Supplementing replacement heifers grazing low-quality forage
Cost difference depends on many factors.
By Jason M. Warner
Protein supplementation to beef cattle grazing low-quality forages is frequently discussed as a method to improve animal performance through increasing forage digestion and intake. In addition to the forage intake aspect, supplementation is necessary when basal forage crude protein levels are less than animal requirements which is often the case with replacement heifers being grown on dormant forage prior to the first breeding season.
While the use of ethanol by-products as protein sources for beef cattle grazing low-quality forages has become more widespread overtime, there is always variability in supply and price of different protein sources both locally and regionally due to many factors. Research evaluating protein sources for developing heifers post-weaning is valuable to aid producers in making informed supplementation decisions, particularly at this time of the year as we look forward toward heifer retention and feedstuff purchasing decisions this fall and winter.
To contribute information in this area, a trial was conducted in west-central Kansas by researchers in the Department of Animal Sciences and Industry at Kansas State University (McMullen et al., 2015; Performance of Beef Replacement Heifers Supplemented With Dried Distillers Grains With Solubles Versus a Mixture of Soybean Meal and Finely Ground Sorghum Grain (newprairiepress.org))[1] McMullen, C. J.; Jaeger, J. R..; Harmoney, K. R.; Waggoner, J. W.; and Olson, K. C. (2015) "Performance of Beef Replacement Heifers Supplemented With Dried Distillers Grains With Solubles Versus a Mixture of Soybean Meal and Finely Ground Sorghum Grain," Kansas Agricultural Experiment Station Research Reports: Vol. 1: Iss. 1.. The objective was to evaluate the effects of daily supplementation of dried distillers grains plus solubles (DDGS) compared to a mixture of soybean meal and fine ground grain sorghum on performance of replacement heifers grazing low-quality dormant native range prior to first breeding.
In this experiment, weaned crossbred (Angus x Hereford) heifers weighing approximately 580 pounds were maintained on native range pastures from mid-January to early-April. The primary grass species present in the pastures included sideoats grama, western wheatgrass, blue grama, Japanese brome and buffalo grass. Forage samples were obtained prior to trial initiation for nutrient analysis (Table 1), and heifers were assigned to pastures with pastures then assigned to one of two supplement treatments.
Treatments included daily supplementation of either DDGS or a mixture of soybean meal and ground grain sorghum. Dried distillers grains plus solubles were fed at just over 4.0 lb per hd per day (as-is basis), while heifers on the soybean meal and ground grain sorghum treatment were fed 3.5 lb per hd per day (as-is basis) to supply similar levels of crude protein daily.
Regardless of the supplement fed, the remainder of the total diet was comprised of grazed native range and free-choice consumption of a mineral and salt supplement. The nutrient composition of both supplements is presented in Table 1. The DDGS fed in the trial originated from a single source, while the soybean meal and fine ground grain sorghum was mixed at the research station to a blend of 73.6% and 26.4%, respectively on a dry matter basis.
As was intended by the researchers, there was no difference in body weight and body condition score between supplementation treatments in January at the initiation of the trial (Table 2). Upon trial conclusion in April, ending body weight and as a result average daily gain also did not differ between treatments. Likewise, body condition score at the end of the treatment period also was not impacted by supplementation.
In this trial, performance of heifers grazing low-quality dormant range was not influenced by the source of supplement when heifers were provided approximately 1.25 lb of supplemental crude protein daily. These data indicate protein sources may be exchanged in nutrition programs for developing heifers with little impact on growth performance provided total protein and energy levels supplied in the diet are similar.
At the levels fed in this experiment, if DDGS was $200 per ton (as-is basis) that would equate to approximately $0.40 per head per day in supplement cost. If soybean meal and grain sorghum were priced at $375 and $138 per ton (as-is basis), respectively, it would equate to approximately $0.55 per head per day.
The significance of the difference in cost between these two supplements in this scenario depends on many factors specific to each operation. The key takeaway point is to know and closely evaluate your supplement costs to aid in guiding the nutrition program and consider total protein and energy intake when exchanging supplement sources.
References[1] McMullen, C. J.; Jaeger, J. R..; Harmoney, K. R.; Waggoner, J. W.; and Olson, K. C. (2015) "Performance of Beef Replacement Heifers Supplemented With Dried Distillers Grains With Solubles Versus a Mixture of Soybean Meal and Finely Ground Sorghum Grain," Kansas Agricultural Experiment Station Research Reports: Vol. 1: Iss. 1.
Warner is an Extension cow-calf specialist in the Department of Animal Sciences and Industry, Kansas State University.
