genetic aspects of milk electrical conductivity in italian brown cattle

Electrical conductivity (EC) of milk is defined as an indicator of the udder health. The EC is a low cost and easy recordable information in dairy herds with automatic milking systems. The heritability of EC showed to be higher than somatic cell count and for this reason might be an useful trait for indirect selection for mastitis resistance. The heritability for EC in Italian Brown cattle was equal to 0.23. Therefore, EC could be useful not only for dairy cows management but also for selection of dairy cows. The high correlation between breeding values for SCC and EC is promising in order for improving mastitis resistance and functional ability of dairy cows

Applicability of different test day models and effect on time at first evaluation of Italian Simmental bulls

Il presente lavoro si prefigge di valutare l’effetto che l’ap- plicazione di diversi modelli test day esercita sul numero di bovine e d’allevamenti coinvolti nel pro- gramma di valutazione, sul numero di tori valutati e sull’età degli stessi alla prima valutazione in una popolazione bovina a ridotta dimensione aziendale. L’applicazione di modelli univariati e multivariati a regressioni casuali comporta una notevole riduzione del numero di bovine e d’allevamenti che apportano informazioni fenotipiche. Tale perdita determina un aumento dell’età alla prima valutazione dei tori che si ripercuote sul progresso genetico annuo

Comparison between two methods of measurement of milking speed in dairy cattle reared in Trento province

Milking speed can be considered an important functional trait in dairy cattle, with regard to udder health, and to improve the dairy profits (Mein, 1998, Blake and McDaniel, 1978; Meyer and Burnside, 1987; Luttinen and Juga, 1997; Dodenhoff et al., 2000, Bagnato et al., 2001). National Breeders Association of Italian Brown and Friesian cattle are official recording milking speed using a flowmeter (Lactocorder by Foss Electric) and subjective evaluation given by the farmer, respectively. The flowmeter is an instrument easily adaptable on different milking machine (Santus and Bagnato, 1999), but it does not allow a complete recording of all cows in all dairy herds, especially when located in mountain area......

Use of sexed semen in Italian Holstein Frieisian cows: a field trial

Aim of this study was to examine the performance of sexed semen in Holstein Friesian cattle in field condition. A total of 1,282 insemination (98% of heifers) were recorded in 92 Italian commercial dairy herds, from September 2002 to December 2003. Four selected Holstein Friesian dairy bulls with sexed semen, produced by flow citometry method, were used. Results are currently recording and they will be discussed. However, a preliminary subset of the first 164 artificial inseminations, using ultrasound, showed a pregnancy rate of 50% with around 90% of females embryos. However, a large variability was showed on these results due to herd, region, sire and their interactions. An economic simulation study, was also conducted in order to verify the most important factors to modify the economical benefits on use of sexed semen. The two most important factors were: price of crossing calves and percentage of sexed semen purity. In conclusion a field application of sexed semen respect to the use of conventional sperm seems to be useful but more data are needed before to clear its economical and technical impacts on animal production sector

Genetic aspects of milk electrical conductivity in Italian Brown cattle

Electrical conductivity (EC) of milk is defined as an indicator of the udder health. The EC is a low cost and easy recordable information in dairy herds with automatic milking systems. The heritability of EC showed to be higher than somatic cell count and for this reason might be an useful trait for indirect selection for mastitis resistance. The heritability for EC in Italian Brown cattle was equal to 0.23. Therefore, EC could be useful not only for dairy cows management but also for selection of dairy cows. The high correlation between breeding values for SCC and EC is promising in order for improving mastitis resistance and functional ability of dairy cows