Most read Calf & Heifer Raising articles
|What's new(er) in colostrum research?|
|Dairy basics - Calf and Heifer Raising|
|Written by Jim Quigley|
|Friday, 20 January 2012 10:31|
This article was #14 of the Top 25 most well-read articles on www.progressivedairy.com in 2012. Click here to jump to the article. It was published in the January 23, 2012 Extra. Click here for the full list of the Top 25.
The single-most overlooked aspect of colostrum management is the management. Every producer understands the importance of feeding high-quality, clean colostrum soon after birth. Many have tried testing colostrum for IgG (using a colostrometer or refractometer) and contamination (using total plate count), but most quit measuring after a while.
Few monitor and manage colostrum on an ongoing basis. I routinely see colostrometers tucked away on a shelf in the farm office or calf barn, unused and sometimes broken. Ditto for the newer Brix refractometers.
Research tells us that there’s huge variation in colostrum IgG from cows. Research also tells us that a lot of colostrum contains too many bacteria, which may sicken calves.
There are ways to correct both of these problems, so the old adages “I measured the colostrum for a while, but there’s nothing I can do even if it’s bad” or “I didn’t see any differences when I tested” just don’t work anymore. Producers need to set up consistent protocols that include measuring, monitoring, training and making decisions based on the data.
Editor's note: We asked author Jim Quigley to provide an update to his April 2011 article, "What's new in colostrum research." Click here to read that article. The article that follows is his updated article.
Every dairy farmer understands the importance of feeding enough high quality colostrum to newborn dairy calves. Researchers from all over the world continue to improve our understanding of the critical topic and are providing producers with new tools and information that will improve our ability to manage colostrum on the farm.
Long term effects of colostrum
Calves were fed first milking colostrum from the dam within about two hours of birth. Calves were then fed colostrum for the next three days, and fed according to the normal milking schedule of the farm.
Subsequent to colostrum feeding, calves were raised according to the normal management of the farm. Colostrum IgG was estimated by colostrometer; serum IgG after consuming colostrum (blood was taken at about 35 hours of age) was measured by radial immunodiffusion, health and growth of calves were monitored throughout the study.
Table 1 shows the “tale of the tape” for this farm. Colostrum quality overall was good – average IgG concentration was 79 g/L, which exceeds the standard of 50 g/L considered “good” quality.
Calves in the lowest serum IgG category (<5 g/L) consumed the least amount of colostrum (1.4 L) and had the lowest average serum IgG concentration (3.7 g/L). These calves were more likely to have scours or respiratory infections during the first 14 days of life, and were bred later than other calves.
Compared to the highest IgG category, calves with <5 g/L were bred an average of 30 days later. These data show clearly that the amount of immunity a calf receives during the first 24 hours of life can affect it throughout the rest of its life.
Measuring colostrum quality
The researchers found that the BRIX refractometer was reasonably accurate when results from all samples were tested. Their results were similar to those reported by Canadian researchers in 2010. However, when the BRIX results were much more closely related to actual IgG concentrations when fresh (not refrigerated or frozen) samples were evaluated. The conclusion of this research group is that samples should be tested for quality using the BRIX refractometer before refrigeration or freezing.
The researchers also evaluated the average IgG concentration from the colostrum samples and determined that IgG in colostrum ranged from <1 to 200 mg/ml, with a mean IgG concentration of 68.8 mg/ml (SD = 32.8). Thirty percent of colostrum was < 50 mg of IgG/ml. IgG concentration increased (P < 0.05) with parity (42.4, 68.6, 95.9 mg/ml in first, second, third and later lactations, respectively.
Researchers at Fresno State monitored colostrum from seven dairy farms in the Central Valley of California over a 12 month period. Dairies ranged in herd size from 800 to 4,000 adult cows. Colostrum samples (n = 546) were collected before first colostrum administration to newborn Holstein heifers. Three of the seven dairies added supplement to colostrum (n = 312).
On these dairies, 2 colostrum samples were obtained, one before adding supplement and one after supplementation. Bacteria counts ranged from 13,420 to 2,171,835 cfu/ml. A total of 41 (17.5%) of the unsupplemented colostrum samples were contaminated (>100,000 cfu/ml). Supplemented colostrum was contaminated in 179 (57.4%) of the cases. Thus, 220 (40.3%) of the total 546 calves were fed contaminated colostrum.
References omitted but are available upon request to