Gestation length, birth weight calving difficulty, calf mortality rate at birth, calf mortality rate from birth to weaning, preweaning calf growth rate and calf 200-d weight were evaluated in a biological type study in which four sire breeds were bred by AI to Hereford dams. Angus and Red Poll sires represented breeds of medium size, and Pinzgauer and Simmental sires represented large breeds. A...

The objective of this study was to examine the prion protein gene locus (PRNP) in Chios sheep. PRNP is linked with scrapie resistance in small ruminants. Here, its impact on milk production (test-day and total lactation yield) and reproduction (age at first lambing, conception rate at first service, and prolificacy) was assessed. Genotyping at codons 136, 154 and 171 (classical scrapie) and 141...

in the present study, to estimate genetic parameters and genetic and phenotypic trends in holstein dairy cows in the north of iran, the records from first lactation of 11398 collected from 1989 to 2006 were used. records were collected from 290 herds. productive traits were 305 day-2x adjusted milk and fat yield and reproductive traits were age at first calving, calving interval and dry days. g...

The study was conducted to estimate the genetic and phenotypic correlations among body measurements, body weight, kidding interval, kidding rate and milk yield in the different breeds of goat. Data was collected on 95 goats of three breeds (Jamunapari, Black Bengal and their crosses (Jamunapari×Black Bengal) through direct observation. The average body weight of Jamunapari goat was 34.75 ± 3.33...

Dairy cattle breeding programs have been based in the selection for traits related to milk production. In this research a data set of 63 herds of East Azerbaijan province Holstein cattle, collected during 2002-2013 by the Iranian Animal Breeding Center was used to estimate the repeatability and heritability of three traits of economic importance. Genetic parameters for first three lactations of...

Two hundred twenty-five lactation and litter performance records from 82 does representing four genetic groups and two diets were analyzed to quantify breed, heterosis, reciprocal F1 cross and diet effects for milk production and associative traits. Doe genetic groups were New Zealand White (NN) and Californian (CC) straightbred and Californian x New Zealand White (CN) and New Zealand White x C...

In the present study a deterministic bio-economic model was used to estimate economic values for reproduction traits (conception rate, twining rate and litter size), production traits (body weight of kid sold at 6.5 months, annual cashmere weight, body weight of doe and annual milk yield) and longevity (survival of doe, survival of kid until weaning and survival of kid until sale age at 6.5 mon...

Two selection goals of inclusion or exclusion of calving interval (CI) in the selection goal function for Holstein cows in Iran, besides milk yield, milk fat percentage, and milk protein percentage, were studied. Four selection indices were composed of using the information on production traits, CI and / or days from calving to first insemination (DFI). The results of the predicted genetic grow...

The objective of this study was to investigate relationships between animal personality (i.e., consistency in behavioral responses, also called temperament) and milk production in dairy cows. There has recently been a growing research interest in animal personality, which in production animals can have an important impact on welfare and production potential. Despite this, the relationship betwe...

Genetic relationships between yield and type traits were investigated using multiple-trait REML procedures with an animal model. Computing strategies were developed to deal with large populations and numbers of traits. Data consisted of records for 3 production and 15 type traits for 20,836 primiparous cows from 1982 to 1988. The model included 2358 herd management effects, 28,749 animal effect...