Will Feeding Silage to Lactating Cows Give my Calves Scours?
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Many cow-calf producers in Nebraska have become accustomed to using distillers grains as a source of both protein and energy to help meet the nutritional needs of lactating cows from calving until green grass is available. Due to the ongoing distillers shortage, many producers are considering including corn silage in the ration to help alleviate some of the energy shortfall in their hay resources. However, concerns have been expressed that silage in the diet will result in diarrhea or scours in their calves.
While this is a critical time for the nursing calf, and producers should be ever vigilant for signs of scours, there are actually a variety of reasons a calf might have a very loose stool and not all of them are cause for concern.
Feeding a diet that is highly digestible and fermented, with a high rate of passage through the digestive system will result in manure that is much more wet and loose than manure from a diet of dry hay and supplemental distillers grains. In dairy cows, a high energy diet has been shown to increase milk production earlier in lactation, and a similar response is likely in beef cows. Increased milk production early in the calf’s life, will also likely result in a looser stool. Additionally, calves begin to nibble at grass and their mother’s feed within a few days of life, and by one month of age, are eating 1% of their body weight on a dry matter basis in feed other than milk. Therefore, they will begin to consume a diet that is responsible for a looser stool just like the cow does. However, dietary related scours do not cause illness and dehydration in the calf.
The health- and life-threatening causes of diarrhea in calves are commonly from a list of infectious pathogens that are shed at low levels by individuals in virtually any group of bovines. Most are viral or protozoal, and some are bacterial. These pathogens are picked up by calves, amplified, and shed at much higher levels into the environment, mainly in feces. Calves born later in the calving season are often born into environments that have much higher levels of these pathogens present than the earliest calves experienced, and as a result, the later-born calves are at higher risk of getting sick. One method that many producers have been successfully implementing in Nebraska for years to break this chain of transmission is called Sandhills Calving. This method involves keeping cow-calf pairs with only calves born in the same one to two week period together until the youngest calves are at least a month old. This prevents amplification of pathogens from continuing to accelerate and provides a fresh start for each one- to two-week cohort of calves.
When cow-calf pairs are in pens in the spring, the calves need a clean, dry place to lie down. Usually, this needs to be somewhere that the cows can’t get into. It needs to be out of the wind. Shelter can be beneficial if the ventilation is adequate. Producers demonstrate a lot of creativity in designing and building simple, cost-effective calf shelters. Sometimes it can be as simple as an electric fence stretched diagonally across the corners of the pen, raised high so calves can go freely underneath, but the cows are fenced out. This allows calves an “escape” where they can lay in some clean dry straw or corn stover.
The best way to judge whether a calf with a loose stool needs treatment is by its attitude and appetite. If it is bright, alert, active and interested in eating, it is likely doing alright. If the calf is listless, moving slowly, ears drooping, and does not appear to be interested in eating or nursing, treatment is likely needed. Fluid replacement is the cornerstone of treatment for scours, though antibiotics may also be necessary in certain situations. A calf that can stand may respond well to treatment with oral electrolytes, but a calf with diarrhea that won’t or can’t stand is very likely in dire need of intravenous fluid therapy. Your veterinarian can help you develop a plan for treating scours in calves if the need arises.
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