There are significant costs associated with reproductive inefficiency in pasture-based dairy herds. This study has quantified the economic effect of a number of key variables associated with reproductive inefficiency in a dairy herd and related them to 6-week calving rate for both cows and heifers. These variables include: increased culling costs, the effects of sub optimum calving dates, incre...

The objective of the present study was to estimate genetic correlations between feed intake and type traits with a view to considering the potential of indirect genetic selection for feed intake using type traits in dairy cattle. Feed intake data on 119,388 first lactation Holstein cows were obtained from Dairy Production Centre of Expertise, Valacta. Type trait records on 93,619 cows were obta...

Heat stress has adverse effects on the reproductive performances of dairy cattle and buffaloes. The dairy sector is a more vulnerable to global warming and climate change. The temperature humidity index (THI) is the widely used index to measure the magnitude of heat stress in animals. The objective of this paper was to assess the decline in performances of reproductive traits such as service pe...

effects of inbreeding coefficient on estimates of genetic parameters, breeding values and genetic trends for production traits (milk, fat and protein yields), reproduction traits (age at the first calving, interval between first insemination to conception, calving interval, interval between calving to first insemination, and calving ease) as well as longevity of holstein cattle in iran were stu...

birth weight (bw) is the first trait recorded fllowing birth. it can influence the performance of thecow and as well impact the performance of the calf it,s duringits maturity. to investigate the effect ofa calf,s bw on the performance of holstein dairy cattle in iran, the records gathered between 1967 and2010 were obtained from the iranian animal breeding center. the data were then used to mod...

Calving is one of the most challenging and painful experiences for dairy cattle a process that involves coping with physical physiological changes, as well environmental management-related stressors. In recent years, it has been argued application cow behaviour knowledge might facilitate their efficacious management during calving. This review aims to summarise discuss current regarding behavio...

Bovine genital campylobacteriosis is one of the most economically important diseases of dairy cattleresulting in lowered fertility, embryo mortality and abortion, repeated returns to service, reduced pregnancyrates and extended calving intervals. While the occurrence of repeat breeding syndrome and abortions arereported from many Iranian dairy cattle farms, little information is available regar...

This study assessed the extent of reproductive losses and associated genetic parameters in dairy cattle, using in-line milk progesterone records for 14 Swedish herds collected by DeLaval's Herd Navigator. A total 330,071 samples were linked to 10,219 inseminations (AI) from 5,238 lactations 1,457 Red 1,847 Holstein cows. Pregnancy loss traits defined as early embryonic (1–24 d after AI), late (...

The aim of the study was to determine the seroprevalance of Chlamydophila abortus in aborting ewes and cattle in the Kars province in the north-eastern part of Turkey. Thirty sheep flocks and 26 herds of dairy cattle out of 4 districts in the province were examined by ELISA. For this purpose, abortion cases of 236 sheep and 192 cows of different breeds and age were investigated serologically du...

Salmonella enterica subsp. enterica-serotypes lead to periodically increased morbidity and mortality in cattle herds. The bacteria can also lead to serious infections in humans. Consequently, Denmark has started a surveillance and control programme in 2002. The programme focuses on Salmonella Dublin which is the most prevalent and most persistent serotype in the Danish cattle population. A fiel...