Start now to ensure a successful calving season
Having a successful calving season can make or break an operation. By the time calving starts, a producer already has a significant investment in their cow herd with winter feeding and management, so maximizing the number of live, vigorous calves is paramount. This all takes planning and anticipating scenarios that might crop up when calving and managing young calves.
A successful calving season starts with the health and nutrition of the cow herd. One of the biggest mistakes a producer can make is trying to control birth weight through cow nutrition during the last third of gestation. Research has demonstrated that in order to lower birth weight, cows need to be body condition score (BCS) 4- or below.
If cows are managed to this low body condition, calves will be weak with lower metabolism, passive immunity will be compromised, and the dam’s rebreeding will be delayed.
Thus, it is important to maintain cows at a solid BCS 5. Research has also demonstrated that even if cows are in proper BCS, if the dams are under nutritional stress, the metabolism of their calves will be decreased, making proper nutrition during the final third of gestation vitally important.
Some producers worry that if nutrition is too high in a cow’s ration, they will have significantly larger than normal calves and increased calving difficulty. Research has not borne this out. When a dam is being fed above nutritional requirements, she will increase BCS. However, fetal weight will not be significantly increased. The only time calving difficulty can become a problem via dams’ nutrition is if cows are managed to a very high BCS causing significant pelvic fat to be accumulated, decreasing the size of the birth canal.
Research has demonstrated that weather patterns during the last third of gestation will impact birth weight. During milder than normal winters, birth weights can be expected to be lighter than normal. Conversely, with unusually cold weather during the last third of gestation, birth weights will be increased, so increased calving difficulty can be anticipated. These increased birth weights are thought to be the result of increased core blood flow during extreme cold.
Before calving season actually starts, all preparations for calving should be completed. Frozen colostrum from a source like a local dairy should be stored along with a stomach tube to deliver it and all obstetric tools such as chains and calf puller cleaned, in good working order, and readily available. A relationship should already have been made with a veterinarian in the case of an extremely hard calving such as the rare case of the need for a cesarean section.
When winter calving, an area to warm calves should be readily available, and facilities to get cows and newborn calves into a clean shelter, if necessary, should have been prepared. During very low temperatures, especially with wind chill, the ability to get a cow in can mean the difference between a live and dead newborn calf.
Cows, and especially heifers, should be checked regularly and problems should be addressed in a timely manner. Depending on how intensive or extensive an operation is managed, the extra labor needed and/or longer hours should be planned into the calendar. It is important to remember that all of a calf’s early immunity comes from the absorption of antibodies from a dam’s colostrum, and the quality of colostrum is in direct proportion to the dam’s immunity. This makes maintaining an excellent cow herd health and vaccination program extremely important to have healthy calves.
Timing of colostrum intake is also extremely important to successful passive immunity. Calving is triggered by a cortisol surge by the fetus. This surge in cortisol by the fetus triggers final maturation of a calf’s lungs and gut, and also causes a maternal hormonal cascade in the dam that results in parturition. This means a calf’s ability to absorb antibodies through the gut starts to decline immediately after being born, shutting down completely approximately 24 hours after birth. The quicker a calf gets up and nurses high quality colostrum, the stronger its immunity will be.
A calf’s ability to absorb macromolecules such as antibodies immediately after birth also means that this is a time that it can easily be infected with possible disease agents. Dirty cows with dirty teats and udders are a scenario for sick calves. This can easily be handled by frequently moving feeding areas on frozen ground, or where mud is a major problem, having frequently cleaned high use pads.
A program to deal with scours should be well thought out and in place prior to calving. This means having all medicines and electrolytes on hand. If scours are an annual problem, vaccinating the cow herd with a scour vaccine should be considered.
Energy reserves in newborn calves are very low, so their ability to handle significant stress is minimal.
Their ability to get out of the wind during cold snaps is critical and having an area that they can get to bedding is very helpful. During mud season, calves should be able to get to dry, clean ground. Responding to weather crises on the fly is a recipe for a disaster. Extreme weather and environmental conditions expected on a farm or ranch should be planned for with scenarios for keeping calves healthy and alive during these situations.
A successful calving season starts now. Once calving begins, it is too late to plan and be proactive, and instead a manager ends up reacting too late for success. The ration of the cow herd should be optimized this time of year to maintain BCS, and a plan to supply high quality colostrum in place via an excellent cow herd health program and balanced last third of gestation nutrition. All preparations for calving difficulty should be completed and a plan to keep the calves in as optimum environment as possible should be in place. Planning now will result in more calves marketed in the fall and quicker rebreeding. All this adds up to improved profitability for an operation. — Dr. Bob Hough, WLJ Correspondent