First milking colostrum is an important source of nutrients, non-specific immune factors and passively absorbed maternal antibodies (immunoglobulins or Ig), critical to promote growth and to protect the newborn calf against infectious disease in the first weeks and months of life, says Sandra Godden, DVM, DVSc, University of Minnesota.
Calves are defined as having failure of passive transfer (FPT) if the calf serum IgG concentration is less than 10 mg/ml when sampled between 24–48 hours of age (NAHMS, 1996). "The 2007 NAHMS dairy study reported that approximately 21 percent of heifer calves suffer from FPT on U.S. dairy farms," explains Godden, speaking at the 2011 Annual Western Veterinary Conference. "Wells (1996) estimated that 31 percent of all neonatal calf deaths in the first 3 weeks of life were attributable to FPT." In addition to increased morbidity and mortality risk, FPT has also been associated with reduced gains and feed efficiency, delayed age at puberty, delayed age at first calving, and reduced first and second lactation milk production (DeNise, 1989; Faber, 2005). "Clearly there are huge health, welfare, performance and economic efficiencies to be captured for producers who can improve their colostrum management practices," Godden says.
Godden offers the five "Qs" of colostrum management which include:
- Quality of colostrum fed (Goal: IgG > 50 g/L)
- Quantity of colostrum fed (Goal: 10 percent of birth weight at first feeding)
- Quickness of the first colostrum feeding (Goal: within 1-2 hours of birth)
- SQueeky clean (bacterial contamination) (Goal:
- Quantifying (monitoring) passive transfer (Goal: ≥ 90 percent of calves with serum TP ≥ 5 g/dl)
Godden says bacterial contamination of colostrum is a relatively new management issue that is actively being researched. Experts have recommended that fresh colostrum fed to calves contain fewer than 100,000 cfu/ml total bacteria count and fewer than 10,000 cfu/ml fecal coliform count (McGuirk and Collins, 2004), she says.
She adds that unfortunately, observational studies have indicated that average levels of bacterial contamination are significantly higher than this cutpoint for much of the colostrum fed on commercial dairies (Poulson et al., 2002; Swan et al., 2007). Because microbial contamination of colostrum can contribute to calfhood disease (and may possibly interfere with passive absorption of colostral antibodies), producers should adopt management strategies to reduce bacterial counts in colostrum fed to calves. "All producers should pay attention to hygiene and sanitation so as to minimize bacterial contamination during the colostrum harvest, storage and feeding processes," Godden says. "Additional tools may include use of colostrum replacers or heat-treating colostrum."