Why measure colostrum quality?
Colostrum is rich in both nutrients and bioactive compounds, such as hormones and growth factors. Ensuring that the proper amount of high quality colostrum is fed to calves just after birth is essential for calves to reap the benefits of both IgG's (immunoglobulins) and these other vital colostral factors that positively affect their health and growth.
Absorption of IgG's
Absorption of igG's by newborn calves is at its best within the first two hours of life, with the ability to absorb decreasing significantly by the time 24 hours have elapsed. Therefore, the immune status of pre-weaned calves directly depends on the quantity and quality of colostrum ingested during the first few hours of life. It is essential that they attain at least 10 mg /mL of serum IgG from colostrum for transfer of passive immunity to be successful.
To make sure that calves ingest and absorb the right quality of colostrum in the right timeframe to be optimally effective, on-farm colostrum quality management and testing is the answer. Using a Brix refractometer for testing colostrum quality is a very good way.
What does a Brix refractometer do and how does it do it?
A Brix refractometer measures the dry matter in colostrum by measuring the refraction of light that shines through the colostrum. Generally speaking, the higher the amount of dry matter, the higher the reading using a Brix refractometer, and the better the quality of the colostrum you're testing. To use a Brix refractometer, a few drops of colostrum are placed on the instrument's prism and the sample cover is lowered. The refractometer is then held up towards the light and the Brix value is read as the line that appears between the dark and light areas on the scale.
4 Good reasons to measure colostrum quality with Brix refractometers:
1. Ease and convenience of use
- While taking samples of colostrum and sending them off to the lab for precise quantification of IgG level would certainly result in an accurate assessment (after waiting quite some time for the results), using a Brix refractometer on-farm to test IgG level is a quick, convenient, and accurate method.
- While glass colostrometers have also been used on-farm for convenience, Brix refractometers are cheaper and are much less fragile.
- Smaller volumes of colostrum are required when using a Brix refractometer (only a few drop needed!) and testing can be done without waiting for the colostrum to reach room temperature, as you should with a colostrometer.
- Brix reading results are known immediately.
2. Cut-points have been tested and validated
- A Brix result of 22% or higher indicates that colostrum is of good quality.
- A result of 18% or lower means that the colostrum has failed quality control.
- If the Brix value is 26% or higher, then colostrum is of the highest quality.
3. Digital Brix refractometers
- Digital Brix refractometers provide additional ease of use.
- The high dry matter content of colostrum can cause a blurred band rather than a distinct line when reading Brix measurements optically, so it can be difficult to determine the exact Brix value with an optical refractometer.
4. A good start = positive effect on performance
- When proper quality colostrum and liquid nutrition are provided to calves, the many benefits include improved health, decreased morbidity and mortality and, most importantly, improved productivity.
- Pre-calving, productivity is measured through feed efficiency, growth and reproduction. Post calving, productivity is measured through increased milk production, increased component yield and an increase in survivability through the end of the 2nd lactation.
- Production increases (per lactation) reported in the literature range from 500 to 1,500 kg of milk when high quality colostrum is followed by a higher plane of liquid nutrition, as the LifeStart Program recommends.
Measuring colostrum quality on a regular basis using a Brix refractometer is a good start towards ensuring effective colostrum management on-farm. When followed by effective calf feeding and rearing protocols, calf health, vitality and performance will increase as well.