The effects of genes are commonly estimated using random regression models based on test-day data and only give a general gene effect. Alternatively, lactation curve models can be used to estimate biological and environmental effects, or to predict missing test-day data and perform breeding value estimation. This study combines lactation curve models and estimation of gene effects to represent ...

Bovine milk proteins has been widely studied because of the strong association and relationship with composition and technological properties of milk. Cow’s milk quality is very important, above all in such countries like Italy, where about 70% of whole milk production is used in cheese-making industry. A reversed-phase highperformance liquid chromatography (RP-HPLC) method was developed to ide...

A total of 5852 records concerning daily milk yield, content of protein and fat, and somatic cell count was recorded in two farms (organic and conventional). Somatic cell count was log10transformed before analysis because was not normally distributed. The mixed model methodology was used according to a repeated-measures scheme, as the restricted maximum likelihood method to estimate lactation c...

A backcross pedigree using dairy East Friesian rams and non-dairy Dorset ewes was established specifically to map quantitative trait loci (QTL) affecting milk production in sheep. Ninety nine microsatellite markers of an initial set of 120 were successfully genotyped and informative on 188 animals of this backcross pedigree. Test-day milk records on individual ewes were used to estimate several...

Persistency of lactation is the ability of a cow to continue producing milk at a high level after the peak of her lactation. Differences in persistency, if not properly accounted for, reduce accuracy of genetic evaluation when incomplete records are used. Persistency has also direct economic value. Reduction of feed, health and reproductive costs are the major factors which favour more persiste...

A PREVIOuS study of the effects of thyroidectomy and thyroid feeding on the lactation of cows has shown that the thyroid gland has a marked influence on the production of milk and milk-fat by the cow [Graham, 1934]. Rises in milk and milk-fat production were shown when desiccated thyroid glands were added to the diet either of thyroidectomised animals or normal animals which were past the peak ...

Cows (n = 21), dried off for a minimum of 45 days, and nulliparous heifers (n = 26), at ages > 18 months old, were placed on a 12-day Lactation Induction (LI) protocol. One group of animals (including both cows and heifers) received 3-minute mammary gland stimulation, along with the LI protocol. Another group, again including both cows and heifers, received no stimulation. Only the LI protocol ...

An experiment was conducted in early lactating buffaloes for the period of 3 months in Jadakheria and Polisimal village of LimkhedaTaluka in Dahod district of Gujarat to assess the effect of supplementation of bypass fat on milk production, composition, body weight change and economic efficiency. Forty buffaloes in their 2nd and 3rd lactation were equally divided in completely randomized design...

the objective of this study was to estimates the genetic and environmental components for the lactation curve parameters, milk yield, age at first calving (afc), calving interval (ci) and somatic cell count (scc) in iranian holstein cows. the dataset consisted of 210625 test day records from 25883 cows with milk yield in the first parity recorded from july 2002 to september 2007 in a total of 9...