Due to drought conditions that have impacted this area since last fall, many livestock producers have limited forage supplies available for this coming winter and in some cases quality of the forage may cause additional challenges.
If you haven’t already done so, now would be a good time to inventory feeds, estimate winter feed needs, get forages tested so you can compare hay quality to animal nutrient requirements, and plan supplement programs if needed. That was one of the key messages in the series of Western Beef Summit meetings held across the area 2 weeks ago by the NDSU Extension Service.
While ruminants like cattle can utilize some lower-quality forages in their diet, trying to overwinter cattle on low-quality forages that don’t meet their nutritional needs can lead to problems. In general, dry-matter intake is typically reduced with low-quality forages and the potential for nutrient deficiencies is increased.
Issues with feeding low-quality forages to overwintering cattle, which in this area are generally pregnant females, can include impaction, weight and body condition losses, lowered immune function, calving difficulty, calf health issues, reduced milk production, and decreased conception rates.
Characteristics of low-quality forages include high fiber content, low crude protein (CP) and energy (total digestible nutrients or TDN) content, and reduced fiber digestibility.
In cattle, nutrient intake must be adequate to support microbial fermentation in the rumen. Adequate dietary protein and energy are critical for microbial growth and production, which supplies the majority of energy used by the cow. Forages are generally considered low-quality if they have less than 7-8% crude protein as microbial fermentation in the rumen is reduced when crude protein levels are less than those values. This results in lowered digestibility and passage rates, both of which impact intake.
Feeding supplemental protein with these types of forages will help considerably in improving forage intake and nutrient utilization. Commonly used supplements include high-quality grass or legume hay, oilseed meals, or byproduct feeds such as corn gluten feed and distillers grains. Self-fed supplements such as protein tubs and blocks may also be used, but producers need to ensure that these products will contribute adequate additional protein to the diet.
While protein is often the focus, forages also may be deficient in energy. If TDN content is less than 50%, it would be inadequate in energy for most classes of livestock.
Energy supplement options include cereal grains, byproduct feeds high in digestible fiber (soybean hulls, wheat midds or beet pulp) or high-quality forage such as alfalfa. Forage intake and digestion can be reduced when feeding high levels of starch-containing grain due to a shift in the rumen microbial population that favors starch-digesting microbes as opposed to fiber-digesting microbes. However, this can still be beneficial if the forage supply is limited by allowing producers to feed higher amounts of grain and reducing the amount of forage in the diet.
In addition to potential protein and energy deficiencies, drought-stress forages may be deficient in minerals and vitamins. These components of feeds are often overlooked; however, they are critical for growth, immune function and reproduction.
The best way to utilize any forage is through proper sampling and laboratory analysis so that the correct supplement can be used if needed.
The best sources for more information or advice would include your local agent with the NDSU Extension Service or feed representative. For more information on feed sampling and analysis, download the NDSU Extension publication “Sampling Feed for Analysis,” which is available at https://www.ag.ndsu.edu/publications/livestock/sampling-feed-for-analysis