Portal de Pesquisa da BVS Veterinária

Tese em Português | VETTESES | ID: vtt-216747

Resumo

As homeothermic animals, pigs manifest maximum performance when kept at comfortable temperature levels, represented by a limit where thermoregulatory processes are minimal. In a stress situation, with a higher energy demand for thermal maintenance, the energy contribution to the productive functions will be reduced, generating health imbalances, drop-in performance rates and welfare problems. The objective of this work was to study the replacement of 5% of starch (ST) per 5% of sunflower oil (SO), with or without restriction, in growing and finishing pigs diet kept under heat stress conditions and evaluate the influence of this strategies on welfare (dirtiness and behavior), performance, meat quality and carcass traits parameters. Seventy-two crossbred males (Iberic x Duroc) (51.00 ± 6.29 kg body weight - BW) were housed in collective pens and randomly distributed according to the initial BW, in climate-controlled rooms under heat stress conditions (30-32°C; 35% to 50% humidity). The experiment lasted 90 days and it was carried out in a randomized block design, in a 2 x 2 factorial, composed of two diets (ST or SO) and two management feed intakes (ad-libitum and restriction).The treatments studied were: 1) control diet (5% ST x 0% SO) with ad-libitum feed intake (n = 18); 2) SO diet (replacement of 5% of ST per 5% SO) with ad-libitum feed intake (n = 18); 3) control diet with restriction feed intake (n = 18); or 4) SO diet with restriction feed intake (n = 18). Feed were provided in two phases, 50 100 Kg BW for growing and 100 140 Kg BW for finishing period, respectively. Pigs behavior and dirtiness score was observed daily, according to the methodology described in the Welfare Quality Protocol for Pigs®. The activities considered were: eating, drinking, lying laterally, lying sternly, exploring the pen, exploring the environment enrichment material and others. Moreover, samples of blood for hemogram analysis were taken at the beginning, at the transition of feed and at the end of the study. The performance (feed intake - FI, average daily gain - ADG and feed conversion ratio - F:G) was weekly assessed. After reach an average of 130 140 kg BW, all animals were slaughtered by carbon dioxide (CO2) stunning in a local slaughtered house. The analysis of meat and carcass quality was performed, in all animals, after 24h post-mortem. The statistical analyses were performed using the Proc Mixed and the Proc Genmond procedures of the Statistical Analysis System (SAS). Tukey-Krammer or Chi-Square test were performed to compare the means of each treatment. The p value for significance was fixed at p< 0.05. In all cases, the models considered the effects of diet (control or SO), regimen (ad-libitum and restricted) and the diet*regimen interaction. In general, there were no effects (p>0.05) of the treatments (interaction diet*regimen) on the analyzed variables (performance, meat quality, carcass traits and dirtiness). During the experimental period, the animals that received the starch diet (control one) associated with the ad-libitum feed management showed reduced activity (exploratory behavior and others) and spend more time on sternly decubitus. Regarding the dirtiness score, the animals fed ad-libitum and the animals that received de starch diet were dirtiest during the experimental period. For performance results, FI was reduced (p<0.05) for pigs that received SO diet, while there was no difference on ADG and, consequently, better values of F:G when compared to those that received the control one. Regarding to meat quality parameters, SO diet resulted in a higher (p<0.05) yield of carcass and oleic fat content in the pigs. In addition, higher values to leanness percentage and yield of carcass was observed on pigs under the restricted regimen, and lower values of BW and carcass weight when compared with the ad-libitum group. In conclusion, the replacement of 5% of starch per 5% of sunflower oil, during high ambient temperature conditions (30-32°C), improved welfare, the feed efficiency and animals carcass characteristics.

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As homeothermic animals, pigs manifest maximum performance when kept at comfortable temperature levels, represented by a limit where thermoregulatory processes are minimal. In a stress situation, with a higher energy demand for thermal maintenance, the energy contribution to the productive functions will be reduced, generating health imbalances, drop-in performance rates and welfare problems. The objective of this work was to study the replacement of 5% of starch (ST) per 5% of sunflower oil (SO), with or without restriction, in growing and finishing pigs diet kept under heat stress conditions and evaluate the influence of this strategies on welfare (dirtiness and behavior), performance, meat quality and carcass traits parameters. Seventy-two crossbred males (Iberic x Duroc) (51.00 ± 6.29 kg body weight - BW) were housed in collective pens and randomly distributed according to the initial BW, in climate-controlled rooms under heat stress conditions (30-32°C; 35% to 50% humidity). The experiment lasted 90 days and it was carried out in a randomized block design, in a 2 x 2 factorial, composed of two diets (ST or SO) and two management feed intakes (ad-libitum and restriction).The treatments studied were: 1) control diet (5% ST x 0% SO) with ad-libitum feed intake (n = 18); 2) SO diet (replacement of 5% of ST per 5% SO) with ad-libitum feed intake (n = 18); 3) control diet with restriction feed intake (n = 18); or 4) SO diet with restriction feed intake (n = 18). Feed were provided in two phases, 50 100 Kg BW for growing and 100 140 Kg BW for finishing period, respectively. Pigs behavior and dirtiness score was observed daily, according to the methodology described in the Welfare Quality Protocol for Pigs®. The activities considered were: eating, drinking, lying laterally, lying sternly, exploring the pen, exploring the environment enrichment material and others. Moreover, samples of blood for hemogram analysis were taken at the beginning, at the transition of feed and at the end of the study. The performance (feed intake - FI, average daily gain - ADG and feed conversion ratio - F:G) was weekly assessed. After reach an average of 130 140 kg BW, all animals were slaughtered by carbon dioxide (CO2) stunning in a local slaughtered house. The analysis of meat and carcass quality was performed, in all animals, after 24h post-mortem. The statistical analyses were performed using the Proc Mixed and the Proc Genmond procedures of the Statistical Analysis System (SAS). Tukey-Krammer or Chi-Square test were performed to compare the means of each treatment. The p value for significance was fixed at p< 0.05. In all cases, the models considered the effects of diet (control or SO), regimen (ad-libitum and restricted) and the diet*regimen interaction. In general, there were no effects (p>0.05) of the treatments (interaction diet*regimen) on the analyzed variables (performance, meat quality, carcass traits and dirtiness). During the experimental period, the animals that received the starch diet (control one) associated with the ad-libitum feed management showed reduced activity (exploratory behavior and others) and spend more time on sternly decubitus. Regarding the dirtiness score, the animals fed ad-libitum and the animals that received de starch diet were dirtiest during the experimental period. For performance results, FI was reduced (p<0.05) for pigs that received SO diet, while there was no difference on ADG and, consequently, better values of F:G when compared to those that received the control one. Regarding to meat quality parameters, SO diet resulted in a higher (p<0.05) yield of carcass and oleic fat content in the pigs. In addition, higher values to leanness percentage and yield of carcass was observed on pigs under the restricted regimen, and lower values of BW and carcass weight when compared with the ad-libitum group. In conclusion, the replacement of 5% of starch per 5% of sunflower oil, during high ambient temperature conditions (30-32°C), improved welfare, the feed efficiency and animals carcass characteristics.

Biblioteca responsável: BR68.1