We have exploited “progeny testing” to map quantitative trait loci (QTL) underlying the genetic variation of milk production in a selected dairy cattle population. A total of 1,518 sires, with progeny tests based on the milking performances of > 150,000 daughtersjointly, was genotyped for 159 autosomal microsatellites bracketing 1645 centimorgan or approximately two thirds of the bovine genome....

Context Urinary nitrogen excretion by grazing cattle causes environmental pollution. Selecting for cows with a lower concentration of urinary may reduce the impact. While is difficult to measure, blood urea (BUN), mid-infrared spectroscopy (MIR)-predicted BUN (MBUN), which predicted from MIR spectra measured on milk samples, and (MUN) are potential indicator traits. Australia New Zealand have i...

the precision and accuracy of national research council (nrc 2001) vs. cornell pennsylvania miner (cpm) softwares were evaluated. sixteen lactating dairy cows (8 in second lactation and 8 in third, with days in milk of 55 ± 31, body live weight = 641 ± 53 kg, milk yield =31.2 ± 2.5 kg/day), were assigned to individual pens in a randomized complete block design, with two blocks of two ration tre...

ABSTRACT The objective of this study was to estimate genetic parameters and trends different conformation management traits regularly measured within the context National Dairy Gir Breeding Program (PNMGL). estimation residual variances for each trait performed using average information restricted maximum likelihood (AI-REML) procedure in AIREMLF90 program software. population divided into thre...

This study investigated whether the prenatal maternal environment in dairy cattle influences the postnatal milking performance of the resulting daughters and grand-daughters. Linear mixed models were used to analyse whole season milk production from ∼ 46,000 Jersey and ∼ 123,000 Holstein Friesian cows in their 1st and 2nd lactations. Variation in the prenatal environment was associated with a s...

This study investigates how a targeted mutation of a paternally expressed imprinted gene regulates multiple aspects of foetal and post-natal development including placental size, foetal growth, suckling and post-natal growth, weaning age and puberty onset. This same mutation in a mother impairs maternal reproductive success with reduced maternal care, reduced maternal food intake during pregnan...

an f2 japanese quail population was developed by crossing two strains (wild and white) to map quantitative trait loci (qtl) for performance and carcass traits. a total of 472 f2 birds were reared and slaughtered at 42 days of age. performance and carcass traits were measured on all of the f2 individuals. parental (p0), f1 and f2 individuals were genotyped with 3 microsatellites from quail chrom...

In this study, maternal effects were described as age of dam at first and second calving, first-lactation body condition score (BCS) of the dam during gestation, and milk yield of the dam. The impact of these effects on first-lactation daughter BCS, fertility, and test-day milk yield was assessed. The effect of milk yield of dam on daughter 305-d yield in the latter's first 3 lactations was als...

Sire genetic evaluations for protein yield, productive life, and selected type traits from the US were correlated with sire evaluations for disease from Denmark and Sweden and were then adjusted to approximate genetic correlations. Disease categories from Denmark included reproductive diseases, foot and leg diseases, metabolic and digestive diseases, and all diseases other than mastitis. Geneti...