Monday, August 26, 2013

Antibody Concentration Really Does Stay the Same
In the September issue of the Journal of Dairy Science researchers report the same results as I noted in my previous posting. This work used colostrum from 24 cows, second lactation and later.
They divided the colostrum into 4 parts depending on stage of milk out - that is, 0-25%, 25-50%, 50-75% and 75-100%. The average antibody levels for these fractions were:
0-25%    = 44.5grams per liter
25-50%  = 49.9
50-75%  = 49.8
75-100%= 47.2
Based on the number of cows the authors conclude there was not a statistically reliable difference among these values. 
(1) On the average roughly one-half of the colostrum collected was substandard in antibody concentration (adequate threshold being 50g/L).
(2)  Wide variation was present among cows in antibody concentration regardless of their lactation number.
(3) Wide variation was present among cows in total colostrum yield with 7/24 cows giving less than 4 liters (4.2 quarts), 13/24 cows giving between 4 and 8 liters (8.4 quarts), and 4/24 giving more than 8 liters.

(4) Fat concentration did vary by fraction with the lowest coming in the first 25% (3.8% fat) and the highest coming in the final fraction - 75-100% (5.7% fat)


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