均纤维直径（AFD）以及髓质纤维比例、髓质（MFP）和死毛（KFP）。每天记录每个地点的降雨量以及最高和最低温度。STP的AFD（P = 0.01）及其相关标准差（P < 0.001）和死毛含量（P = 0.03）均高于EP地点（分别为39.4微米对37.9微米、10.4微米对11.1微米和0.80%对0.68%）。EP的安哥拉山羊在2月剪毛时体重较轻（38.1千克对41.7千克，P = 0.03），剪毛量较少（1.90千克对2.22千克，P = 0.01），马海毛更细（36.4微米对39.3微米，P < 0.001），死毛含量更低（0.52%对0.84%，P < 0.001）。STP在体重、马海毛产量或质量方面没有明显的季节性差异。STP因年份效应导致的含脂马海毛产量（30.6%）、CMFP（22.2%）和AFD（15.7%）的总变异比例是EP的两到三倍。相比之下，年份效应仅占髓质纤维变异的一小部分（2.2%至4.6%）。特定6个月生长期间的降雨累积对BW、GFW、CFW、AFD、AFD的标准差和MFP有正向影响，对CMFP和KFP有负向影响。只有降雨对AFD的标准差和髓质纤维的影响显著（P < 0.05）。年龄对BW（P < 0.001）、CMFP（P = 0.046）、AFD（P < 0.001）、MFP（P = 0.014）和KFP（P = 0.084）有正向影响，对GFW（P = 0.046）和CFW（P = 0.107）有负向影响。本研究记录了山羊的环境和年龄对体重、马海毛产量和纤维特性的影响。
