Calf milk pasteurization
In the ongoing quest for improved biosecurity and maximum dairy herd health, it stands to reason that pasteurizing calf milk would be a worthwhile and beneficial management practice. Yet in reality, conservative industry estimates indicate that far fewer than half of all dairies currently perform any type of heat treatment on waste milk fed to calves. Is calf milk pasteurization effective? Does it address current disease and biosecurity concerns on the average dairy? And if so, what role can dairy practitioners play in promoting its adoption?
Economics of feeding pasteurized colostrum and pasteurized waste milk to dairy calves.
OBJECTIVE
To estimate the marginal contribution of pasteurization of waste milk and colostrum to gross margin per calf at weaning and to estimate the minimum number of cattle on a dairy farm for pasteurization to be profitable.


DESIGN
Randomized, controlled, clinical trial.


ANIMALS
300 Holstein calves.


PROCEDURE
The performance of calves fed pasteurized colostrum and waste milk was compared with the performance of calves fed nonpasteurized colostrum and waste milk. Costs, revenues, and gross margins for the 2 groups were compared.


RESULTS
Calves fed pasteurized colostrum and waste milk were worth an extra $8.13 in gross margin/calf, compared with calves fed nonpasteurized colostrum and waste milk. The minimum number of cattle for which feeding pasteurized colostrum and waste milk was calculated to be economically feasible was 315 calves/d (1,260-cow dairy farm).


CLINICAL IMPLICATIONS
An economic benefit was associated with feeding pasteurized colostrum and waste milk. Additional benefits that may accrue include higher mean weight gain and lower mortality rate of calves as well as calves that have fewer days in which they are affected with diarrhea and pneumonia.
On the fractionation of β-lactoglobulin and α-lactalbumin
Abstract Existing methods for the preparation of α-lactalbumin and β-lactoglobulin are examined critically. It is proposed that the most satisfactory method for the preparation of the whey protein fraction from bovine milk is (NH 4 ) 2 SO 4 fractionation. A number of new gentle procedures for the fractionation of the whey proteins are compared with some existing methods. The distribution of total protein at various stages is determined by total Kjeldahl nitrogen and the kind of protein by starch-gel electrophoresis. The effect of variables, such as pH, salt concentration and temperature on the separation of α-lactalbumin and serum albumin from β-lactoglobulin is studied. Differences in the behavior ( e.g. solubility) of genetic variants of β-lactoglobulin are noted. The solubility of each of the major whey proteins, under similar conditions to those used in the fractionation, is compared with its solubility in the whey protein mixture. The understanding gained of factors important in the fractionation is used in recommending new procedures for α-lactalbumin and β-lactoglobulin isolation.