Effects of the selection process on malondialdehyde, catalase, superoxide dismutase levels, and the performance of gilts under tropical environmental conditions

Background and Aim: Gilt selection has the propensity to improve reproductive performance and promote longevity. However, the impact of this process on oxidative stress biomarker levels remains to be unraveled under tropical conditions. This study aimed to determine the effect of management processes during gilt selection on serum malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD) levels, and the performance of replacement gilts under tropical environmental conditions. Materials and Methods: Two groups of 90 crossbred gilts (mean age: 9.72 ± 0.097 weeks) were selected 2 weeks apart, allotted to six pens of 30, and raised in an open barn with shaded roofs. Following their respective entry weeks, gilts in groups one and two were subjected separately to three subsequent selection processes (involving movements, handling, and examination of structural and reproductive traits) at weeks 12, 17, and 24 in the replacement barn. Grower, finisher, and gestation diets were supplied ad libitum for 25 weeks. Environmental temperature (°C), humidity (%), and light (lux) were recorded. Malondialdehyde, CAT, and SOD levels were assayed using blood samples collected on day 1 of experiment (PRE), and at week 24 in replacement barn (POST). Results: Feed intake, weight gain, and percent selected at week 24 were 1.89 versus 1.90 kg/day, 0.81 versus 0.76 kg/day, and 75.23% versus 64.45% for groups one and two, respectively. Sickness, death, slow growth, leg, and reproductive problems caused 24.76% versus 35.55% of removals in groups one and two, respectively. Serum biomarkers were insignificant at PRE but were elevated at POST, with mean values of 14.25 versus 13.84 uM, 5.10 versus 3.26 nmol/min/mL, and p < 0.05, and 1.13 versus 1.68 U/mL and p < 0.05 for MDA, CAT, and SOD in groups one and two, respectively. Conclusion: The impact of the selection process was meager compared to the adverse effect of high environmental temperatures. The management and selection of replacement gilts in an uncontrolled environmental temperature increase the risk of oxidative stress, especially in tropical regions

Bayesian Modeling of Within-Herd Transmission Dynamics of Swine Influenza Virus

University of Minnesota Ph.D. dissertation. January 2016. Major: Veterinary Medicine. Advisor: John Deen. 1 computer file (PDF); xii, 215 pages.Influenza A virus (IAV), also known as swine influenza virus, commonly circulates in swine populations. IAV infection is a concern to swine producers, veterinarians and the general public, and is considered one of the top three respiratory diseases in terms of frequency of appearance in North American and the cause of an economically important respiratory disease in growing pig populations. On-farm assessment of health on an individual level for IAV infection involves the use of respiratory clinical signs (RCS) and behavioral observations by making inference from RCS to its causes using inductive reasoning as required for a Bayesian approach (BA). Therefore, the aims of this dissertation were to create Bayesian epidemiologic models using inductive reasoning with inverse probability, and to describe and better understand the within-herd transmission of IAV in wean-to-finish pig populations. A Bayesian approach is commonly used in veterinary medicine as it has been part of inductive reasoning regarding interventions, treatments and diagnoses. When veterinarians are managing patients or on-farm assessment of health, veterinarians start with their inferences from history and clinical signs to an underlying cause using inductive reasoning. The diagnostic test accuracies of RCS were 0.38 (95% Credible interval (CrI): 0.28-0.48 for Se) and 0.66 (95%CrI: 0.61-0.71 for Sp). The true IAV prevalence was estimated to be 0.24 (95%CrI: 0.16-0.30) and vaccination reduced such level of prevalence. By accounting for imperfect diagnostic test of RCS, the transmission rate was 1.40 day-1 (95% CrI: 0.42-5.52) and the reproductive number was 4.19 (95%CrI: 1.98-26.29). Waning rate of maternal derive antibodies (MDA) rate for IAV H1N1 was estimated to be 0.016 day-1 (95%CI: 0.013, 0.019) and time to lack of MDA maternal immunity was 64.09 days (95%CI 60.77- 77.40). An epidemic can occur at any point in time during a wean-to-finish period with more than one epidemic peak with low MDA population and the sufficiency of initially infected pigs. IAV transmissibility was elucidated as strongly periodic (p-value < 0.001) with peak timing in mid-June. The absolute IAV intensity was 0.18. The relative IAV intensity was 2.41, implying that IAV disease intensity at the periodic peak was 2.41 times higher compared to that at the periodic nadir. In conclusion, for a swine herd health management perspective, the use of RCS is able to potentially be used as on-farm assessment and measured for IAV transmissibility by inductive reasoning. Heterogeneity of MDA in wean-to-finish pig populations plays a crucial role in enhancing IAV transmission and waning MDA has interfered with vaccination to create more subclinical infections. Vaccination may be able to reduce the true IAV prevalence and has broader implications for the control and perhaps eradication of IAV. IAV transmissibility was elucidated as periodic. Better understanding waning of MDA, periodic IAV transmissibility, persistence and dynamics should result in a better design of the optimal control strategies and periodic IAV vaccination in growing pig populations.Homwong, Nitipong. (2016). Bayesian Modeling of Within-Herd Transmission Dynamics of Swine Influenza Virus. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/178959

Effect of pineapple stem starch feeding on rumen microbial fermentation, blood lipid profile, and growth performance of fattening cattle

Pineapple stem starch (PS) was evaluated for its suitability as a new starch source in concentrate for fattening cattle, based on the growth performance, blood profile, and rumen parameters of 36 steers in a 206-day feeding study. PS was formulated as a 40% concentrate and fed with forage in comparison with ground corn (GC) and ground cassava (CA) formulated at the same level. PS feeding improved weight gain and feed conversion ratio without affecting feed intake. PS did not obviously influence blood lipid profiles throughout the experiment. Ruminal concentration of total short-chain fatty acids (SCFA) increased with PS without affecting SCFA composition throughout the feeding study. Rumen amylolytic group, especially Ruminococcus bromii, was dominant in the rumen microbial community, and showed increased abundance by PS feeding throughout the experiment. These results clearly indicate the potential of PS as a useful starch source for fattening cattle in terms of rumen fermentation and growth performance

Negative Energy Balance in Periparturient Dairy Cows Raised in Small-Holder Farms in Kamphaengsaen District, Nakhon Pathom Province

ABSTRACT Negative energy balance was studied in 45 periparturient dairy cows from 15 small-holder farms in Kamphaengsaen District, Nakhon Pathom Province. Blood samples were collected at 1 week prepartum and 2 and 4 weeks postpartum for evaluation of negative energy balance and to study the relationship between concentrations of serum non-esterified fatty acid, serum glucose and body condition score. The results revealed that there were no significant differences in concentrations of non-esterified fatty acid at 1 week prepartum and 2 and 4 weeks postpartum. The concentrations of serum glucose and body condition score were significantly decreased after parturition. The changes of body condition score between 1 week prepartum and 2 weeks postpartum (r = 0.475) or between 1 week prepartum and 4 weeks postpartum (r = 0.364) were positively correlated with serum concentrations of non-esterified fatty acid at 2 weeks postpartum. In conclusion, periparturient dairy cows of small-holder farms in Kamphaengsaen District, Nakhon Pathom Province had some degrees of negative energy balance as observed by decreased serum glucose concentration and decreased body condition score. The results of this study would be useful for small-scale herd management to prevent periparturient negative energy balance problems and its consequences

Three-Level Mixed-Effects Logistic Regression Analysis Reveals Complex Epidemiology of Swine Rotaviruses in Diagnostic Samples from North America.

Rotaviruses (RV) are important causes of diarrhea in animals, especially in domestic animals. Of the 9 RV species, rotavirus A, B, and C (RVA, RVB, and RVC, respectively) had been established as important causes of diarrhea in pigs. The Minnesota Veterinary Diagnostic Laboratory receives swine stool samples from North America to determine the etiologic agents of disease. Between November 2009 and October 2011, 7,508 samples from pigs with diarrhea were submitted to determine if enteric pathogens, including RV, were present in the samples. All samples were tested for RVA, RVB, and RVC by real time RT-PCR. The majority of the samples (82%) were positive for RVA, RVB, and/or RVC. To better understand the risk factors associated with RV infections in swine diagnostic samples, three-level mixed-effects logistic regression models (3L-MLMs) were used to estimate associations among RV species, age, and geographical variability within the major swine production regions in North America. The conditional odds ratios (cORs) for RVA and RVB detection were lower for 1-3 day old pigs when compared to any other age group. However, the cOR of RVC detection in 1-3 day old pigs was significantly higher (p < 0.001) than pigs in the 4-20 days old and >55 day old age groups. Furthermore, pigs in the 21-55 day old age group had statistically higher cORs of RV co-detection compared to 1-3 day old pigs (p < 0.001). The 3L-MLMs indicated that RV status was more similar within states than among states or within each region. Our results indicated that 3L-MLMs are a powerful and adaptable tool to handle and analyze large-hierarchical datasets. In addition, our results indicated that, overall, swine RV epidemiology is complex, and RV species are associated with different age groups and vary by regions in North America

Data from: Three-level mixed-effects logistic regression analysis reveals complex epidemiology of swine rotaviruses in diagnostic samples from North America

Rotaviruses (RV) are important causes of diarrhea in animals, especially in domestic animals. Of the 9 RV species, rotavirus A, B, and C (RVA, RVB, and RVC, respectively) had been established as important causes of diarrhea in pigs. The Minnesota Veterinary Diagnostic Laboratory receives swine stool samples from North America to determine the etiologic agents of disease. Between November 2009 and October 2011, 7,508 samples from pigs with diarrhea were submitted to determine if enteric pathogens, including RV, were present in the samples. All samples were tested for RVA, RVB, and RVC by real time RT-PCR. The majority of the samples (82%) were positive for RVA, RVB, and/or RVC. To better understand the risk factors associated with RV infections in swine diagnostic samples, three-level mixed-effects logistic regression models (3L-MLMs) were used to estimate associations among RV species, age, and geographical variability within the major swine production regions in North America. The conditional odds ratios (cORs) for RVA and RVB detection were lower for 1–3 day old pigs when compared to any other age group. However, the cOR of RVC detection in 1–3 day old pigs was significantly higher (p 55 day old age groups. Furthermore, pigs in the 21–55 day old age group had statistically higher cORs of RV co-detection compared to 1–3 day old pigs (p < 0.001). The 3L-MLMs indicated that RV status was more similar within states than among states or within each region. Our results indicated that 3L-MLMs are a powerful and adaptable tool to handle and analyze large-hierarchical datasets. In addition, our results indicated that, overall, swine RV epidemiology is complex, and RV species are associated with different age groups and vary by regions in North America

Enhancement of selectivity, 25-hydroxyvitamin D3 level, alkaline phosphatase activity and reproductive performance in gilts and primiparous sows using 14-epimer of 25-hydroxyvitamin D3

Selecting breed-worthy gilts as sow replacements is essential for continuity of pig production cycle. Though vitamin D3 (VD3) is known to enhance reproductive performance of multiparous sows, there is still a knowledge gap on its impact in developing gilts and primiparous sows. This study was aimed to quantify plasma 25-hydroxyvitamin D3 (25(OH)D3), serum alkaline phosphatase (ALP), and examine the reproductive performance of primiparous sows fed diets supplemented with regular VD3, and its 25(OH)D3 epimers. The study sample comprised 10-week-old replacement gilts (50 % Landrace x 50 % Yorkshire, N = 180) assigned in a randomized complete block design to three treatments [2,000 IU/kg of VD3 (T1), 25 µg/kg of 14‑epi-25(OH)D3, half dose (T2), and 50 µg/kg of 25(OH)D3 (T3)] equilibrated to 2,000 IU/kg in base diets. Selections occurred at 22, 27 and 35 weeks of age, respectively. Plasma 25(OH)D3, serum alkaline phosphatase (ALP), bone structure and reproductive performance were analyzed. Dietary treatments influenced carpus (P = 0.023), fore view stance (P = 0.017), infantile vulva (P = 0.014), inverted (P = 0.048), and prominent teat (P < 0.001). Post-partum 25(OH)D3 concentration and ALP activity were elevated by day 25 (P < 0.001). Treatment diets also influenced total born (P < 0.001), born alive (P = 0.048), and still born (P = 0.049). Two factors affect circulating 25(OH)D3 and ALP activity: physiological changes in sows during lactation, and dietary 25(OH)D3 intake. 14‑epi-25(OH)D3 is a potent metabolite for improving maturation of reproductive organs in developing gilts. It also reduces still birth in primiparous sows

Rapid detection and high occurrence of porcine rotavirus A, B, and C by RT-qPCR in diagnostic samples

Rotaviruses are important cause of diarrhea in animals, including humans. Currently, rotavirus species A, B, C, E, and H (RVA-RVC, RVE, and RVH) have been identified in pigs. Traditionally, RVA has been considered the primary cause of diarrhea in pigs, and RVB and RVC had been described sporadically in pigs until recently. Qualitative porcine RVA, RVB, and RVC RT-PCR (RT-qPCR) assays were designed and 7508 porcine diarrheic samples, submitted to University of Minnesota, were tested to estimate the percentage of RVA, RVB, and RVC over a period of approximately 2 years (from 2009 to 2011). The individual RVA and RVC RT-qPCR assays were multiplex into a single RT-qPCR while the RVB RT-qPCR assay remained as an individual RT-qPCR. In total, 83% of the samples were positive for RVA, RVB, or RVC. As expected, RVA was detected at the highest overall percentage (62%). However, 33% and 53% of the samples were positive for RVB and RVC, respectively, indicating that both RVB and RVC are also epidemiologically important in the swine population. RVC was most predominant in young pigs (1-20 days of age), while RVA and RVB were most predominant in ≥21 day old pigs. As diagnostic tools, the developed RT-qPCR assays could successfully discriminate among infecting RV species, which could lead to better surveillance and epidemiological studies for ultimately better prevention and control strategies.publisher: Elsevier articletitle: Rapid detection and high occurrence of porcine rotavirus A, B, and C by RT-qPCR in diagnostic samples journaltitle: Journal of Virological Methods articlelink: http://dx.doi.org/10.1016/j.jviromet.2014.08.018 content_type: article copyright: Copyright © 2014 Elsevier B.V. All rights reserved.status: publishe

Whole Genome Classification and Phylogenetic Analyses of Rotavirus B strains from the United States

Rotaviruses (RVs) are a major etiological agent of acute viral gastroenteritis in humans and young animals, with rotavirus B (RVB) often detected in suckling and weaned pigs. Group A rotavirus classification is currently based on the two outer capsid proteins, VP7 and VP4, and the middle layer protein, VP6. Using RVB strains generated in this study and reference sequences from GenBank, pairwise identity frequency graphs and phylogenetic trees were constructed for the eleven gene segments of RVB to estimate the nucleotide identity cutoff values for different genotypes and determine the genotype diversity per gene segment. Phylogenetic analysis of VP7, VP4, VP6, VP1–VP3, and NSP1–NSP5 identified 26G, 5P, 13I, 5R, 5C, 5M, 8A, 10N, 6T, 4E, and 7H genotypes, respectively. The analysis supports the previously proposed cutoff values for the VP7, VP6, NSP1, and NSP3 gene segments (80%, 81%, 76% and 78%, respectively) and suggests new cutoff values for the VP4, VP1, VP2, VP3, NSP2, NSP4, and NSP5 (80%, 78%, 79%, 77% 83%, 76%, and 79%, respectively). Reassortment events were detected between the porcine RVB strains from our study. This research describes the genome constellations for the complete genome of Group B rotaviruses in different host species