Review: Effects of Ractopamine Hydrochloride (Paylean) on welfare indicators for market weight pigs

This review summarizes the effects of ractopamine hydrochloride (RAC) dose (5, 7.5, 10, and 20 mg/kg) on market weight pig welfare indicators. Ractopamine hydrochloride (trade name Paylean) is a β-adrenergic agonist that was initially approved in the U.S. in 1999 at doses of 5 to 20 mg/kg to improve feed efficiency and carcass leanness. However, anecdotal reports suggested that RAC increased the rate of non-ambulatory (fatigued and injured) pigs at U.S. packing plants. This led to the addition of a caution statement to the Paylean label, and a series of research studies investigating the effects of RAC on pig welfare. Early research indicated that: (1) regardless of RAC administration, fatigued (non-ambulatory, non-injured) pigs are in a state of metabolic acidosis; (2) aggressive handling increases stress responsiveness at 20 mg/kg RAC, while 5 mg/kg reduces stress responsiveness to aggressive handling. Given this information, dosage range for Paylean was changed in 2006 to 5 to 10 mg/kg in market weight pigs. Subsequent research on RAC demonstrated that: (1) RAC has minimal effects on mortality, lameness, and home pen behavior; (2) RAC fed pigs demonstrated inconsistent prevalence and intensity of aggressive behaviors; (3) RAC fed pigs may be more difficult to handle at doses above 5 mg/kg; and (4) RAC fed pigs may have increased stress responsiveness and higher rates of non-ambulatory pigs when subjected to aggressive handling, especially when 20 mg/kg of RAC is fed

Blood immunometabolic indices and polymorphonuclear neutrophil function in peripartum dairy cows are altered by level of dietary energy prepartum

Cows experience some degree of negative energy balance and immunosuppression around parturition, making them vulnerable to metabolic and infectious diseases. The effect of prepartum feeding of diets to meet (control, 1.34 Mcal/kg of dry matter) or exceed (overfed, 1.62 Mcal/kg of dry matter) dietary energy requirements was evaluated during the entire dry period (∼45 d) on blood polymorphonuclear neutrophil function, blood metabolic and inflammatory indices, and milk production in Holstein cows. By design, dry matter intake in the overfed group (n=9) exceeded energy requirements during the prepartum period (-4 to -1 wk relative to parturition), resulting in greater energy balance when compared with the control group (n=10). Overfed cows were in more negative energy balance during wk 1 after calving than controls. No differences were observed in dry matter intake, milk yield, and milk composition between diets. Although nonesterified fatty acid concentration pre- (0.138 mEq/L) and postpartum (0.421 mEq/L) was not different between diets, blood insulin concentration was greater in overfed cows prepartum (16.7 μIU/mL) compared with controls pre- and postpartum (∼3.25 μIU/mL). Among metabolic indicators, concentrations of urea (4.63 vs. 6.38 mmol/L), creatinine (100 vs. 118 μmol/L), and triacylglycerol (4.0 vs. 8.57 mg/dL) in overfed cows were lower prepartum than controls. Glucose was greater pre- (4.24 vs. 4.00 mmol/L) and postpartum (3.49 vs. 3.30 mmol/L) compared with control cows. Among liver function indicators, the concentration of bilirubin increased by 2 to 6 fold postpartum in control and overfed cows. Phagocytosis capacity of polymorphonuclear neutrophils was lower prepartum in overfed cows (32.7% vs. 46.5%); phagocytosis in the control group remained constant postpartum (50%) but it increased at d 7 in the overfed group to levels similar to controls (48.4%). Regardless of prepartum diet, parturition was characterized by an increase in nonesterified fatty acid and liver triacylglycerol, as well as blood indices of inflammation (ceruloplasmin and haptoglobin), oxidative stress (reactive oxygen metabolites), and liver injury (glutamic oxaloacetic transaminase). Concentrations of the antioxidant and anti-inflammatory compounds vitamin A, vitamin E, and β-carotene decreased after calving. For vitamin A, the decrease was observed in overfed cows (47.3 vs. 27.5 μg/100 mL). Overall, overfeeding energy and higher energy status prepartum led to the surge of insulin and had a transient effect on metabolism postpartum

Genetic relationships among temperament, immune function, and carcass merit

Cattle producers historically have selected for docile temperaments simply for management convenience because calmer animals are conducive to safe environments for their peers as well as their handlers. As many producers would acknowledge, there seems to be a relationship between temperament and health, and calmer cattle tend to frequent the working chute for treatment of disease less often. Positive correlations have been found in cattle between temperament traits (chute scores, pen scores, and chute exit velocities) and cortisol concentration in the blood, suggesting that more excitable cattle are easily stressed (Curley et al., 2006; Cooke et al., 2009). In addition, Curley et al. (2007) found that easily excitable animals sustain elevated cortisol concentrations for a longer duration and had greater pituitary and adrenal responses following a stressor than calm cattle. Temperamental cattle have significantly higher mean temperament responses at all points (Oliphint, 2006). Higher basal serum cortisol concentrations may suggest that easily excitable cattle are chronically stressed (Curley et al., 2007), possibly resulting in a compromised immune system, illness, and decreased fat and protein deposition. Common measures of cattle temperament are pen scores, chute scores, and exit velocities. Temperament appears to be moderately heritable, with estimates ranging from 0.15 to 0.44 (Burrow and Corbet, 2000; Kadel et al., 2006; Schrode and Hammack, 1971; Stricklin et al., 1980; Fordyce et al., 1988). If genetic correlations are found between temperament and production traits or immunological factors, they may aid cattle breeders in producing profitable cattle. Such relationships have been found between exit velocity and hot carcass weight (r = -0.54), exit velocity and marbling score (r = 0.10), exit velocity and yield grade (r = -0.22) (Nkrumah et al., 2007), and post-weaning weight gain and exit velocity (Weaber et al., 2006). Bovine respiratory disease (BRD) susceptibility has been estimated to be lowly heritable (Muggli-Cockett et al., 1992; Snowder et al., 2005, 2006, 2007; Schneider et al., 2008). This study was conducted to further investigate the genetic relationships between cattle temperament measured by chute score and exit velocity, immunological factors, and a range of economically relevant performance traits

Genetic parameters estimated at receiving for circulating cortisol, immunoglobulin G, interleukin 8, and incidence of bovine respiratory disease in feedlot beef steers

Citation: Cockrum, R. R., Speidel, S. E., Salak-Johnson, J. L., Chase, C. C. L., Peel, R. K., Weaber, R. L., . . . Enns, R. M. (2016). Genetic parameters estimated at receiving for circulating cortisol, immunoglobulin G, interleukin 8, and incidence of bovine respiratory disease in feedlot beef steers. Journal of Animal Science, 94(7), 2770-2778. doi:10.2527/jas2015-0222Bovine respiratory disease complex (i.e., shipping fever and bacterial bronchopneumonia) is a multifaceted respiratory illness influenced by numerous environmental factors and microorganisms. Bovine respiratory disease (BRD) is just one component of BRD complex. Because BRD is moderately heritable, it may be possible to reduce the incidence of BRD through genetic selection. The objectives of this study were to determine the heritability and associative genetic relationships among immune system traits (i.e., cortisol, total IgG, IgG isotypes, and IL-8) in cattle monitored for BRD incidence. At an average of 83 d after weaning (219 d age and mean = 221.7 kg [SD 4.34]), crossbred Bos taurus steer calves (n = 2,869) were received at a commercial feedlot in southeastern Colorado over a 2-yr period. At receiving, jugular blood samples were collected at 212 (yr 1) and 226 d (yr 2) of age for immune trait analyses. The BRD phenotype was defined as a binomial variable (0 = no and 1 = yes) and compared with immune system traits measured at receiving (prior to illness onset). An animal identified as BRD positive exhibited ? 2 clinical signs (i.e., eye or nasal discharge, cough, lethargy, rapid breathing, acute interstitial pneumonia, or acute upper respiratory syndrome and/or a rectal temperature > 39.7°C). Heritability and genetic correlation estimates for categorical variable BRD, cortisol, IgG, IgG1, IgG2, and IL-8 were estimated from a sire model using ASREML. Heritability estimates were low to moderate for BRD (0.17 ± 0.08), cortisol (0.13 ± 0.05), IgG (0.15 ± 0.05), IgG1 (0.11 ± 0.05), IgG2 (0.24 ± 0.06), and IL-8 (0.30 ± 0.06). A moderate negative genetic correlation was determined between BRD and cortisol (rg = ?0.19 ± 0.32). Moderate positive correlations were found between BRD with IgG (0.42 ± 0.28), IgG1 (0.36 ± 0.32), and IL-8 (rg = 0.26 ± 0.26). Variation in the BRD phenotype and immune system traits suggested herd health improvement may be achieved through genetic selection. © 2016 American Society of Animal Science. All rights reserved

Review: Transport Losses in Market Weight Pigs: I. A Review of Definitions, Incidence, and Economic Impact

Transport losses (dead and nonambulatory pigs) present animal welfare, legal, and economic challenges to the US swine industry. The objectives of this review are to explore 1) the historical perspective of transport losses; 2) the incidence and economic implications of transport losses; and 3) the symptoms and metabolic characteristics of fatigued pigs. In 1933 and 1934, the incidence of dead and nonambulatory pigs was reported to be 0.08 and 0.16%, respectively. More recently, 23 commercial field trials (n = 6,660,569 pigs) were summarized and the frequency of dead pigs, nonambulatory pigs, and total transport losses at the processing plant were 0.25, 0.44, and 0.69% respectively. In 2006, total economic losses associated with these transport losses were estimated to cost the US pork industry approximately $46 million. Furthermore, 0.37 and 0.05% of the nonambulatory pigs were classified as either fatigued (nonambulatory, noninjured) or injured, respectively, in 18 of these trials (n = 4,966,419 pigs). Fatigued pigs display signs of acute stress (open-mouth breathing, skin discoloration, muscle tremors) and are in a metabolic state of acidosis, characterized by low blood pH and high blood lactate concentrations; however, the majority of fatigued pigs will recover with rest. Transport losses are a multifactorial problem consisting of people, pig, facility design, management, transportation, processing plant, and environmental factors, and, because of these multiple factors, continued research efforts are needed to understand how each of the factors and the relationships among factors affect the well-being of the pig during the marketing process

67202; ‡ ‡ Innovative Livestock Solutions, Blackie, Alberta, Canada T0L0J0; § § Livestock Behavior Research Unit

ABSTRAC

Dietary lysine-to-energy ratios for managing growth and pubertal development in replacement gilts

Objective: Our objective was to determine growth rates, body composition, and pubertal development of replacement gilts fed diets with different ratios of standardized ileal digestible (SID) lysine to ME. Materials and Methods: Diets with low, medium, and high ratios of SID lysine to ME (grower: 2.3, 2.6, and 2.8; and, finisher; 1.7, 1.9, and 2.1 g/Mcal) were fed from 100 to 200 d of age, after which gilts were moved from the gilt development unit to sow farms. Boar exposure and estrus detection began at 160 d of age and continued until first detected estrus. Estimates of BW and body composition were determined at 100, 142, 160, and 200 d of age and at puberty. Results and Discussion: Body weights and growth rates were reduced (P \u3c 0.05) as dietary SID lysine–to– ME ratio decreased. Greater SID lysine–to–ME ratios increased the number of gilts that exhibited estrus upon boar exposure, increased the number of gilts with a spontaneous first estrus, reduced the number of gilts requiring P.G.600 (Merck Animal Health, Kenilworth, NJ), and decreased age at first estrus (P \u3c 0.05). Slower growing gilts that weighed less with less backfat were more likely to require P.G.600 to induce puberty (P \u3c 0.05). Implications and Applications: Reducing SID lysine– to–ME ratios in gilt diets can increase the number of gilts within optimal BW range at first estrus, but overall pubertal development is delayed if ratios are reduced below 2.8 and 2.1 g of SID lysine to megacalorie of ME in grower and finisher diets, respectively

Global Effects of Catecholamines on Actinobacillus pleuropneumoniae Gene Expression

Bacteria can use mammalian hormones to modulate pathogenic processes that play essential roles in disease development. Actinobacillus pleuropneumoniae is an important porcine respiratory pathogen causing great economic losses in the pig industry globally. Stress is known to contribute to the outcome of A. pleuropneumoniae infection. To test whether A. pleuropneumoniae could respond to stress hormone catecholamines, gene expression profiles after epinephrine (Epi) and norepinephrine (NE) treatment were compared with those from untreated bacteria. The microarray results showed that 158 and 105 genes were differentially expressed in the presence of Epi and NE, respectively. These genes were assigned to various functional categories including many virulence factors. Only 18 genes were regulated by both hormones. These genes included apxIA (the ApxI toxin structural gene), pgaB (involved in biofilm formation), APL_0443 (an autotransporter adhesin) and genes encoding potential hormone receptors such as tyrP2, the ygiY-ygiX (qseC-qseB) operon and narQ-narP (involved in nitrate metabolism). Further investigations demonstrated that cytotoxic activity was enhanced by Epi but repressed by NE in accordance with apxIA gene expression changes. Biofilm formation was not affected by either of the two hormones despite pgaB expression being affected. Adhesion to host cells was induced by NE but not by Epi, suggesting that the hormones affect other putative adhesins in addition to APL_0443. This study revealed that A. pleuropneumoniae gene expression, including those encoding virulence factors, was altered in response to both catecholamines. The differential regulation of A. pleuropneumoniae gene expression by the two hormones suggests that this pathogen may have multiple responsive systems for the two catecholamines

Differential effects of alprazolam and clonazepam on the immune system and blood vessels of non-stressed and stressed adult male albino rats

Benzodiazepines belongs to one of the most commonly used anxiolytic and anticonvulsant drugs in the world. Full description of toxic effects on different organs is lacking for nearly all the current benzodiazepines. The aim of the current work was to study the immunologic and vascular changes induced by sub-chronic administration of alprazolam and clonazepam in non-stressed and stressed adult male albino rats. Forty-two adult male albino rats were divided into 6 groups (I): (Ia) Negative control rats, (Ib): Positive control rats received distilled water, (II): Stressed rats, (III): Non-stressed rats received daily oral dose of clonazepam (0.5 mg/kg), (IV): Stressed rats received daily oral dose of clonazepam (0.5 mg/kg), (V): Non-stressed rats received daily oral dose of alprazolam (0.3 mg/kg). (VI): Stressed rats received daily oral dose of alprazolam (0.3 mg/kg). At the end of the 4th week, total leukocyte count (WBCs) and differential count were determined, anti-sheep RBC antibody (Anti-SRBC) titer and interleukin-2 (IL-2) level were assessed, thymus glands, lymph nodes, spleens and abdominal aortae were submitted to histopathological examination. Alprazolam was found to induce a significant increase in neutrophil count and a significant decrease in lymphocytes, anti-SRBC titer and IL-2 level with severe depletion of the splenic, thymal and nodal lymphocytes, accompanied by congestion and eosinophilic vasculitis of all organs tested in comparison to clonazepam treated rats. Stress enhanced the toxic effects. It was concluded that the immune system and blood vessels can be adversely affected to a greater extent by short-term chronic administration of alprazolam than by clonazepam, and these toxic effects are aggravated by stress

Impact of group housing of pregnant sows on health

Group housing of sows during gestation is mandatory in the EU since 2013. Compared to housing in individual crates, group housing allows the animals to express normal activity and behavior. The present paper discusses the impact of group housing on health, with emphasis on lameness, aggression and possible spread of infectious diseases. The prevalence of lameness is generally higher in sows housed in group than in sows housed individually. Floor space per sow, group size, pen design and flooring are the main factors of group housing involved in lameness development. Especially floor characteristics are important, and particular attention should be paid to the type, building material and quality of the floor, hygiene and the use of bedding such as straw or rubber mats. Aggression between sows is another critical issue in group housing systems. It occurs predominantly because of competition for access to a limited resource, or to establish a social hierarchy. Key factors to prevent aggression in group housing include gradual familiarization of unfamiliar animals, sufficient space and pen structure during initial mixing, minimizing opportunities for dominant sows to steal food from subordinates, provision of a good quality floor, environmental enrichment and use of straw bedding. Very scarce evidence-based information is available on the relationship between group housing and infectious disease. Compared to individual housing, sows in group housing have more nose-to-nose contact, and they have more oral contact with feces and urine. These factors could contribute to a higher or faster transmission of pathogens, but so far, there is no evidence showing more disease problems in group housing systems. In conclusion, in group housing systems, particular attention should be paid to prevention of lameness and aggression. Management is crucial but also feeding strategies, floor and bedding, and design of housing are very important as relatively minor adjustments may exert major effects on the animals.Peer reviewe