Potential variables for the reproductive success of beef cows were evaluated. Included in model age cow at calving; interval between Julian calving date and end breeding season; body weight conditions calving, 75 days post-partum mean daily variation these dates. Logistic regression was used analysis, with parameters evaluated using odds ratio statistic, estimating chance pregnancy. The rate pr...

The effects of non-genetic factors (sex of calf, calf birth weight, age of cow, season of calving) affecting gestation length (GL) and open days period (OP) in the Ngaoundere Gudali cattle of the Adamawa (Cameroon) was investigated. Mean GL was 293.4 ± 0.4 d. Sex of the calf significantly (P< 0.05) affected GL, with male calves being carried in utero approximately 3 days longer than the females...

Data of 698 Murrah cows sired by 43 bulls maintained at the Central Cattle Breeding Farm, Alamadhi were analysed to study the performance of Murrah buffaloes at the coastal region of Tamil Nadu, India. Least-squares means and genetic parameters were estimated for different first lactation traits. The averages for 305-day and total lactation milk yields were 1616.3 ± 39.6 and 1686.2 ± 44.4 kg, r...

The successful genetic selection for higher milk production caused a dramatic decline in the reproductive performance of dairy cows all over the world during the last decades. Achievement of optimum herd reproductive performance (calving interval of 12 or 13 months with the first calf born at 24 months of age) requires concentrated management activities especially during the first 100 days foll...

Due primarily to a lack of phenotypic data, little research has been undertaken on the genetics of reproductive performance in beef cattle. The objective of this study was to quantify, using data from the Irish national cattle herd, the contribution of additive genetics to phenotypic differences in reproductive performance in beef cattle and to investigate whether routinely available early pred...

BACKGROUND Objectives of the study were to document the impact of some management factors on the occurrence of clinical mastitis in primiparous dairy cows and to identify common udder pathogens of clinical mastitis in freshly calved heifers and multiparous cows on the day of calving. METHODS A one-year study was conducted during 2004 and 2005 in 11 selected Estonian dairy herds. Data consiste...

Productive and reproductive traits have great importance in international dairy cattle breeding objectives. Production, reproduction (days open and calving interval) and pedigree data of Iranian Holstein dairy cattles were collected between 2002 and 2012 from 47 herds in Isfahan province. The data set consisted of 30179 records from 18837 registered IranianHolstein dairy cattles. Single trait r...

In this study 495 smallholder dairy farms in 52 villages of different township in southwestern province of Iran (Chaharmohal and Bakhtiari province) included 1321 lactating cows and 2811 total mature cows (lactating and dry) during winter 2009 to summer 2010 were used to estimate economic opportunities insmallholder dairy farms. Questionnaire survey was used to collect data from last year infor...

An association analysis between T19C polymorphism in bovine PPARGC1A and productive and reproductive traits was performed in a population of 620 and 279 Polish Holstein-Friesian cows, respectively. No relationship was found with milk yield and composition. PPARGC1A genotypes had, however, a significant effect on lengths of calving interval and calving to conception interval, and the T allele wa...