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The aim of the work has been to characterize the Red-White breed on the basis of their blood groups. The blood samples of Red-White breed from Wroclaw region formed the materials for the studies. 5390 head cattle have been examined and 72 B-alleles were found among them, their number in groups ranging from 26 to 64. In most cases, the B-phenogroups occurring most frequently were statistically significant. In the group of sires, the least number of significant differences occurred.
The trial was performed on 208 heifers of Lowland Red-White breed raised in south-western part of Poland /Breeding State Farm in Głogówek, Opole voivodeship/. Their body weight was checked at birth, 18 months of age, 10 days before parturition and 100, 200 and 300 days after calving. The influence of growth rate /daily gains/ of heifers during rearing on body weight before calving, on milk yield during 1-st lactation and on fertility were investigated. There were 3 groups of heifers based on daily gains: to 650 g, from 651 to 750 g and over 750 g. It was found that growth rate and body weight of actually reared heifers of Lowland Red-White breed had no deterimental effect on milk and fat yield during 1-st lactation. Heifers after parturition were losing in average 67,8 kg /11,5%/ of their body weight and were gaining during lactation inaverage 69,3 kg /13,3%/. High milk yield was followed by more severe decrease in body weight after calving and smaller body gain during lactation what was the cause of lengthening of service period and decrease in fertility.
126 primigravida of Lowland Red-White cows at the State Pegigree Breeding Centre in Głogówek were studied. The udder measurements were made in the cows periodically /on 10, 100, 200 and 240 day of lactation/. 10 different measurements for each cow in each period were made. The milk yield on the day of measurement, the udder size and udder yield index were measured as well. The cows were divided into 3 groups in order to analyse the effect of the udder shape on the changes in its size during lactation: I - ball-shaped udders, II - box-shaped udders, III - bowl-shaped udders. The cows were also divided into 3 groups with regard to their milk yield during 305 day lactation. The udder size in the first lactation decreased /except for front part depth, the length of teats and the distance from the floor/ irrespective of the shape and milk yield. Absolute values of all the measurements as well as the dynamics of the changes depended mainly on milk yield. The lowest dynamic in the changes was observed in the cows of the highest milk yield. The udders of different types varied during the whole period of studies as far as it concerns the length of udder basis, udder depth and udder width. Bowl-shaped udders showed the slowest rate of changes in length, width and size and the quickest dynamic of changes in depth and front part length during lactation. The changes in other measurement values of all 3 types of udders were similar.
There were no differences in body weight and height at withers at 360 days of age and in daily gains from 121 to 360 days between Lowland Black- White and Lowland Red-White bulls. Sires of these two breeds with daily body gains exceeding 1300 g produced semen with higher spermatoa concentration and motility. Lowland Black-White bulls with high growth rate produced less semen during two years, their ejaculates had lower volume when compared to their counterparts. Quite opposite results were obtained in high growth rate Lowland Red-White group of bulls. Correlations between body weight at 360 days as well as daily gains and semen traits were weak and often negative within group of Lowland Black-White bulls but within Lowland Red-White bulls all these correlations were stronger and positive. It was concluded that body growth rate of bulls during rearing had no large and negative effect on their subsequent semen production during the first two years of performance in A.I. stations.
Changes of milk and fat yields in the first three lactations of Lowland Red-White /LRW/ and LRW x HF hybrid cows with various contribution of HF genes were investigated. The cows were kept in two big herds with average milk yield 5000 kg per cow per year. The research showed that the hybrid cows had more even first lactation curves when compared to LKW cows. The most even were first lactations of hybrid cows with 25 % share of HF genes. Subsequent lactations of LRW cows were more even when compared to hybrid cows.
The studies were carried out at Bull Rearing Center in Głogówek on 749 bulls. They were raised and evaluated in 1978-1987. Their body weight and height at withers at the age of 360 days and daily weight gain did not change significantly during 10 years. Their average body weight at the age of 360 days was 436.6 kg, the height at withers was 118.3 cm and daily weight gain during the experiment averaged 1308 g. Great differentiation in the values of the analysed traits among the groups of different bulls' sons was observed. Lowland Red-White cross-bred bulls and those of Holstain-Frisian breed had better characteristics that those of Lowland Red-White bulls 30,4% of the total number of bulls were culled. The most common reasons were: lack or weakened libido, leukemia, poor quality semen, negative result of individual evaluation, abnormal constitution of sex organs.
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