Forty-eight Holstein male calves were stratified by origin and body weight and randomly assigned to one of 4 treatment groups. Dietary treatments were administered in 2 phases. In phase 1, treatment groups received the basal diet with no supplemental Zn (control), basal diet plus 20 mg of Zn/kg of DM as ZnSO4 or Zn proteinate (ZnProt), or basal diet plus 20 mg of Zn/kg of DM with 50% of the Zn supplied from each source (ZnM) for 98 d. In phase 2, calves continued to receive the same Zn source fed in phase 1; however, half of the calves in each treatment group were randomly selected to receive 500 mg of Zn/kg of DM (HiZnSO4, HiZnProt, HiZnM) for 14 d. Gain, feed intake, and feed efficiency of calves were not affected by treatment in either phase of the experiment. Treatment had no affect on plasma Zn concentration or alkaline phosphatase activity in phase 1, but liver Zn concentration was greater in calves fed ZnSO4 than those fed ZnProt. In phase 2, plasma Zn was greater in calves fed HiZnProt and HiZnM than in those fed HiZnSO4. Liver Zn was greater in calves fed HiZnProt than in those fed HiZnSO4. Duodenal Zn concentrations were greater in calves supplemented with HiZnProt and HiZnM than those supplemented with HiZnSO4. Liver metallothionein was greater in calves that received 500 mg of Zn/kg than in calves that received 20 mg of Zn/ kg, but was not affected by Zn source. Calves fed HiZnProt and HiZnM had greater kidney Zn concentrations than those fed HiZnSO4. Heart, spleen, testicular, and bone Zn concentrations were not affected by Zn source. Hoof wall samples contained nearly 3-fold greater Zn concentrations than hoof sole. Calves fed ZnSO4 had greater Zn concentration in hoof wall samples than those fed ZnM. Hoof sole Zn concentration was not affected by Zn source or concentration. Plasma and tissue Zn concentrations at harvest were generally similar in calves supplemented with 20 mg of Zn/kg from ZnSO4 or ZnProt. However, when supplemented at 500 mg of Zn/kg, ZnProt was absorbed to a greater extent than ZnSO4, based on higher plasma, liver, duodenal, and kidney Zn concentrations.
We conducted an experiment to determine the effects of dietary copper (Cu) source and level on carcass characteristics, longissimus muscle fatty acid composition, and serum and muscle cholesterol concentrations in steers. Sixty Angus and Angus x Hereford steers were stratified by weight and initial liver Cu concentration within a breed and randomly assigned to treatments. Treatments consisted of: 1) control (no supplemental Cu); 2) 20 mg Cu/kg DM from Cu sulfate (CuSO4); 3) 40 mg Cu/kg DM from CuSO4; 4) 20 mg Cu/kg DM from Cu citrate; 5) 20 mg Cu/kg DM from Cu proteinate; and 6) 20 mg Cu/kg DM from tribasic Cu chloride. A corn silage-soybean meal-based diet was fed for 56 d. Steers were then switched to a high-concentrate diet. Equal numbers (n = 5) of steers per treatment were slaughtered after receiving the finishing diets for either 101 or 121 d. Serum cholesterol was not affected by treatment during the growing phase but was decreased (P < .05) in steers supplemented with Cu by d 84 of the finishing period and remained lower (P < . 05) at subsequent sampling periods. Longissimus muscle cholesterol concentration tended to be reduced (P < .11) by Cu supplementation. Hot carcass weight and backfat were lower (P < .05) in animals receiving supplemental Cu. However, Cu-supplemented and control steers had similar marbling scores. Longissimus muscle polyunsaturated fatty acid concentrations (18:2 and 18:3) were increased (P < .07) and saturated fatty acid concentrations tended (P < . 11) to be reduced by Cu supplementation. These results indicate that as little as 20 mg of supplemental Cu/kg diet can reduce backfat and serum cholesterol and increase muscle polyunsaturated fatty acids in steers fed high-concentrate diets.
Two hundred forty Angus crossbred steers were used to determine the influence of feeding various quantities of wet and dry distillers grains to finishing steers on carcass characteristics, meat quality, retail-case life of ground beef, and fatty acid profile of LM. Three replications of 5 dietary treatments were randomly applied to 15 pens in each of 2 yr. A finishing diet containing dry-rolled corn, soybean meal, and alfalfa hay was fed as the control diet. Wet distillers grains with solubles (DGS) or dry DGS was added to the finishing diets at either 20.0 or 40.0% of the dietary DM to replace all soybean meal and part of the cracked corn in treatment diets. Carcasses of steers fed DGS had greater (P < 0.05) fat thickness (1.47 vs. 1.28 cm), greater (P < 0.05) USDA yield grades (3.23 vs. 2.94), and smaller (P < 0.05) percentage of yield grades 1 and 2 (41.1 vs. 60.4%) than carcasses of steers fed the control diet. Longissimus muscle from steers fed dry DGS had greater (P < 0.05) ultimate pH values (5.52 vs. 5.49) than LM from steers fed wet DGS. Ground beef from steers fed DGS had greater (P < 0.05) concentrations of α-tocopherol (1.77 vs. 1.43 μg/g) than ground beef from steers fed the control diet. Ground beef from steers fed 40% DGS had greater (P < 0.05) thiobarbituric acid-reactive substances (2.84 vs. 2.13 mg/kg) on d 2 of retail display than ground beef from steers fed 20% DGS. Longissimus muscle of steers fed DGS had less (P < 0.05) C17:0 and more (P < 0.05) C18:0, C18:1t, C16:1c9, C18:2c9c12 (where t is trans and c is cis), and total PUFA than LM of steers fed the control diet. Feedlot steers fed DGS may need to be marketed earlier than normal to avoid excess external fat and carcasses with a greater numerical yield grade. These data suggest feeding DGS to finishing steers will have no adverse or beneficial effects on glycolytic variables (dark cutters), retail display life of ground beef, or meat tenderness. However, beef from cattle finished on diets containing DGS will likely have a greater proportion of PUFA and therefore may be more susceptible to oxidative rancidity.
Sulfur-induced polioencephalomalacia (sPEM), a neurological disorder affecting ruminants, is associated with consumption of diets with increased S (high-S). High-S water is commonly found in many western states and is a major source of dietary S for grazing cattle. Consumption of high-S water has been associated with sPEM and decreased performance. Identification of a feed supplement that would counteract the negative effects of high-S water would decrease the incidence of sPEM and prevent performance reductions in regions with problematic water sources. The objectives of this study were to 1) determine the effects of administering high-S drinking water to forage-fed feedlot steers on health and performance, and 2) determine the effectiveness of clinoptilolite, a clay mineral with increased cation-exchange capacity, in negating the effects of high-S drinking water. Yearling steers (n = 96; 318.2 +/- 2.1 kg of BW) were randomly assigned to 1 of 4 treatments for a 77-d trial period: control with low-S water (566 mg of SO(4)/L), high-S water (3,651 mg of SO(4)/L), or high-S water plus clinoptilolite supplemented at 2.5 or 5.0% of the diet DM. Feed and water consumption were measured daily, and all steers were weighed on d -2, -1, 29, 53, 76, and 77. Plasma samples were collected on d 0, 58, and 77, and liver samples on d 0 and 77. There was a greater (P
Uptake and transport of Zn from (65)Zn-labeled ZnSO(4) and Zn proteinate (ZnProt) by ruminal and omasal epithelia were examined by using a parabiotic chamber system. Uptake was measured during a 4-h incubation with 10, 20, or 200 microM Zn as ZnSO(4) or ZnProt in the mucosal buffer (pH 6.0, Krebs-Ringer phosphate). Zinc uptake and transport were also evaluated after simulated ruminal digestion. Buffered ruminal fluid contained a feed substrate and 10 or 200 microM added Zn as ZnSO(4) or ZnProt. In a preliminary experiment, uptake of Zn by omasal tissue was low; thus, the remaining experiments were conducted solely with ruminal epithelium. Incubations to determine the effect of time on Zn uptake from mucosal buffer containing 20 microM added Zn as ZnSO(4) or ZnProt resulted in increased (P < 0.01) Zn uptake as incubation time increased from 30 to 240 min. Zinc uptake was also greater (P = 0.02) from mucosal buffer containing ZnProt compared with ZnSO(4). Zinc uptake from incubations containing 10 or 200 microM was affected by source x concentration (P = 0.05) and concentration x time (P < 0.01) interactions. With 10 microM Zn, uptake was not influenced by Zn source, whereas when 200 microM Zn was added, Zn uptake from ZnProt was greater than from ZnSO(4). Increasing incubation time resulted in increased Zn uptake with 200 microM Zn in the mucosal buffer; however, with 10 microM Zn, uptake did not change after 30 min. After simulated ruminal fermentation, the proportion of Zn in a soluble form was influenced by a source x concentration interaction (P = 0.03). After 18 h of incubation, the proportion of Zn that was soluble was not different between ZnProt and ZnSO(4) in buffered ruminal fluid that contained 10 microM added Zn, but was greater for ZnProt compared with ZnSO(4) with 200 microM Zn in the incubation. Zinc uptake from the aqueous fractions of simulated ruminal digestions containing 200 microM added Zn was greater (P < 0.01) than from those containing 10 microM added Zn. Zinc transport, based on detection of (65)Zn in serosal buffer, did not occur in any of the experiments. The results of the current experiments suggest that absorption of Zn into the bloodstream does not occur from the ruminant foresto-mach; however, Zn uptake occurs in ruminal tissue and is greater from ZnProt than from ZnSO(4).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.