Study On The Adaptability Of Introduced Australian Dairy Cows In Baoji Area

In recent years,with the increase in demand for fresh milk and dairy products,the stock of excellent dairy cows and milk production in China have increased substantially.However,in modern dairy farming,the milk production of local dairy cows in China is gradually unable to meet the high needs of people.And the introduction of high-yield Australian dairy cows could improve the production performance of all aspects of dairy cows.Therefore,it is important to introduce the research on large-scale and efficient breeding technology of Australian dairy cows.This experiment established two groups of Australian dairy cows and local Chinese Holstein cows according to the same breeding level.By recording and counting various indicators,the differences between the introduction of Australian dairy cows and local Holstein cattle were analyzed,and the adaptability of Australian cattle was studied.Then,three groups of Australian dairy cows(scale cattle farm,standardized dairy farm,retail investors)were set up according to different feeding levels.By means of group observation and actual measurement,systematic research was carried out on the appearance,reproductive performance,offspring development,milk production performance and adaptability of Australian dairy cows introduced from Baoji City under different feeding and management methods.According to the research results,it provides a reference plan for dairy cattle breeding management technical specifications and common disease prevention and treatment,and provides scientific information for the management of dairy farms in Baoji City.It is expected to develop the production potential of Australian dairy cows and improve their overall production level.The main results of this study are as follows:1.Compared with the local Holstein cattle,the adult cows introduced into Australian dairy cows are narrower in size and slightly less reproductive.The Australian dairy cows have an initial age of 10.59 months and a primacy weight of 309.93 kg.At 15.42 months of age,the first weight is 365.06 kg,which is less different from the local Holstein cattle,but the Australian cow’s compounding rate(26.76%)is 8.24% lower than that of the local Holstein,and the calving rate(83.47%)is lower than that of the local Holstein cattle were 11.66% lower,and the difference was significant(P<0.05).In terms of milk production performance,Australian dairy cows had higher milk fat percentage,milk protein rate,peak milk and 305 days milk yield than local Holstein cattle(P<0.05),among which Australian dairy cows had a higher milk fat percentage than local Holstein cattle,the milk protein rate is 0.16% higher,the peak milk is 15.81% higher,especially the 305-day milk yield can reach 5.9 tons,which is 6.35% higher than the local Holstein cattle,but the difference in somatic cell number is not significant.Australian dairy cows have shown good adaptability.The cold and heat stress ability,that is,the milk production under extreme temperature conditions can reach more than 8 kg,which is basically consistent with the local Holstein cattle.2.By comparing the differences between different feeding conditions of Australian dairy cows,it can be concluded that in the appearance of the body,the Australian dairy cows in the scale field group,the community group and the retail group have no significant advantage.In terms of reproductive capacity,the scale field group estrus The earliest(11.38 months old,301.58 kg),the earliest breeding(14.80 months old),the lightest weight(341.61 kg),the breeding effect was also good,the compounding rate was 16.7%,and significantly higher than the retail group cows(P<0.05).And the scale group was significantly better than the community group(P<0.05)in milk fat percentage(3.96%),milk protein rate(3.27%),peak milk(26.4 kg)and 305 days milk yield(6.75 tons).The performance is obviously better.3.After the implementation of the high-efficiency culture technology in this test,the elimination rate of imported Australian dairy cows decreased by 4.13%(P<0.05),and the incidence rate decreased by 2.72%,in which mastitis,nutritional metabolic disease,leg and hoof disease and postpartum disease were reduced respectively.0.82%,0.51%,0.76%,0.63%.The compounding rate decreased by 10.06%,and the calving rate increased from 83.47% to 95.28%,a significant increase of 11.81%(P<0.05).The milk protein rate and the 305-day milk yield can reach 3.30% and 6.7 tons,respectively,while the Australian dairy cows in the region are 3.0%～3.2% and 6.0～6.2 tons,respectively,which exceeds the highest range of Australian dairy cows.In conclusion,the milk production performance of Australian dairy cows is higher than that of local dairy cows,and the performance of Australian dairy cows in large-scale farming is higher.After the high-efficiency technology of this experiment,the performance is further improved.