Understanding the Importance and Purpose of Colostrum Feeding in New Born Calves
Ritu Panghal1*, Sarshti2, Swati Dahiya1
1Department of Veterinary Microbiology, 2Department of Animal biotechnology
Lala Lajpat Rai University of Veterinary and Animal Sciences, LUVAS, Hisar-125001
*ritupanghal0@gmail.com
Colostrum is the first milk secreted by dams after the birth of their calves for the next few days (5 days), before the true milk appears. It is the creamy-yellowish, thick and sticky milky fluid that differs in composition from the normal milk. It has more than twice the level of total solids, five times more concentration of proteins and vitamins A, D and E than the whole milk. It is a rich source of vitamins, minerals, energy, immunoglobulins (Igs) and growth factor. The major immunoglobulins in colostrum are: IgG (85 to 95%), IgM (7%), and IgA (5%). It is important for boosting the physiological performance, growth, development and immunological defense of the new born calves.
During gestation, the syndesmochorial placenta (three maternal and three foetal layers) of the dam act as a barrier and separates the maternal & fatal blood supplies that prevents the in-utero transfer of the protective immunoglobulins/ antibodies in calves. Also, the calf is born without a developed and functional immune system and is unable to produce antibodies on its own for some weeks. As a result, the calves are born immunologically naïve and is completely dependent on the passive transfer and absorption of Ig from colostrum called maternal Igs, after birth. This passive transfer of maternal Igs from dams to their new borns through colostrum provides a short-term immunity in them called ‘Passive immunity’.
The passive immunity plays a very important role in the new born calves as the maternal antibodies provides the initial protection to them against various common diseases until their own immature immune system becomes functional. It indirectly reduces the incidences of preweaning calf morbidity and mortality. Additionally, successful passive transfer also provides long-term benefits to calves like reduced mortality in the postweaning period, improved rate of weight gain and feed conversion ratio, better herd immunity, reduced age at first calving, improved first and second lactation milk production, and reduced tendency for culling during the first lactation.
Failure of passive immunity is observed in calves when they do not receive sufficient maternal Igs. This puts them at considerable risk for disease occurrence, mostly enteric infections and their chances for surviving the first few weeks of life are greatly reduced. Lower concentration of disease organisms are required to cause disease outbreak in the calves that do not ingest and absorb these maternal Igs into their bloodstream. Calves without adequate passive immunity are twice more likely to develop a disease and four times more likely to die, in comparison to calves with it.
The successful and adequate transfer of passive immunity through colostrum to new born calves is mainly dependent on the factors characterized as three Qs: Quality, Quantity and Quickly (timing) of colostrum. The quality of colostrum is its concentration of maternal Igs and is related to many factors. The quality is greater in first milking as compared to second or subsequent milkings after the calving, as the Ig transfer from dam’s blood to mammary gland starts four to five weeks prior to calving and usually stops by the time of calving. Beef cows generally have greater colostral Igs than dairy cows. Also, cows in their second or later lactations (older cows) produce colostrum with higher Igs as compared to heifers as older cows have been exposed to a large number of pathogens in their lifespan.
Quantity of colostrum is another important factor that allows the calf to consume sufficient Igs. Only certain amount of maternal Igs could be absorbed from a given quantity of colostrum as there are only limited number of receptors that can carry Igs from the intestine to the blood. Further, timing of first colostrum intake is also very crucial to ensure efficient absorption of the maternal Igs into the calf’s blood as the ability of the intestine to absorb these maternal Igs declines just as the calf ages. Intestinal absorption decreases over time as the cells of intestinal wall matures in the first 12 h, eventually resulting in the complete gut closure and shutting down of their absorption mechanism after 24 h. Moreover, after 24 h the abomasum also starts secreting acids that degrade the Igs. Hence, the antibody transfer is decreased by 5 % for every half hour delay in colostrum feeding after birth.
Considering all the factors, the new born calves should ingest a minimum of 100 to 200 g of Igs within their first three to six hours of life. They should consume at least 2 L of good quality colostrum within first few hours of life and additional 2 L over the next 6-12 h. If the newborn is unable to suckle the milk naturally within 2-3 hrs, they should be feed with a bottle or an esophageal tube because longer the calves are without maternal Igs, higher is the opportunity for the pathogens to cause the disease.
The passive immunity is also known to interfere with the immunity development after vaccination by different mechanisms. The calves therefore, should only be vaccinated once the concentration of the maternal Igs decreases to a level that is non protecting and is no longer critical to development of active immunity. Hence, determination of correct age of primary vaccination in them is very important and crucial when the interference with maternal Igs will be minimum.
Hence, considering the importance of colostrum feeding in new born calves, the farmers should follow a proper colostrum feeding management for the successful calf rearing. This helps in promoting better growth and development in calves. It also increase the overall health of the calves and reduces the mortality and morbidity by protecting against various harmful pathogens.
https://www.pashudhanpraharee.com/colostrum-feeding-a-critical-phase-of-newborn-calf/
