SUMMARY The procedures to be fo llowed and some o f the problems which ing breeding objectives are discussed. Specia l emphasis is given reconcile confl icts between different bases o f evaluation, and it ~o att~ that from,a, long-term viewpoi nt , effic i ~ncy s hould be the goal of ~~econcI where efflclency 1S measured as the rat10 of the v alue of all input br~ of al l outputs. In the shorte...

Timber harvest projections for aspen-dominated forests in the prairie region of Canada include a truncation of the current age distribution, whereby old stands of ®re origin will become rarer on the landscape, while young, post-harvest stands will increase in abundance. To determine the effects this harvesting strategy might have on communities of breeding forest birds, we conducted point count...

Wool and meat contribute to profit in sheep enterprises and both need to be considered in breeding programs. The relative responses expected from selection for a range of traits are presented and the realised responses that have been achieved in Merinos and variation in maternal breeds are illustrated. Knowledge of genetic parameters is required for the development of complex breeding objective...

Animal breeding traditionally has entailed devising means to apply quantitative and population genetic theory to increase productive capacity of livestock. A highly developed and successful industry has been built on foundations established by academic animal breeders. Recent developments in related sciences such as reproductive biology, molecular biology, cellular biology, and cytogenetics off...

Leaf blight and defoliation caused by Cylindrocladium pteridis is one of the main leaf diseases found in Brazilian eucalypt plantations in warm and high rainfall regions. The inter and intraspecific variability in the intensity of defoliation indicate that your control can be achieved by planting resistant genotypes. In order to guide breeding programs and to predict the stability of resistance...

Objectives were to estimate effects of sire breed (Dorset, Finnsheep, Romanov, Texel, and Montadale), dam breed (Composite III and northwestern whiteface), mating season (August, October, and December), ewe age (1, 2, and 3 yr), and their interactions on reproductive traits of F1 ewes. A total of 1,799 F1 ewes produced 3,849 litters from 4,804 exposures to Suffolk rams during 35-d mating season...

A well-defined breeding objective provides commercial producers a mechanism for extracting value from the investment in genomics by seedstock producers. Advantages of genomic prediction include increased accuracy of expected progeny differences (EPDs) for traits that have been components of routine genetic evaluations. Perhaps more importantly, genomic prediction makes it possible to include tr...

The suggestion that modern pasture cultivars persist less well than their predecessors is not supported by facts. However in some regions there is a crisis in farmer experience of persistence of ryegrass pastures, and ryegrass breeding can contribute to a resolution. This paper considers the turnover of tillers in a pasture, the population structure of a grass sward and the involvement of endop...

Milk yield per cow has more than doubled in the previous 40 years and many cows now produce more than 20,000 kg of milk per lactation. The increase in production should be viewed with concern because: i) the increase in milk yield has been accompanied by declining fertility, increasing leg and metabolic problems and declining longevity; ii) there are unfavourable genetic correlations between mi...

The objectives of this study were to determine the selection potential (genetic variation) of sow efficiency traits (prolificacy, longevity), to understand the co-responses (genetic correlations) among sow efficiency traits and other economically important traits (performance, carcass quality, and meat quality), and determine the feasibility of developing breeding value estimates for sow effici...