Study On The Growth And Development Pattern Of Bashiby Sheep

This study aims to understand the advantages and disadvantages of Bashiby sheep in terms of growth and production performance,and to provide reference for its future breeding.The experiment has studied the early growth and development law of Bashiby sheep,slaughter performance at the age of 4.5 months and correlation between weight and body size at the age of12 moths,and the results are as follows:Experiment 1:150 lambs have been selected for the experiment,and all of them are the ones produced during the same estrus period in 2020,including 75 males and 75 females.During the experiment period,the female ones have not been offered supplementary feeding,with house feeding adopted in the early stage and grazing feeding in the later stage.The results are as follows:The weight,body height,body length,chest circumference and tube circumference of Bashiby lambs of both sexes increase fastest at the age of 0 to 30 days,and increase at the slowest rate,all at the age of 90 to 120 days.The growth rate of the body length index and tube circumference index of male lambs reaches the maximum at the age of 0 to 30 days,with an increase rate of15.44 percentage points and 12.54 percentage points respectively,and the maximum increase rate of body index is 3.33 percentage points at the age of 90 to 120 days.The growth rate of length index and bust index of female lambs increases by 13.57 percentage points and 14.82 percentage points respectively at the age of 0-30 days,and the growth rate of the body index reaches the greatest of 2.92 percentage points at the age of 90 to 120 days.Ranging from high to low,the correlation coefficients of body weight and body size of male lambs are 0.971（chest circumference）,0.954（body length）,0.948（body height）and 0.890（tube circumference）;Rang from high to low,the correlation coefficient between weight and body size of female Bashiby lambs are 0.968（chest circumference）,0.957（body length）,0.952（body height）and 0.912（tube circumference）.Experiment 2:In the experiment 32 healthy 4.5-month-old lambs（including 16 male and 16female lambs）have been selected to measure the slaughter performance,Carcass weight,net meat weight,bone weight,net meat ratio,slaughter rate,net meat ratio,and bone-to-meat ratio were measured and calculated sheep by sheep.The results are as follows:Among the slaughter-performance correlations of male Bashiby lambs,there are 7 items of extremely significant positive correlations（P<0.01）,5 items of significant positive correlations（P<0.05）,1item of negative correlation not significant（P>0.05）,1 item of significant negative correlation（P<0.05）,1 item of extremely significant negative correlation（P<0.01）.Among the slaughter-performance correlations of female Bashiby lambs,there are 4 items of highly significant positive correlations（P<0.01）,4 items of significantly positive correlations（P<0.05）,1item of significant negative correlation（P<0.05）,1 item of extremely significant negative correlation（P<0.01）.In the case of male lambs,the regression equation formulas of the pre-slaughter weight,carcass weight and net meat rate are respectively as follows:Y_carcass=0.600X-1.073,Y_net=0.555X-3.237,while as for female lambs,the regression equation formulas of the pre-slaughter weight,carcass weight and net meat rate are respectively as follows:Y_carcass=0.596X-1.442,Y_net=0.446X-0.270.The results of this study can be used as a reference for the slaughter performance of Bashiby sheep.Experiment 3:The experiment has selected 120 healthy Bashiby sheep at the age of 12months,and has measured various data of body size and weight.By using SPSS 26.0,the analysis of correlation,path and stepwise regression has been conducted to finally establish the optimal regression equation for weight and body measurement of both male and female Bashiby sheep.The results are as follows:The weight and the average body size index of Bashiby rams are higher than those of Bashiby ewes.The correlation coefficients between weight and chest circumference of Bashiby rams and ewes are the highest（the coefficients are 0.905 and 0.792,respectively）.The direct effect of weight on the chest circumference of Bashiby rams is the largest（the coefficient of0.582）,while in the case of Bashiby ewes,the direct effect of weight on the body length is the largest（the coefficient of 0.680）.The indirect effect of weight on the body length of Bashiby rams is the largest（the coefficient of 0.705）,and the indirect effect of weight and body height of Bashiby ewes is the largest（coefficient of 1.019）.The optimal regression equation of weight and body size index of Bashiby rams is Y_male=0.784X1+0.479X2+1.128X3+3.407X4-156.287,and the optimal regression equation of weight and body size index of Bashiby ewes is Y_female=-0.611X1+1.177X2+0.612X3+1.851X4-58.85.In summary,the comparative analysis of the above experiments shows that the Bashiby sheep have a good performance in terms of production performance,as well as lamb meat production performance.The above research results can provide a certain theoretical reference for the selection,breeding and promotion of Bashiby sheep.