Milk yield and estrous behavior during eight consecutive estruses in Holstein cows fed standardized or high energy diets and grouped according to live weight changes in early lactation

SUMMARYFood utilization by lactating dairy cows was studied in a randomized experiment covering the first 24 weeks of lactation, with further observations on performance over the remainder of the lactation under farm conditions. Over a 3-year period 90 firstcalf cows each took part in the experiment for one lactation, making six groups of 14–16 animals.For the experimental period a fixed basal diet was given of hay, concentrates, and wet brewer's grains. One group received only the basal ration. Four groups received in addition a fixed concentrates supplement for 4, 8, 12, 16 weeks from calving onwards respectively. The sixth group also had supplementary concentrates for 16 weeks but for weeks 5–12 inclusive the amount was doubled so that this group's diet simulated broadly ad libitum feeding in early lactation.Milk yield was increased by extra concentrates. The greater part of the effect was apparent in the first 2 weeks of different levels of intake, with a further build-up over the next 6–8 weeks. The size of the response fell as time from calving to initiation of different intakes increased. Additional food increased and delayed peak yield level. Persistency of milk yield was not affected by fixed differences in intake. Rate of liveweight change was improved by extra concentrates, less so in the third compared with the first month on treatment.A higher level of feeding in early lactation led to a greater partition of nutrients in mid-lactation to milk at the expense of gains in body reserves. This advantage to milk production extended to the end of lactation. In it the greatest response per unit concentrates was obtained from supplementation in the first 4 weeks of lactation but the total effect was increased by giving a double allowance of concentrates, and by extending the period of extra feeding to 8 weeks after calving.Solids-not-fat content and yield, and fat yield but not fat content, showed a similar response pattern to milk yield.Animal-to-animal variation in output on constant diets was characterized by negative regressions of live-weight change on milk yield. The regression coefficients were greater in early than in mid-lactation but they were constant in size at any one time for the various groups. A change in ration induced a change in output of the individual in which that production pathway favoured naturally by the animal was the more affected.

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Effects of Bovine Somatotropin on Milk Yield and Composition in Holstein Cows in Advanced Lactation Fed Low- or High-Energy Diets

Journal of Dairy Science ◽

10.3168/jds.s0022-0302(00)74899-5 ◽

2000 ◽

Vol 83 (3) ◽

pp. 430-434 ◽

Cited By ~ 7

Author(s):

M.A. Tarazon-Herrera ◽

J.T. Huber ◽

J.E.P. Santos ◽

L.G. Nussio

Keyword(s):

Milk Yield ◽

High Energy ◽

Bovine Somatotropin ◽

Holstein Cows

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Dairy productivity of mixed-aged Holstein cows with prolonged lactation function

Theoretical and Applied Veterinary Medicine ◽

10.32819/2020.84039 ◽

2020 ◽

Vol 8 (4) ◽

pp. 265-268

Author(s):

G. S. Gutsulyak

Keyword(s):

Milk Yield ◽

Live Weight ◽

Holstein Cows ◽

Control Group ◽

Lactation Period ◽

Group V ◽

Productivity Level ◽

Group I ◽

Study Results ◽

High Level

Presented study results of the productivity of mixed-aged cows with prolonged lactation. The formation of experimental groups was carried out according to the principle of analog groups, taking into account breed, live weight, age and physiological condition (lactation):25 animals in groups I, II, III and IV and 10 animals in group V. It was found that with the industrial technology of Holstein cows exploitation, regardless of their age, the duration of the lactation period was almost twice as long as the scientifically substantiated value and ranges from 561.2 to 610.9 days. At the same time, the milk productivity level of the cows in I and IV groups slightly exceeded 13 000 kg of milk per lactation, while in cows if II, III (control), and V groups – this value was higher than 15 000 kg. With prolonged lactation, the milk yield in the experimental groups of animals in terms of 305 days was kept at a fairly high level and there was a definite tendency to an increase in milk yield depending on the age of the animals. The first-calf heifers of group I were characterized by a relatively low milk yield since they gave only 13 291.8 kg of milk for the entire lactation, and in terms of 305 days – 7 944.1 kg, which was 13.57% and compared to III (control) group was 19.54% lower (P < 0.01). Animals of the fifth lactation from group V had the highest milk yield, in which the milk yield per lactation and per 305 days amounted to 15 818.5 kg and 9 716.7 kg of milk, respectively. With intensive exploitation technology and with the increasing age of Holstein cows, complete adaptation occurs, as a result of which their genetic potential for milk production is realized at a high level. This was indicated by the milk yield dynamics in experimental animals of different ages, in which, under the same conditions of feeding and housing, they were gradually increased from the first to the fifth lactation.

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Complete diets for dairy cows: comparisons of feeding to appetite with rationing according to milk yield

The Journal of Agricultural Science ◽

10.1017/s0021859600028707 ◽

1980 ◽

Vol 94 (3) ◽

pp. 715-726 ◽

Cited By ~ 8

Author(s):

J. F. D. Greenhalgh ◽

G. W. Reid

Keyword(s):

Milk Yield ◽

Dry Matter ◽

Energy Content ◽

Energy Requirement ◽

Live Weight ◽

Metabolizable Energy ◽

Dry Matter Intake ◽

Late Winter ◽

Early Lactation ◽

Under Nutrition

SummaryTwo experiments were made, each with 35 autumn-calving cows fed on complete diets containing 40–70% hay and 60–30% concentrates. In both experiments, cows fed to appetite on a diet containing 11 MJ metabolizable energy/kg D.M. for weeks 7–24 of lactation ate about 20% more than cows rationed according to yield, but produced only about 3% more milk. The cows fed to appetite gained more in live weight, but lost their weight advantage during the subsequent grazing season.In Expt 1, a further group of cows were fed to appetite on diets progressively reduced in metabolizable energy content from 11·0 to 9·2 MJ/kg. Dry-matter intake decreased by about 1·2 kg/day per 1 MJ reduction in energy content. The lower dry-matter and energy intakes of cows on this treatment did not significantly reduce their milk yield, but their response when turned out to grass suggested under-nutrition in late winter. In Expt 2, increasing the energy content of the diet in early lactation (weeks 7–12) and reducing it thereafter had no significant effect on milk yield.Within each treatment group there were reasonably close relationships between energy intake and energy requirement. Nevertheless, it seems likely that the efficiency of feed utilization of cows fed on complete diets will be low unless intake is controlled by energy dilution.

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The effect of feeding in early lactation on feed intake, yields of milk, fat and protein and on live-weight change over one lactation cycle in dairy cows

The Journal of Agricultural Science ◽

10.1017/s0021859600043744 ◽

1984 ◽

Vol 103 (3) ◽

pp. 629-637 ◽

Cited By ~ 11

Author(s):

C. L. Johnson

Keyword(s):

Feed Intake ◽

Weight Change ◽

Milk Fat ◽

Live Weight ◽

Early Lactation ◽

Weight Changes ◽

Potential Yield ◽

Energy Deficiency ◽

Ad Libitum ◽

Lactation Cycle

SummaryAn experiment has been made to study the effect of level of feeding in early lactation on the feed intake, yields of milk, fat and protein and on live-weight change over one lactation cycle. Adult British Friesian cows of high potential yield were randomly allocated to high (HP) or moderate (MP) levels of feeding for 20 weeks. They were then randomly allocated within treatments to controlled or ad libitum levels of feeding for the rest of the lactation.There were significant effects of feeding in the early part of lactation on the yields of milk, protein and lactose but not on milk fat or live-weight change. Cows on the MP treatment produced about 450 kg milk from body energy reserves but were unable to supplement fully the dietary energy deficiency. There was no significant response to feeding ad libitum in the second part of lactation and the differences in yields established in the first part were maintained in the second. There was no relationship between feed intake and milk yield for cows fed ad libitum nor did the level of feeding in early lactation influence the level of intake in the later part.There was little agreement between calculated energy balance and the live-weight changes but there was more between live-weight change and condition score.

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Effects of body fatness at lambing and diet in lactation on body tissue loss, feed intake and milk yield of ewes in early lactation

The Journal of Agricultural Science ◽

10.1017/s002185960008789x ◽

1980 ◽

Vol 95 (3) ◽

pp. 497-514 ◽

Cited By ~ 60

Author(s):

R. T. Cowan ◽

J. J. Robinson ◽

I. McDonald ◽

R. Smart

Keyword(s):

Milk Yield ◽

Weight Change ◽

Live Weight ◽

Early Lactation ◽

Body Fatness ◽

Body Protein ◽

Fat Reserves ◽

Complete Diet ◽

Ad Libitum ◽

Body Energy

SUMMARYThirty-six mature Finnish Landrace × Dorset Horn ewes, each suckling two lambs, were used in a comparative slaughter experiment to measure changes in body tissues during early lactation. Two levels of body fatness at lambing were established by giving ewes a complete diet containing 10 MJ metabolizable energy (ME) and 139 g crude protein (CP)/kg d.m. either close to requirements or ad libitum during the second half of pregnancy. In lactation half the ewes in each group were given a complete diet containing either 90 (diet A) or 60 (diet B) % milled hay ad libitum. These diets contained 7·9 and 9·2 MJ ME and 121 and 132 g CP/kg d.m. respectively.Ewes fed at the two levels in pregnancy contained 8·4 and 19·6 kg chemically determined fat 5 days after lambing but had similar amounts of body protein, ash and water. Over 6 weeks of lactation ewes given diet A lost 60 and 69% of these weights of fat respectively, while ewes given diet B gained 5% and lost 30% respectively. Up to 26 g of body protein was lost daily from ewes given diet A but none from ewes on diet B. During early lactation the weight of the empty digestive tract increased while the weights of most other body components, particularly the carcass, decreased. The ratio of body energy change to live-weight change varied from 24 to 90 MJ/kg. Thus live-weight change did not accurately reflect relative or absolute changes in body energy.Voluntary food intake was greater for ewes given the high-energy diet (B) than for those given diet A and was depressed in the fatter ewes. Differences in intake could be explained by the effects of body fatness and diet on the weight of gut contents. Milk yield was not significantly affected by body fat reserves but was higher on diet B than A. Fat content of milk was higher and protein content lower for ewes with the higher fat reserves at lambing.As the contribution of fat loss to energy available for milk synthesis increased there appeared to be a reduction in the energetic efficiency of milk synthesis. A number of possible reasons for this are discussed.

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