Question

if a calf was given born to and was given colostrum measured at 30 g/L at 12 hours after birth what would be some possible implications?

Answer 1

Colostrum is the milk that is produced in the mother immediately after birth. It is rich in IgG antibodies. Calves that are fed colostrum within the first 24 hours after birth will be protected from various common diseases until its own immune system can take over the functions. Ig G1 accounts for nearly 80-90% of IgG in colostrum. Further, colostrum also has IgA and IgM antibodies along with maternal leukocytes.

IgG levels should be more than 25g/L when given to the calf. Otherwise there is higher risk of mortality due to failure of passive transfer. 30g/L is not very high level of IgG in colostrum. Advisable level should be atleast 50g/L in colostrum. Further, the colostrum should be administered within 1-2hr after birth and not later than 6hr. It is advisable to provide colostrum to the calves immediately after birth due to increased absorption and passive transfer of IgG to the calf blood. The intestine of the neonate can selectively absorb the IgG via its enterocytes. Pinocytosis is used for absorption of IgG, which then enter the lymphatics by exocytosis. From the lymphatics, the IgG enters the circulation via thoracic duct. The absorption of IgG however decreases with time. Maximum absorption occurs with 12hrs after birth and as time progresses towards 24hr, absorptive capacity decreases. Gut does not absorb IgG after 36hr, a phenomenon called gut closure. Further, volume of colostrum to be administered to a calf should be 10-12% of their body weight.

If the calf is administered 30g/L of colostrum after 12 post birth, there are greater chances of bacterial and viral infections that affect the calf in the first months of life. This increases the mortality rates in these calves. Diarrhea may also result, due to local effects on the intestine. There is a greater chance of developing bovine respiratory disease. Colostrum not only provides IgG, it also provides glucose and lipids to the newborn. Feeding of colostrum of higher quality, will increase insulin production, which then stimulates IGF1. IGF1 is required for development of the gut. Lipids in the colostrum will allow heat generation in the newborn. Calves fed lower quality colostrum may have difficulties when facing dystocia. Further, amino acids that is present in colostrum help in protein synthesis in the newborn. If 30g/L colostrum is provided, then there will be decreased protein synthesis in the calf that reduces their growth rate. The vitamin provided by colostrum will also be less, affecting the absorptive capacity of the gut for absorbing calcium and other substances.