Lactational performance and energy utilisation in high yielding cows

2000 ◽  
Vol 2000 ◽  
pp. 10-10 ◽  
Author(s):  
D.E. Beever ◽  
A.J. Hattan ◽  
S B Cammell ◽  
D.J. Humphries ◽  
A K Jones
Keyword(s):  
Milk Production ◽  
Dairy Herd ◽  
Milk Quality ◽  
Energy Deficit ◽  
Early Lactation ◽  
Energy Depletion ◽  
Genetic Merit ◽  
Lactational Performance ◽  
Condition Score ◽  
The Uk

Significant increases in genetic merit for milk production in the UK dairy herd have led to high and persistent milk yields becoming relatively common. Data relating this level of performance to the extent of the energy deficit in early lactation, possible impact on milk quality and the contribution of mobilised energy to milk production are relatively scarce. The aim of this study was to compare lactational performance in high- (HYC) and average- (AYC) yielding cows and to reconcile changes in body status (liveweight and condition score) of HYC with associated measurements of energy depletion and repletion.

The effect of heifer rearing regime on body size and milk production during the first lactation

2000 ◽  
Vol 2000 ◽  
pp. 13-13 ◽  
Author(s):  
A.F. Carson ◽  
L.E.R. Dawson ◽  
F.J. Gordon
Keyword(s):  
Milk Production ◽  
Production Systems ◽  
Live Weight ◽  
Dairy Herd ◽  
Lactation Performance ◽  
Frame Size ◽  
Genetic Merit ◽  
Holstein Friesian ◽  
The Uk ◽  
Current Systems

The UK dairy industry has entered a period of rapid increase in cow genetic merit. Feeding and management during the rearing period will influence the extent to which the genetic merit of these animals is realised. Current systems for rearing dairy herd replacements are based on research undertaken in the 1960's and 1970's with animals of lower genetic merit. High genetic merit Holstein Friesian animals have an increased live weight and frame size at maturity compared with their medium merit contemporaries, which may have implications for the optimum weight at first calving. The aim of this study was to determine the effect of rearing regime, in terms of diet offered and target calving weight, on first lactation performance of high genetic merit heifers over a range of milk production systems.

The effects of plane of nutrition and diet type on metabolic hormone concentrations, growth and milk production in high genetic merit dairy herd replacements

2000 ◽  
Vol 70 (2) ◽  
pp. 349-362 ◽  
Author(s):  
A.F. Carson ◽  
A.R.G. Wylie ◽  
J.D.G. McEvoy ◽  
M. McCoy ◽  
L.E.R. Dawson
Keyword(s):  
Weight Gain ◽  
Milk Production ◽  
Live Weight ◽  
Live Weight Gain ◽  
Genetic Merit ◽  
Grass Silage ◽  
Nutrition And Diet ◽  
Condition Score ◽  
Metabolic Hormone ◽  
Diet Type

AbstractSeventy high genetic merit Holstein heifers were used in two experiments to investigate (1) the effects of plane of nutrition and diet type during the pre-pubertal period and (2) the effects of plane of nutrition during the post-pubertal period on metabolic hormone concentrations, growth and milk production. In experiment 1, treatment 1 and 2 heifers were given food to achieve a live-weight gain of 0·70 and 0·95 kg/day from 3 to 10 months of age on a grass silage based diet, while treatment 3 heifers were given food to achieve 0·95 kg/day on a barley straw/concentrate diet. During the pre-pubertal period, heifers reared on treatment 1 had significantly higher growth hormone(GH) concentrations (ng/ml per 1 h) than heifers reared on treatment 2 (P < 0·01) and had significantly lower insulin concentrations than heifers reared on treatment 3 (P < 0·01). Heifers reared on treatment 1 had significantly lower insulin-like growth factor 1 (IGF-1) concentrations than those reared on treatment 3 (P < 0·01). At 10 months of age heifers reared on treatment 1 were of lower condition score (P < 0·01) than those on treatment 2 and had a smaller heart girth diameter (P < 0·01) than those on treatments 2 and 3. During the first lactation, milk yield and composition produced by the heifers was not significantly affected by treatment. In experiment 2, treatment A heifers were given, from 14 to 24 months of age, a low plane of nutrition to allow a live-weight gain of 0·65 kg/day on a grass silage and grass based diet during the winter and summer periods respectively. Treatment B heifers were kept on a high plane of nutrition to allow a live-weight gain of 0·90 kg/day on the same forage along with concentrate supplementation. During the rearing period, GH and IGF-1 concentrations were not significantly affected by treatment. Treatment A heifers weighed less before calving (P < 0·05), had a lower condition score (P < 0·01), and had a smaller heart girth diameter (P < 0·01) than those on treatment B. During the first 10 weeks of lactation, heifers on treatment A had a higher silage dry matter intake and lost less weight (P < 0·05) than those on treatment B, however, by 20 weeks of lactation these effects had disappeared. Milk yield and composition during the first lactation were not significantly affected by treatment. Overall, the findings of experiments 1 and 2 did not show any beneficial effects of higher weights at first calving in high genetic merit Holsteins and therefore indicate that accelerated growth in the pre- or post-pubertal period may not be required.

Effect of body condition at calving and level of feeding in early lactation on milk production of dairy cows

1982 ◽  
Vol 22 (115) ◽  
pp. 9 ◽  
Author(s):  
C Grainger ◽  
GD Wilhelms ◽  
AA McGowan
Keyword(s):  
Milk Production ◽  
Body Condition ◽  
Milk Fat ◽  
Body Condition Score ◽  
Early Lactation ◽  
Input Output ◽  
Fat Percentage ◽  
Feeding Management ◽  
Condition Score ◽  
Degree Of Confidence

Two experiments were carried out to measure effects of body condition at calving and different levels of feeding after calving on milk and subsequent reproduction.In experiment 1, which was conducted in two consecutive years, 162 cows (77 in year 1 and 85 in year 2) were group feed so as to reach a target body condition (condition scores ranging from 3-6) four weeks before calving. During the last four weeks before calving, all cows were managed so as to maintain their individual condition scores. At calving, cows in similar condition of similar breed and with similar previous milk production were allocated to high and low levels of feeding at pasture for the first five weeks of lactation. Mean pasture intakes were 13.0 and 7.0kg dry matter (DM)/cow.d in year 1 and 15.0 and 8.5 kg DM/cow.d in year 2In experiment 2, 40 cows were offered pasture and hay from 20 weeks before calving to achieve a body condition score of either 4 or 6 by two weeks before calving. During the first five weeks of lactation, cows were individually fed in stalls on freshly cut pasture at one of three levels of intake, 7 or 10 kg DM/cow.d or .In both experiments cows were grazed as one group from week 6 to 20 of lactation.Improved body condition at calving resulted in an extra 4.0, 11.0 and 7.4 kg milk fat per unit condition score over 20 weeks of lactation, for year 1 and 2 of experiment 1, and experiment 2, respectively. Cows in poorer condition partitioned a higher proportion of feed energy to liveweight at the expense of milk production than did the cows in better condition. However, increasing the plane of nutrition in early lactation resulted in higher levels of milk production and reduced the need for cows to mobilize bodyreserves. Improved body condition at calving had a positive effect on milk fat percentage, particularly in early lactation, but did not affect milk protein percentage. Input-output relations calculated from the experimental data showed that the benefit sf to improve body condition before calving was less than that of additional feeding after calvin changes in the condition of the cows were taken into consideration (25.8 vs 1 4.6 kg DM to yi kilogram of milkfat). Improvements in condition and feeding in early lactation reduced the anoestrus interval after calving by 5.7 d for each additional condition score at calving and 1. d for each additional kgDM/cow.d fed over weeks 1-5 of lactation. The input-output relations resented will enable farmers to assess the likely consequenes of changes in their feeding management in the crucial peripartum period with a greater degree of confidence than in the past.

Sensitivity of mammary secretory cell turnover to protein restriction and re-alimentation during early lactation

1997 ◽  
Vol 1997 ◽  
pp. 130-130
Author(s):  
M.G. Goodwill ◽  
N.S. Jessop ◽  
J.D. Oldham
Keyword(s):  
Cell Proliferation ◽  
Mammary Gland ◽  
Milk Production ◽  
Secretory Cell ◽  
Protein Restriction ◽  
Secretory Cells ◽  
Early Lactation ◽  
Cell Turnover ◽  
Lactational Performance

Milk production depends on both the number and activity of secretory cells within the mammary gland. Our earlier work showed the sensitivity of lactational performance to changes in diet during lactation (Goodwill et al, 1996). This study investigated the influence of protein undernutrition and re-alimentation on secretory cell proliferation and death in the mammary gland of rats during early lactation.

Influence of Genetic Merit on Fertility Traits of Dairy Cattle on Commercial Farms

2002 ◽  
Vol 2002 ◽  
pp. 126-126
Author(s):  
H.C.F. Wicks ◽  
J.D. Leaver
Keyword(s):  
Dairy Cattle ◽  
Milk Production ◽  
Milk Yield ◽  
Body Condition Score ◽  
Potential Yield ◽  
Genetic Merit ◽  
Condition Score ◽  
Actual Yield ◽  
High Level ◽  
Daily Milk Yield

The selection of dairy cattle for high milk production is thought to be linked to increased problems with fertility. Most research has concentrated on the influence of actual yields rather than the effect of genetic merit on fertility. It has also been reported that by maintaining a high level of herd management the reproductive efficiency problems associated with high milk production can be removed (Nebel and Gilliard, 1993). The current work estimated the influence of genetic merit (defined as PIN95), 90-day daily milk yield, deviation from herd mean 305-day milk yield and body condition score on fertility, in an attempt to assess whether actual yield has more effect than potential yield as indicated by genetic merit.

Prediction of body weight and composition in lactating dairy cows: Relationship between body condition score and body composition

2005 ◽  
Vol 2005 ◽  
pp. 19-19
Author(s):  
T. Yan ◽  
R. E. Agnew ◽  
C. S. Mayne
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Dairy Cows ◽  
Milk Production ◽  
Body Condition ◽  
Body Condition Score ◽  
Early Lactation ◽  
Lactating Dairy Cows ◽  
Condition Score ◽  
Body Concentration

Body condition of lactating dairy cows varies at different stages of lactation. Cows usually mobilise their body reserves to provide energy and protein for milk production in early lactation, and gain weight to deposit energy and protein for pregnancy at a later stage. The objective of the present study was to examine relationships between body condition score (CS) and body concentration of lipid, CP and energy.

The responses of high and medium merit dairy cows to diets differing in grass silage: concentrate ratios, during early lactation

1996 ◽  
Vol 1996 ◽  
pp. 5-5
Author(s):  
C.P. Ferris ◽  
F.J. Gordon ◽  
D.C. Patterson ◽  
C.S. Mayne
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Dairy Herd ◽  
Yield Potential ◽  
Genetic Merit ◽  
The Past ◽  
Grass Silage ◽  
The Uk ◽  
Yield Responses ◽  
Feeding Systems

The genetic merit of the UK dairy herd is increasing rapidly and this trend is likely to continue for the forseeable future. With cows of higher milk yield potential and higher nutrient requirements, feeding systems developed in the past with medium genetic merit animals, may now need to be adapted to meet the needs of high genetic merit animals if nutrition x genotype interactions exist. This would be particularly true to increasing proportion of concentrates in grass silage based diets. This study was undertaken to compare the milk yield responses of high and medium merit dairy cows.

Options to reduce vulnerability to metabolic stress by genetic selection

1999 ◽  
Vol 24 ◽  
pp. 119-127 ◽  
Author(s):  
J. E. Pryce ◽  
P. Løvendahl
Keyword(s):  
Milk Production ◽  
Genetic Selection ◽  
Metabolic Stress ◽  
Live Weight ◽  
Genetic Merit ◽  
Condition Score ◽  
Breeding Programmes ◽  
Selection For ◽  
Breeding Goals ◽  
High Yields

AbstractGenetic selection for milk production has been very successful. However to achieve high yields, the metabolic load on dairy cows is believed to be substantial. If the size of this load is large enough then the animal may become ‘metabolically stressed’. Signs of this may include some sort of distortion of normal physiological function. There is evidence from both population studies and research herds to suggest that intense selection for milk yield has led to a deterioration in some aspects of health and fertility. Genetic correlation estimates between production and measures of fertility are unfavourable. As an example, calving intervals of high merit animals from Langhill are on average 12 days longer than those of average genetic merit, which is mostly due to a delay in days to first heat. It is suggested that some aspects of health and fertility problems in high genetic merit animals are a consequence, in part, of so-called metabolic stress. Future breeding goals should be broadened to include a broad spectrum of traits related to efficient milk production, in addition to either health and fertility traits themselves, or traits believed to be precursors of them, such as those related to metabolic stress. The complexity and subjectivity of metabolic stress and its components makes it very difficult to include in future breeding goals. However, traits related to energy balance, such as some measures of condition score, dry-matter intake and live weight may be useful in breeding programmes where one of the goals is to alleviate metabolic stress.

EFFECT OF COLD EXPOSURE ON MILK PRODUCTION AND ENERGY BALANCE IN THE LACTATING EWE

1984 ◽  
Vol 64 (2) ◽  
pp. 379-389 ◽  
Author(s):  
G. E. McBRIDE ◽  
R. J. CHRISTOPHERSON
Keyword(s):  
Energy Balance ◽  
Milk Production ◽  
Cold Exposure ◽  
Milk Fat ◽  
Experimental Period ◽  
Milk Composition ◽  
Energy Deficit ◽  
Net Energy ◽  
Lactational Performance ◽  
Daily Milk Production

The lactational performances of shorn ewes chronically exposed to a thermoneutral (21 ± 1 °C) or cold (0 ± 1 °C) environment were compared in two experiments. Heat production measured after 1, 21 and 41 days of cold exposure was increased by 20% (P < 0.05), 43% (P < 0.01) and 55% (P < 0.001), respectively, over thermoneutral control values. In both experiments, cold exposure increased milk fat concentration (P < 0.05). Milk protein and lactose concentrations were maintained in exp. 1 but tended to be increased in exp. 2 as a result of cold exposure. Milk obtained from the cold-exposed ewes was characterized by a relative decrease in short-chain fatty acid secretion (P < 0.01). Although milk composition was affected by cold stress, daily milk production was not significantly altered; as a consequence, total energy lost in the milk tended to be slightly higher for the cold-stressed ewes. The increased energy lost as heat and in the milk during cold exposure resulted in a net energy deficit throughout most of the experimental period. The present data suggest that the lactational performance of a ewe nursing a single lamb is not impaired by chronic exposure to an ambient temperature of 0 °C. Key words: Cold, milk production, milk composition, ewes, energy balance

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