Effect of genetic merit, milk yield, body condition and lactation number on in vitro oocyte development in dairy cows

2000 ◽  
Vol 53 (4) ◽  
pp. 981-989 ◽  
Author(s):  
S.E.M. Snijders ◽  
P. Dillon ◽  
D. O'Callaghan ◽  
M.P. Boland
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Body Condition ◽  
Oocyte Development ◽  
Genetic Merit

scholarly journals Effect of dietary-induced increases in circulating insulin concentrations during the early postpartum period on reproductive function in dairy cows

Reproduction ◽  
2002 ◽  
pp. 419-427 ◽  
Author(s):  
JG Gong ◽  
WJ Lee ◽  
PC Garnsworthy ◽  
R Webb
Keyword(s):  
Body Weight ◽  
Dairy Cows ◽  
Milk Yield ◽  
Body Condition ◽  
Reproductive Performance ◽  
Body Condition Score ◽  
Post Partum ◽  
Dietary Treatment ◽  
Genetic Merit ◽  
Selection For

Although it has become increasingly clear that fertility in modern dairy cattle is declining in association with increased milk yields, the underlying mechanism is poorly understood. The first ovulation post partum is delayed in dairy cows undergoing selection for genetic merit for milk yield in association with lower circulating insulin concentrations. The aim of this study was to investigate whether feeding a diet to increase circulating insulin concentrations can overcome this delay in the first ovulation post partum. The experiment was a 2 x 2 factorial design (n = 10 per group) involving diet and genetic merit for milk yield. The dietary treatment started on the day of calving and lasted for 50 days. Plasma samples were collected each day and ovarian ultra-sonography was performed three times a week during the experimental feeding period. Milk yield was recorded each day, and body weight and body condition score were determined each week. Milk samples were collected three times a week from day 50 to day 105 post partum, and reproductive performance data were recorded for all the cows as part of the routine farm practice. The dietary treatment induced significant differences in plasma insulin concentrations in both high and low genetic merit cows. Although high genetic merit cows produced more milk, lost more body weight and had lower body condition scores during the experiment, no significant effect of diet was observed on these measurements. The high insulin inducing diet increased the proportion of cows ovulating within 50 days of calving and reduced the intervals from calving to first ovulation, and tended to reduce the intervals from calving to first service and to conception. These fertility parameters were also more favourable in low than in high genetic merit cows, but no interaction between diet and genetic merit was observed for any of these parameters. Genetic merit, but not diet, also affected the number of services required per conception and the conception rate. In conclusion, these results have confirmed that genetic selection for high milk yield is associated with a decrease in reproductive performance in dairy cows. More importantly, this study has demonstrated that it is possible to alleviate this problem by nutritional manipulation.

scholarly journals Genetic Relationships among Body Condition Score, Body Weight, Milk Yield, and Fertility in Dairy Cows

2003 ◽  
Vol 86 (6) ◽  
pp. 2193-2204 ◽  
Author(s):  
D.P. Berry ◽  
F. Buckley ◽  
P. Dillon ◽  
R.D. Evans ◽  
M. Rath ◽  
...  
Keyword(s):  
Body Weight ◽  
Dairy Cows ◽  
Milk Yield ◽  
Body Condition ◽  
Body Condition Score ◽  
Genetic Relationships ◽  
Condition Score

Reproductive function in average and high yielding dairy cows

2001 ◽  
Vol 26 (2) ◽  
pp. 495-498 ◽  
Author(s):  
Victoria J. Taylor ◽  
Andrew J. Hattan ◽  
Emma C.L. Bleach ◽  
David E. Beever ◽  
D. Claire Wathes
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Post Partum ◽  
Reproductive Function ◽  
Reproductive Activity ◽  
Corpora Lutea ◽  
Genetic Merit ◽  
Standard Management ◽  
Service Conception ◽  
The Difference

AbstractThe resumption of reproductive activity in the early post partum period and the subsequent fertility of dairy cows are of considerable practical and economic importance to the producer. Regular milk progesterone analysis was used in this study to monitor the re-establishment of reproductive cyclicity in animals of average (AGM, n=20) and high genetic merit (HGM, n=28) kept under standard management conditions. The profiles obtained were then characterised into normal and four different types of abnormal activity. Resumption of cycles occurred significantly later in the higher yielding cows than in those of average genetic merit (23 ±2.3 days in HGM cows and 15 ± 1.6 days in AGM cows; P=0.0089). There was a significant increase in the amount of abnormal cycles encountered in the high genetic merit animals compared with average yielding animals (61% and 30% respectively; χ2 test, P=0.045); in particular, the delayed occurrence of ovulation post partum (11% vs 0%) and an increased incidence of persistent corpora lutea (32% vs 20%). For high genetic merit animals, the incidence of abnormal cycles was associated with increased peak milkyields (abnormal cycles: peak milk yield 54.7 ± 1.11 kg/day; normal cycles: peak milk yield 46.4 ± 1.35 kg/day, P=0.002). This relationship was not apparent in average genetic merit animals. First service conception rates were 50% (9/18) for AGM cows and 38% (10/26) for HGM cows (χ2 test, n.s.). The calving to conception interval was 98 ± 9.7 days for AGM animals (n=l7) and 105 ± 9.1 days for HGMs (n=24) (t-test, n.s.). In conclusion, this study confirms that high genetic merit dairy cows have compromised reproductive function in terms of a delayed resumption of cyclicity and an increased incidence of abnormal progesterone cycles, which was associated with higher peak milk yields. There was also a reduced first service conception rate in high yielders although the difference was not significant with this group size.

scholarly journals Non-structural carbohydrates in the nutrition of high-yielding dairy cows during a transition period

2010 ◽  
Vol 55 (No. 11) ◽  
pp. 468-478 ◽  
Author(s):  
K. Poláková ◽  
V. Kudrna ◽  
A. Kodeš ◽  
B. Hučko ◽  
Z. Mudřík
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Body Condition ◽  
Dry Matter ◽  
Rumen Fluid ◽  
Live Weight ◽  
Dry Matter Intake ◽  
Control Group ◽  
Maize Starch ◽  
Milk Performance

The main aim of this study was to investigate experimentally the effect of different composition of non-structural carbohydrates (NFC) in prepartum feed rations administered to high-yielding dairy cows at a high concentration of NFC in the diet on dry matter intake both before and after parturition and on subsequent milk performance, body condition and physiological traits of rumen fluid and blood. Thirty-six high-yielding dairy cows were allocated into one of the three well-balanced groups (K, O, and C), and each group received a different feeding rations. Feeding rations differed in non-structural carbohydrate (NFC) structure. The "K" (control) group received a feeding ration with NFC in the form of maize starch in particular, while the feeding rations of the other two (experimental) groups contained either (besides maize starch) saccharose from dried sugar beet (the "O" group) or a dominant amount of NFC was in the form of saccharose (the "C" group). After calving, all dairy cows were given the same feeding ration from the first day after parturition. The experiment was conducted for 21 days before and 50 days after calving. FR in the form of total mixed ration was offered ad libitum. Dry matter intake, milk performance, body condition, live weight, and blood and rumen parameters were recorded for the duration of the experiment. Average daily dry matter intake before calving was highest in the "K" group (14.32 kg per head). Differences among groups were statistically significant (P < 0.05). Prepartum dry matter consumption dropped as the rate of saccharose in the diet of cows increased. Dry matter consumption levelled off after calving. Milk yield was also highest in the "K" group (43.71 kg/head/day), but fatness of milk and thus the production of fat corrected milk were lowest in this group. The highest milk fat content (4.10%) and fat corrected milk production (44.03 kg/head/day) were recorded in the "C" group, whereas the highest milk protein concentration was found in the milk of the "O" group. The composition of NFC affected dry matter intake before parturition, but these concentrations did not significantly affect dry matter intake, milk yield, milk composition, live weight, body condition or blood serum and rumen fluid parameters after calving

Differences in the behaviour of high and low yielding dairy cows selected by genetic merit

2002 ◽  
Vol 2002 ◽  
pp. 220-220 ◽  
Author(s):  
M.D. Cooper ◽  
D. R. Arney ◽  
C. J. C. Phillips
Keyword(s):  
Coping Strategies ◽  
Dairy Cows ◽  
Milk Production ◽  
Milk Yield ◽  
Dairy Cow ◽  
Detrimental Effect ◽  
Genetic Merit ◽  
High Nutrient

The effects of high milk yields on the behaviour and welfare of the dairy cow are unclear. A high milk yield increases the need to consume sufficient fodder in an attempt to meet high nutrient demands. The failure to meet the demands may result in persistent hunger in the dairy cow having to modify her behaviour by employing various coping strategies. These modifications may help the cow overcome a state of hunger but at the expense of being unable to express other important behaviours. The objective of this study was therefore to determine whether the behaviour and welfare of the genetically high yielding dairy cow is being compromised by the increased nutritional demands of milk production, and to investigate the possibility that an increased amount of time spent in food-directed behaviours may have a detrimental effect on the time available to perform other important behaviours.

scholarly journals Effect of Harvest Time and Microbial Anaerobic Fermentation at Ruminal Degradability, In Vitro Digestibility to Milk Production and Milk Quality for Whole Plant Zhang Hybrid Millet in Dairy Cows

Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 749
Author(s):  
Yujia Tian ◽  
Xuewei Zhang ◽  
Shengli Li ◽  
Kai Liu ◽  
Peng Guo
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Milk Yield ◽  
Anaerobic Fermentation ◽  
Milk Quality ◽  
In Vitro Digestibility ◽  
Harvest Time ◽  
Ruminal Degradability ◽  
Alternative Feedstock

This study assessed whether harvest time and microbial anaerobic fermentation could affect ruminal degradability and intestinal digestibility of whole Zhang hybrid millet, and estimate the effect of microbial anaerobic fermented whole Zhang hybrid millet as feedstuff on milk yield and milk quality. Protein degradation and intestinal digestion were determined using in situ nylon bag technique and three-step in vitro method, respectively. Results showed that harvest time, microbial anaerobic fermentation, or their interaction significantly affected EDDM, EDCP, and EDNDF (p < 0.05). In vitro fermentation was significantly influenced by harvest time. Early harvested samples appeared to have higher Total volatile fatty acid (TVFA) and lower acetate: propionate ratio than late harvested ones (p < 0.01). However, significant effect of harvest time and fermentation was failed to find in the estimation of rumen-undegradable protein (RUP) (p > 0.05). Microbial anaerobic fermented whole Zhang hybrid millet as feedstuff provided similar milk compositions compared with controls, and it significantly reduced SCC (p = 0.04). Milk yield was numerically higher in whole Zhang hybrid millet groups. In conclusion, harvest time and microbial anaerobic fermentation could further improve ruminal utilization of whole Zhang hybrid millet. Whole Zhang hybrid millet could be an alternative feedstock for dairy cows with acceptable safety profile and potential benefit in milk production.

The influence of cow genetic merit for milk production on response to level of concentrate supplementation in a grass based system

2003 ◽  
Vol 2003 ◽  
pp. 57-57 ◽  
Author(s):  
P. Dillon ◽  
J. Kennedy ◽  
P. Faverdin ◽  
L. Delaby ◽  
F. Buckley ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Milk Yield ◽  
Yield Potential ◽  
Genetic Merit ◽  
Concentrate Supplementation ◽  
Holstein Friesian

Pre-1990 published responses to supplementation at pasture ranged from 0.4 to 0.6kg milk/kg concentrate fed. However since 1990 higher responses to concentrate supplementation at pasture have been published (Delaby 2001). The objective of this study was to determine if milk production responses of Holstein-Friesian dairy cows to concentrate supplementation at pasture are influenced by genetic merit (milk yield potential) in a spring calving grass based system of milk production.

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