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...

The objective of this study was to assess the genetic improvement programme of the Mpwapwa dairy cattle breed over the past four decades, based on on-station selection and breeding. Estimates of genetic parameters and genetic trends for total lactation milk yield (LMY), 305-day lactation milk yield (305LMY), lactation length (LL), age at first calving (AFC), and calving interval (CI) were deriv...

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...

this research used the test day data of the milk production of holstein cows from golestan, mazandaran and guilan provinces collected by animal breeding center of iran between the years of 1988-2011. permanent effects of model, including cattle blend, breeding year and season, also percent of holstein gene and age during recording, were used as a secondary variable. all data obtained in this re...

Phenotypic and genetic correlations were estimated between 48 type appraisal traits and first lactation milk production to determine the importance of appraisal traits in a breeding program from 5,024 records from the New York type appraisal program. Most phenotypic correlations amgng the type traits were near zero. Depth of udder was the appraisal trait having the highest correlation with firs...

The objective of this study was to carry out a sensitivity analysis on the impact of various production strategies and performance levels on the relative economic values (REVs) of traits in dairy sheep. A bio-economic model implemented in the program package ECOWEIGHT was used to simulate the profit function for a semi-extensive production system with the Slovak multi-purpose breed Improved Val...

Variance components and breeding values of production traits and somatic cell score of South African Guernsey, Ayrshire, Holstein and Jersey breeds have been estimated using a multi-lactation repeatability test-day model, including tests of the first three lactations as repeated measures and fitting the permanent environmental effect across lactations. Multitrait evaluations were done for the p...

Knowledge about genetic markers linked to genes affecting quantitative traits can increase the selection response of animal breeding programs, especially for traits that are difficult to improve when using traditional selection (Meuwissen and Goddard, 1996; Meuwissen and Van Arendonk, 1992). The seasonal breeding pattern that is commonly observed in temperate sheep breeds is a major obstacle to...

Genealogy and productive information of 48621 dual-purpose buffaloes born in Colombia between years 1996 and 2014 was used. The following traits were assessed using one-trait models: milk yield at 270 days (MY270), age at first calving (AFC), weaning weight (WW), and weights at the following ages: first year (W12), 18 months (W18), and 2 years (W24). Direct additive genetic and residual random ...