نتایج جستجو برای: calving rate
تعداد نتایج: 963622 فیلتر نتایج به سال:
A total of 1385 lactation records of Tharparkar cattle collected from LRS Chandan, Jaisalmer spreading over a period of 33 years were utilized to assess the effects of period and season of birth/calving on age at first calving, calving interval and service period and also studied effect of parity on calving interval and service period. The least-squares means were 1821.86 ± 37.022 days, 414.16 ...
Bone accumulations faithfully record historical ecological data on animal communities, and owing to millennial-scale bone survival on high-latitude landscapes, have exceptional potential for extending records on arctic ecosystems. For the Porcupine Caribou Herd, maintaining access to calving grounds on the Arctic National Wildlife Refuge (ANWR, Alaska) is a central management concern. However, ...
Objective-To assess the effect of lameness on culling of dairy cows in Tehran province. Design- Historical cohort study. Study population and procedures- 7067 first- and second-parity Holstein dairy cows that calved from March, 21 2007 to March, 20 2008 were until next calving or culling. Logistic regression was conducted data. Results-The overall lactational culling rate for eligible cows i...
Iceberg calving from all Antarctic ice shelves has never been directly measured, despite playing a crucial role in ice sheet mass balance. Rapid changes to iceberg calving naturally arise from the sporadic detachment of large tabular bergs but can also be triggered by climate forcing. Here we provide a direct empirical estimate of mass loss due to iceberg calving and melting from Antarctic ice ...
The present research was designed to evaluate the effects of pre and post-partum energy level and feeding pattern on the performance of crossbred dairy cows and their calves under farm conditions. A total of 16 crossbred dairy cows were divided into two equal groups on the basis of their body weight and milk production. One group was given 30% less and the another was given 30% more energy than...
The aim of this study was to determine if, and under what conditions, indoor-housed dairy cows would seek a shelter to calve. Seventy-two Holstein dairy cows were paired by expected calving date and moved into a maternity pen that contained an open area with no cover and a sheltered area that was covered on all sides except for the ceiling and an entrance where cows could freely enter or exit. ...
Calving complications have an incidence on the economic profitability of dairy herds. In the Walloon Region of Belgium, calving ease data recording is being done on voluntary basis since 2000. This allows now the implementation of a genetic evaluation of Holstein dairy cattle addressing the need of dairy breeders to select bulls in order to reduce frequency of calving problems. Calving ease sco...
Records of 547, 2-yr-old heifers of three breed groups were used to evaluate the relative influence of dam's body and pelvic measurements, calf birth weight, sire birth weight and some relative measures (ratios) of calf birth weight and dam weight at calving on calving difficulty. The data were analyzed by regression and least squares procedures. The full model explained 32.5% of the variation ...
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...
Beef cattle production requires reproductive efficiency. However, measures of reproductive traits are not usually collected; consequently, correlated traits that could be used as indicators would be useful. We examined associations between measures of reproductive and productive efficiency that could be used as selection indicators. Data from 194 dams of the genetic groups Angus x Nelore, Carac...
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