Comparative Study On Effects Of Montbeliarde-sired Crossbred Holstein Cows

Increasing inbreeding poses problems to dairy farms because of reduced fitness,fertility, and longevity of Holstein. In order to solve these problems and improve theresistance against roughage and comprehensive economic benefits of beef and dairy, thisstudy aimed to compare the growth-development law、type characteristic、milk traits、feed efficiency at peak lacation、reproduction capability、disease resisrance traits andeconomic benefits of F1heifers (whose male parent was Montbeliarde and female parentwas Holstein) with that of pure Holstein heifers. The results were as follows:1. Body weight of the F1heifers at the age of birth,weaning,6,9,12,15and18month-old were greater than that of pure Holstein, and the difference of body weightbetween two groups was significant before15month-old, but no significant differencewere found between two groups after15month-old; the inflection age of dual-purpose F1was8.94months which was0.38months earlier than that of pure Holstein; the rump widthand cannon circumference of the F1heifers were significantly higher than those of pureHolstein at15month-old（P<0.01）,but the height at withers and body slanting length weresignificantly lower than those of pure Holstein（P<0.05）. In addition, multivariatestatistical analysis showed that the chest circumference and the rump width influenced thebody weight of F1heifers greatly, and its type characteristic was stockiness; however, itwas the body slanting length and the chest circumference influenced body weight of pureHolstein most, and its type characteristic was wide and long.2. Days in milk of the F1heifers at first lactation was13.78days shorter than that ofHolstein cows, while the total milk yield and305-d actual milk yield showed little changes.The peak day and peak yield of the F1heifers were close to Holstein cows, however, thechange of daily milk production was more smoothly than Holstein cows, together withstrong persistence. Fat yield, protein yield, milk fat percentage and milk protein percentageof F1heifers were increased by12.46kg,13.86kg,0.1and0.3percent than Holstein cows,in which the difference of milk fat percentage and milk protein percentage were obvious（P<0.05）and significant（P<0.01）, respectively. The milk flow was22.74%slower.3. Daily dry matter intake per cow of F1heifers at peak lactation at first parity wassignificantly lower than pure Holstein（19.34kg vs.19.98kg）. Daily milk yield wasslightly lower but milk fat percentage and milk protein percentage were significantlyhigher than pure Holstein（P<0.01）. Body weight per cow of F1heifers during the test period was increased by50.15%（10.12kg vs.6.74kg）, the feed efficiency wassignificantly higher than that of pure Holstein（P<0.01）（1.92vs.1.86）. The earning percow of F1heifers was￥1.66higher than that of pure Holstein.4.The calf birth weight of F1heifers was increased by25.18%, compared with that ofpure Holstein（48.18kg vs.38.49kg）, and the difference was significant（P<0.01）. Thegestation length was prolonged for0.78d. Age at first calving, the first estrus after calvingand days open of F1heifers were lower than that of Holstein cows, in which the differenceof age at first calving and days open were significant. Calving ease of F1heifers was lowerthan that of Holstein, but no differences of stillbirths and first-service conception rates ofwere found between them.5. Somatic cell score (SCS) of F1heifers was obviously lower（2.37vs.2.85）, but nodifference of hoof diseases was found compared with Holstein.6.The benefit was calculated combined the indexes of18-month body weight, total3.5%FCM at lactation, days open and somatic cell score (SCS), the result showed that theearning per cow of F1heifers at first lactation was higher about￥4918.15than that of pureHolstein.In conclusion, the effiect of hybridization between Montbeliarde cows and Holsteincows on production performance was obvious, which can improve milk composition,fertility and increase the economic benefit.