Alexander M. Stelzleni

Growing Angus steers (n = 20) were blocked by weight and randomly assigned to one of two treatment groups: Control group (CON, n = 10) fed a feedlot ration ad libitum, or a ruminally protected hydrogenated fat-embedded calcium gluconate (HFCG) treatment group (HFCG, n = 10), which was fed the control ration top-dressed at 16 g/head/day for 55 days. During the slaughter process, digesta samples were collected from the cecum, colon, and rectum. Acetate concentrations were greater in the cecal and rectal digesta of steers (p ≤ 0.05) in the HFCG treatment group. Propionate concentrations were greater in the cecal, colonic, and rectal (p ≤ 0.05) digesta of steers in the HFCG treatment group. Butyrate concentrations were greater (p = 0.098) in the colon digesta of steers in the HFCG treatment group; however, they were not different in the cecal and rectal digesta. To determine the microbial composition within each section of the hindgut, DNA was extracted, and 16S rRNA gene sequencing was performed. Data were analyzed using a General Linear Model with dietary treatment as the main effect. Species richness in the cecum, colon, and rectum was not different between treatments. Erysipelotrichaceae, Peptostreptococcaceae, and Atopobiaceae abundances were increased (p ≤ 0.05) in the cecal bacterial community of steers in the HFCG group, while a significant decrease (p ≤ 0.05) in Rikenellaceae and Muribaculaceae abundances was recorded within the same bacterial community. In the colon bacterial community of steers in the HFCG group, Ruminococcaceae and Muribaculaceae abundances were elevated (p ≤ 0.05), while there was a reduction (p ≤ 0.05) in Lachnospiraceae, Erysipelotrichaceae, Atopobiaceae, and Peptostreptococcaceae abundances. Paeniclostridium, Romboutsia, and Turicibacter abundances were increased (p ≤ 0.05) in the cecal bacterial community of steers in the HFCG group, while there was a decrease (p ≤ 0.05) in Rikenellaceae_RC9 _gut_group abundance within the same bacterial community. In the colon microbiota of steers in the HFCG group, Turicibacter abundance was decreased (p ≤ 0.05). Supplementing growing steers with HFCG impacted some members of the bacterial populations, which have important roles in gut homeostasis and health, along with the formation of beneficial end-products in the gastrointestinal tract.

Objective: This study aims to assess the impact of aging time on the quality of meat, fatty acid profiles, and volatile compounds in cooked Thai native beef. Materials and Methods: The experiment utilized a randomized complete block design, where the aging time (0, 7, 14, 21, and 28 days) served as the treatment and the longissimus thoracis et lumborum muscle from Thai native cattle (n = 4) was considered a block. Results: Meat color and Warner-Bratzler shear force values decreased as the aging time increased. Furthermore, the moisture content decreased while the protein and ash content increased with a longer aging time. The proportions of fatty acids showed significant differences with varying aging times. These fatty acids exhibited the highest proportions in the 14-day dry-aged beef samples. The levels of short-chain aldehydes (pentanal, heptanal, octanal, nonanal, decanal, and 2-non¬enal) and alcohols (1-hexanol and 1-octanol) decreased as the aging time increased. However, there was an increase in long-chain aldehydes (tetradecanal, hexadecanal, heptadecanal, and octadecanal) with longer aging time. In addition, the levels of toluene, dodecane, tridecane, methyl-pyrazine, 2,5-dimethyl-pyrazine, trimethyl-pyrazine, and dimethyl trisulfide were higher in 14-day dry-aged beef compared to beef that had not been aged. Furthermore, a correlation was found between the number of the 6 significant fatty acids in the dry-aged beef samples and the 12 volatile compounds in cooked beef. Conclusion: Our results suggest that aging times significantly influence the fatty acid profiles of Thai native beef, which in turn are correlated with the characteristic volatile compounds.

The objective of this study was to determine the daily dietary nicotinamide riboside (NR) dose required to maximize the delay of subjective muscle fatigue onset. Barrows (N = 100) were assigned to one of five treatments: a conventional swine finishing diet containing 0 (CON), 15 (15NR), 30 (30NR), 45 (45NR) mg·kg body weight⁻¹·d⁻¹ NR, or CON supplemented with 45 mg·kg body weight⁻¹·d⁻¹ NR by drench or cookie dough (DRE). All treatments were administered for the final 11 days of feeding. On supplementation d 10, barrows individually experienced a performance test at 1.09 m/s until they were subjectively exhausted. Wireless electromyography (EMG) sensors were affixed to the biceps femoris (BF), tensor fascia latae (TFL), and semitendinosus (ST) to measure real-time muscle activity. There were no treatment effects for barrow speed (p = 0.57), a tendency for a treatment effect (p = 0.07) for distance, and a treatment effect (p = 0.04) on time to exhaustion. Barrows of the 15NR and DRE treatments had greater (p = 0.05) distances to exhaustion than CON barrows but did not differ from other NR barrows (p > 0.11). Barrows in the 45NR treatment did not differ (p = 0.11) in distance from 30NR barrows but tended to have a greater (p = 0.07) distance compared to CON barrows. All other treatment comparisons did not differ (p > 0.27). Barrows in the DRE treatment moved for longer (p < 0.01) than CON barrows, but all other treatments did not differ from each other (p > 0.15). There was no treatment × period interaction for all muscles’ root mean square (RMS) values (p > 0.16), but there were Period effects for all muscles (p < 0.01) and a Treatment effect (p = 0.04) in the TFL. For all muscles, period 4 had greater RMS values than all other periods (p < 0.01), who did not differ from each other (p > 0.29). In the TFL, CON barrows had greater RMS values during the performance test compared to all NR treatments (p < 0.02), who did not differ from each other (p > 0.18). Overall, NR demonstrates potential in being a useful tool in fatigue prevention, but efficient administration of the compound needs further investigation.

Ruminants are natural reservoirs of Shiga toxin producing Escherichia coli (STEC), and the STEC can be easily transferred to carcasses during the conversion of animals to meat. Three experiments were conducted to validate the efficacy of lactic acid (4%; LA), peroxyacetic acid (300 ppm; PAA), and hot water (80˚C; HW) for their individual or combined abilities to reduce STEC surrogates on bob veal carcasses pre- and post-chill and through fabrication. In experiment 1, hot carcasses (n=9) were inoculated with a 5-strain cocktail (ca. 8 log CFU/mL) containing rifampicin-resistant surrogate Escherichia coli ( E. coli ; BAA-1427, BAA-1428, BAA-1429, BAA-1430, and BAA-1431) and then treated with HW, LA, or PAA. Carcasses were then chilled (0±1°C; 24 h), split in half, and each side was treated with either LA or PAA. In experiment 2, hot carcasses (n=3) were inoculated and chilled (24 h). After 24 h, the carcasses were split, and each side was treated with either LA or PAA. For experiment 3, carcasses (n=3) were chilled for 24 h, split, inoculated, and treated with either LA or PAA. After chilling, carcasses from all three experiments were fabricated to subprimals and the cut surfaces were sampled to determine the translocation. Experiment 1 showed that LA+LA was the most effective ( P ≤ 0.05) treatment for reducing surrogate E. coli on veal. In experiments 2 and 3, LA and PAA were similar ( P > 0.05) in their abilities to reduce E. coli on chilled veal carcasses. In experiments 1 and 2, all antimicrobial treatments resulted in undetectable levels (< 0.2 log CFU/cm 2 ) of surrogate E. coli on cut surfaces after fabrication, while low levels (1.7 and 1.0 log CFU/cm 2 for LA and PAA, respectively) were observed in experiment 3. Of the antimicrobial interventions utilized, lactic acid was more effective for reducing STEC surrogate populations on veal carcasses, pre- and/or post-chill.

The objective of this study was to collect and interpret three-axis acceleration, temperature, and relative humidity data from six locations within commercial transport trailers shipping market-weight pigs. Transport was observed in Kansas (n = 15) and North Carolina (n = 20). Prior to loading, three-axis accelerometers were affixed to six locations on the trailers: top fore (TF), top center (TC), top aft (TA), bottom fore (BF), bottom center (BC), and bottom aft (BA) compartments. Data were post-processed to calculate root-mean-square (RMS) accelerations and vibration dose values (VDV) in the vertical direction and the horizontal plane. These values were compared with exposure action values (EAV) and exposure limit values (ELV), vibration levels deemed uncomfortable and potentially dangerous to humans. Additionally, RMS and VDV were compared among the trailer compartments. The vertical RMS accelerations for all compartments exceeded the EAV for loads measured in Kansas, and for the majority of the compartments measured in North Carolina. Many compartments, specifically the BA compartment from all trips, exceeded the vertical ELV. Regardless of where the data were collected, fewer compartments exceeded the EAV in the horizontal orientation. Only BA compartments exceeded the ELV in the horizontal orientation. There were Area × Level interactions for vertical and horizontal RMS and VDV (P < 0.01). The BF compartment had a greater vertical RMS value than the TF, TC, and BC (P < 0.02) compartments, but did not differ (P = 0.06) from the TA compartment. The vertical RMS of the TA compartment did not differ from the TF, TC, and BC compartments (P > 0.13). The BF compartment had a greater (P = 0.02) vertical VDV value than the TC location, but did not differ from the other locations (P > 0.16). All other locations did not differ in vertical VDV (P > 0.12). The BF compartment had greater horizontal RMS than the TC and TA compartments (P < 0.01), but did not differ from TF and BC compartments (P > 0.12). All other compartments did not differ in horizontal RMS (P > 0.34). All compartments, aside from the BA compartment, did not differ in horizontal VDV (P > 0.19). Vibration analyses indicated the BA compartment had the greatest vertical and horizontal vibrations and a large percentage of the compartments exceed the EAV and ELV, which indicated pigs may have experienced uncomfortable trips that could cause discomfort or fatigue.

ObjectivesWoody breast (WB) myopathy reduces the utility and value of breast meat for the broiler industry. It is hypothesized that WB meat may be included in comminuted products to increase utility and ultimately add value to the broiler industry. Information on the textural and quality characteristics that WB inclusion has on further processed products is limited in the literature. The objective of this research was to evaluate the quality of sausage made with WB meat of varying degrees of severity.Materials and MethodsFor each of three replications, broiler breast meat (normal, moderate WB, and severe WB) and chicken abdominal fat were obtained from a commercial poultry processor. Breast meat was coarse ground (19-mm) and combined with fat (targeting 15%) to produce 10-kg batches representing 25, 50, and 100% moderate WB meat, 25, 50, 100% severe WB meat, and a 100% normal control. The batches were then re-ground (4.8-mm), mixed for 1 min with 1.5% salt, and stuffed into 35-mm natural casings. Links were placed in individual bags, cooked to 70°C in a water-bath, and allowed to cool to room temperature before hardness, cohesiveness, springiness, gumminess, and chewiness were evaluated using texture profile analysis. Individual sausage links were weighed before and after cooking and cook loss was calculated. Data were analyzed using SAS version 9.3 with a fixed effects design with replication as a random effect.ResultsSausage hardness tended to be softer (P = 0.06) as WB inclusion rate and severity increased. Cohesiveness and springiness values were similar between treatments (P = 0.53, P = 0.95, respectively). Gumminess decreased (P < 0.05) as severity and inclusion of WB increased indicating a lack of bind, which was further supported by the decline in chewiness (P < 0.05). The raw 25% moderate WB and 50% severe WB sausage links were similar in lightness values (L*) to the normal sausage links. In cooked sausage, 25% and 50% inclusion of WB meat regardless of severity were similar in lightness values (L*) compared to the 100% normal formulations.ConclusionWith no difference in cook loss (P = 0.08), the data presented indicates that moderate and severe WB meat can be included in the formulation of linked sausages to increase utility and value of broiler WB meat.

ObjectivesBlade tenderization (BT) is used in the beef industry to improve tenderness of steaks prepared from subprimals but can translocate surface pathogens to the interior of meat. Application of antimicrobial solutions on the surface of subprimals prior to blade tenderization can reduce the risk of translocation of surface microorganisms. The objectives of this research were: 1) evaluate the efficacy of antimicrobial interventions applied to inoculated (surrogate Escherichia coli) beef striploins prior to blade tenderization; and 2) examine the transfer of E. coli from inoculated striploins to subsequent non-inoculated subprimals.Materials and MethodsThe anterior portion of whole muscle beef striploins (30.48 cm) were inoculated (lean side) across a 10 cm band with an approximately 8.00 log CFU/mL cocktail containing non-pathogenic, rifampicin-resistant surrogate STEC strains (BAA-1427, BAA-1428, BAA-1429, BAA-1430, and BAA-1431). The inoculated striploins were sprayed with (1) levulinic acid (5.0%) + sodium dodecyl sulfate (0.50%) (LVA+SDS), (2) peroxyacetic acid (2000 ppm; PAA; FCN 1666), (3) acidified sodium chlorite (1200 ppm; ASC), or (4) lactic acid (4.5%; LA) by passing through a spray cabinet and blade tenderized, along with an inoculated, non-sprayed control (CON). To evaluate the potential for cross-contamination of subsequent subprimals, an inoculated striploin (for each treatment) was blade tenderized followed by a non-inoculated beef striploin. For each striploin, surface and subsurface samples (2.54 cm wide) were collected from three different locations including the anterior, middle, and posterior end of each striploin. A total of 30 striploins across three replications were randomly assigned to treatment stratification. Sponge samples were also collected from the blade tenderizer (plate of the blade unit and blades) after each treatment group. Data were analyzed using Proc Mixed (SAS Inst., v.9.4; Cary, NC) as a completely randomized split-plot design. Microbial counts for all samples were log transformed and then analyzed for the main effects of antimicrobial treatment, location (anterior to posterior and surface or interior), and their interaction. Differences were considered significant at α ≤ 0.05.ResultsPAA was more effective in reducing E. coli populations (1.80 log CFU/g; P ≤ 0.05) and had lowest recovery of the microorganism from the striploin subsurface compared to other treatments, followed by LVA+SDS (1.00 log CFU/g). E. coli populations gradually decreased (P ≤ 0.05) on the surface and subsurface as sampling moved anterior to posterior. However, E. coli populations were similar (P > 0.05) on the posterior end of inoculated striploins and the anterior end of the subsequent, non-inoculated striploins, indicating transfer of microorganisms from one striploin to the following striploin. E. coli populations of 3.03 log CFU/cm2 and 2.47 log CFU/cm2 were recovered from the plate of the blade unit and the blades of the blade tenderizer. E. coli populations recovered from the plastic plate (3.46 log CFU/cm2) and blades (2.87 log CFU/cm2) of the blade tenderizer were the similar (P > 0.05) for all treatment groups except for PAA (1.41 log CFU/cm2 and 0.97 log CFU/cm2, respectively).ConclusionThese results showed that PAA and LVA+SDS can be used to improve the safety of blade tenderized beef.