Two hundred twenty-five lactation and litter performance records from 82 does representing four genetic groups and two diets were analyzed to quantify breed, heterosis, reciprocal F1 cross and diet effects for milk production and associative traits. Doe genetic groups were New Zealand White (NN) and Californian (CC) straightbred and Californian x New Zealand White (CN) and New Zealand White x C...

Two of the most important broad classifications of phenotypes for successful dairy production are milk yield and fertility. The nature of the relationship between milk production and reproductive performance of dairy cows is uncertain due to conflicting results reported in many studies. A common deficiency in many such studies is an underappreciation of the dual dimension of the production-repr...

Data from 113 Dutch organic farms were analysed to determine the effect of cross-breeding on production and functional traits. In total, data on 33 788 lactations between January 2003 and February 2009 from 15 015 cows were available. Holstein-Friesian pure-bred cows produced most kg of milk in 305 days, but with the lowest percentages of fat and protein of all pure-bred cows in the data set. C...

Characteristic of the udder, milk traits and their relationship were investigated in 32 Awassi ewes raised in a commercial flock. Commencing one month after lambing milk yield was recorded at monthly intervals until the ewes were dried. Also, the udder traits were measured, including udder width, udder circumference, udder length, distance between teats and length and diameter of both teats. Re...

In the present study, records on 22872 first-parity Holsteins collected from 131 herds by the Animal Breeding and Improvement Center of Iran from 1995 to 2014 were considered to estimate genetic and phenotypic relationships between calving difficulty (CD) and the lactation curve traits, including initial milk yield (Ap), ascending (Bp) and descending (Cp) slope of the lactation curves, peak mil...

Genetic and phenotypic correlations between production traits, selected linear type traits, and somatic cell score were estimated. The results could be useful for breeding programs involving Czech Holstein dairy cows or other populations. A series of bivariate analyses was applied whereby (co)variance components were estimated using average information (AI-REML) implemented via the DMU statisti...

In Australia, dairy cattle account for ~12% of the nation’s agricultural greenhouse-gas (GHG) emissions. Genetic selection has had a positive impact, reducingGHGemissions fromdairy systemsmainly due to increased production per cow,which has led to (1) requiring fewer cows to produce the same amount ofmilk and (2) lowering emissions per unit of milk produced (emission intensity). The objective o...

Received: 7 March, 2014 Accepted: 21 May, 2014 Published: 20 July, 2014 The data consisted of 37118 TD milk record of 5851 primiparous Holstein cows of Tunisia. Herd-years of calving means for milk production traits were clustered in three levels using the CLUSTER procedure in SAS software. Production levels included low, medium and high levels. Genotype by environment interaction were investig...

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 ...

the purpose of the study was to detect the alui and ddei polymorphisms within pou1f1 gene exon 6 and 3'utr region in turkish sheep breeds, and their association with milk productive traits. jugular blood samples were collected from 50 sakiz, 50 white karaman, and 50 awassi sheep using edta as an anticoagulant. pcr-rflp and sequencing analysis were performed to investigate possible polymorphisms...