Supplemental Zinc Sulfate Affects Growth Performance of Finishing Heifers

Zinc is an essential mineral required for normal function of more than 300 enzymes in microorganisms, plants, and animals. Zinc-requiring enzymes participate in metabolism of nucleic acids, proteins, and carbohydrates, all of which are essential for growth of cattle. In addition, zinc is necessary for normal development and function of the immune system. The requirement for zinc in finishing cattle diets has been established at 30 ppm (NRC, Nutrient Requirements of Beef Cattle, 2000), though concentrations recommended by consulting nutritionists and feed manufacturers span a far broader range. The purpose of this study was to evaluate the effects of feeding different levels of zinc on feedlot performance and carcass traits of finishing heifers

Antioxidant Feeding Does Not Impact Incidence or Severity of Liver Abscesses

Liver abscesses are a large source of economic loss in feedlot cattle. Not only do liver abscesses lead to a decrease in feedlot performance, but these livers are condemned in the abattoir and can also lead to a further decrease in carcass value due to trim loss. Tylosin phosphate is a metaphylactic macrolide drug that effectively decreases the occurrence of liver abscesses. The drug is approved by the Food and Drug Administration for over-the-counter use. However, in January 2017 the FDA will require a veterinary feed directive for medically important antibiotics (antibiotics that are used in human health) used in production animal feed. Macrolides are one class of antibiotic that will require a veterinary feed directive. A drug that is accompanied by a veterinary feed directive will require it to be used within the regulations that the FDA has set for the specific drug. This new directive is to encourage the animal production industry to use less medically important antibiotics. It is therefore important to look at alternatives to control liver abscesses in feedlot cattle. Various studies have shown that α-tocopherol acetate increases the humoral response and that ascorbate increases mononuclear lymphocyte counts. These antioxidants are also known to maintain the integrity and structure of ruminal papillae, thereby inhibiting pathogenic bacteria that lead to the formation of liver abscesses from gaining access to the portal blood and then eventually the liver. The objective of this study was to evaluate the impact of antioxidants on feedlot performance, carcass characteristics, and incidence and severity of liver abscesses in finishing heifers

Ruminally-Protected Lysine (SafeGain) Improves Performance of Growing Beef Cattle

Lysine frequently is cited as the first-limiting amino acid for cattle diets. Synthetic lysine, while routinely added to pig diets, is ineffective in fulfilling lysine requirements of cattle due to extensive degradation by microbes within the rumen. Lysine can be encapsulated with compounds, such as saturated fats, that minimize degradation by ruminal microbes, thereby assuring that a greater proportion of the amino acid is available for absorption post-ruminally. The purpose of this experiment was to measure the impact of SafeGain (H.J. Baker & Bro. Inc., Little Rock, AR), an encapsulated form of lysine sulfate, on rate of gain and feed efficiency in backgrounding cattle

Hops Βeta-Acid Extract Yields Feedlot Performance Similar to Rumensin

Hops (Humulus lupulus) have played an integral role in beer manufacturing and are widely known for their antimicrobial and preservative properties. α-acids of hops are extracted and utilized to enhance beer flavor, leaving residues largely composed of β-acids. Beta-acid extracts of hops are structurally similar to ionophores and may express ionophore-like traits. Ionophores, including Rumensin (Elanco Animal Health, Greenfield, IN), are used to improve feed efficiency and to decrease the incidence of digestive disturbances in feedlot cattle. A large portion of in vitro studies show benefits from feeding hops or hop acids with results similar to ionophores; however, live animal experiments are needed to confirm these observations. The objectives of this study were to assess the effects of β-acid extracts of hops on feedlot performance in cattle fed high-concentrate diets and determine a response to varied doses of β-acid extracts of hops

Lactipro (Megasphaera elsdenii) Increases Ruminal pH and Alters Volatile Fatty Acids and Lactate During Transition to an 80% Concentrate Diet

Direct-fed microbials commonly have been used to enhance performance or to decrease shedding of foodborne pathogens in beef cattle. Megasphaera elsdenii is a recently introduced probiotic bacteria marketed under the trade name Lactipro (MS-Biotec Inc., Wamego, KS) and is a key lactate-fermenting bacterium in the rumens of cattle fed high-concentrate diets. Megasphaera elsdenii is responsible for metabolizing up to 95% lactic acid within the rumen, and thus is an important species for controlling occurrence of ruminal acidosis. The objective of this study was to evaluate changes in ruminal pH and volatile fatty acid concentration during the transition from a diet with 60% concentrate to a diet containing 80% concentrate after administering five different oral dosages of Lactipro

Supplemental Zinc Oxide Does Not Interact With Zilmax in Feedlot Steers

Zilmax (Merck Animal Health; Summit, NJ) is in a class of feed additives known as beta agonists and is designed to improve production efficiency in cattle when fed 20 days prior to harvest. Zilmax works by altering deposition of body tissue to more lean muscle than fat. Zinc is an essential mineral necessary for normal growth and development of all mammals. Zinc functions largely in enzymes involved in protein synthesis and carbohydrate metabolism along with many other biological reactions. The purpose of this study was to assess changes in blood components and to evaluate the interactive effects of zinc and Zilmax supplementation on growth and carcass characteristics of finishing steers

Dietary Chromium Propionate Combined with Yeast Minimally Affects Growth Performance and Carcass Traits of Finishing Steers

Chromium (Cr) is an essential micromineral that serves to increase absorption of glucose from blood by potentiating the action of insulin. The ability to increase glucose tolerance could lead to more efficient use of glucose and ultimately to improved growth and efficiency. In addition, Cr may be beneficial in improving the immune response of cattle that are subjected to periods of stress. Organic forms of Cr (i.e., Cr propionate) increase absorption and are more physiologically active than their inorganic counterparts. Chromium propionate is currently the only approved form of organic Cr allowed for supplementation in cattle diets in the United States. Yeast supplements, most commonly in the form of various strains of Saccharomyces cerevisiae, are commonly added to livestock diets as a means of stimulating digestion, intake, and animal performance. The purpose of this experiment was to compare feedlot performance, carcass characteristics, and plasma glucose profiles of cattle fed finishing diets with and without a combination of chromium propionate and yeast supplementation

Menthol Supplementation Has Minimal Effects on Blood Components from Holstein Steers

Menthol is a naturally occurring compound classified as an essential oil that gives plants of the Mentha species their characteristic minty aroma and flavor. Menthol is used as a cooling compound in products ranging from common cold medications to pesticides and has been found to have a wide range of biological activities in different systems within the body. More recently, menthol and other essential oils have been identified as potential alternatives to feed antibiotics and growth promotants. Menthol has been observed to directly affect κ-opioid receptors. Kappa opioid receptors are located in the central nervous system, with a high density found in the hypothalamus. Menthol has been hypothesized to be capable of binding to κ-opioid receptors in the hypothalamus, stimulating neuropeptides involved in the production and release of growth hormone and leading to increased insulin-like growth factor-1 concentration, thus increasing growth. The purpose of this experiment was to evaluate changes in blood metabolites when menthol was incorporated into the diets of steers

Effects of flaxseed encapsulation on biohydrogenation of polyunsaturated fatty acids by ruminal microorganisms: feedlot performance, carcass quality, and tissue fatty acid composition

Citation: Alvarado-Gilis, C. A., Aperce, C. C., Miller, K. A., Van Bibber-Krueger, C. L., Klamfoth, D., & Drouillard, J. S. (2015). Effects of flaxseed encapsulation on biohydrogenation of polyunsaturated fatty acids by ruminal microorganisms: feedlot performance, carcass quality, and tissue fatty acid composition. Journal of Animal Science, 93(9), 4368-4376. doi:10.2527/jas2015-9171The objective of this study was to evaluate the efficacy of protecting PUFA within ground flaxseed against ruminal biohydrogenation by encapsulating them in a matrix consisting of a 1:1 blend of ground flaxseed and dolomitic lime hydrate (L-Flaxseed). Crossbreed heifers (n = 462, 346 +/- 19 kg) were blocked by weight and randomly assigned to pens. Pens were assigned to 1 of 6 dietary treatments in a randomized complete block design. Treatment 1 consisted of a combination of 54.6% steam-flaked corn (SFC), 30.0% wet corn gluten feed, 8.0% roughage, and supplement (0% flaxseed). In treatments 2 and 3, a proportion of SFC was replaced with 3 and 6% flaxseed, respectively; in treatments 4, 5, and 6, SFC was replaced with 2, 4, or 6% L-Flaxseed, respectively. Cattle were fed for 140 or 168 d and then harvested in a commercial abattoir where carcass data were collected. Approximately 24 h after harvest, carcasses were evaluated for 12th-rib fat thickness, KPH, LM area, marbling score, and USDA yield and quality grades. Samples of LM were also obtained for determination of long-chain fatty acid profiles. Cattle that were fed diets with 4 and 6% L-Flaxseed consumed less feed than other treatments (P 0.05). Supplementation with flaxseed increased (P 99%; increases for Flaxseed and L-Flaxseed of 0.095 and 0.140 mg of ALA/g of tissue for each percentage of flaxseed added). This study indicates that a matrix consisting of dolomitic lime hydrate is an effective barrier to ruminal biohydrogenation of PUFA; however, adverse effects on DMI limit the amounts that can be fed

Effects of crystalline menthol on blood metabolites in Holstein steers and in vitro volatile fatty acid and gas production

Citation: Van Bibber-Krueger, C. L., Miller, K. A., Aperce, C. C., Alvarado-Gilis, C. A., Higgins, J. J., & Drouillard, J. S. (2016). Effects of crystalline menthol on blood metabolites in Holstein steers and in vitro volatile fatty acid and gas production. Journal of Animal Science, 94(3), 1170-1178. doi:10.2527/jas2015-8779Fifty-two Holstein steers (573 +/- 9.92 kg BW) were used to determine if oral administration of crystalline menthol would induce changes in endogenous secretions of IGF-1 and circulating concentrations of glucose, lactate, and plasma urea nitrogen (PUN). Steers were blocked by BW and assigned within block to treatment. Treatments consisted of 0, 0.003, 0.03, or 0.3% crystalline menthol (DM basis) added to the diet. Animals were housed in individual, partially covered pens equipped with feed bunks and automatic water fountains. On d 1 of the experiment, blood samples were obtained via jugular venipuncture at 0, 6, 12, 18, and 24 h after feeding. Treatment administration commenced on d 2, and blood samples were again drawn at 0, 6, 12, 18, and 24 h after feeding. This blood-sampling schedule was repeated on d 9, 16, 23, and 30. Plasma was analyzed for PUN, glucose, and lactate concentrations. Serum was used to analyze IGF-1 concentration. Body weights were measured on d 1, 9, 16, 23, and 30. To accompany the live animal phase, in vitro fermentations were performed using ruminal fluid cultures. Measurements included VFA concentrations and fermentative gas production for cultures containing crystalline menthol at 0, 0.003, 0.03, or 0.3% of substrate DM. Addition of menthol to the diet of steers resulted in a treatment x day interaction (P 0.21). In conclusion, menthol supplementation minimally affected blood parameters associated with growth or ruminal fermentative activity