The objective of this study was to analyse the heritabilitiy of the lactational incidence of displaced abomasum (DA) and the relationships of DA with milk production traits in German Holstein cows. Data were recorded between February 1999 and January 2000 in cooperation with five veterinary practitioners. Their veterinary practices were located in the northern part of Lower Saxony. The investigation included 160 dairy farms under the official milk-recording scheme with 9,315 cows. The lactational incidence of the left abomasal displacement amounted to 1.21%, and of the right abomasal displacement to 0.41%, respectively. The linear heritability estimates for the lactational incidences of left and right DA were h(2) = 0.05 +/- 0.012 and h(2) = 0.004 +/- 0.005, respectively. Using the Dempster-Lerner-transformation the corresponding heritabilities were h(2) = 0.53 and 0.09, respectively. Milk losses for the lactation when DA was diagnosed were significant and reached 1016 kg milk, 41 kg fat, 36 kg protein and 0.07% protein. Fat content significantly increased by 0.18%. The analysis could not show significant differences between cows diagnosed with DA and cows not diagnosed with DA in the 305-day milk production traits of the lactation preceding the diagnosis of DA. There was also no indication for an unequal distribution of breeding values for milk performance traits between cows with and without DA. The additive genetic correlations between 305-day milk performance and left DA were low. The results indicated that cows with a high milk production and superior breeding values for milk performance were not exposed to an increased risk for DA.
A whole-genome scan using an affected paternal half-sib design was utilized to detect quantitative trait loci (QTL) for left-sided displaced abomasum (LDA) in German Holsteins. A total of 360 animals from 14 paternal half-sib families were genotyped, for a total of 306 polymorphic microsatellites. For a whole-genome scan, 221 markers were equally distributed over all 29 bovine autosomes, with an average distance of 13.7 cM. For fine-mapping, a total of 85 additional microsatellites were used. We identified genome-wide significant QTL on Bos taurus autosome (BTA) 1 (54.6 to 58.3 cM) and on BTA3 (5.9 cM). Furthermore, 3 chromosome-wide significant QTL were located on bovine chromosomes 21, 23, and 24. In addition, we found 11 QTL that cosegregated in grandsire families but that were not significant in the across-family analysis. These QTL were located on BTA5, 6, 10, 12, 15, 16, 17, 19, 23, and 26. This study is the first report on QTL for LDA and is a first step toward identifying single nucleotide polymorphisms for LDA-QTL.
MudroÀ P., J. Rehage, H. P. Sallmann, M. Höltershinken, H. Scholz: Stress Response in Dairy Cows Related to Blood Glucose. Acta Vet. Brno 2005, 74: 37-42.The aim of this study was to investigate whether different pre-surgical blood glucose concentrations have any effect on the course of cortisol and metabolic responses to surgical stress in dairy cows. Eighteen Holstein-Friesian dairy cows, admitted for treatment of left abomasal displacement (omentopexy), were used in the study. Abdominal surgery (the stressor) was performed in the standing position 16 -24 h after admission and lasted approximately 60 min. Blood samples were drawn from the jugular vein prior to surgery, immediately after and then 2, 5, 24, and 72 h after surgery. In order to test the effect of the different blood glucose levels on stress responses the experimental animals were allocated to two groups: 1) six hypoglycaemic cows (glucose < 2.4 mmol/l); 2) twelve normoglycaemic cows. Surgery increased blood glucose in both groups (p < 0.001), however, the glucose rise was less distinct in the hypoglycaemic cows. The surgical stress resulted in a significant increase in plasma cortisol concentrations in both groups (p < 0.001), however there was no difference in cortisol responses between the groups. Similarly, surgery enhanced the blood concentrations of free fatty acids (FFA) and L (+)-lactate in both groups (p < 0.001). In contrast, β-hydroxybutyrate concentrations slightly declined after surgery. On the basis of this study there appears not to be any effect of different plasma glucose on the cortisol and metabolite responses in stressed dairy cows. Therefore, it can be concluded that mechanisms regulating peripheral cortisol concentrations, and thus the animal stress response, are more dependent on the intensity of the stressful stimulus than on the energetic status of animal.
Abstract. Title of the paper: Milk yield an milk quality of beef cows during the suckling period The milk yield of suckling cows is an important requirement for the growth of weaning calves. The daily milk yield of 57 suckling cows was recorded in different stages of suckling period. As methods of the milk recording were used "weigh – suckle – weigh" and machine milking with application of oxytocin. The means of the 200 days milk yield were 1,754 kg in suckling cows of the Red Angus breed at Hungarian farm and 2,868 kg for different genotypes on a grassland location in the North of Germany. On average, the percentage of milk fat was x = 4.26 % ± 1.17 %, of protein x = 3.62 % ± 0.39 % and of lactose x = 4.80 % + 0.35 %, respectively. Significant relations were recorded between the milk yield in the first 6th months of suckling period and the daily weight gain (coefficients from r = 0.541 to r = 0.581).
Abstract. Title of the paper: Relationship between feed intake, side fat thickness and special parameters of rearing Performance of lactating sows A total of 106 Camborough sows were used to study the relationship between feed intake, side fat thickness at the end of pregnancy, their change during lactation and special parameters of rearing Performance. Sows with a high side fat thickness at the end of pregnancy realised a lower feed intake during lactation (r = −0.206*) but a higher loss of side fat thickness (r = −0.499**) than sows with worse body condition. High feed intake during lactation stimulates a high number of weaned piglets (r = 0.299*) and the weight of weaned litter (r = 0.321*). The amount of feed intake in first week of lactation is most important for it. Generally, sows with a high predisposition for mobilisation of body fat and high intake of food during lactation realised the significant highest rearing Performance (r = 0.436***).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.