The objective of this study was to confirm the relationship among body condition score at the time around parturition, milk yield in subsequent lactation, reproductive efficiency and BCS development in Czech Fleckvieh dairy cows. The BCS and milk yield were measured once a month and the cows were divided into groups according to their BCS before and after calving. Next, data from the database o...

Differences in conception rate to first service between artificial inseminations (AI) carried out by commercial AI operators (CAI) or do-it-yourself operators (DIY), between natural service (NAT) and AI, between different AI sires, and between fresh and frozen-thawed semen, on Irish commercial dairy farms, were studied using logistic regression. The study comprised 12,933 potential first insemi...

Trait-by-trait and multiple trait bioeconomic modeling were used to derive farm-specific economic weights (EW) for a wide range of traits under different production and economic circumstances to define breeding objectives for Holstein dairy cattle in Iran. Production parameters and economic data were gathered on 10 dairy farms from March 2008 to February 2010. The EW (economic values multiplied...

Abstract The objective of this study was to characterize calvings with low and high difficulty based on the productive reproductive performance dairy cows. Calvings were grouped in no calving assistance, assistance. original data set comprised 1,902 records obtained from a large farm Southeast Brazil. Factor analysis applied using SAS® Studio 3.8 statistical program through factor procedure, co...

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...