In recent years, there has been a growing interest in feeding phytogenic products to poultry for their growth and health benefits. The objective of this experiment was to determine the effects of a phytogenic feed additive on turkey poult performance and digestive physiology over a 6-week brooding period. In total, 864 male Hybrid Converter turkey poults were obtained from a local commercial hatchery on day-of-hatch and placed into floor pens with clean pine shavings. The treatments were randomly assigned including an industry-type corn-soybean meal positive control (PC), a similar diet with a 1.5% reduction in crude protein and key amino acids (NC), or the NC with the addition of Digestarom® (PFA) included at a rate of 1 g/kg. Body weight gain (BWG), feed intake (FI), feed efficiency (FE), and mortality were recorded throughout the experiment. On day 14 poults fed the PFA had significantly higher BWG compared to the PC and NC fed birds. By day 42 birds fed the PC and PFA diets had significantly higher BWG compared to the NC, and the PC had significantly higher FE compared to the NC and PFA fed birds. No differences in FI or mortality were observed throughout the experiment. There were no significant differences in AMEn, crude protein digestibility, or nutrient transporter or pancreatic enzyme mRNA expression among treatments. However, aminopeptidase activity tended to be lower in the ileum of poults fed the PC or PFA diets compared to the NC, suggesting that the PFA may be improving protein utilization. Evaluation of a phytogenic feed additive on performance, nutrient digestion, and absorption in turkey poults Charles A. Zumbaugh III Abstract for General Public Recent regulations and customer demand have severely restricted the use of antibiotics in poultry production. Historically, antibiotics have been included in poultry diets at sub-therapeutic concentrations to improve performance and reduce disease incidence. Since this restriction, producers have experienced increased feed conversion ratio, decreased body weights, and increases in morbidity and mortality. Not only does this present an animal welfare issue, but producers experience decreased profits due to the decrease in performance associated with restricted antibiotic use. Many researchers are investigating the ability of alternative feed additives to help mitigate the lost performance this restriction has caused. One such alternative is a class of compounds known generally as phytogenic feed additives. These are herbs, spices, and associated products which can be included into the diet at relatively low concentrations. Previous research has demonstrated the ability of phytogenic feed additives to positively influence performance and gastrointestinal tract health, primarily in broiler chickens. Therefore, the objective of this thesis is to investigate the effect of a commercially available phytogenic feed additive on the performance, nutrient digestibility, and absorption in turkey poults over the first six weeks of feeding. Previous indications with th...

Mycotoxins are naturally-produced hazards that result from molds grown on cereal grains and other commodities. These molds may produce carcinogenic mycotoxins, which can be harmful to humans and animals. Removing broken kernels has been demonstrated to reduce mycotoxin concentration, but with high variability. Therefore, two experiments were conducted to quantify the magnitude of natural mycotoxin concentration that may be reduced by cleaning corn. Two loads of corn that were naturally contaminated with mycotoxins were procured. Corn for Experiment 1 was contaminated with aflatoxin (1,074 parts per billion; ppb), fumonisin (8.3 parts per million; ppm), and ochratoxin A (206 ppb), while corn for Experiment 2 was contaminated with only fumonisin (5.5 ppm). Corn was cleaned by mechanical sieving. For each experiment, corn was divided into twenty 150 kg runs. Runs were randomly assigned to 1 of 4 experimental treatments: 1) no screen 2) 12.7 mm screen, 3) 4.8 mm screen, and 4) 12.7 + 4.8-mm screen. The corn cleaner was sanitized between runs. Three 5 kg corn samples were collected from each run, and analyzed for mycotoxin concentration. In Experiment 1, cleaning reduced (P < 0.05) aflatoxin and fumonisin concentration by an average of 26% and 45%, respectively, compared to the original uncleaned corn level, but did not impact (P > 0.10) ochratoxin A. The resultant screenings had nearly 4 times the aflatoxin (4,224 ppb) and 7.5 times the fumonisin concentration (60.4 ppm) as the uncleaned corn. In Experiment 2, cleaning reduced (P < 0.05) fumonisin concentration by 32%. The resultant screenings had 19.6 times the fumonisin concentration (65.4 ppm) as the uncleaned corn. To determine the effect that cleaning corn may have on nursery pig growth performance, 360 nursery pigs were used in Experiment 3 to evaluate the impact of cleaning or pelleting on growth performance. Treatments were arranged in a 2 × 3 factorial with corn type (uncleaned vs. cleaned) and feed form (mash vs. pelleted from either mill A or B). Neither cleaning corn nor pellet mill type affected (P > 0.19) nursery pig growth performance. Pelleting improved (P < 0.0001) gain to feed ratio (G:F) by 7.6% compared to mash diets. These data suggest that cleaning is an effective method to legally reduce aflatoxin and fumonisin concentration, but does not impact animal growth performance. Screenings should be used cautiously when feeding to animals.

A total of 80 crossbred, high-risk heifers (initially 250 ± 4.2 kg BW), were transported from an Oklahoma City, Oklahoma sale barn to the Kansas State University Beef Cattle Research Center. Cattle were unloaded and randomly placed into one of four receiving pens and provided ad libitum hay and water. Each pen was randomly assigned to one of four rest-times before processing: 1) immediately upon arrival (0); 2) after a 6-h rest period (6); 3) after a 24-h rest period (24); and 4) after a 48-h rest period (48). After all cattle were processed, heifers were allotted into individual pens with ad libitum access to a receiving ration and water. Heifers were weighed individually on d 0, 7, 14, 21, 28 and 35 to calculate average daily gain (ADG). Feed added and refusals were measured daily to determine dry matter intake (DMI). A fecal egg count reduction test and analysis of blood serum metabolites were also conducted. All data were analyzed using the GLIMMIX procedure of SAS (v. 9.4, Cary, NC) with individual animal as the experimental unit. Processing time did not impact (P > 0.05) heifer BW or ADG. From d 0 to 35, DMI decreased linearly (P = 0.027) as rest time increased. The number of days for heifers to reach a DMI of 2.5% BW was linearly increased (P = 0.023) as rest time increased. There was no evidence of differences (P ≥ 0.703) among rest times for feed efficiency. While morbidity did not differ between treatments (P > 0.10), mortality increased linearly (P = 0.026) as the time of rest increased. A significant processing time × day interaction (P < 0.0001) was observed for the prevalence of fecal parasites, where the percentage of positive samples was significantly lower 14-d after anthelmintic treatment, regardless of the processing time. Serum IBR titer for heifers processed at either 0 or 6-h upon arrival was significantly higher (P < 0.01) on d 35 compared to d 0. Heifers processed after a 48-h rest period had significantly higher glucose values (P < 0.01) on d 0 compared to heifers processed at 0, 6, or 24-h. In summary, rest time prior to processing did not impact receiving calf growth performance. A 6-h rest period upon arrival appeared to be most beneficial to DMI. Anthelmintic treatment at processing reduced the parasitic load in heifers processed at all times. Vaccine titer did not increase after initial processing in heifers processed 24- or 48-h after arrival, indicating the seroconversion of IBR antibodies during the longer rest period.

The objective of this experiment was to evaluate the effect of grain sorghum inclusion on the apparent total tract digestibility of lamb diets. This experiment utilized 24 Rambouillet lambs (46.1 ± 3.90 kg) that were previously used in a growth experiment. Animals were housed in 1 of 24 pens with 1 lamb per pen and 6 pens per treatment. Lambs were randomly assigned 1 of the 4 treatment diets prior to the growth experiment and remained on the same treatment for over the 10-d experimental period. Treatments included 1) Control (0% sorghum inclusion); 2) Sorg10 (10% corn substituted for sorghum); 3) Sorg20 (20% corn substituted for sorghum); and 4) Sorg30 (30% corn substituted for corn). Diets were ground using hammermill and titanium dioxide was added to the ground diet at 0.4% as an indigestible marker. Lambs were fed these diets for 7-d prior to fecal sample collection to allow for steady-state marker concentrations. Fecal grab samples were collected every 6 hours over the final 3 d and were composited by animal to represent each 2-hour period of a 24-hour cycle. Feed and composited fecal samples were analyzed for crude fat, crude protein, ADF, NDF, and ash. Data were analyzed using the LM function in R with a fixed effect of treatment. Significance was defined at P < 0.05 and means were separated using Tukey’s HSD where appropriate. Sorghum inclusion did not affect (P > 0.16) crude protein, crude fat, or acid detergent fiber digestibility. Neutral detergent fiber digestibility was reduced (P = 0.02) for animals consuming Sorg20 and Sorg30 compared with the control, and Sorg10 was intermediate. Organic matter digestibility tended to decrease (P = 0.08) with increasing sorghum inclusion. In conclusion, replacing corn with sorghum at levels up to 30% had minimal impact on nutrient digestibility in growing lambs.

This experiment compared the performance response of supplementing corn gluten feed (CGF) or corn to calves grazing stockpiled tall fescue pastures over a 70-d period. Forty-four Angus x Simmental calves (238 ± 4 kg) were stratified across 6 treatments by BW and sex in a 2 x 3 factorial arrangement. Calves were supplemented cracked corn (n = 16) or CGF (n = 18). Calves were housed in 2 pastures and supplemented individually using the SmartFeed Pro feeding system, with all treatments represented in each pasture. Supplement DMI was programmed at 0.59, 0.87, or 1.13% BW. Calves which failed to train to the feeding system (n = 10) were treated as an un-supplemented control. Weight and flesh condition score (FCS) were recorded every 14-d, and ultrasound 12th rib fat thickness (FT) was measured on d 0 and 70. Data were analyzed with PROC GLM in SAS with supplement type as a main effect, sex as a fixed effect, and group as a random effect. Individual supplement DMI was included in the model as a covariate rather than a main effect due to high variation. Significance was defined at P ≤ 0.05 and means were separated using LSD. Initial BW, FCS, and FT were similar (P ≥ 0.12) among treatments. No differences (P ≥ 0.25) were observed in supplement DMI throughout the experiment. No differences (P ≥ 0.64) were observed in ADG and supplement G:F through 14 d. Through d 28 to 70, CGF-fed calves had greater (P ≤ 0.03) ADG and supplement G:F relative to corn-fed calves. Final FCS was greater (P < 0.01) for CGF-supplemented calves relative to those supplemented corn, though FT was not different (P = 0.87). These data indicate that supplementing CGF rather than corn yields a greater performance response in beef calves grazing stockpiled tall fescue.