Background: The bovine AGPAT6 gene is one of the potential candidate genes governing milk fat synthesis.Objectives: Identification of single nucleotide polymorphisms (SNP) in the targeted region of AGPAT6 gene and their effect on expected breeding values (EBV) of first lactation milk production traits viz. fat %, fat yield and 305 days milk yield in Karan Fries (KF) breeding bulls were so...

The objective of this study was to investigate the phenotypic relationship between common health disorders in dairy cows and lactation persistency, uncorrelated with 305-d yield. The relationships with peak yield and days in milk (DIM) at peak were also studied. Daily milk weights and treatment incidence records of 991 Holstein lactations from experimental dairy herds at Virginia Tech and Penns...

assessing the effects of monensin on economic factors of milk (percents of protein and fat), and quality of milk fat during early lactation. thirteen multiparous holstein cows were blocked into a control and a treatment group from 3 weeks prepartum to 45 days postpartum according the number of their calving. the groups received similar diets. the treatment group received monensin added to grain...

The accuracy and precision of 3 lactation models was estimated by summarizing means and variability in projection error for next-test milk and actual 305-d milk yield (M305) for 50-d intervals in a large Dairy Herd Improvement Association data set. Lactations were grouped by breed (Holstein, Jersey, and crossbred) and parity (first vs. later). A smaller, single-herd data set with both Dairy Her...

Nutrition has a significant effect on reproduction and lactation in Ruminant. Supply of require nutrient of dairy cows and ewes in early lactation is the main challenges that will be considered, since in most cases the animals facing negative energy balance after calving and the beginning of the period of lactation. Negative energy balance may sometimes result in reduced livestock production an...

Estimated breeding values of test-day (TD) and 305-day milk yield were calculated to compare ranking of animals on the basis of two information sources under an animal model. Two statistical models were used to analyze 780 first lactation (305-day) and monthly milk yield records. The first model was an individual animal model to analyze lactation milk yield with period-season of calving as fixe...

The objective of this research was to estimate genetic parameters of first-lactation body condition score (BCS), milk yield, fat percentage (Fat%), protein percentage (Prot%), somatic cell score (SCS), milk urea nitrogen (MUN), lactose percentage (Lact%), and fat to protein ratio (F:P) using multiple-trait random regression animal models. Changes in covariances between BCS and milk production t...

The nonlinear effects of inbreeding were studied by comparing linear and curvilinear regression models of phenotypic performances on inbreeding coefficients for production traits (milk, fat, and protein yields) of Holstein cows in their first lactation. Three different regression models (linear, quadratic, and cubic) were introduced separately into a single-trait, single-lactation, random regre...

Plant essential plant oils (EO) are volatile aromatic compounds with antimicrobial activity that can alter ruminal fermentation when used as dietary supplements. A feeding trial was conducted to determine the effects of dietary supplementation of periparturient and early lactation dairy cows with a specific mixture of EO. Forty multiparous Holstein cows were randomly assigned to either control ...