Embedded microcomputer-based force plate system validation when evaluating lameness severity differentiation under an induced synovitis model in lactating dairy cattle.

Bovine lameness has relatively large negative economic and welfare implications on the U.S. dairy industry. Due to the ramifications, early lameness detection will aid in assisting dairy producers to mitigate downstream effects through early treatment. The objective of this study was to determine the minimum standing time required among 2-, 3-, 4-, 5-, and 10 min time intervals to obtain an accurate weight distribution estimate for each leg when attempting to detect lameness. An embedded microcomputer-based force plate system was developed to measure vertical forces from individual cow limb weight distribution to detect bovine lameness when utilizing an induced synovitis lameness model. The force plate has four quadrants, with each load cell quadrant measuring the force placed on it from a single limb. The force plate recorded weight (kg) every second from each load cell quadrant, after which, a 60 s moving average for weight distribution was calculated. A sequential study design was employed to evaluate non-lame and induced lameness to ensure time requirements were consistent. Prior to induction, the force plate system was used to measure weight distribution every second for 15 min. After lameness induction, additional 15 min increments were recorded every 24 h for seven days. Lameness was induced by injecting the left hind distal interphalangeal joint in three cows with amphotericin B, 12 h prior to the start of the study. Data were analyzed using a linear mixed effect that included the fixed effects of day relative to lameness induction, time period, foot and injected foot. Cow within replicate was included as a random effect. Cumulative minutes were assessed up to 15 min by comparing the least square rolling 60 s cumulative means expressed as a percentage of each animal's BW percentage placed on each leg for 2-, 3-, 4-, 5-, and 10 min intervals. Results indicate that the minimum time needed for accurate lameness detection in cows was 2 min.

Impact of health challenges on pig growth performance, carcass characteristics, and net returns under commercial conditions.

Understanding how disease affects commercial production is imperative for pig producers to quantify its full impact on pig performance, carcass quality, and net returns. The objective of this experiment was to assess the productivity and economic importance of naturally occurring health challenges (HC) under commercial conditions. Three 1,000 pig grow-finish facilities received 936 pigs each. The experimental period started approximately 34 d post placement at an average start BW of 13.1 ± 0.2 kg. Barns were characterized based on the relative HC, determined by diagnostic assessments as the main characterization tool, along with other health indicators. Barns were characterized as low challenge health (LCh), moderate challenge health (MCh), and high challenge health (HCh). All barns tested positive for porcine reproductive and respiratory syndrome virus infection prior to the start of the experiment. Additionally, the MCh and HCh barns experienced influenza type A virus of swine. Similar to commercial production conditions, the disease challenge was not imposed but rather occurred naturally. Reduced ADG, ADFI, and G:F were observed with an increased HC (P < 0.001). Similarly, mortality was increased when the HC increased (P < 0.001). Decreased ADG increased days to achieve harvest BW, by 10 and 15 d in the MCh and HCh treatments compared with LCh, respectively (P < 0.001). No differences were observed for percent lean, loin depth, or fat depth (P > 0.10). The economic impact of the HC was assessed by applying these growth performance data to two economic models encompassing the two main marketing methods used by U.S. pig producers: fixed-weight and fixed-time. Financial losses attributed to the variation in disease severity that occurred in the present study ranged from $8.49 and $26.10 U.S. dollars (USD)/pig marketed using a fixed-market weight model, or between $11.02 and $29.82 USD/pig using a fixed-time model, depending on feed costs and market hog prices. In conclusion, increasing severity of HC under commercial conditions reduced ADG by 8% and 14% and resulted in mortality as high as 19.9%. Losses of $8.49 to $29.82/pig marketed underscore the potential magnitude of the economic impact of mixed etiology concurrent diseases in pork production.

SID lysine requirement of immunologically and physically castrated male pigs during the grower, early and late finisher periods.

The main objective of this experiment was to determine the standardized ileal digestible (SID) Lys requirement of immunologically castrated (IC) and physically castrated (PC) male pigs during 3 growth phases. An additional objective was to compare the ADFI of PC and IC after the second anti-gonadotropin releasing factor (GnRF) injection. Three hundred male pigs (PIC 359 × C29), 150 each of IC and PC, were allotted to 1 of 5 treatments: 80, 90, 100, 110, or 120% of the estimated Lys requirement using the modeling program. Pigs remained on the same treatment throughout each of the 3 phases. Lysine requirements were determined at 3 stages of growth starting at a BW of 30.0 ± 0.8, 64.7 ± 1.4, and 111.9 ± 1.9 kg for IC and 32.4 ± 0.6, 69.8 ± 1.0, and 114.5 ± 1.3 kg for PC. Anti-GnRF injections were administered to IC at 11.5 and 19 wk (average BW = 96.3 ± 1.8 kg) of age. The one-slope broken line regression and quadratic plateau models were used, and the best model was selected based on the Akaike information criterion. The IC SID Lys requirements based on ADG were 1.03, 0.97, and 0.55% and for G:F, the requirements were 0.99, 0.72, and 0.55% for phases 1, 2, and 3, respectively. For PC, the SID Lys requirements based on ADG were 0.86, 0.62, and 0.47% and for G:F were 0.86, 0.58, and 0.47% for phases 1, 2, and 3, respectively. Immunologically castrated pigs had greater SID Lys requirements for phases 1 and 2 compared to PC (0.17 and 0.35% points greater for ADG and 0.13 and 0.14% points greater for G:F for phases 1 and 2, respectively). After the second injection, when IC pigs are believed to become physiologically more similar to PC pigs, the SID Lys requirements continue to be greater for IC (0.55 vs. 0.47% for both ADG and G:F). The ADFI of IC increased 4 d after the second injection relative to PC. By 2 wk post second injection, the ADFI of IC exceeded that of PC ( < 0.05). Adopting immunological castration as a management tool requires an understanding that IC need to be fed differently compared to PC, to maximize growth performance. Immunologically castrated pigs have a greater SID Lys requirement throughout the grower and finishing periods compared to the PC.

Vaccination mitigates the impact of PRRSv infection on the pharmacokinetics of ceftiofur crystalline-free acid in pigs.

The pharmacokinetics of intramuscularly administered ceftiofur crystalline-free acid (CCFA) were determined in pigs that were clinically healthy (n = 8), vaccinated with a Porcine reproductive and respiratory syndrome modified live virus (PRRS MLV) (n = 10), challenged with wild-type porcine reproductive and respiratory syndrome virus (PRRSv) VR-2385 (n = 10), or vaccinated with PRRS MLV and later challenged with wild-type PRRSv VR-2385 (n = 10). Animals were given a single dose of CCFA intramuscularly at 5 mg/kg body weight. Blood was collected at 0 (pretreatment), 0.25, 0.5, 1, 6, 12, 24, 48, 96, 144, 192, and 240 h postinjection. Plasma was analyzed using liquid chromatography-mass spectrometry. Plasma concentration-time curves for each group were evaluated with noncompartmental modeling. When compared to control animals, those receiving the PRRSv wild-type challenge only had a lower AUC0-last , higher Cl/F, and higher Vz/F. The PRRSv wild-type challenge only group had the longest T1/2λ . The Cmax did not differ among all four treatments. Control animals had no statistically significant differences from animals vaccinated with PRRS MLV alone or animals vaccinated with PRRS MLV and later challenged with wild-type PRRSv. Our results suggest that PRRSv wild-type infection has the potential to alter CCFA pharmacokinetics and PRRS MLV vaccination may attenuate those changes.

Systematic Epidemiological Investigations of Cases of Senecavirus A in US Swine Breeding Herds.

Epidemiological investigations were conducted on a case series of six Senecavirus A (SVA)-affected breeding herds in the United States to determine potential routes of introduction and enhance the swine industry's knowledge of SVA's clinical presentation and spread. Each SVA-affected herd was evaluated using a standard form to ensure that all relevant data were collected. The form was used to guide a detailed discussion about the clinical presentation of SVA and risk events that occurred in the 4 weeks prior to the first observation of clinical signs with the herd veterinarian and farm personnel. Each event was then subjectively assigned a risk level of low, medium or high likelihood for SVA introduction by the investigation team. The clinical presentation of SVA varied by case. All SVA-affected herds (six of six) reported increases in pre-weaning mortality and sow anorexia. Vesicular lesions were observed in four of six herds, and mild-to-moderate neonatal diarrhoea was observed in three of six herds. No gross anatomic or histologic lesions were observed in neonatal pigs that tested positive for SVA via PCR. Multiple potential routes of introduction were identified. Events subjectively rated as high risk for SVA introduction were on-farm employee entry (six of six), carcass disposal (four of six), cull sow removal (three of six) and breeding replacement entry (two of six). Non-swine domestic animals, rodents, other visitors, repairs outside swine barns, feed delivery, weaned pig removal and semen entry were assigned a high risk level in one of six herds. Cases occurred in breeding herds of all sizes with variable biosecurity in both swine dense and swine sparse areas.

Review: Assessment of completeness of reporting in intervention studies using livestock: an example from pain mitigation interventions in neonatal piglets.

Accurate and complete reporting of study methods, results and interpretation are essential components for any scientific process, allowing end-users to evaluate the internal and external validity of a study. When animals are used in research, excellence in reporting is expected as a matter of continued ethical acceptability of animal use in the sciences. Our primary objective was to assess completeness of reporting for a series of studies relevant to mitigation of pain in neonatal piglets undergoing routine management procedures. Our second objective was to illustrate how authors can report the items in the Reporting guidElines For randomized controLled trials for livEstoCk and food safety (REFLECT) statement using examples from the animal welfare science literature. A total of 52 studies from 40 articles were evaluated using a modified REFLECT statement. No single study reported all REFLECT checklist items. Seven studies reported specific objectives with testable hypotheses. Six studies identified primary or secondary outcomes. Randomization and blinding were considered to be partially reported in 21 and 18 studies, respectively. No studies reported the rationale for sample sizes. Several studies failed to report key design features such as units for measurement, means, standard deviations, standard errors for continuous outcomes or comparative characteristics for categorical outcomes expressed as either rates or proportions. In the discipline of animal welfare science, authors, reviewers and editors are encouraged to use available reporting guidelines to ensure that scientific methods and results are adequately described and free of misrepresentations and inaccuracies. Complete and accurate reporting increases the ability to apply the results of studies to the decision-making process and prevent wastage of financial and animal resources.

Comparison among gilts, physical castrates, entire males, and immunological castrates in terms of growth performance, nitrogen and phosphorus retention, and carcass fat iodine value.

The main objective was to determine the nitrogen and P retention and energy digestibility of immunological castrates (IC), entire males (EM), physical castrates (PC), and gilts (G) during 3 growth phases. A second objective was to compare growth performance among the sexes. The final objective was to determine the carcass iodine value (IV) among the sexes. Twelve individually housed pigs (PIC 337 × C22/29) of each sex with an initial mean BW of 35.7 ± 0.6 kg and a final BW of 145.0 ± 1.3 kg were evaluated. Anti-gonadotropin-releasing factor injections were administered at d 23 and 15 for groups 1 and 2, respectively. The second injection was given on d 56 of the 98-d experiment. Nitrogen, P, and energy digestibility were measured the last 3 d of the 10-d metabolism period starting at mean BW of 39.5 ± 0.6, 73.7 ± 0.8, and 105.5 ± 0.9 kg for periods 1, 2, and 3, respectively. The third collection started 14 d after the second injection. Entire males and IC had superior overall ADG compared to PC and G ( < 0.05). Entire males and G had the lowest overall ADFI, and PC had the greatest, with IC being intermediate ( < 0.05). Entire males were overall the most efficient, followed by IC, with PC and G being the least efficient ( < 0.05). Immunological castrates and EM had similar nitrogen retention (g/d) for the first 2 collection periods ( > 0.05). In the third collection period, nitrogen retention of IC was similar to that of both EM and PC ( < 0.05). Phosphorus retained (g/d) was not different among the sexes in the first collection; during the second collection, EM retained the greatest amount of P, G and PC retained the lowest, with IC being similar to all sexes. For the third collection, IC had P retention similar to that of EM, EM had retention similar to that of PC, and PC had retention similar to that of G ( > 0.05). However, G retained less P than EM or IC ( < 0.05). Apparent total tract digestibility of DM and GE and the DE of the diet did not differ among the sexes in any of the collection periods ( > 0.05). The jowl IV was the lowest in IC and PC and highest in EM, with G being similar to all sexes ( < 0.05). For the belly, EM had the highest IV, with the other 3 sexes being similar. In conclusion, 2 wk after the second injection, IC transition to become more similar to PC in terms of nitrogen utilization but are still similar to EM in P utilization. These data suggest a feeding program for IC that is intermediate between EM and PC is required to meet their nutritional requirements.

Measuring the efficacy of flunixin meglumine and meloxicam for lame sows using a GAITFour pressure mat and an embedded microcomputer-based force plate system.

Pain associated with lameness on farm is a negative affective state and has a detrimental impact on individual farm animal welfare. Animal pain can be managed utilizing husbandry tools and through pharmacological approaches. Nonsteroidal anti-inflammatory drugs including meloxicam and flunixin meglumine are compounds used in many species for pain management because they are easy to administer, long lasting, and cost-effective. Assessing an animal's biomechanical parameters using such tools as the embedded microcomputer-based force plate system and GAITFour pressure mat gait analysis walkway system provides an objective, sensitive, and precise means to detect animals in lame states. The objectives of this study were to determine the efficacy of meloxicam and flunixin meglumine for pain mitigation in lame sows using the embedded microcomputer-based force plate system and GAITFour pressure mat gait analysis walkway system. Lameness was induced in 24 mature mixed-parity sows using a chemical synovitis model and compared 3 treatments: meloxicam (1.0 mg/kg per os), flunixin meglumine (2.2 mg/kg intramuscular) and sterile saline (intramuscular). Weight distribution (kg) for each foot was collected twice per second for a total of 5 min for each time point using the embedded microcomputer-based force plate system. Stride time, stride length, maximum pressure, activated sensors, and stance time were collected using 3 quality walks (readings) for each time point using the GAITFour pressure mat gait analysis walkway system. Sows administered flunixin meglumine or meloxicam tolerated more weight on their lame leg compared with saline sows (P < 0.005). Sows administered flunixin meglumine or meloxicam had smaller differences in stance time, maximum pressure, and activated sensors between the sound and lame legs compared with saline-treated sows between 37 and 60 h after lameness induction (P < 0.03). In conclusion, flunixin meglumine and meloxicam administration mitigated pain sensitivity in sows after lameness induction when pain sensitivity was evaluated with the embedded microcomputer-based force plate system and GAITFour pressure mat gait analysis walkway system. Analgesic drugs may be a key tool to manage negative pain affective states associated with lameness.

Impact of an experimental PRRSV and Streptococcus suis coinfection on the pharmacokinetics of ceftiofur hydrochloride after intramuscular injection in pigs.

This study determined the impact of porcine reproductive and respiratory syndrome virus (PRRSV) and Streptococcus suis coinfection on the pharmacokinetic (PK) profile of ceftiofur hydrochloride in pigs after intramuscular (i.m.) injection. Eighteen clinically normal crossbred gilts were assigned by weight into a challenge group (10 pigs) and control group (eight pigs). Pigs in both groups received a single i.m. injection of ceftiofur hydrochloride (Excenel RTU Sterile Suspension; Zoetis) at a 5 mg/kg BW dose. Serial blood samples were collected to characterize the plasma concentration curve. After a 10 days drug washout period, the challenge group was inoculated with 2 mL of PRRSV isolate VR-2385 (10(5.75) 50% tissue culture infective doses per mL) intranasally and 8 days later inoculated S. suis. When clinical disease was evident, the second PK assessment began in both challenge and control groups. Coinfected pigs demonstrated lower values of AUC and CMAX , but higher values of Cl/F and Vz/F indicating drug kinetics were altered by infection. The data from this study have implications on ceftiofur treatment regimens in diseased pigs.

Pharmacokinetics of meloxicam in mature swine after intravenous and oral administration.

The purpose of this study was to compare the pharmacokinetics of meloxicam in mature swine after intravenous (i.v.) and oral (p.o.) administration. Six mature sows (mean bodyweight ± standard deviation = 217.3 ± 65.68 kg) were administered an i.v. or p.o. dose of meloxicam at a target dose of 0.5 mg/kg in a cross-over design. Plasma samples collected up to 48 h postadministration were analyzed by high-pressure liquid chromatography and mass spectrometry (HPLC-MS) followed by noncompartmental pharmacokinetic analysis. Mean peak plasma concentration (CMAX ) after p.o. administration was 1070 ng/mL (645-1749 ng/mL). TMAX was recorded at 2.40 h (0.50-12.00 h) after p.o. administration. Half-life (T½ λz ) for i.v. and p.o. administration was 6.15 h (4.39-7.79 h) and 6.83 h (5.18-9.63 h), respectively. The bioavailability (F) for p.o. administration was 87% (39-351%). The results of this study suggest that meloxicam is well absorbed after oral administration.

Using classification trees to detect induced sow lameness with a transient model.

Feet and legs issues are some of the main causes for sow removal in the US swine industry. More timely lameness detection among breeding herd females will allow better treatment decisions and outcomes. Producers will be able to treat lame females before the problem becomes too severe and cull females while they still have salvage value. The objective of this study was to compare the predictive abilities and accuracies of weight distribution and gait measures relative to each other and to a visual lameness detection method when detecting induced lameness among multiparous sows. Developing an objective lameness diagnosis algorithm will benefit animals, producers and scientists in timely and effective identification of lame individuals as well as aid producers in their efforts to decrease herd lameness by selecting animals that are less prone to become lame. In the early stages of lameness, weight distribution and gait are impacted. Lameness was chemically induced for a short time period in 24 multiparous sows and their weight distribution and walking gait were measured in the days following lameness induction. A linear mixed model was used to determine differences between measurements collected from day to day. Using a classification tree analysis, it was determined that the mean weight being placed on each leg was the most predictive measurement when determining whether the leg was sound or lame. The classification tree's predictive ability decreased as the number of days post-lameness induction increased. The weight distribution measurements had a greater predictive ability compared with the gait measurements. The error rates associated with the weight distribution trees were 29.2% and 31.3% at 6 days post-lameness induction for front and rear injected feet, respectively. For the gait classification trees, the error rates were 60.9% and 29.8% at 6 days post-lameness induction for front and rear injected feet, respectively. More timely lameness detection can improve sow lifetime productivity as well as animal welfare.

Evaluation of mechanical and thermal nociception as objective tools to measure painful and nonpainful lameness phases in multiparous sows.

The objective of this study was to quantify pain sensitivity differences using mechanical nociception threshold (MNT) and thermal nociception threshold (TNT) tests when sows were in painful and nonpainful transient lameness phases. A total of 24 mixed parity crossbred sows (220.15 ± 21.23 kg) were utilized for the MNT test, and a total of 12 sows (211.41 ± 20.21 kg) were utilized for the TNT test. On induction day (D0), all sows were anesthetized and injected with Amphotericin B (10mg/mL) in the distal interphalangeal joint space in both claws of one randomly selected hind limb to induce transient lameness. Three days were compared: (1) D-1 (sound phase, defined as 1 d before induction), (2) D+1 (most lame phase, defined as 1 d after induction), and (3) D+6 (resolution phase, defined as 6 d after induction). After completion of the first round, sows were given a 7-d rest period and then the procedures were repeated with lameness induced in the contralateral hind limb. During the MNT test, pressure was applied perpendicularly to 3 landmarks in a randomized sequence for each sow: 1) middle of cannon on the hind limb (cannon), 2) 1 cm above the coronary band on the medial hind claw (medial claw), and 3) 1 cm above the coronary band on the lateral hind claw (lateral claw). During the TNT test, a radiant heat stimulus was directed 1 cm above the coronary band. The data were analyzed using the MIXED procedure in SAS with sow as the experimental unit. Differences were analyzed between sound and lame limbs on each day. For the MNT test, pressure tolerated by the lame limb decreased for every landmark (P < 0.05) when comparing D-1 and D+1. The sound limb tolerated more pressure on D+1 and D+6 than on baseline D-1 (P < 0.05). Thermal stimulation tolerated by the sound limb did not change over the 3 d (P > 0.05). However, the sows tolerated less heat stimulation on their lame limb on D+1 compared to D-1 levels (P < 0.05). Both MNT and TNT tests indicated greater pain sensitivity thresholds when sows were acutely lame.

Impact of oral meloxicam on circulating physiological biomarkers of stress and inflammation in beef steers after long-distance transportation.

Transportation stress can result in significant economic losses to producers due to decreased animal productivity and increased medication costs associated with sickness such as bovine respiratory disease (BRD). Meloxicam (MEL) provides pain relief and anti-inflammatory effects in cattle for several days after a single oral treatment. Our hypothesis was that MEL administration before shipping would reduce the impact of long-distance transportation on circulating physiological biomarkers of stress and inflammation in beef steers. Ninety-seven beef steers were blood sampled for baseline biomarker determination and then randomly assigned to receive either 1 mg/kg MEL (n = 49) or a placebo (CONT; n = 48) per os before a 1,316-km transportation event lasting approximately 16 h. Calves were then blood sampled on arrival and 5 d later. Changes in the hemogram, circulating plasma proteins, total carbon dioxide (TCO2), fibrinogen, substance P (SP), cortisol, haptoglobin (Hp)-matrix metalloproteinase-9 (MMP-9) complexes, and tumor necrosis factor α (TNFα) between treatments over time were compared using a mixed effects model with statistical significance designated as P < 0.05. Analysis of covariance was conducted to assess the relationship between circulating MEL concentrations and biomarker changes over time. An increase in neutrophil, platelet, monocyte, white blood cell, and red blood cell counts occurred after transportation (P < 0.0001) and a decrease in lymphocyte count were observed (P < 0.0001). Meloxicam treatment reduced the stress-induced neutrophilia (P = 0.0072) and circulating monocyte count (P = 0.013) on arrival. Mean corpuscle hemoglobin (P = 0.05), mean corpuscle volume (P = 0.05), and lymphocyte count (P = 0.05) were also greater in the CONT calves compared with MEL calves after transportation. Furthermore, Hp-MMP-9 complexes, TCO2, TNFα, plasma proteins, and SP increased and cortisol decreased after shipping (P < 0.01). Meloxicam treatment tended to reduce serum cortisol concentrations (P = 0.08) and there was evidence of a time × treatment interaction (P = 0.04). An inverse relationship between plasma MEL concentrations and circulation cortisol concentrations (P = 0.002) and neutrophil (P = 0.04) and basophil counts (P = 0.03) was also observed. The results suggest that MEL administration may reduce the impact of long-distance transportation on circulating physiological biomarkers of stress and inflammation in beef calves.

Development and refinement of a technique for short-term intravascular auricular vein catheter placement in mature sows.

Intravenous drug administration in adult swine is difficult to perform due to inaccessible superficial veins and thick subcutaneous fat layers. However, successful intravenous drug administration is critical for many biomedical applications including pharmacokinetic studies as extravascular drug administration can influence the drug's absorption and elimination rate. The purpose of this study was to develop and refine an effective technique for indwelling auricular vein catheter placement in the conscious mature sow. We developed a protocol using a topical anesthetic cream and minimal physical restraint to place indwelling catheters in the auricular vein of six multiparous sows. This method was quick (3 min 20 s ± 8 s [mean ± SE per catheter]), effective (11/12 catheters successfully placed) and reliable, allowing a large drug volume (20-22 mL) to be administrated successfully during the trial without relying on prolonged restraint or general anesthesia of the sow.

Pain management in the neonatal piglet during routine management procedures. Part 2: grading the quality of evidence and the strength of recommendations.

Piglets reared in swine production in the USA undergo painful procedures that include castration, tail docking, teeth clipping, and identification with ear notching or tagging. These procedures are usually performed without pain mitigation. The objective of this project was to develop recommendations for pain mitigation in 1- to 28-day-old piglets undergoing these procedures. The National Pork Board funded project to develop recommendations for pain mitigation in piglets. Recommendation development followed a defined multi-step process that included an evidence summary and estimates of the efficacies of interventions. The results of a systematic review of the interventions were reported in a companion paper. This manuscript describes the recommendation development process and the final recommendations. Recommendations were developed for three interventions (CO2/O2 general anesthesia, non-steroidal anti-inflammatory drugs (NSAIDs), and lidocaine) for use during castration. The ability to make strong recommendations was limited by low-quality evidence and strong certainty about variation in stakeholder values and preferences. The panel strongly recommended against the use of a CO2/O2 general anesthesia mixture, weakly recommended for the use of NSAIDs and weakly recommended against the use of lidocaine for pain mitigation during castration of 1- to 28-day-old piglets.

Genetic associations for gilt growth, compositional, and structural soundness traits with sow longevity and lifetime reproductive performance.

The objective of this study was to estimate genetic associations for gilt growth, compositional, and structural soundness with sow longevity and lifetime reproduction. Performance and pedigree information from 1,447 commercial females from 2 genetic lines were included in the data analyzed. Growth was expressed as days to 113.5 kg BW (DAYS) and compositional traits included loin muscle area (LMA), 10th rib backfat (BF10), and last rib backfat (LRF). Structural soundness traits included body structure traits [length (BL), depth (BD), width (BWD), rib shape (BRS), top line (BTL), and hip structure (BHS)], leg structure traits [front legs: legs turned (FLT), buck knees (FBK), pastern posture (FPP), foot size (FFS), and uneven toes (FUT); rear legs: legs turned (RLT), leg posture (RLP), pastern posture (RPP), foot size (RFS), and uneven toes (RUT)], and overall leg action (OLA). Lifetime (LT) and removal parity (RP) were considered as longevity traits whereas lifetime reproductive traits included lifetime total number born (LNB), lifetime number born alive (LBA), number born alive per lifetime day (LBA/LT), and percentage productive days from total herd days (PD%). Genetic parameters were estimated with linear animal models using the average information REML algorithm. Second, to account for censored longevity and lifetime reproduction records, genetic parameters were estimated using Markov Chain Monte Carlo and Gibbs sampling methods. Similar estimates were obtained across the analysis methods. Heritability estimates for growth and compositional traits ranged from 0.50 to 0.70 and for structural soundness traits from 0.07 to 0.31. Longevity and lifetime reproductive trait heritability estimates ranged from 0.14 to 0.17 when REML was used. Unfavorable genetic correlations were obtained for DAYS with LT, RP, LNB, LBA, and PD% and for LRF with PD%. However, LMA was favorably associated with LT, RP, and LNB. Moderate to high correlations were obtained for BL and BRS with all longevity and lifetime reproductive traits. Correlations of BWD with LT and RP were moderate. Associations for leg soundness traits with longevity and lifetime reproductive traits were mainly low and nonsignificant (P ≥ 0.10). However, RLP was moderately correlated with LBA/LT and PD%. Current results indicate that selection for fewer DAYS has an antagonistic effect on lifetime performance. Furthermore, great BL, flat BRS, narrow BWD, and upright RLP seem detrimental to sow longevity and lifetime reproduction.

2011 and 2012 Early Careers Achievement Awards: farm and pig factors affecting welfare during the marketing process.

The objective of this paper is to review the scientific literature to identify on-farm factors that contribute to market weight pig transportation losses. Transportation of market weight pigs is an essential element to the multisite pork production model used in the United States. In 2011 alone, approximately 111 million market weight pigs were transported from the finishing site to the abattoir. For pigs, the marketing process can present a combination of potentially novel, physical, and/or unfamiliar experiences that can be stressful. If the pig cannot cope with these sequential and additive stressors, then an increased rate of transportation losses could occur with a detrimental effect on pork carcass value. Current yearly estimates for transport losses are 1 million pigs (1%). A variety of market weight pig and farm factors have been reported to detrimentally affect transportation losses. By understanding how pigs interact with their environment during marketing, researchers, producers, and personnel at the abattoir may begin to identify, prioritize, and attempt to minimize or eliminate these stressors. This process will ultimately decrease transportation losses, improve pork quality, and increase profitability.

Genetic parameters for growth, body composition, and structural soundness traits in commercial gilts.

The objective of this study was to estimate genetic parameters for growth, body composition, and structural soundness traits in commercial gilt lines. The data included 1,449 gilts: 462 females from a grandparent maternal line and 987 from a parent maternal line. Growth was expressed as number of days to a constant 113.5 kg BW (DAYS) and compositional traits included loin muscle area (LMA), 10th rib backfat (BF10), and last rib backfat (LRF). Subjective structural soundness evaluation was completed using a 9-point scale and included: body length (BL), body depth (BD), body width (BWD), rib shape (BRS), top line (BTL), and hip structure (BHS); front legs: legs turned (FLT), buck knees (FBK), pastern posture (FPP), foot size (FFS), and uneven toes (FUT); rear legs: legs turned (RLT), leg posture (RLP), pastern posture (RPP), foot size (RFS), and uneven toes (RUT); and overall leg action (OLA). Genetic parameters were estimated with multivariate linear animal models, using the average information REML algorithm. Heritability estimates for growth and body composition traits ranged from 0.50 to 0.70, for body structure traits from 0.15 to 0.31, for leg structure traits from 0.07 to 0.31, and the estimate for OLA was 0.12. Several moderate to high genetic correlations were obtained among body structure traits, whereas correlations among leg structure traits were mainly low and nonsignificant. A strong correlation was found between FPP and OLA (P < 0.001); more upright FPP coincided with inferior OLA. Furthermore, FBK and FFS appeared to be favorably associated with OLA (0.05 < P < 0.10). Body structure trait correlations among each other and with leg soundness traits were primarily favorable. Correlations indicated that great BL and high BTL coincided with each other and deterioration of other structural soundness traits. Although genetic correlations obtained for DAYS and backfat measurements with structural soundness traits had an unfavorable trend, they were mainly low to moderate (i.e., simultaneous genetic improvement would be possible, including adversely associated traits). Due to greater heritabilities, faster genetic change could be expected for compositional and body structure traits than leg structure traits. Because of the genetic relationship among the trait groups, using information across traits when making selection decisions could result in genetic improvement among leg soundness traits.

Validation of a lameness model in sows using physiological and mechanical measurements.

The objective of this study was to develop a validated, transient, chemically induced lameness model in sows using subjective and objective lameness detection tools. Experiment 1 determined an effective joint injection technique based on volume and placement of dye using feet collected from 9 finisher pigs and 10 multiparity cull sow carcasses. Experiment 2 confirmed the injection technique in live animals and produced a transient clinical lameness in 4 anesthetized sows injected with amphotericin B (15 mg/mL) in the distal interphalangeal joints of the claw. Clinical lameness was assessed by a categorical lameness scoring system, and a postmortem visual confirmation of joint injection technique was obtained. In Exp. 3, 6 sows were injected with 0, 10, or 15 mg/mL amphotericin B in either the left or right hind foot and were monitored until clinical resolution. Treated sows demonstrated elevated clinical lameness scores. These changes resolved by 7 d after lameness induction. Control sows injected with sterile saline developed a clinical lameness score of 0.5, which resolved 72 h post injection. In Exp. 4, 36 sows were injected with 10 mg/mL amphotericin B in 1 of 4 injection sites (left front claws, right front claws, left rear claws, and right rear claws). All injected sows exhibited a decrease in maximum pressure, stance time, and number of sensors activated on the GaitFour (P < 0.05) sensor system. A static force plate also demonstrated a decrease in weight (kg) being placed on the injected foot when all feet were injected (P ≤ 0.05). Injection of amphotericin B induced a predictable acute lameness that resolved spontaneously and is an effective method to model lameness in sows.

Loading gantry versus traditional chute for the finisher pig: effect on welfare at the time of loading and performance measures and transport losses at the harvest facility.

The objectives of these studies were to evaluate the loading system effects [traditional chute (TC) vs. prototype loading gantry (PLG)] on i) welfare measures at loading and ii) performance measures and transport losses at the harvest facility for the market-weight pig (Sus scrofa). This study compared first pull (FP), which was the first group of pigs, and close out (CO), which was the last group of pigs marketed from a finishing facility. Experiment 1 evaluated 74 loads for welfare measures at loading on the farm, and Exp. 2 evaluated 497 loads for performance measures and transport losses at the harvest facility. Data were analyzed using the PROC Mixed procedure for Exp. 1 and PROC GLIMMIX procedure of SAS for Exp. 2. In Exp. 1, pigs loaded using the PLG had fewer (P × 0.0002) electric prod touches, slips, falls, vocalizations, and pile ups compared with pigs loaded on the TC during FP and CO. In Exp. 2, there were no (P > 0.05) differences for any performance measures between loading systems or by pull. Pigs loaded using the prototype PLG loading gantry experienced fewer (P = 0.03) total transport losses than pigs loaded using the TC in the FP. In conclusion, the prototype loading gantry improved all welfare measures at the time of loading and reduced overall total transport losses. These studies demonstrate that loading systems that improve on-farm swine welfare at loading and reduce transport losses at the harvest facility can be designed.