Influence of supplemental magnesium, tryptophan, vitamin C, and vitamin E on stress responses of pigs to vibration

The Role of Vitamins in Mitigating the Effects of Various Stress Factors in Pigs Breeding

Good practices in farm animal care are crucial for upholding animal well-being, efficiency, and health. Pigs, like other farm animals, are exposed to various stressors, including environmental, nutritional, chemical, psychological, physiological, and metabolic stressors, which can disrupt their internal balance and compromise their well-being. Oxidative stress can adversely affect animal performance, fertility, and immunity, leading to economic losses for farmers. Dietary considerations are hugely important in attaining these objectives. This paper reviews studies investigating the impact of additional vitamin supplementation on stress reduction in pigs. Vitamin A can be beneficial in counteracting viral and parasitic threats. Vitamin B can be a potential solution for reproductive issues, but it might also be beneficial in reducing the effects of inappropriate nutrition. Vitamin C plays a vital role in reducing the effects of heat stress or exposure to toxins in pigs. Vitamin D proves to be beneficial in addressing stress induced mostly by infections and weaning, while vitamin E has been shown to mitigate the effects of toxins, heat stress, or transport stress. This review highlights the potential benefits of these dietary antioxidants in maintaining pig health, enhancing productivity, and counteracting the adverse effects of various stressors. Understanding the role of vitamins in pig nutrition and stress management is vital for optimising farm animal welfare and production efficiency.

Vitamin E supplementation improves post-transportation systemic antioxidant capacity in yak

This study was aimed to evaluate the effects of post-transportation vitamin E (VE) supplementation on health condition, blood biochemical parameters, blood antioxidant indices and blood metabolomics in yak. Five yaks were used in this study. After 2100 km of highway transportation from Riwoqe county to Rongchang County, Chongqing, blood was collected immediately after arrival and these samples served as the baseline (control, CON_VE). A VE injection (40 mg/kg) was then performed and blood samples were collected 10 days later. Injection of VE led to lower serum VE concentration. Relative to the CON_VE, VE injection led to greater concentrations of creatinine and lower concentrations of glutamate pyruvic transaminase, alkaline phosphatase, aspartate aminotransferase, total bilirubin, indirect bilirubin, direct bilirubin, UREA and glucose. Compared with CON_VE, VE injection led the lower serum level of malondialdehydeand greater serum level of glutathione s-transferase, glutathione peroxidase, glutathione reductase and glutathione peroxidase 4. Based on metabolomics analysis, 119 differentially altered serum metabolites (P<0.05 and VIP>1.0) were identified with VE injection relative to CON_VE. VE injection resulted in changes of lysophosphatidylethanolamine, lysophosphatidylcholine, phosphocholine, choline, malate, citrate, α-Oxo-glutarate, phenylalanine, 3-Phenylpropanoic acid and 3-(3-Hydroxyphenyl) propanoic acid. These metabolites are associated with lipid metabolism, tricarboxylic acid cycle and oxidative stress. Overall, our study indicates that VE injection can alleviate transportation stress in yak partly through protecting liver and kidney, and improving antioxidant defense systems.

Tranquillizing Effect of Passiflora incarnata Extract: Outcome on Behavioral and Physiological Indicators in Weaning Pigs with Intact Tails

Simple Summary

Post-weaning is the most critical phase in pig farming, characterized by efforts to ensure health, performance and welfare of animals. Despite that EU Directive 2008/120/EC prohibits the practice of tail docking, it is still commonly applied in intensive farming to avoid tail biting. From a nutritional perspective, the dietary supplementation with natural extracts with calming properties could represent a promising approach to overcome common production stressors, reducing abnormal behaviors such as tail biting. This study intended to determine the effects of the dietary inclusion of Passiflora incarnata, known for its tranquillizing activity, on skin lesions, thermal imaging, behavior, salivary cortisol and IgA levels on post-weaning piglets reared with intact tails. Growth performances were also monitored. No differences were recorded between diets regarding growth performance, whereas findings concerning aggressive and abnormal behaviors, such as tail and ear biting, and lower levels of cortisol confirmed the hypothesis of the calming effect of P. incarnata on post-weaning piglets.

Abstract

Tail docking has been used in the pig industry to decrease the occurrence of tail biting behavior. This abnormal behavior has a multifactorial origin since it is a response to simultaneous environmental, nutritional and management changes. Given the calming properties of Passiflora incarnata, we hypothesized that dietary supplementation with the extract in weaned pigs could result in a modification of behavior and physiologic indicators linked to stress. Weaned piglets (n = 120, mean body weight 9.07 ± 2.30 kg) were randomly allocated to one of two dietary treatments: control diet (CON) and CON supplemented with 1 kg/t of P. incarnata (PAS). The trial was 28 days long. The presence of skin lesions was assessed at d-1, d-10, d-19, and d-28, and saliva samples were collected for IgA and cortisol determinations at the same sampling times. Results showed the PAS group was characterized by equal growth performance as the CON group, fewer ear lesions (p < 0.05), less aggressive behavior (p < 0.001), higher enrichment exploration (p < 0.001) and lower cortisol levels (p < 0.01). Time effect was observed for tail lesions (p < 0.001) and behavioral observations (p < 0.001). Additional research is required to determine the effect of P. incarnata extract using a larger number of animals and longer period of supplementation when risks associated with tail biting are uncontrolled.

Potential improvements of the cognition of piglets through a synbiotic supplementation from 1 to 28 days via the gut microbiota

The influence of feed supplements on behavior and memory has been recently studied in livestock. The objectives of the study were to evaluate the effects of a synbiotic on: an episodic-like (SOR: Spontaneous Object Recognition), a working (BARR: Fence barrier task), a long-term (TMAZE: Spatial T-maze task) memory test and on gut microbiota composition. Eighteen female piglets were supplemented from 1 to 28 days of age with a synbiotic (SYN), while 17 served as control (CTL). Feces were collected on days 16, 33 and 41 for 16S rRNA gene composition analyses. In the SOR, SYN piglets interacted more quickly with the novel object than CTL piglets. In the BARR, SYN piglets had shorter distances to finish the test in trial 3. In the TMAZE, SYN piglets were quicker to succeed on specific days and tended to try the new rewarded arm earlier during the reversal stage. Difference of microbiota composition between treatments was nonexistent on D16, a tendency on D33 and significant on D41. The synbiotic supplement may confer memory advantages in different cognitive tasks, regardless of the nature of the reward and the memory request. Difference in memory abilities can potentially be explained by differences in microbiota composition.

Is Magnesium Supplementation an Effective Nutritional Method to Reduce Stress in Domestic Pigs? A Systematic Review

In commercial pig production, stressful events are common and can have detrimental impacts on the pig's health and welfare, as well as on the performance of the farm. Supplementary magnesium may reduce stress, and subsequent harmful and aggressive behaviors, that occur during stressful events, such as regrouping. However, reports on the efficacy of this treatment are mixed. We aimed to systematically review the studies in which magnesium was given to pigs to examine the effects on measures of stress. Of the 16 studies included in the final corpus, 10 reported at least one statistically significant beneficial effect of supplementary magnesium on reducing stress. However, two studies found that magnesium significantly increased stress suggesting supplementary dietary magnesium may be harmful in some cases. Overall, there are a limited number of studies investigating the possible effect of magnesium on reducing stress in pigs, and although results were varied, the majority found beneficial effects of supplementary magnesium.

Strategies to Combat Heat Stress in Broiler Chickens: Unveiling the Roles of Selenium, Vitamin E and Vitamin C

Heat stress compromises efficient poultry production by impairing growth performance and increasing mortality. Mechanisms to dissipate excess heat divert energy from efficient production. This includes increased energy expenditure for respiration, oxidative stress and micronutrient absorption. The fortification of diets with particular feed additives has been known as one of the most important approaches to minimize the negative impacts of heat stress on broiler production. In this context, the promising functional feed additives appeared to be selenium and vitamins E and C. The fortification of broiler diets with these feed additives has been proven to enhance the function of vital organs, immune system response and growth performance of broilers under heat stress. The current review highlights recent successful experiences in the alleviation of heat stress symptoms in broilers using the above-mentioned additives. Selenium and vitamins E and C enhanced production performance in broiler chickens challenged with acute heat stress. The combination of these additives, by employing multiple mechanisms and through synergistic effects, improves heat stress symptoms more efficiently than their individual forms. Emerging literature reveals that selenium and vitamins E and C are involved in close interactions to protect proteins and lipids from oxidative damage and boost immune system function.

Effects of Three Distinct 2-Week Long Diet Strategies After Transport on Weaned Pigs' Short and Long-Term Welfare Markers, Behaviors, and Microbiota

Alternative feed supplements have shown promising effects in terms of performance, but their effects on welfare have had little evaluation. In the present study, we aimed at evaluating the effect of diet supplementation on welfare indicators. A total of 246 piglets were weaned and transported for 12 h. After transport, they were assigned to one of 3 diets for a 14-day period: A-an antibiotic diet including chlortetracycline and tiamulin, NA-a control diet without any antibiotic or feed supplement, GLN-a diet including 0.20% L-glutamine. After the 14-day period, all piglets were fed the same diet. Tear staining was measured 11 times post-weaning (from d0 to 147). Skin lesions were counted before and after weaning (d-2, 2, and 36). Novel object tests (NOT) were done in groups 4 times post-weaning (d17, 47, 85, 111). Samples for 16S rRNA gene composition were collected prior to transport (d0), following the 14-day period (d14) and at the conclusion of the nursery phase (d34). The NA pigs appeared less interested in novel objects. On d17, they avoided the object less than A pigs (P < 0.05). They spent less time exploring the object on d85 and took longer to interact with the object on d111 than A and GLN pigs (P < 0.05). NA pigs also appeared more sensitive to environment and management. They had larger tear stains than GLN pigs on d84 and 110 (P < 0.05). On d2, NA pigs had more lesions than A and GLN (P < 0.01). In terms of microbiota composition, GLN had higher α-diversity than A and NA (P < 0.001). Differences between dietary treatments were absent at d0, were demonstrated at d14 and disappeared at d34. Pearson correlations between aggression, stress and anxiety indicators and bacterial populations were medium to high from 0.31 to 0.69. The results demonstrate that short-term feeding strategy can have both short- and long-term effects on behavior and welfare, that may partly be explained by changes in gut microbiota composition. Supplementation with GLN appears to confer similar benefits to dietary antibiotics and thus could be a viable alternative.

Effects of dietary oregano essential oil and vitamin E supplementation on meat quality, stress response and intestinal morphology in pigs following transport stress

This study investigates the effects of dietary oregano essential oil (OEO) and vitamin E (Vit E) supplementation on meat quality, stress response and intestinal morphology in pigs following transport stress. A total of 288 finishing pigs were randomly assigned to three groups: a basal diet or a basal diet supplemented either with 200 mg/kg Vit E or 25 mg/kg OEO. After a 28-day feeding trial, total of 132 finishing pigs according diet and transport stress were assigned to one of four treatment groups: 1) control treatment without transport stress (Control group), 2) control treatment with 5-hr transport stress (Negative group), 3) Vit E treatment with 5-hr transport stress and 4) OEO treatment with 5-hr transport stress. Transport stress pigs had lower muscle 45 min pH (pHi) and higher drip loss than control pigs. Dietary OEO and Vit E supplementation significantly increased 45min pH under transport stress, and the OEO groups produced lower 24-hr drip loss values (P<0.05) than that of pigs from the negative group. The OEO-supplemented pigs showed decreased serum levels of creatine kinase (CK) and cortisol (P<0.05), and decreased Hsp 27 (heat shock protein 27) and Hsp 70 (heat shock protein 70) mRNA expression in the muscle (P<0.05). Additionally, histological analysis revealed intestinal epithelial damage in transport stress pigs that was reversed by dietary supplementation with OEO. In conclusion, supplementation with dietary OEO may be superior to supplementation with dietary Vit E in alleviating the meat quality, stress response and intestinal morphology of pigs after challenge due to transportation stress.

Effect of dietary magnesium supplementation in alleviating stress associated with road transportation in weaned lambs

Magnesium (Mg) supplementation has shown to modulate the stress responses to transport in other species. An experiment was designed to evaluate the effect of Mg for alleviating stress associated with road transportation in lambs. Two groups (n = 18 each) of 4-month old male crossbred lambs (24 ± 4.5 kg) were fed a basal diet comprising oaten hay, pellets and barley, that contained 0.17% Mg. One group was supplemented with magnesium oxide, such that dietary Mg was 0.41%. At the end of the 2-week supplementation period, the lambs were transported by road for 8 h. Blood samples were collected before supplementation, 1 h before transport, within 0.5 h post-transport, at 2 h post-transport and 5 days post-transport. Data were analysed using a repeated-measure analysis of variance and linear mixed model with treatment within time interaction. Supplementation with dietary Mg in the form of MgO increased serum Mg concentrations (1.16 mmol/L ± 0.012, compared with 1.09 mmol/L ± 0.013 in the control group; P < 0.05), but had no effect on alleviating stress during transportation. Transport resulted in a significant increase in serum cortisol, which returned to pre-transport levels 2 h after transport. The serum β-hydroxybutyrate was significantly higher 5 days after transport. The post-transport average feed intake and the average daily gain were significantly lower than pre-transport values, suggesting that the stress of transportation resulted in a decrease in feed intake post-transport, which could have implications on liveweight gain of animals after transportation.

Effect of vitamin levels and different stocking densities on performance, nutrient digestibility, and blood characteristics of growing pigs

This study was conducted to evaluate the effects of dietary vitamin levels and stocking densities on growth performance, nutrient digestibility, and blood characteristics in growing pigs. A 2×3 factorial (two vitamin levels, three regimens of stocking densities) arrangement was utilized with 96 pigs (23.10×0.95 kg initial body weight and 63 d of age) for 36 d. The pigs were allocated to pens with different stocking density (0.64, 0.48, and 0.38 m(2)/pig, respectively). The diets used in this study were a normal diet (based on NRC) and a high level of vitamin diet (2-fold higher than normal diet). The ADG and ADFI of pigs were decreased as the stocking density increased (p = 0.03 and p = 0.01, respectively). The G/F of pigs was 5% lower in the high vitamin treatment (p = 0.03) as compared with the control treatment. The apparent total tract digestibility (ATTD) of DM and N digestibility was negatively affected by the high level of vitamin in diets (p = 0.05 and p = 0.04, respectively). Moreover, a significant and negative effect on the ATTD of N was detected in the large groups (linear, p = 0.02). Blood cortisol concentration was increased with increasing stocking density (linear, p = 0.05), and was decreased by high level of vitamin (p = 0.04) at the end of this experiment. Stocking density also caused a linear reduction in WBC concentration (p = 0.05). Our data indicated that the principal effect of stocking density was not reliant on dietary vitamin levels. In conclusion, results indicated that doubling the vitamin supplementation did not improve the growth performance of pigs in high density. However, the blood cortisol concentration was decreased but the ATTD of N digestibility was impaired by high level of vitamin diet.

A pilot study to determine if a dietary mineral supplement can affect reactivity to stimuli by horses in training

Trainers have reported horses to be calmer and easier to train after receiving a calcium- and magnesium-rich mineral supplement derived from a calcified algae source. The purpose of this study was to test whether horses receiving this supplement were calmer than horses receiving a placebo. Fourteen 2-year-old Arabians in training were subjected to a ‘moving object reactivity test’ (MORT) and ‘handling reactivity test’ (HRT). The MORT involves quickly raising a bag suspended from the ceiling and scoring horses' reactions. The HRT involves placing horses into breeding stocks and scoring the horses’ nervousness. Horses were equipped with heart rate (HR) monitors and were scored by four observers blinded to treatment. Reactivity scores and HR were used to randomly striate the horses into two groups: a treated group (MIN) receiving 100 g of Aquacid/horse/day and a control group (CO) receiving a placebo. After supplementation for 60 days, horses were retested. Using PROC Mixed, changes from day 0 were examined. In the MORT, CO had an increase of 29 bpm (P=0.001), while MIN only showed a trend to increase (12 bpm; P=0.1). There was no difference between treatments (P=0.12). Reactivity scores during the MORT were not different between treatments (P=0.14) with CO horses increasing by 0.58 (1 to 5 scale) and MIN horses by 0.31. In the HRT, the peak HR of CO increased from day 0 by 17 bpm (P=0.009), but only by 11 bpm in the MIN (P=0.08). Reactivity scores for MIN horses improved by 0.45 (scale from 1 to 4) while the CO worsened by 0.04. Neither HRT measurement was significant (P=0.41 and P=0.33, respectively). Limited treatment differences suggest greater subject numbers were needed due to variability in behavioural responses despite some outcomes favouring MIN. Though inconclusive, results suggest anecdotal claims of calming effects may warrant further investigation.

Effects of Short-term Feeding Magnesium before Slaughter on Blood Metabolites and Postmortem Muscle Traits of Halothane-carrier Pigs

Fifty-four, mixed-sex, halothane-carrier crossbred (Yorkshire×Landrace) pigs with an average initial BW of 108.2±0.8 kg were randomly allotted to one of three dietary treatments for 5 d before slaughter: i) a control corn-soybean meal finisher diet devoid of supplemental magnesium; ii) a diet supplemented with 1.5 g/kg of elemental Mg from magnesium acetate; and iii) a diet supplemented with 1.5 g/kg of elemental Mg from magnesium sulfate heptahydrate. Serum creatine kinase (CK), lactate and glucose were analyzed at slaughter. Muscles from longissimus (LM) were packaged and stored to simulate display storage for muscle lactate and glycogen determinations at 0, 1, 2, 3, and 4 d. Mg supplementation reduced (p<0.05) serum CK and lactate concentration, but had no effect (p>0.05) on serum glucose. Daily change of muscle lactate concentration linearly increased (p<0.01), while glucose concentration linearly decreased (p<0.05) as storage time increased in all treatments. However, dietary Mg acetate and Mg sulfate supplementation in pigs elevated (p<0.05) muscle glycogen and reduced (p<0.05) muscle lactate concentrations, especially during the first 2 d of display, compared with pigs fed the control diet. This study suggests that short-term feeding of magnesium acetate and magnesium sulfate to heterozygous carriers of the halothane gene has beneficial effects on stress response and pork quality by improving blood and muscle biochemical indexes.

The influence of a magnesium-rich marine extract on behaviour, salivary cortisol levels and skin lesions in growing pigs

Growing pigs can display undesirable behaviours, reflecting or causing poor welfare. Addition of magnesium (Mg) to the diet could reduce these, as Mg supplementation has been associated with improved coping ability in response to stress. This study examined the effect of supplementation with a Mg-rich marine extract-based product (Supplement) on the behaviour, skin and tail lesion scores and salivary cortisol concentrations of growing pigs. At weaning (28 days), 448 piglets were assigned to either Control or Supplement (0.05%) diets in single-sex groups of 14. Four weeks later (c. 17 kg), pigs were blocked according to weight and back test scores. Seven piglets from each pen were mixed with seven from another pen of the same sex and dietary treatment to yield the following groups: control male, Supplement male, control female and Supplement female (n = 4 of each). This marked the start of the 9-week experimental period. Instances of the following behaviours were recorded in each pen for 8 × 2 min periods 1 day/week: aggression (fight, head-knock and bite); harmful (tail-in-mouth, ear-chewing and belly-nosing); and sexual/mounting behaviour. Four focal pigs were selected from each pen, and their behaviour was continuously recorded for 2 × 5 min periods on the same day. Saliva was collected once per week at 1000 h by allowing pigs to chew on a cotton bud for c. 1 min. Salivary cortisol was analysed in duplicate by an enzyme immunoassay. Skin and tail lesions were scored according to severity 1 day/week. There were fewer aggressive incidents in Supplement pens (P < 0.01), and mounting behaviour (performed only by males) was almost three times lower in Supplement than in control pens (P < 0.01). However, there was no effect of Supplement on the incidence of each of the harmful behaviours. Behaviour of the focal pigs showed no treatment effect on the duration or incidence of aggressive behaviour. However, Supplement pigs spent less time performing harmful behaviours compared with control pigs (P < 0.001). Supplement had no effect on the occurrence or severity of tail-biting outbreaks or on tail lesion scores. However, Supplement females had lower skin lesion scores, in particular in the ears and shoulders (P < 0.01). Finally, Supplement pigs had lower salivary cortisol concentrations (P < 0.01). Mounting is a major welfare concern in uncastrated pigs, and therefore this represents an important welfare benefit of Supplement. Reduced salivary cortisol, in conjunction with reduced skin lesion scores in supplemented females, suggests that addition of a Mg-rich marine extract improved pig welfare in this system.

Effects of water supplementation with tryptophan and vitamin B6 or feeding hydrogenated fat on reducing hunger-induced drinking pre-slaughter in pigs

Faucitano, L., Torrey, S., Matte, J. J., del Castillo, J. R. E. and Bergeron, R. 2012. Effects of water supplementation with tryptophan and vitamin B6 or feeding hydrogenated fat on reducing hunger-induced drinking pre-slaughter in pigs. Can. J. Anim. Sci. 92: 319–326. A current food safety challenge at pig slaughter plants comes with the presence of stomachs filled with liquid induced by hunger-related drinking in lairage. With the objective to reduce hunger-related excess drinking, 30 barrows were assigned to three treatments (10 pigs per treatment): (1) unsupplemented water or feed regimen (CONT), (2) L-Tryptophan (3 g L−1) and vitamin B6 (10 mg L−1) in the drinking water for 5d (TRP-B6), (3) hydrogenated fat (HF) supplemented at 10% in the diet for the last day of feeding before pre-slaughter fasting. As compared with CONT, neither TRP-B6 nor HF supplementation influenced behaviour in lairage and water intake at anytime over the pre-slaughter fasting period as reflected on stomach weight and its liquid content at slaughter (P>0.10). However, in HF-fed pigs plasma non-esterified fatty acids concentrations tended to be lower (P=0.09) while carcass yield was higher (P=0.04) than CONT pigs. It appears, therefore, that neither drinking water supplementation with TRP-B6 for 5 d nor feeding HF the last day before slaughter can be recommended strategies to limit excess water drinking prior to slaughter and liquid stomach content at slaughter. However, dietary HF supplementation the last day before slaughter may attenuate the effects of fasting on body energy reserves and improve carcass yield.

Acupuncture Improves Sleep Conditions of Minipigs Representing Diurnal Animals through an Anatomically Similar Point to the Acupoint (GV20) Effective for Humans

Acupuncture, an alternative medicine, has been widely applied for people with sleep disturbances; therefore, the effects should be evaluated objectively. Micro-minipigs (MMPigs), the smallest miniature pigs for animal experiments, were used. Acupuncture was performed at two different points: Dafengmen is located on the head and is an anatomically similar point to human-Baihui (GV20), an effective acupoint for sleep disturbances in humans; pig-Baihui is on the back. The procedure was performed as follows: shallow, within 5 mm depth for several seconds; deep, 10–20 mm depth for 20 min. The sleep conditions were evaluated by actigraph, and the amount of catecholamine in pooled urine after acupuncture treatment. MMPigs with deep acupuncture at Dafengmen showed significantly efficient values on actigraph and catecholamine analysis as compared with untreated MMPigs. The effective acupoint for sleep conditions in the porcine model is at an anatomically similar point to humans, rather than the point determined by traditional Chinese medicine.

Fruit, vegetable, and fish consumption and heart rate variability: the Veterans Administration Normative Aging Study

BACKGROUND

Higher intakes of fruit, vegetables, and dark fish may prevent sudden cardiac death and arrhythmias, but the exact mechanisms are not fully understood.

OBJECTIVE

We examined whether high consumption of fruit, vegetables, and dark fish would be associated with beneficial changes in heart rate variability (HRV).

DESIGN

HRV variables were measured among 586 older men with 928 total observations from November 2000 to June 2007 in the Normative Aging Study, a community-based longitudinal study of aging. Dietary intake was evaluated with a self-administered semiquantitative food-frequency questionnaire and categorized into quartiles.

RESULTS

After controlling for potential confounders, intake of green leafy vegetables was positively associated with normalized high-frequency power and inversely associated with normalized low-frequency power (P for trend < 0.05). These significant associations were retained after further adjustment for healthy lifestyle factors, such as physical activity and use of multivitamins. No significant association was seen between HRV measures and intakes of other fruit and vegetables, vitamin C, carotenoids, tuna and dark-meat fish, or n-3 (omega-3) fatty acids. An effect modification of intake of noncitrus fruit by obesity and of total vegetables and cruciferous vegetables by cigarette smoking was seen, which warrants further investigation.

CONCLUSION

These findings suggest that higher intake of green leafy vegetables may reduce the risk of cardiovascular disease through favorable changes in cardiac autonomic function.

Effects of supplementing two levels of magnesium aspartate and transportation stress on pork quality and gene expression of micro-calpain and calpastatin of finishing pigs

The objective of this study was to investigate the effects of supplementing swine finishing diets with two levels of magnesium aspartate (MgAsp) and short-term transportation stress on blood parameters, pork quality and the mRNA abundance of p-calpain and calpastatin in muscles of finishing pigs. Thirty-six crossbred finishing pigs (mean BW 90 kg) were assigned randomly to 0, 1000, or 2000 mg supplemental Mg from MgAsp per kg of diet for five days before slaughter. Then six pigs from each dietary treatment were subjected either to no transportation stress (NTS) or 2 h of transportation stress (TS). Transportation stress resulted in higher concentrations (p < 0.01) of serum calcium, glucose and cortisol, lower pH (p < 0.01), higher Warner-Bratzler shear force (WBSF) (p < 0.05) and higher calpastatin mRNA abundance (p = 0.05) of longissimus muscle (LM) compared with NTS treatments. Supplementation of MgAsp in TS treatments increased serum Mg concentration (p < 0.05) at 2000 mg of Mg/kg, reduced drip loss (p < 0.05) and improved pork quality colour (p < 0.05) at 2000 mg of Mg/kg, and decreased 1-day and 3-day WBSF (p < 0.05) at 1000 mg of Mg/kg compared with TS treatments fed the control diet. It is concluded that supplementation of MgAsp improves water-holding capacity and pork colour, and alleviates the negative effects of transportation stress on meat tenderness.

Influence of olfactory substances on the heart rate and lying behaviour of pigs during transport simulation

This study investigated the effect of olfactory substances on the heart rate and lying behaviour of pigs during transport simulation. Five treatments were tested through the application of each substance to pigs’ snouts with a paintbrush. These consisted of: 1) control treatment (wiping without product); 2) 2 ml of a synthetic, maternal-like pheromone; 3) 5 ml of a synthetic, maternal-like pheromone; 4) a commercial, non-relevant odour and 5) 2 ml of a placebo (solvent of the synthetic pheromone without active ingredients). In total, 90 pigs took part in this study and each treatment was tested on a group of three pigs with six replicates per treatment. Pigs were vibrated in the vertical direction in a transport simulator with a frequency of 8 Hz and an acceleration of 3 m s−2. Cardiac activity and lying behaviour during vibration were quantified. The effect of vibration was found to be statistically significant, ie causing an increase in heart rate and numbers of ventricular ectopic beats (VEB). Both 2 and 5 ml of synthetic pheromone were generally found to decrease the minimum, mean, and peak heart rate values in comparison with the other treatments (in particular the control and the non-relevant odour group) but only minimum heart rate reached statistical significance. However, the number of VEBs was highest for these two synthetic pheromone groups during vibration. No dose-dependent synthetic pheromone effects were found and there were no differences in the amount of time pigs spent lying. The use of olfactory substances may support pigs’ ability to cope with real transport conditions thereby improving their welfare.

Influence of supplemental magnesium, tryptophan, vitamin C, vitamin E, and herbs on stress responses and pork quality

This study investigated the effects of supplemental Mg, Trp, vitamin C, vitamin E, and herbs on stress responses, skin lesions, and meat quality of slaughter pigs (106.0 +/- 8.6 kg of BW). These 5 supplements were tested in 4 similar experiments. In Exp. 1, 2 treatments were tested: 1) control treatment without supplementation, and 2) supplementation of an herbal product (2.5 g/L of drinking water for 2 d). Eighty-eight pigs per treatment were involved, of which 40 were selected for meat quality measurements (over 4 replicates). The experimental design of Exp. 2 and 3 was the same as Exp. 1, except that in Exp. 2 Mg (3 g/L of drinking water for 2 d) was supplemented and in Exp. 3 Trp (6 g/kg of feed, as-fed basis) was supplemented. In Exp. 4, 3 treatments were tested: 1) control treatment without supplementation, 2) supplementation of vitamin C (300 mg/kg of feed for 21 d, as-fed basis), and 3) supplementation of vitamin E (150 mg/kg of feed for 21 d, as-fed basis). In Exp. 4, 66 pigs per treatment were used, of which 42 were evaluated for meat quality (over 6 replicates). Pigs supplemented with vitamin E ate less than control (P = 0.03) or vitamin C-supplemented pigs (P = 0.03). Pigs were transported to a commercial slaughterhouse and were slaughtered after a lairage period. Blood sampling at slaughter revealed no differences between the control and supplemented pigs in plasma cortisol, glucose, lactate, or creatine kinase concentrations. Pigs provided with Mg (P = 0.002) or Trp (P = 0.04) had lower plasma NEFA concentrations than control pigs, and pigs supplemented with vitamin C had greater concentrations than the control (P = 0.03) or vitamin E-supplemented pigs (P = 0.01). Supplementation of the herbal product increased the frequency of pigs with shoulder (P = 0.05) and loin lesions (P = 0.03), whereas Mg lowered the incidence of loin lesions (P = 0.01). Measurements of pH and temperature in the LM and biceps femoris 45 min postmortem revealed no differences among treatments, and no influence of treatments on LM pH, electrical conductivity, and water holding capacity was observed 48 h postmortem. Compared with the control loins, loins of pigs supplemented with vitamin C (Japanese color scale, L*, and a* value; P < 0.05) or vitamin E (Japanese color scale and a* value; P < 0.03) were redder and less pale, and the loin of vitamin E-supplemented pigs was more yellow (b* value; P = 0.04). Generally, Mg could lower loin damage, whereas vitamin C and vitamin E supplementation resulted in a color improvement of the loin.