AN ALTERNATIVE METHOD FOR ANALYZING FORAGE/LIVESTOCK SYSTEMS

A mixed integer program solves for profit-maximizing forage and beef enterprises. Dry matter, total digestible nutrients, and crude protein characterize livestock nutritional needs and production of warm and cool season forages.Livestock Production/Industries,

Buyer preferences for feeder calf traits

The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311

Knowledge, attitudes, and practices regarding ticks, tick-borne pathogens, and tick prevention among beef producers in Oklahoma

Tick-borne diseases are increasing in the United States, with regional need to understand how knowledge of ticks translates into preventative behavior among specific occupational groups. Little is known regarding what livestock producers know about ticks and their perceived personal and herd-based risk despite being one of the largest agro-industries in the United States. Using a nonprobability convenience sampling protocol, 183 beef producers representing 65% of the counties in Oklahoma completed a 15-question survey focused on knowledge of ticks and perceived risks ticks pose to their cattle and themselves, their methods of prevention (personal and their cattle), and sources of information. Most producers thought ticks were not a major problem for their cattle (58%), themselves, their families, and those who worked for them (66%). Most were personally concerned about spotted fever group rickettsiosis (79%) but had never heard of ehrlichiosis (9%). Eighty-five percent used at least one type of personal protective behavior, and 86% used at least one source of information for issues with ticks on their cattle. As the first published tick-focused survey involving livestock producers in the United States, it is apparent that beef producers in the central region are cognizant of ticks on their cattle and perceive ticks to be a risk on some level. However, increasing their knowledge of all areas of ticks and tick-borne pathogens, especially preventative measures for humans and cattle, is needed.Peer reviewedEntomology and Plant PathologyAnimal and Food Science

Vitamin E supplementation of newly arrived feedlot calves

Seven hundred fifteen crossbred (primarily British) calves purchased in southern Oklahoma and northern Texas auction barns were received at the Willard Sparks Beef Research Center, Stillwater, OK, and used to study effects of duration (days) of vitamin E feeding during a 42-d receiving period on animal performance, health, and serum cholesterol and vitamin E concentrations. Upon arrival, calves were blocked by load (seven loads), sorted by BW (light, n = 4 pens per load; and heavy, n = 4 pens per load), and assigned randomly to one of four dietary treatments (n = 2 pens per load; 14 pens per treatment). Experimental diets were formulated to provide 2,000 IU calf^-1 d^-1 of supplemental vitamin E (DL-alpha-tocopherol acetate) for 0 (CON), 7 (E7), 14 (E14), or 28 (E28) d. Vitamin E was delivered in a pelleted supplement that was added to the basal diet in decreasing concentrations as DMI increased (2.0 kg of DMI = 6%; 4.0 kg of DMI = 4%; and 6.0 kg of DMI = 2%). Serum samples were collected on d 0, 14, 28, and 42 for determination of cholesterol, alpha-tocopherol (d 0, 28, and 42), and antibody (IgG) concentrations. Duration of vitamin E supplementation did not affect ADG (0.98 kg/d; P = 0.56) or G:F (0.189; P = 0.87). Serum cholesterol concentrations decreased (day effect; P < 0.001) for all treatments from d 0 (average = 127 mg/100 mL) to 14 (average = 62 mg/100 mL). Serum alpha-tocopherol decreased (day effect; P < 0.001) from d 0 (5.2 micro-g/mL) to 28 (1.8 micro-g/mL); however, on d 28, a greater (P < 0.001) serum alpha-tocopherol concentration was observed for E28 (3.4 micro-g/mL) calves than for CON (1.1 micro-g/mL), E7 (1.2 micro-g/mL), or E14 (1.5 micro-g/mL) calves. Respiratory disease was diagnosed in 64.6% of calves in this study. Medical costs were less (P = 0.08) for calves fed vitamin E for 28 d ($4.88/calf) than for calves fed the control diet ($6.29/calf). Carcass characteristics were not affected (P = 0.19 to 0.88) by dietary treatments. Supplemental vitamin E formulated for 2,000 IU calf^-1 d^-1 had little influence on performance and overall health status of calves under our experimental conditions; however, the increased serum concentrations of alpha-tocopherol when vitamin E was fed for 28 d suggests that any potential effects of vitamin E on health status might be time-dependent.Peer reviewedAnimal ScienceVeterinary PathobiologyVeterinary Medicine OutreachStatistic

Feed Investment Study: Summary

The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311

Effects of including saponins (Micro-Aid\u3csup\u3e®\u3c/sup\u3e) on intake, rumenfermentation and digestibility in steers fed low-qualityprairie hay

Sixteen ruminally cannulated crossbred steers (529 ± 45 kg initial body weight, BW) wereused to evaluate in situ dry matter (DM), neutral detergent fiber (aNDF), and N degrada-tion characteristics of low-quality prairie hay, blood urea-N (BUN) and rumen fermentationparameters in steers provided a protein supplement with or without Micro-Aid®(MA; plantderived saponin). Steers were allowed ad libitum access to chopped prairie hay (49 g crudeprotein (CP)/kg DM and 738 g aNDF/kg DM) and randomly assigned to one of four treat-ments: (1) no supplement (C), (2) cottonseed meal and wheat middlings: 920 g DM/d (PC;positive control), (3) MA added to PC to supply 1 g MA/d (MA1), and (4) MA added to PCto supply 2 g MA/d (MA2). Steers were individually supplemented 920 g DM once daily at08:00 along with a vitamin and mineral mix to ensure requirements were met. Orthogonalcontrasts were used to determine the effects of protein supplementation, addition of MAand level of MA inclusion. During in situ phase, forage samples were incubated for a 96 hperiod. Protein supplementation increased DM intake (DMI), particulate passage rate (Kp),and rumen digestibility of DM and NDF (P \u3c 0.001), but there was no effect on rumen Ndegradability. The inclusion of MA did not impact DMI in either phase. Compared to PC,MA decreased Kp(27.8 and 22.7 g DM/kg/h, respectively; P = 0.02), resulting in an increasein rumen aNDF and DM digestibility (P \u3c 0.001). However, there was no influence of MA onapparent total tract digestibility in the metabolism phase. Rumen protozoa concentrationswere suppressed (P = 0.01) with MA inclusion while lactate concentrations and microbialcrude protein (MCP) flow to the small intestine were increased (P = 0.05). There was noimpact on BUN, rumen ammonia, pH, volatile fatty acid (VFA) concentrations or N balancefor MA compared to PC diets. Supplementation improved N balance, MCP synthesis andincreased total concentrations of VFA and independent acetate and propionate concentra-tions. In conclusion, including MA in protein supplements increased rumen DM and a NDFdigestibility of forage, reduced protozoa concentrations and increased daily outflow of MCP.This is indicative of increased rumen fermentation rate and may ultimately impact animalperformance via increased energy and amino acid supply to the small intestine. However,more research is needed to validate this potential impact on animal performance