The welfare of ill and injured feedlot cattle: a review of the literature and implications for managing feedlot hospital and chronic pens.

By definition, ill and injured animals are on the negative valence of animal welfare. For beef cattle kept in feedlot settings, advances in cattle health management have resulted in a greater understanding and prevention of illness and injury. However, the management of cattle once they become ill and injured is an understudied area, and there are gaps in knowledge that could inform evidence-based decision-making and strengthen welfare for this population. The aim of this review is to provide a comprehensive overview of the acquired knowledge regarding ill and injured feedlot cattle welfare, focusing on existing knowledge gaps and implications for hospital and chronic pen management and welfare assurance. Ill and injured feedlot cattle consist of acutely impaired animals with short-term health conditions that resolve with treatment and chronically impaired animals with long-term health conditions that may be difficult to treat. A literature search identified 110 articles that mentioned welfare and ill and injured feedlot cattle, but the population of interest in most of these articles was healthy cattle, not ill and injured cattle. Articles about managing ill and injured cattle in specialized hospital (n = 12) or chronic (n = 2) pens were even more sparse. Results from this literature search will be used to outline the understanding of acutely and chronically ill and injured feedlot cattle, including common dispositions and welfare considerations, behavior during convalescence, and strategies for identifying and managing ill and injured cattle. Finally, by working through specific ailments common in commercial feedlot environments, we illustrate how the Five Domains Model can be used to explore feelings and experiences and subsequent welfare state of individual ill or injured feedlot cattle. Using this approach and our knowledge of current industry practices, we identify relevant animal-based outcomes and critical research questions to strengthen knowledge in this area. A better understanding of this overlooked topic will inform future research and the development of evidence-based guidelines to help producers care for this vulnerable population.

From birth to lying on- or under a supplemental heat source: How long does it take for half the litter to lie down and how long do they stay?

Piglets are susceptible to hypothermia because they lack hair and energy reserves, have a large surface area to body weight ratio, and have poor body thermostability. Different heat sources are used on farm, but it is not known how long it takes half a litter to locate it and lie down. The objectives of this study were to determine 1) how long it took for ≥ 50% of piglets to locate and lie on- or under the supplemental heat source for ≥ 5 min after the birth of the last-born pig and, 2) how long this cohort of piglets laid on- or under the heat source. A total of 12 sows were enrolled in the study (parity 1 = 4; 3 = 2; 4 = 2; 5 = 2; and 7 = 2). The stall containing one sow and her litter was the experimental unit. Two treatments were compared: 1) Baby Pig Heat Mat-Single 48 (MAT) and 2) Poly Heat Lamp (LAMP). Temperature was 32°C for both heat source treatments. Sow and litter video recordings occurred continually over a 24-h period on the day of farrowing. Two measures were determined 1) how long it took for ≥ 50% of piglets to locate and lie on- or under the supplemental heat source for ≥ 5 min after the birth of the last-born pig (h:min), and 2) how long this cohort of piglets laid on- or under the heat source (min:sec). Lying was defined as either sternal or lateral recumbency with ≥ 75% of the piglet's body touching the heat mat or inside the lamp heat circle. Production records were used to verify farrowing date, total number of piglets born, and born alive. No cross fostering occurred during this study. All data will be presented descriptively. On average, sows assigned to the LAMP treatment took ~2 ½-h to farrow, and for sows assigned to the MAT ~3 ½-h, respectively. Piglets took between ~5-h (LAMP) and ~9-h (MAT) for ≥ 50% of piglets to locate and lie on- or under the supplemental heat source for ≥ 5 min after the birth of the last piglet. Cohort of piglets laid on- or under the heat source as follows, LAMP piglets spent ~29 mins lying and for MAT piglets ~42 mins, respectively. Average pre-weaning mortality was 11% (LAMP) and 18% (MAT). The MAT heat source used less energy than the LAMP (16 vs. 63 kWh) over the study duration. To the authors' knowledge, this is the first published study using a continuous sampling method to precisely examine a new measure (time needed for ≥ 50% of piglets to locate and lie on- or under the supplemental heat source for ≥ 5 min after the birth of the last-born piglet) and to determine how long this cohort of piglets laid on- or under the heat source. Our findings show an immense range in locating and lying under- or on the heat source. Therefore, we suggest that caretakers should assist all piglets to locate the heat source after farrowing is complete to improve piglet livability.

Validation of Standing and Locomotion Scoring, Behavioral Assessments, and Mechanical Nociceptive Threshold Testing on Naturally Occurring Sow Lameness.

The objective of this study was to validate standing and locomotion lameness scoring, mechanical nociceptive threshold testing, and behavioral profile tools for the diagnosis of naturally occurring lameness etiologies in pigs. A total of 55 crossbred gilts and sows obtained from a commercial farm were enrolled in the study; with sound pigs classified as controls (8) and the remainder as lame due to integumentary (20), musculoskeletal (15), and combinations of integumentary and musculoskeletal (12) etiologies. Standing and locomotion lameness, mechanical nociceptive threshold (MNT) test, pig-human interventions, and latency to complete an obstacle course were evaluated. Standing and locomotion lameness scoring systems, MNT, and pig behavior (latency) were capable of discriminating between animals with mild organic lameness and animals that were sound and may have utility on the farm for staff to use to identify and manage lame animals. In rare instances, the tools used here were able to discriminate between broad categories of lameness etiology.

Improving young pig welfare on-farm: The Five Domains Model.

Considering welfare through the "neonatal and nursery pig perspective" is an exciting approach and one that resonates with consumers. Overlaying this with the Five Domains Model, as we suggest in this review, points to practical on-farm improvements that provide each pig the opportunity to experience positive mental states. The Five Domains Model is broken into physical and functional states, which include Domain 1: Nutrition, Domain 2: Physical Environment, Domain 3: Health, and Domain 4: Behavioral Interaction, and Domain 5: Mental State. The Five Domains Model can build on the breadth and depth of swine welfare science to highlight opportunities to improve welfare on-farm. In Domain 1, management of increasingly large litters is considered, with examples of sow vs. artificial rearing, colostrum quality and quantity, and creep feed management strategies. Efforts can result in positive mental states such as feeling full and content and the ability to experience the pleasure of drinking and food tastes and smells. Domain 2 considers space complexity and access to key resources, along with thermal and physical amenities, to promote feelings of physical comfort. Domain 3 considers pig health in three broads, yet inter-linking categories 1) congenital and hereditary health, 2) environmental pathogen load, and 3) colostrum quality and quantity, and its effect on the microbiome. Improvements can result in a pig that displays vitality and feels healthy. Domain 4 provides the pig opportunities to express its rich behavioral repertoire, specifically positive social interactions, play, and exploration. These efforts can result in pigs feeling calm, safe, comfortable, having companionship, engaged, interested, and rewarded. In conclusion, using the Five Domains Model can highlight numerous opportunities to improve current and future housing and management through the "neonatal and nursery pig perspective" with a focus on inducing positive mental states that can result in improved quality of life and welfare state.

Considering welfare through the "neonatal and nursery pig perspective" is an exciting approach. Overlaying this with the Five Domains Model, as we suggest in this review, points to practical on-farm improvements that provide each pig the opportunity to experience positive mental states. The first four domains consider physical and functional states; with Domains 1 through 4 being Nutrition, Physical Environment, Health, and Behavioral Interaction, respectively. All interweave with Domain 5: Mental state. A plethora of examples are discussed; Domain 1 critiques optimal colostrum intake, and milk and feed quality that result in feelings of fullness and contentment. Domain 2 considers space complexity, key resource access, and thermal and physical amenities with these efforts resulting in feelings of comfort and agency. Domain 3 discusses congenital and hereditary health, environmental pathogen load, colostrum quality and quantity effects on the microbiome, and how these improve pig vitality and feelings of good health and fitness. Domain 4 discusses opportunities for the pig to express its behavioral repertoire, particularly positive social interactions, play, and exploration with feelings of control and agency. Improvements will result in pigs feeling calm, safe, comfortable, enjoying companionship, engaged, interested, and leading a rewarding life.

The Use of Attractants to Stimulate Neonatal Piglet Interest in Rope Enrichment.

In the United States swine industry, preweaning mortality represents the highest mortality rate of any production phase, nearly half attributed to crushing. The overarching aim of this study was to determine if enrichment ropes would entice neonatal piglets away from the sow and reduce preweaning mortality. Rope enrichments were provided to 161 piglets from 26 sows after farrowing. Ropes were dipped in sunflower oil (n = 7), semiochemical (n = 8), or milky cheese (n = 11). Piglet purposeful rope investigations, weight gain, and mortality were recorded. On Day 2, 75% of piglets touched the enrichment at least once, and frequency ranged from 1 to 21 investigations across all treatments. Frequency (p = 0.20) and duration (p = 0.21) of investigations were not affected by treatment. Preweaning litter average weight gain did not differ between treatments (p = 0.71). MC (milky cheese) piglets had the lowest percent mortality when the enrichment ropes were present (Days 2 to 5, p = 0.01), and SC (semiochemical) piglets had the lowest percent mortality after the enrichment ropes were removed (Days 6 to weaning, p < 0.0001). This proof-of-concept study highlights the potential value of neonatal piglet environmental enrichment.

Dietary zinc concentration and lipopolysaccharide injection affect circulating trace minerals, acute phase protein response, and behavior as evaluated by an ear-tag-based accelerometer in beef steers.

To assess plasma trace mineral (TM) concentrations, the acute phase protein response, and behavior in response to a lipopolysaccharide (LPS) challenge, 96 Angus cross steers (average initial body weight [BW]: 285 ± 14.4 kg) were sorted into two groups by BW (heavy and light; n = 48/group), fitted with an ear-tag-based accelerometer (CowManager SensOor; Agis, Harmelen, Netherlands), and stagger started 14 d apart. Consecutive day BW was recorded to start the 24-d trial (days -1 and 0). Dietary treatments began on day 0: common diet with either 30 (Zn30) or 100 (Zn100) mg supplemental Zn/kg DM (ZnSO4). On day 17, steers received one of the following injection treatments intravenously to complete the 2 × 3 factorial: 1) SALINE (~2-3 mL of physiological saline), 2) LOWLPS: 0.25 µg LPS/kg BW, or 3) HIGHLPS: 0.375 µg LPS/kg BW. Blood, rectal temperature (RT), and BW were recorded on day 16 (-24 h relative to injection), and BW was used to assign injection treatment. Approximately 6, 24 (day 18), and 48 (day 19) h after treatment, BW, RT, and blood were collected, and final BW recorded on day 24. Data were analyzed in Proc Mixed of SAS with fixed effects of diet, injection, diet × injection; for BW, RT, dry matter intake (DMI), plasma TM, and haptoglobin-repeated measures analysis were used to evaluate effects over time. Area under the curve analysis determined by GraphPad Prism was used for analysis of accelerometer data. Body weight was unaffected by diet or injection (P ≥ 0.16), but there was an injection × time effect for DMI and RT (P < 0.05), where DMI decreased in both LPS treatments on day 16, but recovered by day 17, and RT was increased in LPS treatments 6 h post-injection. Steers receiving LPS spent less time highly active and eating than SALINE (P < 0.01). Steers in HIGHLPS spent lesser time ruminating, followed by LOWLPS and then SALINE (P < 0.001). An injection × time effect (P < 0.001) for plasma Zn showed decreased concentrations within 6 h of injection and remained decreased through 24 h before recovering by 48 h. A tendency for a diet × time effect (P = 0.06) on plasma Zn suggests plasma Zn repletion occurred at a greater rate in Zn100 compared to Zn30. These results suggest that increased supplemental Zn may alter the rate of recovery of Zn status from an acute inflammatory event. Additionally, ear-tag-based accelerometers used in this study were effective at detecting sickness behavior in feedlot steers, and rumination may be more sensitive than other variables.

Measuring birth weight and umbilical cord diameter at birth to predict subsequent performance in swine.

In the swine industry, pre-weaning mortality, umbilical hernia incidence and pig market weight are a few contributing factors affecting profitability and welfare on farm. Therefore, the ability to reliably predict any of these outcomes is valuable to swine operations. Mortality during the pre-weaning phase, umbilical hernia incidence and poor-quality finisher pigs can represent a multi-million dollar loss and increase in welfare concerns to the producer. Consequently, the objective of this study was to evaluate whether birth weight (BW), umbilical cord diameter at birth (UCD), and the calculated umbilical diameter at birth to birth weight ratio (UCD:BW), are potential indicators of both placental efficiency and relative defect size in the abdominal musculature as well as reliable predictors of pre-weaning mortality, umbilical hernia incidence, and pig body weight at 150 d of age in a commercial facility. Mixed sex commercial piglets were followed through production. Four hundred sixty-five piglets were weighed within 1 h of birth, and the UCD was determined using digital calipers, these animals were followed through weaning. Three hundred eighty-five pigs of the 465 were followed through the post-wean phase in the nursery facility and checked for umbilical hernia incidence. Finally, of the 385 pigs, 177 pigs were assessed for umbilical hernia incidence and weighed a final time at the grower-finisher facility. All data were analyzed using PROC Logistic and PROC GLM procedures. The variables of UCD:BW and BW were significantly associated with the probability of increased pre-weaning mortality (P < 0.001). For example, piglets with a low UCD:BW, but an increased BW had the greatest survival rate. Umbilical diameter (UCD) was not significantly associated with pre-weaning mortality. Post-weaning mortality was not significantly affected by UCD:BW, BW, or UCD variables. Umbilical hernia incidence was not significantly affected by UCD:BW at the nursery phase or growing-finishing phase. Pig body weight at 150 d of age was significantly affected by UCD:BW, BW, and UCD variables (P < 0.001). For example, piglets that had a larger UCD weighed more at 150 d of age. In conclusion, measuring the calculated UCD:BW has the potential to be a novel tool for future research looking into the impacts of umbilical measurements as it relates to placental function, fetal development, piglet survivability and impacts on future performance of the animal.

Innovative strategies for managing swine welfare during the COVID-19 pandemic in Iowa.

Coronavirus Disease 2019 (COVID-19) was declared a global pandemic on March 11, 2020 by the World Health Organization and its impact on animal agriculture in the United States was undeniable. By April, COVID-19 resulted in the simultaneous closure or reduced operations of many meat processing plants in the upper Midwest, leading to supply chain disruptions. In Iowa, the leading pork production and processing state, these disruptions caused producer uncertainty, confusion, and stress, including time-sensitive challenges for maintaining animal care. The Iowa Resource Coordination Center (IRCC) was quickly created and launched by the Iowa Department of Agriculture and Land Stewardship (IDALS). The IRCC included public representation from the Iowa Pork Producers Association (IPPA), Iowa Pork Industry Center (IPIC), and Iowa State University Extension and Outreach, and private partners including producers, veterinarians, and technical specialists. Supporting swine welfare, the IRCC provided information on management strategies, dietary alterations to slow pig growth, alternative markets, on-farm euthanasia, and mass depopulation under veterinary oversight. In a crisis, Iowa created a model that reacted to producers' pragmatic, mental and emotional needs. This model could be quickly replicated with an introduction of foreign animal disease.

A novel environmental enrichment device increased physical activity and walking distance in broilers.

Modern broilers are selected for fast growth and a large proportion of breast tissue, contributing to a top-heavy phenotype, leg disorders, and inactivity as birds reach market weight. Therefore, the objective was to motivate broilers to move through environmental enrichment. A total of 1,200 Ross 308 broilers were housed in pens of 30 for 6 wk: 600 birds were exposed to a novel laser enrichment device (LASER) and 600 were control. Each device projected 2 randomly moving red laser dots onto the floor 4 times/day for 4-min "laser periods." Seven LASER and 7 control pens, with 5 focal birds/pen (n = 70), were randomly selected to be video-recorded day 0 to 8 and once weekly for the remainder of the trial. Videos were analyzed to measure broiler time-budget and behaviors such as latency to feed and distance walked during laser periods. Focal birds were gait scored weekly on-farm. A test of the human-approach paradigm was carried out on weeks 1 and 6 on all pens. LASER birds were more active on days 0, 1, 3, 4, 5, 7, and 8, moving 254% more on day 7 (P ≤ 0.05). Time spent active was increased in LASER treatment by 114% on week 2; 157% on week 3; 90% on week 4; and 82% on week 5. LASER birds spent more time at the feeder on days 0, 1, 2, 5, 8, and on weeks 1 and 5, with 84% more time at feeder than control on day 5 (P ≤ 0.05). LASER birds walked further during laser periods on day 0 to 8, reaching 646.5 cm greater (day 1), and on weeks 2, 3, 4, and 5, with an increase of 367.5 cm on week 2 (P ≤ 0.05). Over week 1 to 6, 60.54 ± 7.4% of focal birds in the laser treatment were at the feeder during or within 5 min following laser periods. The laser enrichment device was successful in stimulating broiler physical activity and feeding, and did not negatively impact walking ability.

Development and Validation of Broiler Welfare Assessment Methods for Research and On-farm Audits.

Required auditing of on-farm broiler welfare in the United States has increased; however, a lack of validated tools exists for assessment of enrichment. National Chicken Council (NCC) guidelines were used on a subset of 300 Ross 308 broilers out of 1200 to validate and adapt welfare measures. Half of the broilers were exposed to environmental enrichment, hence these measures were used to evaluate the enrichment within the context of behavior and welfare, although the nature of the enrichment is not described in detail here as the aim is to serve solely as a description and validation of methods using a subset of example data. Birds were recorded in repeated 4-min periods to quantify behavior and walking distance. Outcomes were categorized to improve auditing and make recommendations to producers and researchers. Bone mineral density, content, and breaking strength were successful in determining numerical differences. Quantifying lameness using an enclosed walkway and measuring footpad dermatitis weekly are recommended on-farm. We recommend including additional measures not required by the NCC: monitoring breast condition in the flock and including a behavior component with a scoring ethogram.

The impact of an introductory animal handling course on undergraduate students who lack previous livestock handling experience.

A majority of animal science undergraduates have limited livestock handling experience when they come to college. To address this issue, a course based on livestock handling, safety, and welfare was implemented in the Department of Animal Science at Iowa State University. This study aimed to (i) determine whether the course was effective at improving the comfort level of a student while handling livestock and (ii) identify demographic factors that contributed to student performance in the course. The course was delivered as an 8-wk, lecture-laboratory format. Each semester, a precourse survey and precourse exam were administered during the first class period (N = 87). The survey collected self-reported demographic information, prior livestock handling experience, and comfort level by specie. The exam tested the prior knowledge of each student. At the semester conclusion, a postcourse survey and postcourse exam were given to determine whether the course was effective at improving comfort and knowledge levels of each student, respectively (N = 75). Students from farm backgrounds outscored urban students by 5.56 ± 2.96% on the precourse exam (P = 0.06). Cumulative grade point average at the time of the course (GPA) had a role in the preexam score (P = 0.003) while gender, semester, involvement in 4H (cooperative extension program) or Future Farmers of America (FFA), and high school or collegiate judging were not factors in the preexam score (P > 0.10). Background and student rank did not have an effect on the postcourse exam score (P = 0.96 and P = 0.58, respectively). As expected, GPA was significant when fit as a covariate (P < 0.001) in the postcourse exam model. Upon course completion, students reported that their comfort level while handling livestock had increased for all livestock species. The largest increases were observed with poultry (37.8% to 66.9%) and dairy (49.3% to 84.3%). Of the 75 students polled, 96% felt that the hands-on approach was beneficial at reinforcing lecture material, and 100% reported that they were more likely to voluntarily interact with livestock inside or outside of the classroom setting after course completion. In conclusion, some demographic attributes play a role in student performance at the beginning of the course, but these factors are no longer significant after completion of the course. In addition, the level of comfort with and knowledge of livestock handling, safety, and welfare all improved, which shows that the course was successful at achieving the intended learning outcomes.

Nutrient evaluation of a pork by-product and its use as environmental enrichment for managed large exotic cats.

North American zoological institutions typically feed ground raw meat diets to large exotic cats. These diets typically are nutritionally complete, but lack physical properties characteristic of whole prey. Lack of mastication and prey manipulation may contribute to behavioral and health challenges. Pork by-products may provide environmental enrichment to mitigate these challenges. The objectives of this study were to evaluate a pig head for nutritional composition and to determine if a pig head was biologically relevant environmental enrichment for managed large exotic cats. Pig heads consisted of: DM: 48.5%; OM: 60.7%; CP: 38.4%; fat: 22.0%; CF: 13.5%; TDF: 3.4%; GE: 4.1 kcal/g DM. Five individually housed exotic cats (Panthera tigris tigris, Panthera tigris altaica (n = 2), Panthera tigris jacksoni, Panthera leo) were observed in 2-h blocks, 24-h before pig head introduction (Baseline), at time of pig head introduction (Enrichment) and immediately after the pig head was removed (Post Enrichment) via instantaneous scan sampling for 4 consecutive weeks. Active behaviors were 55.7% higher on Enrichment compared to Baseline days, and 26.4% higher compared to Post Enrichment days (p<0.0001). Active behaviors were 39.8% higher on Post Enrichment compared to Baseline days (p<0.0001). Total active behaviors were highest (p<0.0001) in week 3 and lowest (p<0.0001) in week 4 with differences as high as 64.5% seen among weeks. In conclusion, pig heads have potential to provide nutrient dense enrichment to large exotic cats, and employing a pig head as environmental enrichment increased active behaviors and did not lose novelty.

Teaching Tip: The Development of an Interactive Computer-Based Training Program for Timely and Humane On-Farm Pig Euthanasia.

With extensive knowledge and training in the prevention, management, and treatment of disease conditions in animals, veterinarians play a critical role in ensuring good welfare on swine farms by training caretakers on the importance of timely euthanasia. To assist veterinarians and other industry professionals in training new and seasoned caretakers, an interactive computer-based training program was created. It consists of three modules, each containing five case studies, which cover three distinct production stages (breeding stock, piglets, and wean to grower-finisher pigs). Case study development was derived from five specific euthanasia criteria defined in the 2015 Common Swine Industry Audit, a nationally recognized auditing program used in the US. Case studies provide information regarding treatment history, clinical signs, and condition severity of the pig and prompt learners to make management decisions regarding pig treatment and care. Once a decision is made, feedback is provided so learners understand the appropriateness of their decision compared to current industry guidelines. In addition to training farm personnel, this program may also be a valuable resource if incorporated into veterinary, graduate, and continuing education curricula. This innovative tool represents the first interactive euthanasia-specific training program in the US swine industry and offers the potential to improve timely and humane on-farm pig euthanasia.

A Hypothesis and Review of the Relationship between Selection for Improved Production Efficiency, Coping Behavior, and Domestication.

Coping styles in response to stressors have been described both in humans and in other animal species. Because coping styles are directly related to individual fitness they are part of the life history strategy. Behavioral styles trade off with other life-history traits through the acquisition and allocation of resources. Domestication and subsequent artificial selection for production traits specifically focused on selection of individuals with energy sparing mechanisms for non-production traits. Domestication resulted in animals with low levels of aggression and activity, and a low hypothalamic-pituitary-adrenal (HPA) axis reactivity. In the present work, we propose that, vice versa, selection for improved production efficiency may to some extent continue to favor docile domesticated phenotypes. It is hypothesized that both domestication and selection for improved production efficiency may result in the selection of reactive style animals. Both domesticated and reactive style animals are characterized by low levels of aggression and activity, and increased serotonin neurotransmitter levels. However, whereas domestication quite consistently results in a decrease in the functional state of the HPA axis, the reactive coping style is often found to be dominated by a high HPA response. This may suggest that fearfulness and coping behavior are two independent underlying dimensions to the coping response. Although it is generally proposed that animal welfare improves with selection for calmer animals that are less fearful and reactive to novelty, animals bred to be less sensitive with fewer desires may be undesirable from an ethical point of view.

Daily feeding regimen impacts pig growth and behavior.

A primary swine production goal is to increase efficiency of lean tissue gains. While many swine production systems currently utilize ad libitum feeding, recent research suggests that altering feeding patterns may impact feed efficiency. Therefore, the objective of this study was to compare two feeding patterns and evaluate their impact on whole body tissue accretion, feeding behavior and activity in growing pigs. Forty eight individually housed gilts (55.9±5.2kg on test BW) were assigned into one of two feeding treatments: 1) Free access to the feeder (Free Access) or 2) twice daily access where gilts were allowed to eat ad libitum between 08:00-09:00h and again from 17:00-18:00h (2×). Pig performance was recorded weekly for 55days and average daily gain (ADG), average daily feed intake (ADFI), and gain:feed (G:F) was calculated. Body composition was assessed in 12 gilts per treatment using dual X-ray absorptiometry (DXA) at day -3 and 55 of treatment, and tissue accretion rates were calculated. Gilt behaviors were assessed via video analysis during week 7 and included time spent eating, feeding rate, enrichment interaction, postural changes, standing, sitting, and lying behaviors. Gilts fed 2× had lower ADG and ADFI compared to Free Access gilts (P≤0.01); however, no treatment difference in G:F was observed (P=0.83). At day 55 gilts fed 2× had a lower fat:protein compared to Free Access gilts (P=0.05). Fat, lean, and protein accretion rates were lower in gilts fed 2× compared to those fed Free Access (P=0.01). Gilts fed 2× ate less frequently and for a shorter duration of time, interacted with enrichment more frequently (P≤0.005), and tended to have less frequent postural changes compared to Free Access gilts (P=0.08). No treatment differences were observed in duration of time spent standing, sitting, or lying (P≥0.39). Although feed regimen did not alter feed efficiency, these data indicate that twice daily feeding reduced gilt adiposity and growth without altering the pig's behavioral expression of hunger. Therefore, twice daily feeding may be a method of increasing percent of lean tissue without negatively impacting gilt welfare.

Pharmacokinetics of flunixin meglumine in mature swine after intravenous, intramuscular and oral administration.

BACKGROUND: The purpose of this study was to determine intravenous (IV), intramuscular (IM) and oral (PO) FM PK in mature swine. Appropriate pain management for lameness in swine is a critical control point for veterinarians and producers, but science-based guidance on optimal housing, management and treatment of lameness is deficient. Six mature swine (121-168 kg) were administered an IV, IM, or PO dose of flunixin meglumine at a target dose of 2.2 mg/kg in a cross-over design with a 10 day washout period between treatments. Plasma samples collected up to 48 hours post-administration were analyzed by high pressure liquid chromatography and mass spectrometry (HPLC-MS) followed by non-compartmental pharmacokinetic analysis. RESULTS: No adverse effects were observed with flunixin meglumine administration for all routes. Flunixin meglumine was administered at an actual mean dose of 2.21 mg/kg (range: 2.05-2.48 mg/kg) IV, IM and PO. A mean peak plasma concentration (CMAX) for IM and PO administration was 3748 ng/ml (range: 2749-6004 ng/ml) and 946 ng/ml (range: 554-1593 ng/ml), respectively. TMAX was recorded at 1.00 hour (range: 0.50-2.00 hours) and 0.61 hours (range: 0.17-2.00 hours) after PO and IM administration. Half-life (T ½ λz) for IV, IM and PO administration was 6.29 hours (range: 4.84-8.34 hours), 7.49 hours (range: 5.55-12.98 hours) and 7.08 hours (range: 5.29-9.15 hours) respectively. In comparison, bioavailability (F) for PO administration was 22% (range: 11-44%) compared to IM F at 76% (range: 54-92%). CONCLUSIONS: The results of the present study suggest that FM oral administration is not the most effective administration route for mature swine when compared to IV and IM. Lower F and Cmax of PO-FM in comparison to IM-FM suggest that PO-FM is less likely to be an effective therapeutic administration route.