Economic weights have been estimated in two breeds (Latxa and Manchega) using economic and technical data collected in 41 Latxa and 12 Manchega dairy sheep flocks. The traits considered were fertility (lambing per year), prolificacy (number of lambs), milk yield (litres) and longevity (as productive life, in years). A linear function was used, relating these traits to the different costs in the...

The imprinted insulin-like growth factor 2 gene (IGF2) encodes a fetal mitogenic hormone protein (IGF-II) and has previously been shown to be associated with performance in dairy cattle. In this study we assessed genotype-phenotype associations between four single nucleotide polymorphisms (SNPs) located within the bovine IGF2 locus on chromosome 29 and a range of performance traits related to m...

The relative weighting on traits within breeding goals are generally determined by bio-economic models or profit functions. While such methods have generally delivered profitability gains to producers, and are being expanded to consider non-market values, current approaches generally do not consider the numerous and diverse stakeholders that affect, or are affected, by such tools. Based on prin...

Milk records from Ayrshire, Brown Swiss, Guernsey, Jersey, and Milking Shorthorn cows that first calved between 18 and 35 mo were combined with scores for linear type traits collected before 43 mo during first lactation to study herd life and lifetime profitability. Profitability (discounted relative net income) was the value of milk, calves, and cow salvage minus fixed costs, operating costs, ...

in order to estimate economic values of productive traits (meat, milk and wool) in taleshi native sheep breed of iran, records from economic parameters and performance of local taleshi flocks were used. the economic values of traits were used to select the maximum profit estimation also to study the sensitivity rate of the model the effects of 20 percent increase / decrease in the price of milk...

Dairy sires were ranked for overall merit by an average daughter's contribution to farm net profit. Biological characteristics of sires and economic factors of a dairy farm were linked by linear programming. Availability and constraints of resources were in the model. Average daughter's returns over variable costs attributable to sire proofs for several traits was the measure of sire's net meri...

The aim of this study was to refine the position of previously detected quantitative trait loci (QTL) on bovine chromosome 14 affecting milk production traits, using both linkage analysis (LA) and combined disequilibrium and linkage analysis (LDLA) methods, in Iranian Holstein dairy cattle. Analysis data was LRT (likelihood ratio test) and computed using the DMU (estimate the (co)variance compo...

The relationships between goat κ-casein (CSN3) variants and milk composition were studied in 1143 goats from 4 breeds (Camosciata, Frisa, Orobica, Verzasca). Individual milk samples were analysed by isoelectrofocusing. The effect of CSN3 type on protein and casein content was evident, B variant being associated to higher levels of both traits. Since the B variant is mainly present in local capr...

The aims of this study were to estimate the genetic variation of traditional milk coagulation properties (MCPs), milk acidity, curd firmness (CF) modeled on time t (CF(t) ; comprising: RCT(eq), rennet coagulation time estimated from the equation; CF(P), the asymptotic potential curd firmness; k(CF), the curd firming instant rate constant; and k(SR), the syneresis instant rate constant) and maxi...

quantitative trait loci (qtl) affecting milk production traits on bovine chromosome 6 close to the opn gene location have been identified through several whole genome scans. opn is a phosphoprotein, synthesized in a variety of tissues and cells and secreted into body fluids. in this study, dna was isolated from blood samples collected from 398 holstein cows in tehran and esfahan provinces. dna ...