Browsing by Author "Neary, Joseph M."
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Item Body weight and implant effects on animal performance, sera metabolites, and blood pressure in feedlot cattle(2017-11-14) Vogel, Tyler; Johnson, Bradley J.; Neary, Joseph M.; Sarturi, Jhones O.The study objective was to evaluate growth performance, sera metabolites, carcass characteristics and pulmonary arterial pressure as effected by body weight and implant status. Crossbred steers (n = 20) were used in a 2 × 2 factorial design: [body weight: light (L), or heavy (H); implant: Non-implanted (NoIMP), or Implanted (IMP)] with steer as the experimental unit. Initial weights for L and H steers were 398 ± 27.6 and 547 ± 25.2 kg, respectively. Implanted steers received a Revalor-200 (200 mg TBA + 20 mg E2, Merck Animal Health, Madison, NJ) on d 0. Cattle within treatments were group housed in common pens (n = 5 steers/pen). Bodyweight, blood samples, and pulmonary arterial pressure were collected on d 0, 14, 35, 70 and 104. Cattle were fed once daily to provide ad libitum access to feed. The finishing diet contained (DM basis) 13.3% CP, 2.13 Mcal/kg NEm, and 1.45 Mcal/kg NEg. Growth performance and carcass traits were analyzed using the MIXED procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC). Sera metabolites were analyzed as repeated measures over time, with day as the repeated measure. For all analyses, an α level < 0.05 determined significance. Heavy cattle consumed 2.2 kg more per head of DM daily than L cattle (10.14 vs 7.90 kg/d) and IMP steers consumed 1.0 kg more DM daily than NoIMP steers (9.52 vs 8.57 kg/d). Cumulative ADG did not differ between the L and H steers (1.41 vs 1.52 ± 0.06 kg; P = 0.20). Implanting increased (P < 0.01) ADG by 39 % (1.22 vs 1.70 ± 0.06 kg). No differences (P > 0.05) in ADG were observed in NoIMP vs IMP cattle beyond d 70 (1.21 vs 1.01 ± 0.16 kg; P = 0.38). Serum urea - N concentrations were lower (P < 0.01) in L cattle subjected to IMP during the study and tended to increase over time for the other treatments. Ribfat, HCW, LM, marbling score, calculated YG, and EBF were greater (P ≤ 0.05) in H vs L. IMP cattle had heavier HCW (P < 0.01) but decreased marbling scores (P = 0.05) compared to the NoIMP group. Mean pulmonary arterial pressure was greater (P < 0.01) for H vs L cattle which may predispose heavier cattle to right - sided heart failure. The steroid implant had no effect on pulmonary arterial pressure (P > 0.49). The study reaffirms the effects of implanting on growth performance and carcass characteristics in cattle. In addition, elevated BW leads to increased pulmonary arterial pressures which increases the risk of right sided heart failure.Item Body Weight and Steroidal Implants Impact Animal Growth Performance, Sera Metabolites, and Pulmonary Arterial Pressure in Feedlot Cattle(2020) Vogel, Tyler A.; Neary, Joseph M.; Smith, Zachary K.; Johnson, Bradley J.The study objective was to evaluate steer growth performance, sera metabolite responses, carcass characteristics, and pulmonary arterial pressure as affected by body weight at time of implantation and steroidal implant administration. Crossbred steers (n = 20) were used in a 2 × 2 factorial arrangement of treatments in a completely randomized design experiment, Factors included: body weight: light (L), or heavy (H) and implant: Non-implanted (NoIMP), or Implanted (IMP) with steer serving as the experimental unit for all analyses. Initial weights for L and H steers were 398 ± 27.6 and 547 ± 25.2 kg, respectively. Implanted steers received a terminal implant (200 mg trenbolone acetate and 20 mg estradiol-17β; Revalor-200; Merck Animal Health, Madison, NJ) on d 0. Cattle within treatments were group housed in common pens (n = 5 steers/pen). Bodyweight, blood samples, and pulmonary arterial pressure were collected on d 0, 14, 35, 70 and 104. Cattle were fed a common diet once daily to provide ad libitum access to feed. The finishing diet contained (DM basis) 13.3% CP, 2.13 Mcal/kg NEm, and 1.45 Mcal/kg NEg. Growth performance (body weight and ADG) and carcass traits were analyzed using the MIXED procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC). Sera metabolites were analyzed as repeated measures over time, with day as the repeated measure. For all analyses, α level < 0.05 determined significance. Heavy steers consumed 2.2 kg more per head of DM daily than L cattle and IMP steers consumed 1.0 kg more DM daily than NoIMP steers. Cumulative ADG did not differ between the L and H steers (1.41 vs. 1.52 ± 0.060 kg; P = 0.20). Implanting increased (P < 0.01) ADG by 39% (1.22 vs. 1.70 ± 0.060 kg). No differences (P > 0.05) in ADG were observed in NoIMP vs. IMP cattle beyond d 70 (1.21 vs. 1.01 ± 0.16 kg; P = 0.38). Sera urea-N concentrations were decreased (P < 0.01) in L cattle subjected to IMP during the study and tended to increase over time for the other treatments. Ribfat, HCW, LM, marbling score, calculated YG, and estimated EBF were greater (P ≤ 0.05) in H compared to L. Steers from IMP had heavier HCW (P < 0.01) but decreased marbling scores (P = 0.05) compared to NoIMP. Mean pulmonary arterial pressure was greater (P < 0.01) for H compared to L steers which may predispose heavier cattle to right-sided heart failure. The steroid implant had no effect on pulmonary arterial pressure (P > 0.49). The study reaffirms the effects of implanting on animal growth performance and carcass characteristics in cattle. In addition, elevated BW leads to increased pulmonary arterial pressures which may increase the risk of right-sided heart failure.Item Confined versus conventional cow-calf management systems: Implications for calf health(2017-05) Burson, William C.; Rathmann, Ryan J.; Bernhard, Bryan C.; Sarturi, Jhones O.; Neary, Joseph M.; Jackson, Samuel P.The objective of the current research was to determine the effects of confined versus conventional cow-calf management systems on calf health. In the first experiment, the goal was to evaluate production parameters at the time of calving, calf morbidity/mortality, and growth performance in two variations of confined cow-calf management systems relative to a conventional, pasture-based system from the time of calving until weaning. A total of 250, British x Continental crossbred, pregnant, first-calf heifers were blocked by breeding service type (AI vs. natural) and assigned to one of three treatments within a randomized complete block design: 1) Conventional, pasture-based calving system (PAS) (n = 84; BW = 505.05 ± 40.51 kg); 2) Continuously confined calving system (CONF) (n = 83; BW = 507.36 ± 44.89 kg); and, 3) Sandhills calving system (SH) (n = 83; BW = 502.51 ± 54.37 kg). Immediately prior to calving, the PAS assigned heifers were moved to an 80-acre, split-fenced pasture containing dormant, improved grasses. The CONF cattle were assigned to feedlot pens (2 pens/block; 20-21 hd/pen) and remained in this location from the beginning of calving until the time of weaning. The SH cattle began in pens identical to CONF; however, after half of the heifers in the pen calved or no more than 14 d from the beginning of calving, remaining bred heifers were moved to a clean pen (4 pens/block; 10 to 11 hd/pen). Supplemental colostrum was provided only to calves born in confinement. The relative proportion of normal and minimally assisted births versus extremely difficult births was increased in the confined treatments (P = 0.03). The PAS calves experienced a greater incidence of failure of passive transfer when compared to calves born in the SH treatment (P = 0.01) and tended to differ from calves born in the CONF group (P = 0.06). Calf morbidity rates differed among all treatments (P ≤ 0.01) (CONF, 68.49%; SH, 47.37%; PAS, 2.47%). Furthermore, the incidence of calf scours was reduced in SH vs. CONF (P = 0.03). Mortality was increased in confined treatments relative to PAS (P < 0.01). At weaning, antibody titers against BVD1 and BRSV were reduced in PAS compared to confined treatments (P ≤ 0.04). Calves in the PAS treatment demonstrated greater ADG and weaning weight relative to the confined treatments (P ≤ 0.03). Data from this evaluation suggest that impaired health and subsequent growth performance of calves born in a feedlot setting could dramatically influence the profitability of confined cow-calf operations. In the second experiment, the objective was to characterize the immune and clinical response of calves that were raised in two variations of confined management systems relative to a conventional system when challenged with infectious bovine rhinotracheitis (IBR) and Mannheimia Haemolytica (MH). Preconditioned steer calves (n = 24) were used within a completely randomized design to evaluate the effects of management systems. The previously imposed treatments were: 1) Conventional, pasture-based production system (PAS) (n = 8; BW = 272.90 ± 27.51 kg); 2) Continuously confined production system (CONF) (n = 8; BW = 234.24 ± 17.74 kg); 3) Sandhills production system (SH) (n = 8; BW = 241.95 ± 35.83 kg). Calves were challenged with an intranasal dose of IBR and placed in a barn containing individual stalls. After 72 h, cattle were administered an intratracheal dose of MH. At -72, 0, 2, 6, 12, 24, 48, 72, 168, and 336 h relative to MH inoculation, rectal temperature (RT) was measured and cattle were assigned a clinical severity score (CS). Additionally, peripheral blood was collected via jugular venipuncture at strategic time points for the evaluation of: 1) proinflammatory cytokines; interleukin-1 beta (IL1), interleukin-6 (IL6), tumor necrosis factor-alpha (TNFa), and interferon-gamma (INFy); 2) haptoglobin; 3) hematology; and, 4) antibody titers. Calves from the SH treatment exhibited the greatest RT following immune challenge when compared to either CONF or PAS calves (P < 0.01). Furthermore, CONF calves recorded greater RT when compared to the PAS treatment (P < 0.02). Calves in the SH treatment exhibited the greatest CS over time (P < 0.01). The concentration of INFy, IL1, and IL6 was reduced in PAS cattle when compared the confined treatments (P ≤ 0.01). Calves in the SH treatment demonstrated the greatest concentration of haptoglobin when compared to the PAS and CONF groups (P ≤ 0.01). A treatment related tendency was detected (P < 0.01); SH calves tended to demonstrate reduced VN titers 7 d post-MH relative to the CONF and PAS treatments. These results indicate that management systems can exert an influence on immune responsiveness. Cattle from the SH treatment exhibited the most apparent difficulty coping with disease. This conclusion was supported by increased RT, CS, and haptoglobin concentration; furthermore, SH cattle tended to demonstrate a weaker antibody response to IBR. Collectively, both experiments indicate that considerable challenges exist when operating the cow-calf enterprise in confinement; thus, management strategies to improve performance in these management systems should be further investigated.Item Development of phamaceutical strategies to mitigate the negative effects of stress on pigs undergoing segregated early weaning (SEW)(2017-05) Wooten, Hailey; Rakhshandeh, Anoosh; McGlone, John J.; Neary, Joseph M.While beneficial for sow productivity and biosecurity, weaning before 4 weeks of age leads to systemic inflammation and adversely impacts the digestively physiology and post weaning growth of pigs. Cortisol and catecholamines influence immune function and shift metabolism as part of the stress response during weaning. However, little is known about the extent of their effects during weaning. We conducted two studies to evaluate the effect of a cortisol agonist (dexamethasone; DEX), cortisol antagonist (metyrapone; MET), and a catecholamine derived beta agonist (ractopamine; RAC) on growth performance, immune system stimulation, and intestinal health of early weaned pigs. All weaned pigs were fed a corn-soybean meal based starter diet (14.2 MJ/kg ME and 9 g/kg SID lysine). In the first study, 32 gilts and 32 barrows (BW 4.8 ± 0.7 kg) were weaned at 21 ± 1 days of age and placed in treatment groups based on a 4 x 2 factorial arrangement in a completely randomized design. The main factors were i) sex (barrow vs. gilt), and ii) treatment (Control, 0.2 mg DEX/kg of BW, 0.6 mg DEX/kg of BW, and 1.0 g MET/kg of BW). Body weight (BW) was measured 24 h prior to weaning, at weaning, every 24 h post weaning for 7 d, and then once a week until 49 ± 1 d of age. Overall DEX treated pigs had higher BW than control pigs (P < 0.02). However, there was a sex effect (P <0.01) and sex*treatment effect (P <0.01). Gilts receiving the 0.2 and 0.6 DEX doses had higher BW than control gilts (P < 0.01). Compared to control barrows, 0.2 dose DEX treated barrows had lower BW and while 0.6 dose barrows had no differences in BW. Both MET treated barrows and gilts had higher BW than control gilts (P < 0.05) and a tendency to have higher BW than control barrows (P < 0.10). In the second study, 30 gilts (BW 5.6 ± 0.85 kg) were randomly placed into 5 treatment groups (n=6); suckling treated with saline (UWS), weaned treated with saline (CON), weaned treated with 0.2 mg DEX/kg BW (WCA); weaned treated with 0.25 mg RAC/kg BW (RAC), and weaned treated with both DEX and RAC (WCA+RAC). The UWS group remained with the sow for the duration of the study while all other groups were weaned at 23 ± 2 d of age. Body weight (BW) was measured daily and blood plasma was collected 0, 24, 96, and 120 h post weaning. All gilts were euthanized 120 h post weaning and mucosal scrapings/tissue samples of the jejunum were collected for histomorphology and gene expression analysis. WCA pigs had higher BW than CON (P < 0.01) while both RAC and WCA+RAC pigs did not. Plasma levels of IL-1β and haptoglobin were lower in WCA pigs compared to CON (P < 0.02). Plasma total antioxidant capacity was higher in WCA pigs compared to both CON and UWS groups (P < 0.01). Jejunum tissue of WCA pigs had a higher gene expression of claudin-4 and a lower expression of IL-18 than CON (P < 0.01). Jejunum mucosal scrapings of WCA pigs had a lower expression of IL-18 than CON pigs (P < 0.02), but no differences in the gene expression of tight junction proteins. Together the results from both studies suggest that treating with a cortisol agonist improves post weaning growth by subsiding systemic inflammation and potentially improving barrier function, but the optimum dose is dependent on sex.Item Effects of various nutritional supplements on the development, innate immunity, and gastrointestinal health of young dairy calves(2018-08) Liang, Yu; Ballou, Michael A.; Machado, Vinicius; Neves, Rafael; Neary, Joseph M.; Hall, Nathaniel J.The neonatal calves are extremely susceptible to enteric diseases during the first few weeks of life. According to the report form USDA, the mortality rate of newborn calves is about 10%; however, the death caused by enteric diseases accounts for 50% of mortality. On the other hand, antimicrobials are widely used in the dairy industry in the past decades; but the concern has been increased for using antibiotic in recent years. Therefore, there is more interesting to find alternatives to antibiotic use which has similar efficacy as antibiotic in decreasing diseases. Some studies have been conducted to investigate effects of those nutritional supplements on growth performance and health on swine and poultry industry. For current research, yeast cell wall, various strains of probiotic, egg protein, and hydrolyzed yeast will be investigated for effects on growth performance, innate immunity, and gastrointestinal development in young dairy calves. In first study, effects of Provia® (Bacillus coagulans 6086) and OmniGen AF® alone or in combination on growth performance, innate leukocyte responses, and enteric health of pre-weaned and immediate post-weaned dairy calves were evaluated. Treatments in this study were: CON: base milk replacer and calf starter; PV: 2 x 109 CFU/d of Bacillus coagulans 6086 in milk replaer and 2 x 109 CFU of Bacillus coagulans 6086 per kg of the base calf starter; OG: 12g/d of OmniGen-AF in milk replacer and 12 g of OmniGen-AF per kg of the base calf starter; OG+PV: supplement with both of the Bacillus coagulans 6086 and OmniGen-AF. The PV supplemented calves had greater ADG from d 71 to d 84 during post-weaning period. There were no treatment differences in the percentage of calves that scoured throughout the study. The results of this study indicated that neither Provia, Bacillus coagulans 6086 nor OmniGen-AF greatly influenced the growth performance or enteric health during the pre-weaned or immediate post-weaned periods. The impact of a blend of a strain of Lactobacillus casei and an Enterococcus faecium strain on physiological response to an oral Salmonella enterica serotype Typhimurium challenge in neonatal Jersey calves was investigated in second study. The treatments in this study were: CON: base milk replacer; CON+ST: base milk replacer with Salmonella typhimurium challenge on d 7; PRO+ST: base milk replaer with a blend of a strain of Lactobacillus casei and an Enterococcus faecium strain and challenged with Salmonella typhimurium on d 7. Serum haptoglobin and urea N concentrations were increased on d 10 in CON+ST comparing to PRO+ST. In contrast, PRO+ST had greater rectal temperature after challenge than CON+ST. Further, neutrophil percentages in PRO+ST were greater than CON+ST or CON. However, 7 of 8 calves in PRO+ST had elevated neutrophil percentages on d 10 relative to d 7, whereas 4 of 8 calves among the CON+ST had reduced neutrophil percentages on d 10 relative to d 7. The ratios of villi height to crypt depth in both of duodenum and ileum were greater in PRO+ST than CON+ST calves. These data indicated that supplementing neonatal calves with the blend of probiotics used in the current study improve the pathophysiological response and small intestinal health and development with an enteric Salmonella typhimurium challenge. The objective of final study is to determine the impacts of supplementing a blend of yeast culture, yeast extract, hydrolyzed yeast, and immunized egg antibodies on the growth performance and health of calves challenged with Salmonella typhimurium. There are 4 treatments in current study: CON: base milk replacer; CON+ST: base milk replacer with Salmonella typhimurium challenge on d 7; CA: milk replacer supplemented with 16 mL/d CalfAce; CA+ST: base milk replacer supplemented with 16 mL/d CalfAce and challenged with Salmonella typhimurium on d 7. The calves with challenge had decreased starter intakes. CalfAce supplementing calves decreased serum haptoglobin concentration. Calves supplemented with CalfAce had greater villi height to crypt depth ratio in duodenum when compared to non-supplemented calves. In conclusion, CalfAce supplementing calves reduced both of systemic and local inflammatory response and improved the gastrointestinal health.Item Evaluation of yeast, nonsteroidal anti-inflammatory, and metaphylaxis products in feedlot cattle: Mitigation of bovine respiratory disease and feedlot performance(2018-08) Word, Alyssa Brook; Ballou, Michael A.; Carroll, Jeffery A.; Burdick Sanchez, Nicole; Neary, Joseph M.; Holland, BenBovine respiratory disease (BRD) is the leading cause of morbidity and mortality in United States feedlots. Economic consequences associated with BRD include treatment costs, potential performance reduction, and increased labor requirements. Feedlot BRD is historically difficult to study as it is a disease of multi-factorial nature with low predictability. Therefore, improved means of BRD prevention and treatment as well as improved methods of studying BRD in newly received feedlot cattle continue to be important factors in reducing this economic burden and improving beef cattle health. The objective of the first study was to evaluate the feeding of a combination Saccharomyces cerevisiae live yeast and S. cerevisiae yeast cell wall supplement compared to a negative control in beef heifers administered a BRD challenge. Thirty-two heifers were challenged intra-nasally with 1 × 108 plaque forming units (PFU) of Bovine Herpesvirus-1 (BHV-1) followed by of 3.0 × 107 colony forming units (CFU) of Mannheimia haemolytica 72 h later. Blood was collected for 72 h following the M. haemolytica challenge. Heifers fed yeast had similar vaginal temperature to control heifers and serum concentrations of cortisol, leukocyte, haptoglobin, and NEFA were unaffected by the inclusion of dietary yeast (P ≥ 0.13). However, concentrations of serum glucose were greater (P = 0.01) in cattle fed yeast when while serum concentrations of urea N were decreased (P = 0.03) when cattle were fed yeast. While feeding the combination live yeast and yeast cell wall supplement did not affect the response of the immune variables measured to a BRD challenge, some aspects of the metabolic response to a live BRD challenge were improved when yeast was included in the diet. The objective of the second study was to evaluate the effects of inclusion of the same combination live yeast and yeast cell wall product in the diet of feedlot heifers on growth performance, carcass characteristics, and health during the feeding period. A generalized randomized complete block design with 2 time blocks, 2 treatments, and 8 pen replications per treatment (70 heifers/pen) was used in heifers fed for 166 d. Live growth performance measured by final BW, ADG, DMI, and G:F were not affected by the dietary inclusion of yeast (P ≥ 0.40). Similarly, carcass characteristics including HCW, dressing percentage, and distribution of quality and yield grades were unaffected by the dietary inclusion of yeast (P ≥ 0.28). Morbidity and mortality were also unaffected by treatment (P ≥ 0.14). Inclusion of the live yeast and yeast cell wall product did not affect the feedlot performance or overall health of heifers experiencing low morbidity and mortality during the feeding period. The third study was conducted to evaluate the effects of altered timing of administration of transdermal flunixin meglumine (FM) on the immune and metabolic response of beef heifers administered a BRD challenge. All heifers were challenged intra-nasally with 1 × 108 PFU of BHV-1 followed by 1.18 × 106 CFU of M. haemolytica 72 h later. Four treatments were used where transdermal FM was applied at the time of arrival, at the time of BHV-1 challenge, at the time of M. haemolytica challenge, or not at all (8 heifers/treatment). Vaginal temperature was similar when transdermal FM was applied at arrival or not at all, but reduced when transdermal FM was applied at the time of BHV-1 or M. haemolytica challenge (P = 0.04). Immune and metabolic variables measured including leukocyte counts, pro-inflammatory cytokines, NEFA, urea N, and haptoglobin were unaffected by administration of transdermal FM for 72 h following the BRD challenge (P ≥ 0.16). However, neutrophil oxidative burst capacity and L-selectin expression decreased following administration of transdermal FM (P ≤ 0.09). Application of transdermal FM was therefore effective for the reduction of pyrexia when applied during the BHV-1 or M. haemolytica challenge without affecting the immune or metabolic response to the BRD challenge, with the exception of a slight reduction in neutrophil functionality that could result in reduced neutrophil associated inflammation in cattle receiving transdermal FM. The fourth study was conducted to evaluate a multi-site field experimental design used to study relative efficacies of metaphylaxis products in feedlot cattle at high-risk for the development of BRD. Four locations enrolled 5,222 steers, bulls, and heifers in 3 treatments: gamithromycin (Zactran, 6 mg/kg BW), tildipirosin (Zuprevo, 4 mg/kg BW), or tulathromycin (Draxxin, 2.5 mg/kg BW) administered on-arrival. Treatments were mixed within pens and data were analyzed as a nested design such pen was nested within feedlot location. No treatment × feedlot interactions were detected for any variable analyzed (P ≥ 0.11). Morbidity from BRD was reduced in cattle receiving tulathromycin compared to tildipirosin, and tildipirosin compared to gamithromycin. Mortality was reduced in tulathromycin and similar between tildipirosin and gamithromycin. Similarly, HCW was heaviest when cattle received tulathromycin and similar between tildipirosin and gamithromycin. Advantages of the study design included the spread of labor and infrastructure strain associated with BRD outbreaks in large groups of cattle over multiple feeding locations and over time, theoretically equal exposure of animals in all treatments to pathogen exposure or any other random variation associated with pen, and the increased probability of consistent blinding of feedlot personnel to treatment. Disadvantages included the difficulty of measuring treatment feed intakes, limitation to studying means of prevention that are applied directly to the animal, and difficulty in enforcing different post-metaphylaxis intervals for each treatment. These data support the continued need for BRD research in the feedlot setting. While the inclusion of S. cerevisiae in the diet may affect some aspects of the metabolic response when cattle are immunologically challenged, these data do not support improvement to feedlot performance when cattle are at low-risk of BRD development. Furthermore, these data provide some evidence that application of transdermal FM during a BRD event could be an effective means of pyrexia reduction without affecting the immunological and metabolic responses to a BRD challenge, and with minimal reduction in leukocyte functionality. Finally, a multi-site field model where animals within treatment are mixed in a pen could provide a viable alternative to the randomized complete block design for the field study of BRD where large numbers of cattle at high-risk for BRD development are enrolled at one time and where infrastructure or labor limitations exist.Item Immunological effects of pre-weaning plane of nutrition and yeast fermentation products on respiratory disease in dairy calves(2016-11-21) Sharon, Kate; Ballou, Michael A.; Carroll, Jeffery A.; Trojan, Sara J.; Neary, Joseph M.; Burdick Sanchez, NicoleRespiratory disease continues to be responsible for the majority of morbidity and mortality in cattle. Explanations for this are many; however some influences may include early-life nutrition, stress and other immune-compromising factors. In addition, routine antibiotic usage is being increasingly scrutinized. For this reason, both improved management practices and alternative therapies are significant. Early-life nutrition can influence productivity later in life; therefore, potential improvement of disease resistance during the pre-weaning period may be possible. Natural immune-enhancing products are also proving to be beneficial. Yeast products, specifically Saccharomyces cerevisiae and its derivatives have been shown to enhance immune variables. Bovine respiratory disease complex (BRDC) includes viral and bacterial pathogens; two specific pathogens include BHV-1 and M. haemolytica. A sensible disease model includes both a viral and bacterial component to emulate a BRDC infection. Limited data are available in combined viral-bacterial challenges; therefore, multiple doses of M. haemolytica were utilized. This challenge model aimed to induce morbidity but not induce mortality. In the first study, the objectives were to determine if pre-weaning plane of milk replacer nutrition influenced health and performance of high-risk Holstein bull calves. Calves were fed either a high (HPN; 830g DM/d of milk replacer during the first 10 d and 1080g from 11d until weaning) or a low plane of milk replacer nutrition (LPN; 445g DM/d of milk replacer until weaning) through weaning. Calves fed the HPN performed better than LPN calves in the first 25 d both in ADG and G:F as well as having greater final body weights. However, calves on the HPN had greater incidence of bloat and scouring but there was no difference in antibiotic treatment frequency. The results of this study suggest risk for gastrointestinal issues is greater in HPN calves, but performance is improved. In the second study, the effect of plane of milk replacer nutrition and M. haemolytica (MH) dose were studied in Holstein calves during a viral-bacterial respiratory challenge. Calves were challenged with 1.5 x 108 PFU/mL/nostril of bovine herpesvirus-1 (BHV-1) and with either 106, 107, or 108 CFU of MH 3 d later. Four LPN calves either died or were euthanized soon after the 144 h observation period, while all HPN calves survived the entire observation period. Calves previously fed a LPN had greater plasma haptoglobin and neutrophil concentrations as well as greater rectal temperature during the BHV-1 challenge. Haptoglobin and neutrophil concentrations as well as inflammatory cytokines were greatest in calves receiving the highest MH dose at various time points following the MH challenge. The BHV-1 neutralizing antibody titer dilution concentrations were similar between treatments immediately before the BHV-1 challenge; however, 9 d after the challenge the HPN calves had greater antibody titers compared to LPN calves. These data demonstrate that greater doses of MH increase the acute inflammatory response and prolong inflammation and that calves previously fed a LPN responded more severely to the combined viral-bacterial respiratory challenge. The second study also investigated metabolic responses to a combined viral-bacterial respiratory challenge. Calves previously fed a HPN were heavier than LPN calves; however no difference in ADG or starter intake per kg BW0.75. Serum glucose concentrations were greater throughout the challenge in HPN calves. Following the MH challenge, LPN calves had numerically greater serum NEFA and serum urea nitrogen concentrations. Further, calves receiving 108 MH had the greatest NEFA concentrations. Calves fed a LPN during pre-weaning appeared respond more severely by evidence of reduced glucose concentrations and increased NEFA concentrations suggesting intensified immune cell energy requirements and a more severe infection. Calves fed a LPN during pre-weaning may experience greater disease during a respiratory challenge. In the third study, the effects of a Saccharomyces cerevisiae fermentation product, NutriTek (Diamond V, Cedar Rapids, IA), on leukocyte functionality and ex vivo cytokine production during a dexamethasone (DEX) challenge was studied. Holstein steers were supplemented with 0, 20, 40, or 60 g/head/d of NutriTek. Dexamethasone was administered via jugular catheter at 0.1 mg/kg BW at 0, 6, and 12 h. Total leukocytes counts and neutrophil concentrations increased with NutriTek dose. NutriTek did not affect neutrophil L-selectin concentration. Phagocytosis and oxidative burst function recovered better in neutrophils and monocytes with increasing NutriTek dose. Overall, NutriTek supplementation influenced peripheral neutrophil concentrations and may have increased recovery of neutrophil and monocyte function. In the fourth study the effects of a Saccharomyces cerevisiae fermentation product, NutriTek (Diamond V, Cedar Rapids, IA), fed to Holstein steers during a viral-bacterial respiratory challenge was investigated. Holstein steers were supplemented with 0, 20, 40, or 60 g/head/d of NutriTek. All calves were challenged with 1.5x108 PFU/mL/nostril of bovine herpesvirus-1 and with 106 CFU of M. haemolytica (MH) intratracheally 3 d later. NutriTek did not affect rectal temperature or total leukocytes counts and peripheral neutrophils. However, there was evidence for acute effects of NutriTek as lymphocyte concentrations were different among treatments. Inflammatory markers, including serum haptoglobin and ex vivo TNF-α production were not affected. These results indicate that NutriTek may influence some acute leukocyte responses during a viral-bacterial respiratory challenge, but did not have strong influences on measures of inflammation or disease. Overall, these data support there are differences in inflammatory and metabolic responses in calves fed different planes of nutrition during respiratory disease. Calves fed greater planes of nutrition may benefit during disease. Further, Saccharomyces cerevisiae fermentation product, NutriTek (Diamond V, Cedar Rapids, IA) may influence some leukocyte populations and function. However, these data cannot conclude significant immunological effects from this product.Item Investigations into antioxidant effects of rutin supplementation on neonatal Holstein calves and broilers(2019-08) Shellenberger, Nicholas; Neary, Joseph M.; Machado, Vinicius; Ballou, Michael A.The purposes of this study were to determine if the naturally occurring flavonoid quercetin, as its glucorhamnoside rutin, has favorable effects on reducing gastrointestinal permeability and reducing susceptibility to hypoxia-induced pulmonary hypertension in neonatal Holstein calves. A 2 x 2 between-subjects factorial design was conducted using Holstein steers (n = 16). Factors included oxygen-level (simulated altitude of 4,572 m versus 975 m) and quercetin supplementation as its glucorhamnoside rutin (4g of quercetin per day versus 0 g per day). Two-days post-arrival (Day 0 of study) the calves were blocked by body mass into treatment groups and both treatments initiated. Pulmonary arterial pressures were measured on Day 12. On Day 14, calves were orally administered lactulose (0.45 g/kg) and mannitol (0.15 g/kg) and serum concentrations of these substances measured by high performance liquid chromatography mass spectrometry four-hours post feeding. Calves were euthanized on Day 15 and tissue sections collected from the lung, liver, jejunum, and ileum for histological evaluation and semi-quantitative scoring of lesions. Hypoxia, but not rutin (P ≥ 0.31), was found to be associated with intestinal permeability. The lactulose-mannitol ratio was 0.54 ± 0.13 in hypoxic calves and 0.02 ± 0.13 in normoxic controls (P = 0.02). Hypoxia (P < 0.001) and, possibly, rutin (P = 0.07) were associated with mean pulmonary arterial pressure. There was a tendency toward a hypoxia-rutin interaction (P = 0.13). Calves fed rutin under hypoxic conditions (mPAP = 59 ± 7 mm Hg) had a lower mPAP than calves that were not fed rutin (mPAP = 80 ± 7 mm Hg) (P = 0.13). Under normoxic conditions calves fed rutin (mPAP = 30 ± 7 mm Hg) had similar mPAP to control calves (mPAP = 28 ± 7 mm Hg). Paradoxically, however, a greater proportion of calves fed rutin had histological evidence of pulmonary arteriolar hypertrophy (P = 0.045) and adventitial hyperplasia (P = 0.01) than negative controls. In conclusion, the findings of this study indicate that hypoxia deleteriously increases intestinal permeability in neonatal calves. The flavonoid quercetin, as its glucorhamnoside rutin, had no protective effect on intestinal permeability and, although it tended to reduce the severity of hypoxia-induced pulmonary hypertension, a greater proportion of calves fed rutin had histological lesions consistent with pulmonary arteriolar remodeling.The purposes of this study were to determine if the natural antioxidants quercetin and curcumin have favorable effects on growth performance and physiology of growing broiler chickens. A completely randomized design was conducted using Cornish x White Rock cross commercial broilers (n = 72). Three weeks after arrival (Day 0 of the study), the birds were randomly divided into four treatment groups: control, quercetin, quercetin plus curcumin (low), and quercetin plus curcumin (high). Oxyhemoglobin saturations and weight of the birds were measured once per week. At six weeks of age the broilers were euthanized, and the hearts of three representative birds from each pen were dissected and weighed for calculation of the right: total ventricular weight ratio (RV:TV ratio). The spleen and liver were also dissected and weighed to compare organ weights across all treatment groups. In addition, feed consumption was measured daily by weighing feed containers each time new feed was added. There were no significant differences in final weights among treatments (P = 0.15). The mean ± SD of the birds at the end of the study (wk. 6) was 2666 ± 316 g. The feeding of antioxidants had no effect on oxyhemoglobin saturation (P = 0.46). Paradoxically, however, oxyhemoglobin saturation increased by two percent per week over the course of the study (P < 0.001). Liver weight (P = 0.31), spleen weight (P = 0.23), and total ventricular weight ratio (P = 0.34) were all not effected by treatment. In addition, feed conversion ratio by week was not found to be different among treatment groups (P = 0.97). The feeding of antioxidants did effect blood antioxidant concentration among treatment groups (P = 0.0001), with controls having the lowest blood antioxidant concentration, followed by low dose quercetin and curcumin, quercetin only group, and finally high dose quercetin and curcumin. In conclusion, the findings of this study suggest that supplementation of the diet fed with quercetin, curcumin, or combination of both did not have a positive effect on growth performance or improve broiler arterial oxyhemoglobin saturation.Item Investigations into bovine cardiopulmonary physiology and disease(2016-11-28) Gulick, Amy Katherine; Neary, Joseph M.; Gonzales, Joaquin U.; Ballou, Michael A.Cor pulmonale is right-sided congestive heart failure (RHF) in cattle due to pulmonary hypertension. Historically, this disease has been associated with high altitudes, where the hypobaric hypoxia causes pulmonary vasoconstriction, and eventual vessel remodeling, which leads to pulmonary hypertension. However, this disease has been found to occur at moderate altitudes as well. Additionally, the incidence of this disease is increasing in North American feedlots. The pathophysiological mechanism behind RHF is not fully understood; however, there is known to be an association be-tween RHF and respiratory disease, a common affliction of feedlot and dairy cattle in the US. Respiratory disease and RHF have similar clinical signs, which makes diagnosis and treatment a challenge. In addition, liver disease is a common pathological condition associated with RHF. The liver has a high oxygen demand, so it is considered to be at-risk for hypoxia-induced damage due to venous congestion, secondary to cor pulmonale. The goal of this thesis was to better understand the mechanisms behind right heart failure, and its associations with respiratory disease and liver disease. This thesis contains three independent studies. The first (Study 1) was a cohort study of five herds, based at different altitudes. This study found that calves born and raised under the hypobaric hypoxic conditions of high altitude have a greater alveolar ventilation rate, but not hematocrit than do calves born and raised at lower altitudes. The goal of the second study (Study 2) was to determine if any evidence of cor pulmonale was found at a moderate altitude. Postmortem examinations were performed at a feedlot (n=16) and dairy (n=4) at an altitude of 975 m. Two animals died of RHF, with secondary bronchopneumonia, 11 animals died of pneumonia, and 7 animals died of miscellaneous causes. All animals, regardless of cause of death, showed postmortem lesions of varying severity, consistent with pulmonary hypertension, right heart failure, and liver disease. The third study (Study 3) further explored the relationship among pulmonary hypertension, central venous pressure, and liver disease in yearling steers during the finishing phase, at a moderate altitude of 975 m. This study found that there was a positive association between mean central venous pressure (CVP) and mean pulmonary arterial pressure (PAP) at 6 d (P = 0.02), and there was a positive tendency of correlation between CVP and PAP at 54 d (P = 0.08) prior to slaughter. There was an increase (P < 0.01) in mean PAP from 47 ± 8 mmHg at 54 d before slaughter to 55 ± 7 mmHg at 6 d before slaughter. This suggests the severity of pulmonary hypertension worsens through the finishing phase. Additionally, all animals examined for postmortem lesions (n = 10) were found to have hepatic damage, with the most severe lesions seen in the animals with high mean CVP. Yet, all 10 animals had serum biochemistry within or near normal limits. This indicates that serum biomarkers may not be sufficient indicators of liver disease in cattle. The pathophysiological con-sequences of high PAP are not fully understood. Physiological and pathological investigations conducted as part of this thesis indicate that mean PAP is high in feedlot cattle and may have deleterious effects on other organs, such as the liver.Item Investigations into cardiopulmonary diseases of bovine calves(2018-08) Church, Dee; Neary, Joseph M.; Rathmann, Ryan J.; Jackson, Samuel P.The purposes of study one were to determine if the successful treatment of bovine respiratory disease (BRD) in suckling calves was associated with a long-term increase in mean pulmonary arterial pressure (mPAP) and, to screen for associations between blood leukogram variables and mPAP. A cohort of Red Angus calves (n=74) were followed from birth to weaning at an altitude of 975 m. Calves were weaned at 172 ± 14 days when their mPAP was measured and whole blood collected. Thirty calves that had been treated for BRD (34 to 45 days prior) and 30 calves that had not required treatment for BRD were sampled. Treatment for BRD had no effect on mPAP (P = 0.37). Mean mPAP was 48 ± 8 mm Hg (± SD) with a minimum of 34 mm Hg and a maximum at 69 mm Hg. Weaning weight and sex tended to be associated with mPAP, but they explained just 5% of the variation in mPAP (P = 0.08; Adj. r2 = 0.05). Fibrinogen (P = 0.008) and absolute lymphocyte count (P = 0.06) were negatively associated with mPAP, whereas absolute monocyte count was positively associated with mPAP (P = 0.01). The findings of this study suggest that pre-weaning treatment for BRD does not increase a calves’ post-weaning risk of congestive right heart failure. Further, components of the immune and acute phase response system may play a role in the development and progression of pulmonary hypertension. The goal of the second study was to evaluate the effect of hypoxia on intestinal permeability and cardiopulmonary physiology in 2-month old calves. Calves were exposed to normoxic (975 m altitude; controls) or hypoxic (4,570 m altitude) conditions for 2-weeks. Pulmonary arterial pressures and intestinal permeability to mannitol and lactulose were assessed on Days 0 and 14. Calves were euthanized on Day 15. Two control calves shed occult fecal blood on Day 3; consequently, all calves were treated for coccidiosis. Control calves tended to have greater mean pulmonary arterial pressure than hypoxic calves at Day 0 (P = 0.17), but there was no difference between groups at Day 14 (P = 0.47). On average, mean pulmonary arterial pressure increased by 16 ± 2 mm Hg from Day 0 to 14 (P < 0.001). Serum lactulose was 0.8 ± 0.4 mg/L greater in the control group than the hypoxic group on Days 0 and 14 (P = 0.08). Serum mannitol was 2.0 ± 0.8 mg/L greater in control calves than hypoxic calves on Day 0 (P = 0.009) but there was no difference between groups at Day 14 (P = 0.61). In summary, hypoxia did not affect intestinal permeability, but the results were confounded by intestinal disease. Interestingly, the two calves that had bloody scours had the greatest pulmonary arterial pressures and diffuse alveolar damage. The findings of this study provide preliminary evidence that intestinal disease may contribute to the development of pulmonary diseases in cattle.