Mammalian milk fat concentration and composition are variable and responsive to nutritional factors. First described over one and a half centuries ago, diet-induced milk fat depression (MFD) is characterized by a decrease in milk fat yield of up to 50% with no change in milk yield or yield of other milk components. MFD is classically observed in ruminants fed highly fermentable diets or diets t...

The present experiment aimed to evaluate the effect of HMBi on the production performance and metabolism in dairy cows. Thirty multiparous Holstein dairy cows under similar conditions were randomly assigned to three dietary treatments; i) Control, a basal diet; ii) T1, a basal diet plus HMBi (0 g prepartum and 18 g postpartum); and iii) T2, a basal diet plus HMBi (10 g prepartum and 18 g postpa...

abcg2 (atp binding cassette subfamily g member 2) gene, located on chromosome 6 encodes the abcg2 protein that transports various xenobiotics, cytostatic drugs across the plasma membrane as well as cholesterol into milk. a single nucleotide change (a/c) in base 86 of exon 14 is capable of encoding a substitution of tyrosine with serine in the abcg2 gene and increase milk yield while decreasing ...

Control of milk composition is of importance in dairy ewes because milk is mostly used for cheese making. Besides numerous factors that alter milk composition, knowledge on the effects of nutrition is useful for it concerns both yield and milk content. Furthermore, modification of nutrition is a powerful and short-term means of altering milk composition. Global effects of nutrition are to be se...

BACKGROUND Waste animal fat is a promising feedstock to replace vegetable oil that widely used in commercial biodiesel process, however the high content of free fatty acid in waste fat makes it unfeasible to be processed with commercial base-catalytic process. Enzymatic process is preferable to convert waste fat into biodiesel since enzyme can catalyze both esterification of free fatty acid and...

Calving records from the Animal Breeding Center of Iran collected from January 1993 to December 2007 and comprising 1 163 594 Holstein calving events from 2 552 herds were used to evaluate reported perinatal calf mortality, 305-d milk yield, 305-d fat yield of milk and 305-d fat percentage of milk in singleand twin-births. A logistic regression model was constructed to analyze calf mortality be...

A total of 125 Russian Red Pied cows were genotyped for the prolactim-related gene. The PRL-RsaI genotypes were analysed using the Polymerase chain reaction -restriction fragment length polymorphism (PCR-RFLP) method. In this breed, the frequencies of alleles were as follows;  A= 0.794 and B= 0.206. The frequencies of AA, AB and BB genotypes were 0.598, 0.392 and 0.01; respectively. Results sho...

The objective of this research was to determine the effect of the use of rennet substitute on composition and yield of Minas Padrão cheese. Pasteurized and standardized milk (3.0% fat) was divided into 2 parts and prepared for each treatment varying the rennet: batch 1(BOV), commercial calf rennet (Chymosin and pepsin) and batch 2 (QPF), commercial rennet substitute Chy-max (Chymosin) and conve...