Scours Protection Starts In The Dry Period
This article was written by Chris Schneider, DVM, cattle technical services veterinarian, Merck Animal Health.
The dry period presents a key time frame to incorporate prevention points that not only guard cow health, but also the health of their offspring against the No. 1 cause of neonatal calf deaths. Scours accounts for half of all deaths of pre-weaned calves. Of those calves, 74% are treated with antibiotics. But, the cost of scours goes far beyond loss of life and cost of treatment – it can also have a negative effect on milk production in the first lactation.
Limiting the impact of scours starts in the dry-period and requires effective management of three areas: environment, cow, and colostrum.
As a baseline for cow and calf health management, focus on limiting potential environmental bacteria threats. Keep in mind, bacteria need a food source, such as manure, along with a moist, warm environment to thrive.
Make bedding management a primary area of focus. In the summer months, or in areas where heat stress is common, bacteria thrive. Regardless of the time of year, maintaining a clean, dry calving area minimizes a calf’s exposure to bacteria.
Providing adequate ventilation can also reduce the rate at which bacterial populations spread. Sufficient air exchange helps to remove heat from the environment that triggers growth of pathogens. Ventilation systems should work across all seasons.
A calf is completely dependent on the maternal antibodies derived from its mother’s high-quality colostrum until its own immune system is fully developed. When a cow is vaccinated with a scours vaccine, its calf receives those antibodies through colostrum ingestion. So, by vaccinating cows and first-calf heifers in late gestation, we can reduce the risk of neonatal calf scours in the period just after birth. With the right vaccine, costly losses can be prevented, and the next generation of the herd will have a healthy and productive start in life.
It’s important to note that only dam scours vaccines protect calves against all four major disease-causing pathogens and eliminate the need to adequately manage oral vaccination in individual calves.
Here are some considerations for choosing a scours vaccine:
• Broad-spectrum protection – Calf scours can be caused by a multitude of bacterial and viral pathogens, with coronavirus and rotavirus being the most frequently diagnosed causes of viral scours, so choose a vaccine that offers complete scours protection. In addition, look for the broadest spectrum clostridial protection, along with E. coli type K99 protection, to help prevent intestinal infections.
• Subunit technology – Look for a sophisticated subunit E. coli technology. Subunit vaccines include antigenic components of a pathogen that are capable of inducing a protective immune response. In the case of E. coli, this technology can provide a very strong and extremely targeted E. coli immune response. However, some subunit technologies can lead to adverse vaccine reactions. For complete peace of mind when vaccinating pregnant cattle, look for a scours vaccine with sub-unit technology that reduces the risk of an adverse response by limiting exposure to potentially dangerous endotoxins while providing maximum protection.
• Flexible dosing schedule – Use a scours vaccine with a patented water and oil adjuvant to stimulate long-lasting immunity, which also provides for flexible dosing. That way, depending on your dry period length, you can time vaccination in order to maximize immune properties within the colostrum, which is produced by the pregnant cow up to five weeks before she calves.
Vaccination of dry cows and heifers, coupled with high-quality colostrum ingestion, will help protect calves and give them the healthy start they need. It’s estimated that one-third of calf deaths in the first three weeks of life are due to inadequate colostrum intake, which makes excellent colostrum management in those first few hours post-birth critical.
Dairies can achieve high-quality colostrum through management practices, including providing a high-quality diet for dry cows, ensuring they are in good general health and minimizing stresses like overcrowding in late pregnancy. Additionally, proper heat stress management helps maximize colostrum quality and its absorption upon administration at birth of the calf. Following these guidelines enhances the immune properties of colostrum by vaccinating cows during the dry period.
Calves should be born in a clean, dry and well-observed environment. The cow can be allowed to lick the calf for 20 minutes to help dry it and stimulate breathing. Within 30 minutes of being born, the calf should be moved to a nursery and fed its first meal of colostrum, which should be tested to ensure high levels of antibodies and low levels of bacteria.
Large calves, such as Holsteins, need one gallon of colostrum that is warmed to 100 to 105 degrees Fahrenheit. Smaller Jersey calves need two to three quarts of warmed colostrum. The sooner the calf is fed colostrum, the more likely it will have optimal absorption of antibodies to protect against scours.