[Investigation of influence factors on quantity of first colostrum in Holstein Friesian cows and their relation to postpartum calcium concentration].
OBJECTIVE
The aim of this study was to investigate the factors that affect the quantity of the first colostrum in Holstein Friesian cows and the relationship to the blood serum calcium concentration postpartum. It should be verified whether: 1. the lactation number is the main influencing factor; 2. the quantity of the first colostrum is etiologic for developing parturient paresis.


METHODS
An observational study was conducted from April 2012 to March 2013 at a commercial dairy farm (2278 Holstein Friesian cows). The analysis comprised the following variables: blood serum concentrations of calcium, phosphorus, non-esterified fatty acids, and β-hydroxybutyrate; back-fat thickness; daily milk production; calving data; lactation number; male parent of the cow; length of gestation; age at first calving; duration of the dry period; fertility parameters of prelactation; diseases during the dry period and up to 3 days postpartum. A stepwise analysis of the data for correlations and influencing factors was conducted by means of variance, correlation, and multiple linear regression analyses.


RESULTS
The mean colostrum quantity was 5.6 kg with a standard deviation of 3.41 kg. A number of influencing factors affected the colostrum quantity. One quarter of the variability of the colostrum quantity could be explained by the influencing factors examined. A dominant effect of the lactation number was not confirmed. Instead, the effect of the lactation number was attenuated by the more potent factors milk production in the following lactation period, diseases after calving, duration of the dry period, the male parent of the cow (genetics), and the weight of the calf.


CONCLUSIONS
Selective breeding for high milk production and using bulls whose female offspring have high milk production can at the same time lead to breeding for high colostrum quantities. A dry period duration of 50 days is recommendable with respect to colostrum quantity. The two hypotheses could not be confirmed.
Dr. Maria Karl, Höhenweg 21 a, 15366 Hoppegarten, E-Mail: maria.klingbeil@web.de.
Maria
M
Karl
Rudolf
R
Staufenbiel
D000818:Animals; D001947:Breeding; D002118:Calcium / Q000097:blood*; D002417:Cattle / Q000502:physiology*; D003126:Colostrum / Q000502:physiology*; D005260:Female; D007774:Lactation / Q000502:physiology; D008297:Male; D008892:Milk / Q000737:chemistry; D049590:Postpartum Period
D002118:Calcium
Dairy cow; breeding value; calcium metabolism; etiology; hypocalcemia; lactation number; parturient paresis