Nutrient Management in Beef Feedlots and Forage Replacement with Byproduct and Crop Residues

Finishing cattle performance and mass balance was evaluated with Micro-Aid was fed in diets containing wet distillers grains plus solubles (WDGS) at 35% (DM basis). Micro-Aid is a feed ingredient derived from a Yucca extract which contains saponins, and was included in the treatment diet at 1 g/hd daily in the supplement. There was no difference in performance and carcass characteristics between treatments. In the winter experiment, cattle fed Micro-Aid had a greater amount of OM and DM removed from the pen surface. Micro-Aid in the diet increased the amount of manure N and decreased N lossis in the winter. The addition of Micro-Aid in the diet resulted in no difference in nutrient mass balance during the summer. There was no difference in N excreted in manure or lost via volatilization in the summer experiment. Supplementing cattle grazing smooth bromegrass pasture with crop residue and byproducts may be a viable option to extend the grazing season or increase carrying capacity. Two experiments (2010 and 2011) were conducted to determine the effect on forage intake of supplementing cattle grazing smooth bromegrass pasture with a byproduct and crop residue blend. Cattle grazed at 1) the recommending strocking rate (7.56 AUM/ha in 2010 or 9.46 AUM/ha in 2011) with no supplementation (CON) or 2) double the recommended stocking rate (15.1 AUM/ha in 2010 and 18.9 AUM/ha in 2011) with supplementation (SUP). In experiment 1 (2010) nonpregrnant, nonlactating cows grazed smooth bromegrass pasture from mid April to mid Spetmeber. Supplemented cows were fed a 35% Synergy and 65% wheat straw mixture daily. The ensiled mixture (46.6% DM) was fed from late April to mid-August and a fresh mixture (30.7% DM; mixed at feeding time) from mid-August to mid-September. In experiment 2 (2011), cows with spring born calves at side grazed from early May to mid-September. A fresh supplement of 30% MDGS and 70% cornstalk blend was fed daily. No differences in performance or diet quality were observed. Consequently, supplement replaced 40% of grazed forage intake in 2010 and 36.3% of forage intake in 2011. Supplementing byproduct and crop residue mixtures can replace forage intake of cattle grazing smooth bromegrass pasture. Advisors: Galen E. Erickson and Terry Klopfenstei

Supplementing Cow-Calf Pairs Grazing Smooth Bromegrass

A three-year study evaluated supplementing ethanol co-products mixed with low-quality forage to cow-calf pairs grazing smooth bromegrass as a method to replace grazed forage intake. Supplementing a 30:70 modified distillers grains plus solubles:cornstalks mixture reduced estimated grazed forage intake by approximately 40%. Doubling the stocking rate and supplementing did not impact cow or calf performance. A summer supplementation program designed to reduce grazed forage intake is a viable strategy for increasing stocking rate if forage for grazing is limited

Effect on Performance and Nutrient Mass Balance of Feeding Micro-Aid in Wet Distillers Grains Plus Solubles Diets

Finishing cattle performance and mass balance were evaluated when Micro- Aid® was fed in diets containing wet distillers grains plus solubles (WDGS). There was no difference in performance and carcass characteristics between treatments. In a WINTER experiment, cattle fed Micro-Aid had a greater amount of OM and DM removedin manure. Micro-Aid in the diet increased the amount of manure N and decreased N losses in the WINTER. There was no difference in N excreted in manure or lost via volatilization in the SUMMER experiment

Byproducts with Low Quality Forage to Grazing Cattle

Sixteen cows grazing smooth bromegrass pasture were unsupplemented or supplemented a 35:65 Synergy:straw mixture. Grazed forage intake was replaced about 50% with supplementation, with no differences in cow performance. In a second experiment conducted over two summers, yearling steers grazing native range were fed a mixture of 70:30 or 60:40 hay:WDGS or 60:40 straw:WDGS. During the first year, all steers fed byproduct-forage mixtures had greater ADG than control steers. During the second year, steers supplemented with byproduct-hay mixtures had similar gains as control while steers supplemented byproduct-straw mixtures gained less. Supplementing WDGS and low quality forage reduced forage intake by 17 to 22% in Experiment 2

Atrial fibrillation genetic risk differentiates cardioembolic stroke from other stroke subtypes

Objective: We sought to assess whether genetic risk factors for atrial fibrillation (AF) can explain cardioembolic stroke risk. Methods: We evaluated genetic correlations between a previous genetic study of AF and AF in the presence of cardioembolic stroke using genome-wide genotypes from the Stroke Genetics Network (N = 3,190 AF cases, 3,000 cardioembolic stroke cases, and 28,026 referents). We tested whether a previously validated AF polygenic risk score (PRS) associated with cardioembolic and other stroke subtypes after accounting for AF clinical risk factors. Results: We observed a strong correlation between previously reported genetic risk for AF, AF in the presence of stroke, and cardioembolic stroke (Pearson r = 0.77 and 0.76, respectively, across SNPs with p 0.1). Conclusions: Genetic risk of AF is associated with cardioembolic stroke, independent of clinical risk factors. Studies are warranted to determine whether AF genetic risk can serve as a biomarker for strokes caused by AF.status: publishe