Thin Cows
Nutrition plays a direct role in the production of colostrum. Undernourished cows may not have received enough energy, protein, minerals and vitamins during the gestation period and, therefore, the ability to produce quality colostrum is reduced. As body condition decreases so does the amount and concentration of immunoglobulins in colostrum.
First-calf heifers
Colostrum quality and quantity is usually lower in first-calf heifers. There is also a higher likelihood that first-calf heifers may lack good "mothering instinct" and will not allow the calf to immediately suckle, or, may reject the calf altogether.
Colostrum replacement products
There are a number of colostrum replacement products commercially available today. Care should be taken in selection of the product to ensure you are getting a replacement and not a supplement. Although similar, replacements have higher concentrations of immunoglobulins(Ig), specifically IgG, than supplements and are intended to serve as the sole source when fresh colostrum is not available.
There are other nutrients such as sugars, fats, vitamins and minerals in replacements, but there can be variability in the quality and digestibility of products based on the source of these nutrients and the method of processing. Be sure to carefully read and follow the manufacturer's instructions since products may vary in how they are mixed and the number of recommended feedings.
You should consult your veterinarian to help you make a more informed purchasing decision for the colostrum replacement product that is suited best for your operation. This decision is an important one because you only get one chance to start a calf off right.
Source: University of Nebraska