Colostrum management practices that improve the transfer of passive immunity in neonatal dairy calves: A scoping review

Abstract

The objective of this scoping review was to describe the literature on the characteristics and management practices of colostrum feeding and their associations with the level of transfer of passive immunity (TPI) in dairy calves. Observational and experimental studies were searched in 5 electronic databases and 3 conference proceedings. Two reviewers independently screened primary studies, either analytic observational or experimental studies written in English. Studies on dairy or dual-purpose calves with passive immunity analyzed by blood sampling between 1 to 9 days of age were included. All studies had to compare at least one colostrum intervention or risk factor and their association with passive immunity. Of the 3,675 initially identified studies, 256 were included in this synthesis. One hundred and ninety-five were controlled trials, 57 were cohort studies, and 4 were cross-sectional studies. The effect of colostral quantity at first feeding was investigated in 30 controlled studies including studies that were comparable to each other. The effect of colostral quality was explored in 24 controlled studies with inconsistent criteria used to define the quality. The effect of the timing of first feeding of colostrum was investigated in 21 controlled studies, where the timing of feeding ranged widely from immediately after birth to 60 h of age. Only 4 controlled studies evaluated the relationship between bacterial load in the colostrum and TPI in dairy calves. Of the 256 total studies, 222 assessed blood IgG concentration while 107 measured blood total protein concentration. We identified a gap in knowledge on the association between passive immunity in dairy calves and the bacterial load in colostrum, or the timing of harvesting colostrum from the dam. A possible quantitative synthesis could be conducted among the studies that evaluated colostral quantity at the first feeding in relation to TPI in dairy calves.

Investigation of brix refractometry for estimating bovine colostrum immunoglobulin G concentration

“…Newborn calves are born agammaglobulinemic and are dependent on the successful transfer of passive immunity (TPI) for optimal health and wellbeing ( 1 , 2 ). Current best practices recommend that calves be fed 150–200 g of bovine colostral immunoglobulin G (IgG) within 2 h of birth, followed by an additional feeding of 75–100 g of IgG, 6–12 h after the first feeding ( 3 ).…”

“…Dairy operations testing first-milking colostrum with a Brix refractometer often use a single threshold of ≥22% to ensure that the concentration of IgG is at least 50 g/L ( 3 , 5 , 6 ). The 50 g/L threshold has become the gold standard for first-milking colostrum ( 2 – 4 ). Feeding 4 L of first-milking colostrum within 2 h of birth, followed by an additional 2 L fed 6–12 h later, is a common practice in the industry.…”