Fatty acid composition influences the nutritional quality of milk and the technological properties of butter. Using a prediction of fatty acid (FA) contents by mid-infrared (MIR) spectrometry, a large amount of data concerning the FA profile in bovine milk was collected. The large number of records permitted consideration of more complex models than those used in previous studies. The aim of th...

The length of the antibiotic withdrawal period after intramammary treatment was influenced by the milk yield of dairy goats during this trial. Shorter withdrawal periods were seen in relatively high yielding dairy goats (production above 1.5 l per day) compared to low producers (less than 1.3 l per day). High yielding goats treated with Curaclox LC (Norbrook [Pharmacia AH]) had a withdrawal per...

Twenty-four lactating and 13 nonlactating Alpine goats were used to determine effects of stage of lactation and dietary concentrate level on energy utilization. Diets comprising 60 or 20% concentrate (60%C and 20%C, respectively) were consumed ad libitum by lactating animals and at a level of intake near maintenance by nonlactating animals. Measurement periods were d 25 to 31 (early), 87 to 94 ...

The high number of clinical mastitis recurring within the same lactation in dairy cows constitutes one of the factors of overdispersion in standard Poisson models. Our method, based on biological parameters, i.e., recurrence hazard in relation to udder exogenous infection (Rex) or recurrence hazard and rate in relation to endogenous infection (Ren), produced a model capable of integrating a pos...

The objective of this study was to analyze the correlation between Holstein body conformation traits and milk production traits in the Shanghai region. In total, 871 Holstein cows were randomly chosen from 28 dairy farms in Shanghai at second stage of lactation as the object of our study. Five milk production traits, including 305-d milk yield, butter fat percentage, milk protein percentage, pe...

Six groups of Sahiwal-Friesian crossbred cows, namely M50-1, M50-2, M50-3, M56, M63 and M75-1 were evaluated. In total 180 cows were used and milk collected was evaluated for composition and quality. The effect of genotypes was significant (P≤0.05) only for titrable acidity (TA) and milk yield (MY). The M50-1 had the highest milk yield per day (8.73 ± 1.65 kg) but this was not significantly dif...

The objective of this study was to determine the effects of stage of lactation (SOL) and time of year on plasmin-derived proteolytic activity in the milk of pasture-fed dairy cows in New Zealand. Four herds of 20 Friesian cows were used, one herd calving in each of January, April, July and October. Cows grazed ryegrass/white clover pasture only, except during June (winter) when all cows receive...

Genetic parameters for body weight (BW), body condition score (BCS) and dry matter intake (DMI) of dairy heifers were estimated using covariance function (CF) methodology. Data were from 469 Holstein heifers of the Langhill Dairy Cattle Research Centre and included observations at calving and at 3, 5, 10, 20, and 25 weeks of lactation. The experiment comprised a selection line and a control lin...

The decline in milk yield after peak lactation in dairy animals has long been a biological conundrum for the mammary biologist, as well as a cause of considerable lost income for the dairy farmer. Recent advances in understanding the control of the mammary cell population now offer new insights on the former, and a potential means of alleviating the latter. The weight of evidence now indicates ...