Horn flies (Haematobia irritans (L.)) are considered the most important external parasite that negatively affects pasture-based beef systems with losses estimated to exceed $1 billion annually to the U.S. beef industry. Control strategies have relied heavily on insecticide applications to control horn flies and are implemented when the economic threshold of 200 flies/animal have been exceeded. When horn fly populations are maintained below 200 flies/animal by treating them with insecticides then the level of stress annoyance behaviors such as leg stomping, head throwing, and skin twitching decreases while grazing increases. While most stocker operators utilize some type of fly control these are rarely used as a single pharmaceutical technology to aid in performance of the animals. Additional pharmaceutical technologies are utilized in combination of others, with the use of de-wormers and implants showing the largest impact with performance of stockers. The objective of this study was to compare a commercial injectable insecticide, LongRange, to an insecticidal ear tag for horn fly control and determine the impact of weight performance on stockers when fly control technologies were used in combination with implants versus no implants.

Objective Objective: To determine the growing calf response when fed Enogen Feed corn silage containing an alpha amylase expression trait. Study DescriptionStudy Description: Crossbred steers of Tennessee origin (n = 352) were used to determine the effects on performance when fed Enogen Feed corn silage with either Enogen Feed corn or control corn at ad libitum intake.The Bottom Line The Bottom Line: When fed in an ad libitum fashion to growing calves, Enogen Feed corn silage improves the efficiency of feed conversion by 4.4% and average daily gain by 6.0%. AbstractIn 2017, a growing calf study conducted at the Kansas State University Beef Stocker Unit determined that feeding Enogen Feed corn as either dry-rolled or whole-shelled yielded a positive feed efficiency response of 5.50%. It is not known what the extent of the feed efficiency response is when the alpha amylase enzyme trait is present in either grain and/or silage. In order to determine the growing calf response to Enogen Feed corn silage when fed with Enogen Feed corn or control corn, 352 crossbred steers of Tennessee origin that were used on a previous study at the Kansas State University Beef Stocker Unit were reallocated to pens based on weight. Steers were fed a total mixed ration once daily for 90 days. The four treatment diets were formulated to provide 50 Mcal net energy for gain/100 lb. Cattle off-test weights tended to be greater for calves fed Enogen Feed corn silage. Overall, feed efficiency improved by 4.40% and average daily gain improved by 6.00% for calves fed Enogen Feed corn silage.

Objective Objective: : To determine the response of growing calves when fed Enogen Feed (Syngenta) corn, containing an alpha amylase expression trait.Description Description: : A total of 384 English crossbred steers having an average weight of 538 lb and originating from Texas were used to determine the effects on performance when fed Enogen Feed corn as either whole shelled or processed as dry-rolled at ad libitum intake.The Bottom Line: The Bottom Line: When fed in an ad libitum fashion to growing calves, Enogen Feed corn improves feed efficiency of growing calves by 5.50%.

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Objective Objective: To evaluate the digestibility parameters of growing cattle when fed Enogen Feed corn. Study Description Study Description: Seven cannulated Holstein steers were used to determine the effects on digestibility when fed Enogen Feed corn (Syngenta) as whole-corn or processed as dry-rolled at ad libitum intake. The Bottom Line The Bottom Line: When Enogen Feed corn was fed in an ad libitum fashion to growing calves, dry matter and organic matter are digested to a greater extent relative to yellow corn.

One hundred twenty individually fed steers (initial BW 283 kg) were utilized in an 84-d growing trial to evaluate effects of increased metabolizable lysine from non-enzymatically browned soybean meal (SoyPass) in grass hay based diets containing wet distillers grains plus solubles (WDGS). Treatments were arranged as a 2 × 3 factorial design with two levels of WDGS (20% or 35% of DM) and three levels of supplemental SoyPass replacing 0%, 30%, or 60% of WDGS. The statistical model included animal as the experimental unit and level of WDGS and SoyPass substitution were included as fixed effects. Covariate regression was used to test for linear and quadratic interactions between WDGS and SoyPass substitution. No interactions were detected for ADG between SoyPass supplementation and level of WDGS in the diet (P = 0.76). Additionally, SoyPass inclusion had no effect on ADG (P = 0.49). However, ADG was increased for steers consuming the 35% WDGS diet compared to steers offered the 20% WDGS diet (1.13 vs. 0.86 kg/d, respectively; P < 0.01). A SoyPass × WDGS interaction was detected for DMI (P = 0.01). As SoyPass replaced WDGS in the 35% diet, DMI increased linearly from 8.10 to 8.93 kg/d (P = 0.01). In the 20% WDGS diet, DMI decreased as SoyPass replaced 60% of the WDGS compared to 30% (7.68 vs. 8.36, P = 0.02). Therefore, G:F decreased linearly (P = 0.01) as SoyPass replaced WDGS in the 35% treatment and increased quadratically (P = 0.02) for the 20% WDGS treatment. Furthermore, BUN increased linearly as SoyPass replaced WDGS in the 20% diet (P = 0.01) but was not affected by SoyPass substitution in the 35% diet. Overall, results indicate forage-based growing diets formulated with low-levels of WDGS (< 20%) may be deficient in metabolizable lysine, which could be supplied with SoyPass.

Data were compiled from an experiment evaluating the effects of month of calving, wintering system, and calf management on cow and calf performance to model the amount of water (green and blue) required to produce beef in Nebraska production systems. The referenced study was conducted over four years utilizing 217 cow/calf pairs per year. Cows were wintered on either native range or corn residue and month of calving was March, June, or August. Calves were managed as calf-feds or yearlings and only steer calves were included in the model. A 365-d period was utilized to estimate the cow’s contribution of water inputs based on dry matter intake throughout the year varying by production system. Diet characteristics, dry-matter intake, days on feed, average daily gain, and hot carcass weight were measurements used to estimate water utilization by the calves. The total water footprint was calculated by dividing the total amount of water used for each system (L) by the amount of boneless beef produced (kg). Production systems where cows were wintered on corn residue utilized 18% less water than systems utilizing native range as a wintering source, because of water allocations using the value fraction method. Increasing the dietary inclusion of distillers grains from 0% to 40% decreased the water footprint in the finishing phase by 29%. Utilizing by-products in replacement of primary crops decreases the overall water footprint of production. Across all scenarios modeled, more than 50% of the water footprint was allocated to the cow grazing rainfed pasture (green water) and over 98% of the water footprint was allocated to growing feed. Improvements in crop water use efficiency will benefit livestock production. The water footprint of the beef systems analyzed was 80% green water as rain, minimizing the environmental impact of beef production on freshwater use and ecological water balance.

Effects of dietary energy level and intake of corn by-product-based diets on antibody production, acute phase protein response, stress, and immunocompetency of healthy and morbid newly received growing cattle were evaluated. Four dietary treatments were formulated to supply 0.99, 1.10, 1.21, and 1.32 Mcal NEg/ kg DM and were offered at 100%, 95%, 90%, and 85% of ad libitum based on 0.99/100 treatment intake, respectively. Thirty-two pens were utilized with approximately 12 animals/pen. Four animals from each pen (32/dietary treatment) were randomly selected and used to serve as a subset to monitor immune function and acute phase proteins following a split-plot design. In addition, two animals were randomly and independently selected from each pen (16/dietary treatment) and used to measure fecal cortisol metabolite. Additionally, animals removed from the pen one (M1), two (M2), or three (M3) times and classified as morbid were bled in conjunction with a healthy control (H) removed at the same time and the serum analyzed for the same parameters. A quadratic response to time (P < 0.01) was detected for haptoglobin concentrations and for antibody titers for bovine viral diarrhea type 1 (BVD-I) and infectious bovine rhinotracheitis (IBR; P < 0.01). Haptoglobin was lowest on arrival, highest on day 14, and similar to baseline levels by day 27. Titer levels for BVD-I and IBR were lowest on arrival, higher on day 14, and significantly higher on day 27. Titers for bovine viral diarrhea type 2 (BVD-II) responded linearly (P < 0.05) with lower levels on arrival and highest levels on day 27. Haptoglobin was elevated in morbid animals compared to healthy pen mates (P < 0.05). Titer levels for BVD-I and IBR were also higher in healthy animals compared to animals pulled for morbidity (P < 0.01). Fecal cortisol was higher on arrival than on day 14 (P < 0.05). Dietary treatment had no effect on any of the parameters investigated. In summary, high-energy receiving diets based on fermentable fiber from by-products can be fed to newly received growing cattle without negative effects on antibody production toward vaccines, inflammation, or overall stress. In addition, haptoglobin concentrations and titer levels for BVD-I and IBR viruses are higher in healthy animals compared to sick animals.