| In order to compare the effects of different weaning days on the growth and development of Arbas cashmere goat lambs,24 healthy Arbas goat male lambs with similar birth time,similar weight and same sex were selected and divided into 4 groups,which were recorded as 30-day weaning group,40-day weaning group,50-day weaning group and 60-day control group.The lambs in the early weaning group were used by one-time weaning method,and a 10 day transition period was set,and the milk substitute powder was 150 m L/bid in the first 5 days,and 200 m L/d of milk substitute powder was supplemented in the last 5 days,and the control group was fully breastfed.The test lambs were measured every 10 days,and jugular venous blood was collected before 60 days and 90 days in the morning to measure blood biochemistry,trace elements and non-specific immune indexes.At the end of the trial period,3 animals from different weaning age groups were randomly selected and slaughter according to the traditional Mongolian sheep slaughtering method to determine the slaughter performance.Rumen and small intestine samples were taken separately and stored for later use.Paraffin sections observed tissue morphological development,high-throughput sequencing determined rumen microflora,gas chromatography determined fermentation parameters,and real-time PCR determined the expression of small intestinal nutrient uptake carrier genes.The results are as follows:1.Different early weaning time had less influence on the average daily weight gain and average body size of Albas cashmere goat lambs,but it has an influence on the blood biochemical and trace element index.The 30-day weaning group gained weight slowly at the beginning of weaning,creatinine and total bilirubin were significantly lower than those in the control group(P<0.05),and iron was lower than the normal reference value.There were no significant differences in body condition,blood biochemistry and trace elements in the weaning group at other days of age(P>0.05).There was no significant difference in non-specific immune indexes between groups(P>0.05).2.Different early weaning times had an effect on the slaughter performance of Arbas cashmere goat lambs,and the organ index was not significantly different between the groups(P>0.05),but the carcass weight of the 30-day weaning group was significantly lower than that of the control group(P<0.05),and the slaughter rate was significantly lower than that of the other groups(P<0.05).3.Different early weaning times had limited effect on rumen growth and development in Arbas cashmere goat lambs.The composition and structure of rumen microflora are relatively stable,and the richness and diversity are also relatively stable There were no significant differences in rumen p H and rumen fermentation parameter concentrations between groups(P>0.05).There was also no significant effect on the rumen histomorphology during the growth phase.4.Early weaning has an effect on the growth and development of the small intestine of Arbas cashmere goat lambs.The expression of nutrient carrier genes in the weaning group at 30 days was low,which was very different from that in the control group(P<0.01),and the gene expression of nutrient carrier genes in the weaning group at 50 days was not significantly different from that in the control group(P>0.05).The villus length and crypt depth were not significantly different between the groups(P>0.05).The results showed that early weaning of Arbass cashmere goat lambs was feasible,and the various indexes of the 30-day weaning group were significantly different from those in the control group,and it was not suitable for selection as weaning age.The40-day and 50-day weaning groups had good developmental performance.Considering the comprehensive benefits,40 days of age is the best choice for weaning age. |
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