Effect of supplemental tryptophan, vitamin E, and a herbal product on responses by pigs to vibration1

Abstract

Economic losses related to increased stress during the transport of pigs are well documented. The effects of supplementing of tryptophan (Trp), vitamin E, or a herbal product via feed or drinking water were investigated in terms of effects on stress response in pigs during transport simulation. The study consisted of three analogous experiments. For the testing in each experiment, the pigs (23.5+/-3.2 kg) were allocated to one of two treatments, with and without supplementation of a product. The applied doses were Trp (5 g/L drinking water for 3 d), vitamin E (additional amount of 300 mg/kg feed for 21 d, as-fed basis), and Sedafit (2.5 g/L drinking water for 2 d). Sedafit is a commercial herbal product containing Valeriana officinalis L. and Passiflora incarnata L. as active components. In each experiment of the study, at least 47 pigs were involved, which were treated in groups of 3. The day before transport simulation, a Holter device was attached to the pigs to produce an electrocardiogram during the night (rest values), as well as during vibration in the transport simulator (1.2 Hz, 1 m/s2), where the behavior of the pigs (standing-sitting-lying) was also observed. Samples of saliva (taken before, during, and after [3x] vibration) and blood (taken before and after vibration) were analyzed for cortisol and intermediate metabolites (glucose, lactate, creatine kinase, and nonesterified fatty acids), respectively. Pigs supplemented with Trp tended to spend more time lying down during the second hour of vibration (P < 0.05). Vitamin E decreased the peak heart rate (P < 0.05), ventricular ectopic beats (P < 0.01), and ST elevation (P < 0.10). The supplementation of Sedafit resulted in smaller increases of the investigated heart variables (minimum heart rate, P < 0.05; ventricular ectopic beats, P < 0.05; ST elevation, P < 0.01) during and after stress evocation compared with the control group. None of the tested products influenced the intermediate metabolites; one possible explanation for this finding may be that peak values were reached before the time of bleeding. In conclusion, Trp had a positive behavioral effect in this experiment, and vitamin E and Sedafit mediated an increase in some heart variables, suggesting sedative and antianxiety effects.

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

“…In order to verify potential effects of dietary Trp on behaviour, as observed by Peeters et al (2004) and Li et al (2006), pigs were videotaped 2 d prior to initiation of treatments (i.e., 7 d before slaughter) and 4 d after the first treatment application (i.e., 1 d before slaughter) in their home pens in order to measure activities and postures of pigs. One camera per pen was mounted from the ceiling.…”

“…Besides alleviating the stress of handling, transport and physical exercise (Peeters et al 2004;Guzik et al 2006;Li et al 2006), Trp decreases appetite in pigs (Chung et al 1991). Therefore its use may be beneficial to alleviate hunger in fasted pigs.…”

Do mood disorders play a role in pig welfare?

“…Piglets reject diets low in L-tryptophan (0.11% as fed-basis) and prefer diets containing adequate levels of this amino acid (Ettle and Roth, 2004). As regards behaviour, tryptophan supplementation (via feed or drinking water) has been reported to reduce the duration of fighting among unfamiliar pigs (Li et al, 2006) and increase the time spent lying in pigs subjected to transport simulation (Peeters et al, 2004). Dietary supplementation with tryptophan induces a reduction in the plasma concentrations of noradrenaline (Koopmans et al, 2005), while there is disagreement as to the responses induced with respect to cortisolemia (Peeters et al, 2004;Koopmans et al, 2005Koopmans et al, , 2006.…”

“…As regards behaviour, tryptophan supplementation (via feed or drinking water) has been reported to reduce the duration of fighting among unfamiliar pigs (Li et al, 2006) and increase the time spent lying in pigs subjected to transport simulation (Peeters et al, 2004). Dietary supplementation with tryptophan induces a reduction in the plasma concentrations of noradrenaline (Koopmans et al, 2005), while there is disagreement as to the responses induced with respect to cortisolemia (Peeters et al, 2004;Koopmans et al, 2005Koopmans et al, , 2006. In the latter case, the inconsistency of findings may depend either on the different doses of tryptophan used in the various experiments or on an inner depressed-aptitude of swine which is not necessarily related to external stress agents or noxiae.…”

Modelling feeding behaviour, rate of feed passage and daily feeding cycles, as possible causes of fatigued pigs

“…Many possible causes of fatigued pigs have been suggested in the literature including pre-transportation handling, group sizes, temperature during transport, nutrition status, etc. (Peeters et al, 2004;Ellis and Ritter, 2005;Lewis and McGlone, 2007).…”