1
A total of sixty one entire males (Landrace; Large White and Pientrain) were selected after a DNA Test to determine NN or nn animals. Therefore, the animals were distributed in 6 pens according to halothane genotype and dietary treatments (3 different diets). The three experimental treatments were as follows: a commercial diet based on 30% of barley, 26% of soybean meal, 15% of maize and 12% of wheat was prepared (control diet); Mg supplemented diet: control diet + 1.28 g MgCO3/kg and Trp supplemented diet: control diet + 5 g L-Tryptophan per kg. All the experimental diets were offered to the animals five days before slaughter. At slaughter, behavioural parameters were evaluated previous and while the stunning process. Additionally, corneal reflexes were also recorded after stunning process.
During the five days of study, no differences were observed on feed intake amongst the experimental diets. However, lower feed intake was observed for nn pigs than for NN (P<0.01). No differences were observed amongst treatments on the behaviour of the animals before slaughter (P>0.05). Halothane positive animals fed with the Mg supplemented diet increased the time to first retreat attempt before stunning than those fed the control diet. No effects on animal behaviour were observed due to Trp supplementation. Moreover, in the group of animals fed the Mg supplemented diet, the nn animals showed later (P<0.01) first retreat attempt than NN. No effects on carcass quality and meat quality parameters were observed neither for the animals fed the Mg supplemented diets nor for the Trp supplemented diets.
It is concluded that the Mg supplementation of pig diets may have a positive effect on animal welfare of nn pigs at slaughter.
N Panella-Riera, A Dalmau, E Fabrega, M Font I Furnols, M Gispert, J Tibau, J Soler, A Velarde, MA Oliver and M Gil. 2008 Livestock Science,115:107-117.
