Novelty causes elevated heart rate and immune changes in pigs exposed to handling, alleys, and ramps

Posted in: Welfare by admin on January 1, 2008 | No Comments

Economic losses related to the handling of pigs are well known throughout the industry (Tarrant, 1989). Handling effects on pig stress are complicated and few studies have quantified stress responses in common handling situations. In times of stress, the HPA (hypothalamic pituitaryadrena axis) axis is activated and glucocorticoids are released into the blood of the pig. Stress also causes changes in measures of the immune system (McGlone et al., 1993; Morrow-Tesch et al., 1994; Hicks et al., 1998; Salak-Johnson and McGlone, 2007). Alongside endocrine and immune responses to stress, stressed animals may undergo physiological changes such as increased heart and respiration rates that lead to an increase in body core temperature. Heart rate can be determined by use of telemetry to obtain undisturbed responses within experimental groups (Von Borell, 2001; Von Borell et al., 2007; Marchant-Forde et al., 2003a,b). The main hypothesis for this study was that when pigs are exposed to a novel environment they would have a higher heart rate and an overall stress response compared with those pigs that were habitualized with the environment. We also sought to determine if minimal training to remove novelty would reduce the stress experience for pigs destined for transport to slaughter. The ultimate goal is to reduce or eliminate stress-induced problems with pig losses during transportation and handling. Ten test subject pigs were selected per treatment. The first (trained) group was trained to navigate a course including a ramp. Testing was daily for seven days. Once training was completed, the trained and control (naïve) groups were exposed to a fixed course, the course and ramp (both up and down) while heart rates, time, handling difficulty, and blood were collected to determine the innate responses. It was concluded that heart rates of trained pigs were reduced significantly compared to naïve pigs travelling the same course. Both handling ease and handling time were significantly improved for the trained pigs compared to naïve pigs. Blood immune measures indicated reduced stress among trained pigs that had lower neutrophil numbers and lower total and average phagocytosis compared with naïve pigs. This study demonstrated that the exposure of pigs to a novel environment clearly causes a mild physiological response. Alleys and ramps do not inherently stress pigs, but rather novel experiences cause handling problems and a stress response and minimal training can reduce the stress experience for the pig.

For more information the full article can be found at http://www.journals.elsevierhealth.com/periodicals/livsci

Survival of classical swine fever virus at various temperatures in faeces and urine derived from experimentally infected pigs

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Indirect transmission of classical swine fever virus (CSFV) can occur through contact with mechanical vectors, like clothing and footwear or transport vehicles, contaminated with the secretions or excretions of infected pigs. A prerequisite for indirect transmission is survival of the virus on the mechanical vector. Consequently, to obtain more insight into these transmission routes, it is important to know how long the virus remains viable outside the host. In this study we examined the survival of classical swine fever virus in faeces and urine derived from pigs intranasally inoculated with a highly or moderately virulent CSFV strain. Faeces and urine were collected between days 5 and 36 post-inoculation, and stored at 5, 12, 20, and 30 8C. Next, the virus titres were determined in the samples by virus titration, and a random selection of these samples was also analyzed by quantitative real-time reverse transcription polymerase chain reaction (qRRT-PCR) to determine the viral RNA decay. Survival curves were generated, and it was shown that the inactivation rate was inversely related to the storage temperature. Average halflife values were between 2 and 4 days at 5 8C, and between 1 and 3 h at 30 8C. Significant differences were observed in survival between virus strains in faeces, however, not in urine. The reduction in viral RNA during the entire study period was limited. This
study provided detailed information on survival of CSFV in excretions of infected pigs, which can be used to improve control measures or risk-analysis models.

For more information the full article can be found at http://www.sciencedirect.com/science/journal/03781135

Relationship between serum acute phase protein concentrations and lesions in finishing pigs

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To establish the relationship between serum levels of three acute phase proteins, haptoglobin (Hp), C-reactive protein (CRP) and serum amyloid A (SAA), and the occurrence and severity of lesions at slaughter, a study was carried out using 70 fattening pigs from a finishing unit. It was found that serum levels of CRP, SAA and Hp were significantly higher in pigs with clinical signs of disease than in apparently healthy animals. Additionally, in apparently healthy pigs, serum levels of Hp and CRP were significantly higher in animals with lesions than those without lesions. The extent and severity of lung lesions were related to serum levels of Hp.

For more information the full article can be found at  http://www.sciencedirect.com/science/journal/10900233

Utilization of distillers dried grains with solubles and phytase in sow lactation diets to meet the phosphorus requirement of the sow and reduce fecal phosphorus concentration

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This study was completed to determine the potential for using distillers dried grains with solubles (DDGS) in diets with or without phytase to provide available phosphorus, energy, and protein to highly productive lactating sows without increasing their fecal phosphorus. The results indicate that highly productive sows can sustain lactation performance with reduced fecal phytate phosphorus when fed DDGS and phytase in lactation diets.

Influence of dietary fiber on luminal environment and morphology in the small and large intestine of sows

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This study determined the effect of feeding different types of amounts of dietary fiber (DF) on luminal environment and morphology in the small and large intesting of sows. It was shown that there was an increased retention time, decreased amount of material, and a decreased tissue weight after feeding the low-fibre diet compared to the high-fibre diet. It was also concluded that feeding the diet providing the greatest amount of fermentable carbohydrates resulted in significant morphological changes in the colon compared with the low-fibre diet.

Growth performance, carcass characteristics, meat quality, and tissue histology of growing pigs fed crude glycerin-supplemented diets

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The effects of dietary crude glycerin on growth performance, carcass characterisits, meat quality idices, and tissue histology is growing pigs was determined in a feeding trial. It was found that dietary treatment did not affect blood metabolites or frequency of lesions in the examined tissues. This experiment shows that pigs can be fed up to 10% crude glycerin with no effect of pig performance, carcass composition, meat quality, or lesions score.

Triticale as a replacement for wheat in diets for weaned pigs

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The nutritional value of triticale for weaned pigs is poorly characterized.
Six mash diets containing either 66.5% one of two wheat samples or one of four winter or spring triticale cultivars were fed
to 72 pens of weaned pigs for 28 d. Average daily feed intake and gain did not differ between pigs fed wheat and triticale
diets (P>0.05). Replacing wheat with triticale increased feed efficiency by 0.02 for spring triticale and 0.03 for winter
triticale (P<0.001). Apparent total tract digestibility of dry matter, crude protein, and gross energy was 1.2, 2.5, and 1.0% higher, respectively, for the triticale diets than the wheat diets (P<0.05). The nutritional value of the four triticale samples was 1.5% higher for energy than the two wheat samples included in western Canada diets for weaned pigs.

Genetic parameters and predicted selection results for maternal traits related to lactation efficiency in sows

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The objectives of this study were to estimate genetic parameters for lactation efficiency (LE), its underlying traits, and to predict the consequences of current selection strategies in dam lines. Inclusion of LE in the breeding goal will improve stayability, as defined by the first-litter survival of sows and LE itself, without
negative consequences for other economically important traits. Nevertheless, it might be worthwhile to
design a breeding goal in which LE increases and feed intake remains unchanged.

Selected parameters in urine as indicators of milk production in lactating sows: A pilot study

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This study aimed to investigate whether urine parameters could be used to predict milk production in sows. It was found that the absolute concentrations, the ratios relative to creatinine, and the fractional excretions of all elements in urine were not significantly associated with milk production and further research is necessary.

On the rewarding nature of appetitive feeding behaviour in pigs (Sus scrofa): Do domesticated pigs contrafreeload?

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Contrafreeloading is the phenomenon that animals prefer to ‘‘work’’ for food even though ‘‘free’’ food is
available nearby. In this study,we investigated whether pigs express contrafreeloading in a test situation where
the searching, finding and consuming of food items resembles a natural foraging situation. For that purpose, we
investigated whether pigs prefer an environment with straw and hidden food rewards (chocolate raisins) to an
environment with straw, but without hidden food rewards and with food rewards ‘‘freely’’ available in a trough. The results show that pigs express contrafreeloading when using a natural foraging task and they suggest that the reinforcing effects of anticipation, which occurs during natural foraging in the delays between searching and finding food, may contribute to the observed expression of contrafreeloading in pigs.