Precalving and early lactation factors that predict milk casein and fertility in the transition dairy cow

Sinclair et al. (1993) found that a diet formulated to be synchronous with regard to hourly release of nitrogen and energy increased microbial protein synthesis by 14% in sheep. Dairy cows in early lactation experience a shortfall of energy and protein, with available protein determining the overall efficiency of metabolism (MacRae and Lobley, 1986) and subsequent milk production. It is therefore necessary to maximise microbial protein yield during this period. In this study diets were designed for lactating dairy cows to contain the same feed ingredients, but to release nitrogen and energy in the rumen at different times. Rumen fermentation parameters, nutrient flows to the small intestine and production performance were investigated.

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Glucagon, insulin, and growth hormone responses to glucose infusion in lactating dairy cows

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1985.248.1.e108 ◽

1985 ◽

Vol 248 (1) ◽

pp. E108-E114 ◽

Cited By ~ 8

Author(s):

J. L. Sartin ◽

K. A. Cummins ◽

R. J. Kemppainen ◽

D. N. Marple ◽

C. H. Rahe ◽

...

Keyword(s):

Growth Hormone ◽

Dairy Cow ◽

Glucose Infusion ◽

Early Lactation ◽

Adaptive Responses ◽

Exogenous Glucose ◽

Lactating Dairy Cows ◽

Nutrient Partitioning ◽

Hormone Responses ◽

G Ratio

Early lactation in the dairy cow is associated with an increased demand for energy that can only be met by hormone-mediated partitioning of nutrients. The purpose of this study was to determine adaptive responses of basal and glucose-stimulated glucagon (IRG), insulin (IRI), and growth hormone (GH) concentrations to early lactation. Blood was collected via jugular cannulas from nonpregnant nonlactating (NPNL) cows and cows 14 days antepartum (AP) and 5 and 30 days postpartum (PP). Basal concentrations of IRI decreased with lactation, IRG was essentially unchanged, and GH was increased with lactation. The molar IRI/IRG (I/G) ratio was decreased from 4.6 at day 14 AP to 1.3 at day 30 PP. The effects of exogenous glucose (0.56 mM/kg body wt) on IRI were greatest during pregnancy and declined with lactation. IRG responses to glucose were similar except in NPNL cows, which had a minimal but prolonged IRG inhibition, GH responses to glucose infusion were absent in NPNL cows and were most significant at 5 days PP. The decreased I/G and elevated GH concentrations suggests that both IRG and GH play a role in nutrient partitioning during early lactation.

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Effect on forage intake and milk production of including maize silage in early or mid lactation in dairy cow rations based on grass silage

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600020948 ◽

1991 ◽

Vol 1991 ◽

pp. 144-144 ◽

Cited By ~ 1

Author(s):

R H Phipps ◽

R F Weller ◽

W J Fisher ◽

T Poole

Keyword(s):

Milk Production ◽

Dairy Cow ◽

Early Lactation ◽

Maize Silage ◽

Pricing Policy ◽

Current Trial ◽

Grass Silage ◽

Forage Intake ◽

Milk Marketing

Preliminary studies at the Bernard Weitz Centre have shown that maize silage has the potential to increase forage intake and milk production. The trend towards earlier calving, encouraged by the Milk Marketing Board pricing policy, means that maize silage may not be available for early lactation; as most farmers rely on the current seasons crop, and few carry stocks over from the previous year. The objective of the current trial was to determine the eflect on forage intake and milk production of incorporating maize silage into grass silage based rations either from early or mid-lactation.

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Pasture allowance and duration: the effect of restriction on dry-matter intake, energy balance and indicators of metabolic health in early lactation dairy cows

Animal Production Science ◽

10.1071/an20066 ◽

2021 ◽

Vol 61 (1) ◽

pp. 17

Author(s):

Aisling Claffey ◽

Luc Delaby ◽

Eva Lewis ◽

Tommy M. Boland ◽

Norann Galvin ◽

...

Keyword(s):

Energy Balance ◽

Dairy Cow ◽

Dry Matter ◽

Climatic Factors ◽

Metabolic Health ◽

Dry Matter Intake ◽

Control Treatment ◽

Early Lactation ◽

Short Term ◽

Grass Growth

Context Pasture allowance (PA) in early lactation is widely acknowledged to influence animal performance; however, climatic factors can limit grass growth in early spring, resulting in potential feed deficits on farm. Aim The present study determined whether PA restrictions imposed in early lactation impair energy balance and metabolic health of the cow. Methods One hundred and five cows were assigned to one of seven grazing treatments from 14 March to 4 July 2016 (16 weeks). The control-treatment cows were offered a PA to achieve a post-grazing sward height of 3.5 cm. The cows on the remaining treatments were offered a PA representing 60% of that offered to the control cows for a duration of 2 or 6 weeks from 14 March (mid-March; MMx2 and MMx6), 28 March (end-March; EMx2 and EMx6) or 11 April (mid-April; MAx2 and MAx6). Measurements were collected over the final 2-week period of the restriction for each individual restricted treatment and the control treatment. Key results Restricting PA in early lactation (34–88 days in milk) resulted in a mean reduction in dry-matter intake (DMI) of 25%; however, DMI as a proportion of the control treatment declined for EMx6 (75% of control DMI achieved) and MAx6 (65%) compared with the MMx6 (78%), which may be attributable to changes in the sward, as the plant changes from the vegetative to reproductive phase during this period. The reduction in milk production, relative to the control treatment, was similar among all restricted treatments (18%), resulting in a 1.1-kg reduction in milk output per 1-kg reduction in DMI. However, there was no effect of PA restriction or duration on body condition score, energy balance or blood metabolites, suggesting that the animals used in the current study made sufficient physiological adaptions to partition energy for the maintenance of body reserves. Conclusion In conclusion, short-term restrictions of PA up to 25% of DMI, for up to 6 weeks, can be used as a management strategy to cope with feed deficits in early lactation without impairing normal metabolic function of the early lactation dairy cow. Implications The results of the present study identified the ability of the early lactation dairy cow at grass to adapt to short-term deficits in pasture availability, without affecting the metabolic functioning of the animals

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The influence of the source of dietary fat on dairy cow performance

Proceedings of the British Society of Animal Production (1972) ◽

10.1017/s0308229600017463 ◽

1988 ◽

Vol 1988 ◽

pp. 108-108

Author(s):

M.M. Abubakar ◽

P. Rowlinson ◽

D.S. Parker ◽

D.G. Armstrong

Keyword(s):

Energy Density ◽

Dietary Supplement ◽

Dairy Cow ◽

Dietary Fat ◽

High Energy ◽

High Energy Density ◽

Energy Deficit ◽

Dietary Energy ◽

Early Lactation ◽

Cow Performance

It is well established that the dairy cow experiences a period of dietary energy deficit in early lactation. With its high energy density, fat has tremendous potential as a dietary supplement at this time providing it is included in a form and at a level which does not interfere with rumen function. The paper presents results from a trial investigating dairy cow performance when fed concentrates containing either a liquid (LF) or a dried protected fat (DF).

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