Insecticide ear tags numerically improve grazing cattle performance

Stocker cattle grazing pastures during the summer months face challenges due to horn flies, which can result in reduced weight gains and less efficient use of forages. One strategy for controlling horn flies is insecticide-impregnated ear tags. The use of pesticide ear tags may be an effective management practice to improve overall productivity during a grazing season. The objective of this study was to evaluate the efficacy of insecticide ear tags as a means of improving growth of stocker calves grazing native pastures in the Flint Hills region of Kansas

Effects of yeast combined with chromium propionate on growth performance and carcass quality of finishing steers

Citation: Vanbibber-Krueger, C. L., Axman, J. E., Gonzalez, J. M., Vahl, C. I., & Drouillard, J. S. (2016). Effects of yeast combined with chromium propionate on growth performance and carcass quality of finishing steers. Journal of Animal Science, 94(7), 3003-3011. doi:10.2527/jas2016-0454A combination of yeast and chromium propionate (Y+Cr) was added to the diets of crossbred finishing steers (n = 504; 402 kg ± 5.76 initial BW) to evaluate impact on feedlot performance and carcass traits. We hypothesized supplementation of Y+Cr would increase growth of feedlot steers. Steers with initial plasma glucose concentrations ?6.0 mM were stratified by initial BW and randomly allocated, within strata, to receive 0 (control) or 3.3 g/d Y+Cr. Steers were further divided into heavy and light weight blocks with 6 pens/diet within each weight block. Cattle were housed in dirt-surfaced pens with 21 steers/pen and had ad libitum access to feed. Body weights were measured at 21-d intervals. Blood samples were collected on d 49 and 94 from a subset of steers (5/pen) for analyses of plasma glucose and lactate concentrations. At the end of the finishing phase, animals were weighed and transported 450 km to an abattoir in Holcomb, KS. Severity of liver abscesses and HCW were collected the day of harvest, and after 36 h of refrigeration, USDA yield and quality grades, LM area, and 12th rib subcutaneous fat thickness were determined. There were no treatment × time × weight block interactions (P > 0.05) and no treatment × block interaction for ADG, DMI, or final BW (P ? 0.06), but a treatment × block interaction (P = 0.03) was observed for G:F, in which control, light cattle had poorer efficiency compared with other groups. Treatment × weight group interactions were observed for overall yield grade and carcasses that graded yield grade 1 (P ? 0.04). Light steers supplemented with Y+Cr had decreased overall yield grade and increased percentage of carcasses grading yield grade 1 compared with their control counterparts, with no differences observed for heavy steers. Regardless of weight group, a greater percentage of carcasses from steers supplemented with Y+Cr graded yield grade 2 (P = 0.03) and fewer carcasses from steers supplemented Y+Cr graded yield grade 3 (P 0.10). Overall, yeast in combination with chromium propionate may improve feed efficiency and decrease yield grade of light cattle but had no effect on remaining carcass traits and blood constituents. © 2016 American Society of Animal Science. All rights reserved

Flake Density, Roll Diameter, and Flake Moisture All Influence Starch Availability of Steam-Flaked Corn

Steam-flaked corn is commonly fed in feedlot finishing diets because steam-flaking improves starch availability and nutrient utilization, thus improving the overall feeding value of corn. In most operations which utilize steam-flaked corn, grain is processed to a pre-determined flake density by setting the rolls to a specific separation distance and using tension to hold rolls together. Flaked grain is most often produced to a bulk density between 24 and 32 lb/bu, with a common recommendation of 27 lb/bu for corn; however, flake density among steam-flakers within a single mill and among feedlots can vary greatly. Flaking to a similar density using 2 flakers does not ensure similar starch availability. The degree of starch gelatinization or starch availability of steam-flaked corn can be estimated using analytical procedures such as enzymatic hydrolysis, gas production, and steam-flaked corn gelatinization methods. Routinely evaluating starch availability is used as a quality control method to standardize the steam-flaking process to ensure within-day and day-to-day manufacturing consistency. The concentration of readily available starch in steam-flaked corn is indicative of the rate of starch fermentation in the rumen. When starch is too readily available and is fermented at an excessively rapid rate, acid can accumulate in the rumen, reducing ruminal pH, and ultimately resulting in increased prevalence of digestive disturbances. Factors that contribute to variation between feedlot operations with respect to steamflaked corn quality include type and dimensions of flaking equipment, grain type, grain variety and moisture content, roll wear, and steam-flaking procedures. Sampling and handling procedures contribute to precision of results; therefore, sampling procedures need special attention, and consistency must be evaluated when attempting to determine starch availability of steam-flaked corn. The objective of this study was to evaluate starch availability of steam-flaked corn comparing roll dimensions and steam-flaked corn flake densities among flaking systems and feedyards and to provide information on the equipment utilized, steam-flaked corn flaking procedures, and to define current manufacturing practices of steam-flaking in commercial feedlot operations

Relationship Between Trauma Sustained at Unloading and Carcass Bruise Prevalence in Finished Cattle at Commercial Slaughter Facilities

Bruising in cattle can be an indicator of poor animal welfare, as well as a significant cause of economic loss due to decreased carcass value. Previous literature suggests sources of trauma causing bruising in beef carcasses include horn prevalence, rough transport conditions, cattle handling techniques, cattle temperament, and vehicle design; however, evidence of correlations between such trauma and actual carcass bruising is limited. The objective of this study was to evaluate the relationship between trauma sustained at unloading and carcass bruise prevalence in finished cattle at commercial slaughter facilities

Freezing Strip Loin and Top Round Steaks Improves Warner-Bratzler Shear Force

Postmortem aging of steaks is a common practice used to improve tenderness of beef steaks. The impact of proteolysis and improvement in tenderness due to aging varies among muscles. When designing research protocols, samples for Warner-Bratzler shear force (WBSF) are often frozen for later analysis because of convenience and time limitations. Freezing stops postmortem aging and allows for storage until meat can be cooked for WBSF and/or sensory analysis. However freezing meat may cause damage to cell membranes resulting in lower Warner-Bratzler shear force (improved mechanical tenderness), lower water holding capacity, and greater moisture loss during cooking. Several researchers have indicated that freezing strip loin (Longissimus muscle) steaks may lower Warner-Bratzler shear force (improve tenderness) compared with those not previously frozen and sheared fresh. However, these results have been inconclusive for steaks from other muscles. Therefore, the objective of this study was to determine the effects of postmortem aging time and freezing on Warner-Bratzler shear force of six muscles from the beef hindquarter

A supplement containing multiple types of gluconeogenic substrates alters intake but not productivity of heat-stressed Afshari lambs

Citation: Mahjoubi, E., Amanlou, H., Yazdi, M. H., Aghaziarati, N., Noori, G. R., Vahl, C. I., . . . Baumgard, L. H. (2016). A supplement containing multiple types of gluconeogenic substrates alters intake but not productivity of heat-stressed Afshari lambs. Journal of Animal Science, 94(6), 2497-2505. doi:10.2527/jas2015-9697Thirty-two Afshari lambs were used in a completely randomized design with a 2 x 2 factorial arrangement of treatments to evaluate a nutritional supplement designed to provide multiple gluconeogenic precursors during heat stress (HS). Lambs were housed in thermal neutral (TN) conditions and fed ad libitum for 8 d to obtain covariate data (period 1 [P1]) for the subsequent experimental period (period 2 [P2]). During P2, which lasted 9 d, half of the lambs were subjected to HS and the other 16 lambs were maintained in TN conditions but pair fed (PFTN) to the HS lambs. Half of the lambs in each thermal regime were fed (top-dressed) 100 g/d of a feed supplement designed to provide gluconeogenic precursors (8 lambs in HS [heat stress with Glukosa {HSG}] and 8 lambs in PFTN [pair-fed thermal neutral with Glukosa]) and the other lambs in both thermal regimes were fed only the basal control diet (HS without Glukosa [HSC] and pair-fed thermal neutral without Glukosa). Heat stress decreased DMI (14%) and by design there were no differences between the thermal treatments, but HSG lambs had increased DMI (7.5%; P < 0.05) compared with the HSC lambs. Compared with PFTN lambs, rectal temperature and skin temperature at the rump, shoulder, and legs of HS lambs were increased (P < 0.05) at 0700 and 1400 h. Rectal temperature at 1400 h decreased for HSG lambs (0.15 +/- 0.03 degrees C; P < 0.05) compared with HSC lambs. Despite similar DMI between thermal treatments, ADG for HS and PFTN lambs in P2 was decreased 55 and 85%, respectively, compared with lambs in P1 (P < 0.01). Although the prefeeding glucose concentration was not affected by thermal treatment or diet, HSG lambs had increased postfeeding glucose concentration compared with HSC lambs (P < 0.05). In contrast to the glucose responses, circulating insulin was influenced only by thermal treatment; HS lambs had increased insulin concentration (P < 0.01) before feeding and decreased concentration (P < 0.05) after feeding compared with PFTN lambs. Heat-stressed lambs had decreased NEFA concentration before feeding (P < 0.01) but not after feeding relative to PFTN lambs. Although this nutritional strategy did not affect ADG, the lower rectal temperature in HSG lambs indicates that dietary inclusion of a mixture of glucogenic precursors can potentially benefit animal health during HS

High Energy Digestible Fiber-based Diets Improve Efficiency in Growing Heifers

An inherent challenge of long hauled, highly stressed calves is decreased feed intake upon destination arrival. Highly stressed, newly received stocker calves not consuming adequate amounts of energy are prone to a variety of disorders such as Bovine Respiratory Disease Complex and decreased performance throughout the feeding period. One mechanism that can be used to increase energy intake upon arrival is to make the diet more energy dense. Often times, this is accomplished by the addition of cereal grains high in fermentable carbohydrate including starch. Unfortunately, this has also been linked to increasing morbidity due to metabolic disorders. The goal of this study was to analyze the effects of limit-fed diets containing increasing amounts of energy from highly digestible fiber in by-product feeds on health and performance of newly received stocker calves

Restricting Intake and Increasing Energy Improves Efficiency in Newly Received Growing Cattle and Zelnate Has No Effect

Objectives: Study effects of two limit-fed diets formulated to provide two levels of dietary energy and offered at two different intake rates to target similar gains and analyze the efficacy of a novel DNA-immunostimulant administered on arrival. Study Description: A 56-day pen study was conducted utilizing 370 Angus × Brahman heifers shipped from Florida (1,455 mi) to study the effects of limit-feeding at 2 intakes based on prior research conducted at the Kansas State University Beef Stocker Unit, Manhattan, KS, to achieve similar gains and effects of Zelnate under the dietary conditions. The Bottom Line: Limit-feeding a higher-energy, lower-roughage diet at 2.2% of body weight daily is a more efficient feeding strategy than offering a higher-roughage, lower-energy diet at 2.4% of body weight daily to achieve similar gains, and Zelnate administered on arrival had no effect on performance or health

Programming a Variety of Gains Is Possible by Controlling Intake of a Single High-Energy By-Product-Based Diet Early in the Receiving/Growing Period Without Affecting Efficiency

Objective: Analyze the effects on performance when feeding a high-energy by-product-based diet to newly received growing cattle. Description: A total of 400 Angus × Hereford heifers originating from Montana were used to determine the effects on performance when intake of a high-energy corn by-product-based diet is increased to near ad libitum intake. The Bottom Line: One high-energy diet based on wet corn gluten feed can be offered to achieve a variety of gains efficiently by only altering the amount of feed offered