نتایج جستجو برای: calving month
تعداد نتایج: 145034 فیلتر نتایج به سال:
Abstract. Understanding calving processes and their controls is of importance for reducing uncertainty in sea level rise estimates. The impact tidal fluctuations frontal melt on patterns has been researched through both modelling observational studies but remains uncertain may vary from glacier to glacier. In this study, we isolate various different impacts a terminus understand influence the t...
During the periparturient period, some impairment of immune defences were observed. Reference values for the different non-specific immune parameters in cows are not generally available, thus limiting the application of these parameters in dairy practice. This paper reports the data on the measurements of different parameters in the blood, and explores the possible influence of the herd on the ...
This research was conducted with the aim of genetically analyzing of raw (RM) and energy-corrected (EC) test day milk in Iranian first lactation Holstein cows. A total of 774,013 test day records belonging to 88,456 first-parity Holsteins (three times milking a day) calving during 1997-2009 in 165 herds (six provinces) was used. Genetic analysis was carried out by a fixed regression test day mo...
Past research has suggested that during the calving period, caribou (Rangifer tarandus) in Arctic Alaska generally avoid areas within 1 km of oilfield roads with traffic. However, avoidance is not absolute, and caribou may habituate to infrastructure (e.g., buildings, roads, well pads) and human activity. We conducted road-based surveys of caribou in oilfields on Alaska’s Arctic Coastal Plain d...
The paper studies indices of lipid metabolism, immunoglobulins in blood serum heifers different breeds. Black-and-white, Simmental, Aberdeen-Angus, mongrel cattle was selected for this study. Each breed the group consisted 10 heads. study lipids dynamics experimental showed, concentration gradually increased and by 5th month reached maximum values. By end pregnancy on 9th month, a decrease all ...
The objective of this study was to estimate genetic correlations between calving difficulty score and carcass traits in Charolais and Hereford cattle, treating first and later parity calvings as different traits. Genetic correlations between birth weight and carcass traits were also estimated. Field data on 59,182 Charolais and 27,051 Hereford calvings, and carcass traits of 5,260 Charolais and...
Bovine perinatal mortality is an increasing problem in dairy industries internationally. The objective of this study was to determine the risk factors associated with high and low herd-level calf mortality. Thirty herds with a history of either high (case) or low (control) calf mortality were recruited. A herd-level questionnaire was used to gather information on management practices likely to ...
Monthly estimates of 24-h milk yield were obtained on 160 spring-calving and 153 fall-calving crossbred cows containing various proportions (0, 1/4 or 1/2) of Brahman breeding, all bred to Limousin sires. Milk production was measured using weigh-suckle-weigh procedures. Interactions between crossbred group and season of calving were not significant. Across seasons, milk production rarely was af...
The objectives of this research were to characterize dry period lengths for US Jerseys, determine the effects of days dry (DD) on subsequent lactation actual milk, fat, and protein yields, fat and protein percentages, somatic cell score (SCS), and days open (DO), and to determine the dry period length that maximizes yield across lactations. Field data, collected through the Dairy Herd Improveme...
Adjustment factors for age and month of calving were developed from Holstein lactation m r d s in Ecuador. Age factors were similar to those in the United States, but calendar month effects were small, apparently because of uniform feeding and management as the result of a similar climate throughout the year. Genetic evaluations were computed with the USDA animal model system but without identi...
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