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What’s new in colostrum research?

Jim Quigley Published on 30 August 2011

The importance of colostrum feeding is well understood by dairy producers and calf raisers. New research is further refining our understanding of the value of colostrum feeding.

Developments in technology are providing new and better tools to manage and implement a colostrum-feeding program. Here is a sampling of some of the new research to help better manage this critical part of the calf’s life.

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Feeding methods and rates
An age-old debate revolves around whether calves should be fed by nipple bottle or esophageal feeder. Notwithstanding the additional expertise required to properly use an esophageal feeder and welfare concerns, the esophageal feeder is increasingly popular as a means to deliver large amounts (up to four quarts) of colostrum.

But what of IgG absorption when calves are fed by esophageal feeder? Early research suggested that IgG absorption may be reduced (approximately 10 percent) when calves are tubed, as colostrum enters the rumen and it may take some time for it to pass through the abomasum and into the intestine.

Colostrum fed by nipple bottle will bypass the rumen and directly enter the abomasum, thereby speeding the flow of colostrum into the intestine.

A recent study fed calves either 1.5 or 3 L of colostrum replacer providing 100 or 200 grams of IgG, respectively. Calves were fed either by nipple bottle or esophageal feeder.

Serum IgG concentrations were about 20 percent lower (P < 0.05) when calves were fed by esophageal feeder. On the other hand, when a larger volume (3 L) was fed, there was no difference between treatments.

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The lack of difference at 3 L may be because a greater proportion of the 1.5 L would stay in the rumen when fed by esophageal feeder, whereas a greater volume of a 3 L feeding would overflow the rumen and move more quickly into the abomasum and small intestine for more rapid IgG absorption.

What effect does stimulation of the calf by “artificial mothering” have on the calf’s ability to absorb IgG? A recent study published in the Journal of Dairy Science studied vigorous physical stimulation (drying the calf with soft towels for about 15 minutes and speaking to the calf) or no stimulation on IgG absorption.

Calves were single- birth heifer calves with a calving ease score of 1 to 3 on a five-point scale (1 = no assistance; 2 = easy pull; 3 = moderate pull). Calves were fed a commercial colostrum replacer to eliminate effects of colostrum quality on IgG absorption.

There was no effect of stimulation on absorption of IgG. Of course, stimulating calves by drying them with clean towels can have many positive effects – to promote breathing, dry the calf to retain warmth, remove placental fluid and meconium and stimulate the calf to stand and nurse.

In the latter study, calves were fed by esophageal feeder, so stimulatory effects on the calf’s ability to consume colostrum were not measured.

Measuring colostrum IgG
Measuring colostrum accurately and quickly has been a challenge for many years. The colostrometer is widely used but is less-than-optimal due to its sensitivity to temperature, season and other factors.

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Recently, Bielmann et. al. used a BRIX refractometer to estimate the IgG content of colostrum from 288 colostrum samples from three farms. The refractometer was compared to IgG concentration of fresh or frozen colostrum.

The prediction of IgG using the BRIX refractometer was adequate – overall, the refractometer accounted for about 50 percent of the variation in IgG concentration.

A BRIX refractometer estimates total sugar content (or BRIX) in liquids. A BRIX refractometer is used in several industries including wine making, in which it measures the amount of sugar content of grape juice used to make wine.

When a liquid contains other dissolved solids, BRIX estimates total solids content. BRIX estimates of poor-quality, fair-quality and good-quality colostrum corresponded to <19 percent, 20 to 21.9 percent and 22 percent and over, respectively. BRIX refractometers are inexpensive, simple to use and are less sensitive to variations in temperature compared to a colostrometer.

Pasteurization
Pasteurizing colostrum is tricky, but when done properly it can markedly reduce the number of bacteria in colostrum, which reduces the risk of transmitting diseases to the newborn calf.

Pasteurizing colostrum must be done carefully. A recent trial suggests that when pasteurization temperature reaches 60°C (140°F), loss of IgG (particularly IgG1) increases. Even a few degrees above 60°C can dramatically reduce recovery of IgG.

Producers should monitor colostrum pasteurization temperatures very closely to ensure their equipment is working properly and have a well-designed maintenance plan for their pasteurizer.

Pasteurization can not only reduce bacteria in colostrum, but some new data suggests it may even boost absorption of IgG. Research from Penn State reported calves absorbed more IgG from pasteurized colostrum than from colostrum not pasteurized. Researchers are not sure why IgG absorption is improved, but it may be due to fewer bacteria interfering with IgG absorption.

Colostrum supplements and replacers
There are situations on every dairy farm when colostrum is unavailable, low quality (low IgG concentration), contaminated with pathogens or cannot be fed to calves in a reasonable amount of time after birth. These are situations when colostrum supplements and replacers can be used to augment and improve a dairy’s colostrum program.

Over the past few years, more types of products have come to the market and the calf raiser has more choices than ever.

Colostrum supplements may be defined as those products that contain less than 100 grams of IgG in a dose. These products are intended to be fed in addition to maternal colostrum.

Some researchers have suggested it’s best to feed a supplement as an additional feeding rather than mixing with colostrum. They argue that mixing colostrum and a supplement can increase the osmolality of the mixture so that the calf will have difficulty absorbing the IgG and nutrients.

Colostrum replacers are products containing 100 grams of IgG or more and are intended to be fed instead of colostrum. Replacers contain nutrients to typically provide complete nutrition for the calf (protein, fat, vitamins, minerals) in addition to the supply of immunoglobulins.

Recent research with replacers have asked the questions “Is there a benefit to using a replacer to reduce the risk of transmission of important diseases?” and “Do calves fed colostrum replacers perform as well as calves fed whole colostrum?”

These two questions were answered in a pair of papers by Dr. Patrick Pithua of the University of Minnesota. In the first paper, Pithua and coworkers evaluated the risk of transmission of Mycobacterium avium subsp. paratuberculosis (MAP), the organism that causes Johne’s disease.

In this study, calves born on 12 dairies in Wisconsin and Minnesota were fed maternal colostrum (n = 261) according to the normal management on the farm or were fed a commercial plasma-derived colostrum replacer (n = 236) according to label directions.

After the initial 24 hours, calves were housed, managed, fed and raised similarly. Calves were bred and entered the milking string after calving. Each cow was tested for MAP at 30, 42 and 54 months old. Testing was both by ELISA for serum antibodies and fecal sampling.

Calves fed the colostrum replacer were significantly (P < 0.06) less likely to become infected with MAP compared to calves fed maternal colostrum. The reduction of risk of infection with Johne’s was 44 percent – i.e., calves fed the replacer were 44 percent less likely to get Johne’s disease than calves fed colostrum.

This is no real surprise, as we’ve long suspected that colostrum was a potent vector for transmission for Johne’s.

In a follow-up study, the researchers reported on reproduction and lactation in the calves that reached maturity. Calves fed maternal colostrum (n = 261) and calves fed replacer (n = 236) had similar rates of death loss and culling prior to calving so that 198 (76 percent) and 165 (70 percent) of the calves freshened at an average of 24 months.

There was no effect of colostrum treatment on reproduction, longevity or total milk production during the first two lactations. Calves fed MC and CR produced a total of 22,681 kg (49,988 lbs) and 22,944 kg (50,566 lbs) of milk during their first two lactations.

This is particularly interesting because at 24 hours old, calves fed the replacer had lower serum IgG concentrations compared to calves fed colostrum. Other research concluded that increased levels of serum IgG at 24 hours old improved health, growth and subsequent milk production in cattle.

We’ve long assumed that more is better. However, research suggests factors other than serum IgG in calves may be important to subsequent production. Differences between maternal colostrum and plasma-derived colostrum replacers may be important also.

Summary
More and better knowledge can help producers make better management decisions about the critical colostrum-feeding period. It’s up to producers to incorporate strategies that work for them.

Considering the importance of the colostrum-feeding period to future health and productivity, every producer should consider these new research findings and tools with great interest.  PD

References omitted due to space but are available upon request. Click here to email an editor.

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Jim Quigley

Vice President and Director of Calf Operations
APC Inc.

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