A cow herd’s nutrient requirements are greatest from immediately after calving through peak milk production.
“Inadequate nutrition during this time may have immediate impacts in terms of lower calf birth weights, weak calves and/or increased death loss, and decreased milk production,” says Janna Kincheloe, the North Dakota State University Extension Service’s area livestock systems specialist at the Hettinger Research Extension Center.
“However, the consequences of low body condition at calving also can extend out to the breeding season,” she adds. “Research indicates cows with a body condition score of less than 5 at calving are more likely to have difficulty resuming estrous cycles, which can increase the number of days to conception and reduce overall conception rates.”
Although the majority of producers are well aware of the importance of late gestation nutrition programs, cold temperatures and wind chills across North Dakota the past several months have added stress and increased nutrient requirements beyond what might have been expected. Feeding lactating cows to meet increased nutrient requirements and maintain or improve body condition is challenging and expensive this time of year if cows already are thin.
Even if additional nutrients are provided, increased requirements for milk production make increasing body condition extremely difficult, particularly in old cows and young cows that still are growing, according to NDSU Extension beef cattle specialist Carl Dahlen.
“There is no shortcut to reproductive success that doesn’t involve good management,” he says. “Now is a good time to take a critical look at the situation and determine what steps need to be taken to help lessen potential negative impacts of cows calving in less than ideal body condition.”
The nutrient density of rations for cows in late gestation or early lactation should be at least 60 percent total digestible nutrients and 10 percent crude protein. Producers should test the feed to determine nutrient deficiencies and to choose a suitable supplement if necessary.
John Dhuyvetter, area Extension livestock systems specialist at the North Central Research Extension Center near Minot, suggests feeding heifers and thin cows separately from mature cows if facilities are available to help minimize competition for feed.
In addition to providing proper amounts of energy and protein, producers need to ensure they have an adequate mineral supplementation program in place prior to breeding. Minerals such as calcium, phosphorus and manganese are important for reproduction, health and growth, which are all areas that drive profit potential in beef operations.
Producers also could consider feeding an ionophore, which is a class of feed additives that alters bacterial populations in the rumen and improves feed efficiency. “Ionophores have been shown to have positive impacts on reproductive processes and carry the added benefit of helping control and/or prevent coccidiosis when fed at appropriate levels,” Dhuyvetter says. “Coccidiosis can be transmitted to calves through infected fecal material or contaminated udders, so by addressing this issue in the cows, we can potentially reduce exposure of newborn calves to this costly disease.”
Dahlen says that components of estrous synchronization protocols also may help improve fertility in a portion of noncycling cows. Exogenous progestin (progesterone) sources such as melengestrol acetate (MGA) or controlled internal drug release devices (CIDRs) that are used in synchronization protocols can initiate estrus in some noncycling cows.
“It is important to recognize that these techniques are not a substitute for adequate nutrition, and optimal pregnancy rates will be achieved with a body condition score of 5 or better and an increasing plane of nutrition,” he says. “At this time, MGA is only labeled for use in heifers; however, CIDRs may be used in heifers and mature cows. Producers need to determine if these programs are cost-effective and choose appropriate protocols for their individual situation.”
Kincheloe also has this advice: “Because nutritional status and body condition score at calving are critical indicators of the ability of cows to achieve reproductive success, producers may want to check with neighbors or Extension personnel who have experience with condition scoring and ask for assistance in evaluating their herd in an unbiased manner.”
Additional resources on body condition scoring, feed testing and ration development are available through your county office of the NDSU Extension Service.
Source: North Dakota State University