Genetic Evaluations of Dairy Bulls for Daughter Energy Balance Profiles Using Linear Type Scores and Body Condition Score Analyzed Using Random Regression

A significant factor in improving the performance of dairy cows is their physiological ability to correct a negative energy balance (NEB). This study, using Simmental (SIM) and Holstein-Friesian (HF) cows, aimed to assess changes in NEB (non-esterified fatty acid; body condition score; and C16:0, C18:0, and C18:1) and its effect on the metabolic efficiency of the liver (β-hydroxybutyrate and urea). The effects of NEB on daily yield, production at peak lactation and its duration, and changes in selected milk components were assessed during complete lactation. Up to peak lactation, the loss of the body condition score was similar in both breeds. Subsequently, SIM cows more efficiently restored their BCS. HF cows reached peak lactation faster and with a higher milk yield, but they were less able to correct NEB. During lactation, their non-esterified fatty acid, β-hydroxybutyrate, C16:0, C18:0, C18:1, and urea levels were persistently higher, which may indicate less efficient liver function during NEB. The dynamics of NEB were linked to levels of leptin, which has anorectic effects. Its content was usually higher in HF cows and during intensive lactogenesis. An effective response to NEB may be exploited to improve the production and nutritional properties of milk. In the long term, it may extend dairy cows’ productive life and increase lifetime yield.

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Prediction of energy status in first lactation dairy heifers

Animal Science ◽

10.1017/s0003356100027823 ◽

1985 ◽

Vol 41 (2) ◽

pp. 167-175 ◽

Cited By ~ 4

Author(s):

M. J. Ducker ◽

Rosemary A. Haggett ◽

W. J. Fisher ◽

S. V. Morant

Keyword(s):

Energy Balance ◽

Confidence Interval ◽

Body Condition ◽

Weight Change ◽

Body Condition Score ◽

Live Weight ◽

Blood Metabolites ◽

Energy Status ◽

Dairy Heifers ◽

Condition Score

ABSTRACTData from a large controlled experiment to investigate the effect of level of nutrition on reproductive performance were used to assess the value of production and blood measures as indicators of energy status in lactating dairy heifers. Live-weight change showed the strongest and most consistent relationship to mean energy balance (the difference between metabolizable energy intake and that used for milk production and maintenance) (P < 0·01 to P < 0·001). Body-condition score at a particular time was more closely related to mean energy balance in the preceding 4-week period (P < 0·05) than current energy balance. There was also a lag in the relationship between energy balance and live-weight change and mean body-condition score. Ultrasonic back fat measurements were significantly correlated with both loin and tailhead body-condition score (P < 0·001) but were more strongly related to mean energy balance in the preceding period (P < 0·05 to P < 0·001) than the body-condition scores.Blood samples were taken from all heifers 2 weeks before calving and 1, 5, 9, 13 and 18 weeks after calving and were analysed for 13 constituents. Concentrations of blood metabolites did not show consistently strong correlations with mean energy balance. The only blood metabolite to be measurably affected by the nutritional treatments applied in lactation was β-hydroxybutyrate.At best, combinations of production measures and blood metabolites were only able to predict the mean daily energy balance with a 95% confidence interval of ±20 MJ for an individual animal although this confidence interval was reduced to ±3 MJ for 100 animals.

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