The Breeding Production Trail And The Affecting Factors Of Breeding Efficiency In Ningxia Tan Sheep

Tan sheep is a kind of seasonal reproduction sheep,no obvious estrus,which is characterized by large fat tail.The tail affects the natural mating of Tan sheep seriously in some sheep,resulting in a high proportion of unpregnant Tan sheep,the low breeding efficiency,affecting the economic benefits of farmers.So the key to improve the reproduction efficiency is improving the breeding benefits and promoting the healthy development of industry in Tan sheep.Researchers have put forward the idea of industrialized and intensive sheep and efficient and high frequency sheep breeding,forming a set highly efficient breeding system based on the test estrus,the same period/induced estrus,artificial insemination,simultaneous lambing,lamb cultivation,early weaning and so on,trying to solve the problem of low efficiency of Tan sheep breeding by the efficient breeding technology,and now remarkable results has been achieved,but the application is not extensive.In view of the low production efficiency of Tan sheep population in Ningxia,and to promote the efficient breeding technology in Ningxia Tan sheep test,the breeding population of Tan sheep was tested in this experiment,,and according to the actual situation of breeding sheep to analyze the factors affecting the reproductive efficiency of Tan sheep,we can make recommendations to improve its reproductive efficiency finally.Began in August 8,2016,tan sheep provided by the sheep farm were randomly selected 312 as the experiment sheep and began to test estrus.On September 15 th,the ewes of normal estrus were inseminated artificially,and returning estrus sheep were performed artificial insemination continually.The ewes with no estrus and abnormal estrus were treated with different induced estrus treatments,and then the treated estrus ewes were breeding.In February of the following year,ewes began lambing,then the lambs were nurtured in 15 days after the lamb birth,and recorded the birth weight of lambs and 15 days,30 days,45 days and 60 days weight.According to the experiment results and process,the problems existing in the breeding and production of sheep farm were found,and we can put forward the main problems and improvement measures for Tan sheep breeding.The results of the experiment is:1.312 ewes in the experiment group entered the breeding before test estrous,214 nature estrous ewes(68.6%),23 estrous cycle abnormal ewes(7.4%),75 no estrus ewes(24%).Take estrus synchronization treatment in the ewes with abnormal estrous cycle,and take induceestrus process in the ewes with no estrus.After the first treatment,the estrous rate was 63.3%,abnormal estrus rate was 52.2%,while no-estrus rate of which was 66.7%;the treatment of sheep with no estrus still after the first treatment was changed for the second repeated treatment,and the rate was 38.9%,abnormal estrus rate of which was 0%,while no-estrus rate of which was 56%;the treatment of sheep with no estrus still after the second treatment was changed for the third repeat treatment,and estrous rate was 27.3%,abnormal estrus rate of which was 36.4%,while no-estrus rate of which 18.2%.The total estrus rate was 94.9% after three times of repeated insemination ewes.2.The total pregnancy rate was 71.6% after f breeding.The first pregnancy rate was 48%,pregnancy rate in ewes with normal estrus cycle of which being 53.3%,pregnancy rate in ewes with abnormal estrus cycle of which being 12.5%,pregnancy rate in ewes with no estrus being 39.4%.The pregnancy rate of the second breeding ewes was 39.7%,pregnancy rate in ewes with normal estrus cycle of which being 38.5%,pregnancy rate in ewes with abnormal estrus of which being 45.5%,and the pregnancy rate in ewes with no estrus being 45.9%.The pregnancy rate of the third breeding ewes was 17.8%,the pregnancy rate in ewes with normal estrus cycle among which being 17.6%,the pregnancy rate in ewes with abnormal estrus of which being 0%,and the pregnancy rate in ewes with no estrus being 22.2%.3.A total of 212 ewes were lambed in the experiment ewes,and the lambs rate were115%.Lambs were nurtured and recorded weight.Lambs were born with a weight of 4.54 kg,a 15-day-old body weight of 7.57 kg,a 30-day-old body weight of 10.62 kg,a 45-day-old body weight of 13.96 kg,and a 60-day-old body weight was 17.53 kg.4.After the breeding production test,the normal breeding of ewes accounted for 67.9%,not normal breeding of ewes for 32.1%,which eventually induced estrus 3 times after the non-estrus ewes accounted for 5.1%,not pregnant ewes with repeatedly insemination for12.5%,empty pregnant ewes for 11.2%,frail or diseased ewes for 3.2%.On the final induction of estrus 3 times after the non-estrus ewes,not pregnant ewes with repeated insemination(breeding 4 times and above did not pregnant ewes)and empty pregnant ewes(neither return estrus nor lamb)suggested sheep field to fall into disuse.The results showed that the factors affecting the reproduction efficiency of ewes were mainly no-estrous,and the no pregnant and frail and diseased ewes had a certain proportion in the flock.Such as timely elimination of ewes with abnormal breeding,optimizing the herd structure,it is possible to improve the reproduction efficiency of the Tan sheep population,reduce the cost of breeding,and ultimately improve the efficiency of farming.