Producer Breeding Objectives and Optimal Sire Selection

Breeding Objectives and Desired-Gain Selection Index for Rayeni Cashmere Goat in Pasture System

The aim of this study was to define breeding goals and determine the suitable selection index in Rayeni cashmere goat using simulated data. To select animals for increased quantity of meat, milk and cashmere produced, body weight of the doe (BWD), milk weight (MW), cashmere weight (CW), weight of kids for sale (WK) and number of kids for sale per doe (NK) was used as selection criteria. Four se...

Breeding and Genetics: Dairy Crossbreeding and Breeding Objectives

First-parity Holstein (H), Normande-Holstein (NxH) crossbred, Montbeliarde-Holstein (MxH) crossbred and Scandinavian-Holstein (SxH) crossbred cows calving from June 2001 to December 2003 were compared for dystocia and stillbirths from seven California herds. Dystocia scores ranging from 1 (no assistance) to 5 (hard pull) and stillbirths (1 for alive and 0 for dead) were recorded for 1695 Holste...

Breeding objectives for Targhee sheep.

Breeding objectives were developed for Targhee sheep under rangeland production conditions. Traits considered were those for which EPD were available from the US National Sheep Improvement Program and included direct and maternal effects on 120-d weaning weight (WW and MM, respectively); yearling weight (YW); yearling fleece weight, fiber diameter, and staple length; and percent lamb crop (PLC)...

Opposing selection and environmental variation modify optimal timing of breeding.

Studies of evolution in wild populations often find that the heritable phenotypic traits of individuals producing the most offspring do not increase proportionally in the population. This paradox may arise when phenotypic traits influence both fecundity and viability and when there is a tradeoff between these fitness components, leading to opposing selection. Such tradeoffs are the foundation o...

The Importance of Sire Selection