Increases in milk yield from genetic selection may be accompanied by correlated increases in genetic susceptibility to clinical mastitis and somatic cells. Unlike clinical mastitis, somatic cell scores can be easily determined and recorded and are related to milk loss from subclinical mastitis. Selection against high somatic cell scores should decrease incidence of clinical mastitis and provide...

The objectives of this study were to derive economic values in broiler breeding and to determine their relationship with production circumstances. Economic values were derived using a deterministic economic model based on profit equations with a fixed amount of broiler meat output of the production system. Nonintegrated and the integrated broiler production systems were studied. The difference ...

________________________________________________________________________________ Abstract The objective of the study was to estimate genetic and phenotypic parameters for sow productivity traits of South African Large White pigs, using data from the Integrated Registration and Genetic Information Systems. The analyses were done on 29 719 records for 7 983 sows from 29 herds, which farrowed betw...

This research develops an evolutionary growth theory that captures the interplay between the evolution of mankind and economic growth since the emergence of the human species. The theory suggests that the struggle for survival that had characterized most of human existence generated an evolutionary advantage to human traits that were complementary to the growth process, triggering the take-o® f...