The influence of pregnancy and the beginning of lactation on pelage traits in cashmere goats

The aim of this study was to investigate the effect of pregnancy followed by the beginning of lactation on fibre traits in cashmere goats. Two groups of cashmere-bearing goats aged between 2-3 years were used. The control group (A) included 12 non-lactating, non-pregnant subjects. The experimental group (B) included 12 goats mated during the first week of June, in order to have pregnancy and the beginning of lactation coincide with the period when cashmere normally grows. As expected, Liveweight significantly varied in Group B during the last two months of pregnancy, when foetal growth reaches its maximum, and following delivery. Hair patch weight, because of the continuous growth of primary and secondary fibres, increased significantly during the trial (P<0.001). The physiological status considered negatively affected (P<0.05) the total mean growth rate of cashmere fibres and, as a result, their length. Cashmere daily growth rate values varied significantly (P<0.05) throughout the experiment, while the effect of the physiological status was noted only in November – December. Furthermore, this parameter also seems to be influenced by climatic factors and, in particular, environmental temperature, as shown by the negative correlation (r = - 0.28; P<0.05) between cashmere daily growth rate and environmental temperature. Guard hair length and growth rate did not differ between the two groups, however, they were influenced by time. Cashmere yield and cashmere production were lower in group B (P<0.05). No differences between groups were observed for cashmere diameter. Overall, pregnancy and the consequent period of lactation negatively influenced cashmere rather than guard hair fibres. These negative effects were noted in quantitative terms as yield and production dropped by 37% and 43%, respectively. We hypothesise that the complete overlap of pregnancy and lactation with the period of cashmere growth reduced the number of secondary active follicles and their degree of activity and caused an increase in competition for the partitioning of nutrients between hair follicles and the gravid uterus, first, and then the mammary gland, later.