Influência do enriquecimento ambiental sobre as performances zootécnicas e comportamento dos coelhos em crescimento
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2016-07-29
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O objectivo deste trabalho foi o de estudar as performances produtivas e o comportamento de coelhos em engorda, sujeitos a diferentes tratamentos em que os factores de variação foram a colocação de objectos, tamanho das jaulas, número de animais por jaula e a densidade). Nos estudos do comportamento foram analisadas mais duas variáveis, para além das referidas anteriormente, o efeito da idade dos animais e do período do dia em que foi realizada a amostragem. Foram utilizados 180 animais (Neozelandês x Californiano) de ambos os sexos, alojados num pavilhão com ambiente controlado e sujeitos a um fotoperíodo de 12 horas de luz (08:00h às 20:00h), que foram controlados desde o desmame (35 dias de idade) até ao abate (70 dias de idade). Os animais foram distribuídos de forma aleatória pelos 8 tratamentos considerados e alojados nas jaulas. Foram consideradas as seguintes variáveis: colocação ou não de objectos nas jaulas (latas de refrigerantes e pedaços de madeira), número de animais por jaula (1, 2 ou 4 coelhos/jaula), tamanho das jaulas (grandes: 0,3 m2 ou pequenas: 0,15 m2), e a densidade (7 coelhos/m2 ou 13 coelhos/m2). Semanalmente foram efectuadas pesagens individuais dos animais e controlado o consumo de alimento para determinação das performances produtivas (peso vivo, ingestão diária de alimento, ganho médio diário e eficiência alimentar). Durante toda a fase de engorda e semanalmente, o comportamento dos coelhos foi gravado por uma câmara de vídeo, sendo cada jaula filmada 4 vezes por dia (08:30h, 11:30h, 15:30h e 18:30h), e tendo cada filmagem a duração de 2 minutos. Com base nas filmagens foram elaborados etogramas e registados os comportamentos mais usuais.
O enriquecimento ambiental com objectos e a densidade não tiveram nenhum efeito significativo sobre as performances produtivas. O tamanho da jaula não influenciou de forma significativa o PV e a EA. No entanto, verificou-se um maior GMD no período 2 (49-70 dias) nas jaulas pequenas quando comparadas com as jaulas grandes (46,7 e 43,6g, respectivamente) e uma maior IMD no período 1 (35-49 dias) nas jaulas grandes quando comparadas com as jaulas pequenas (118,4 e 111,0g/dia, respectivamente). O número de coelhos por jaula não afectou significativamente o PV, mas o GMD no período 1 (35-49 dias) foi superior para as jaulas com 2 coelhos e inferior para as jaulas com 1 coelho (43,1 e 38,1g, respectivamente). A EA no período 1 (35-49 dias) também foi superior para as jaulas com 2 coelhos e inferiores para as jaulas com 1 coelho (0,383 e 0,335, respectivamente).
O comportamento “deitado em estado de alerta” foi realizado com mais frequência pelos animais alojados em jaulas sem objectos do que pelos animais nas jaulas enriquecidas (46,17 e 40,03%, respectivamente). O comportamento “dormir” foi realizado com mais frequência pelos animais das jaulas pequenas e o comportamento “brincar lata” foi realizado com mais frequência pelos animais das jaulas grandes. Nas jaulas com 4 coelhos os comportamentos realizados com mais frequência foram o “comer” e o “brincar lata” e os comportamentos menos frequentes foram o “dormir” e o “roer madeira”. Nas jaulas com 1 animal os comportamentos “dormir” e “roer madeira” foram realizados com mais frequência, enquanto que o comportamento “brincar lata” foi o menos frequente. Nas jaulas enriquecidas com objectos, com diferentes tamanhos e com diferentes números de animais por jaula não foram observados comportamentos anormais significativos. O comportamento “movimento rápido”, que é um comportamento anormal, foi mais observado pelos animais das jaulas de baixa densidade do que pelos animais das jaulas de elevada densidade (0,59 e 0,24%, respectivamente). O comportamento “brincar lata” foi mais observado nos animais das jaulas de elevada densidade quando comparadas com os animais das jaulas de baixa densidade (0,25 e 0,08%, respectivamente). De acordo com estes resultados verifica-se uma maior interacção com as latas de refrigerantes nos diferentes tratamentos do que com os pedaços de madeira. Também não foram observados quaisquer sinais de agressividade entre os animais ao longo do período de engorda.
Nas condições em que foi desenvolvido o trabalho e considerando o período total da engorda, o enriquecimento ambiental não afectou as performances de crescimento dos coelhos e o seu bem-estar animal não nos pareceu significativamente melhorado
The aim of this work was to study productive performances and behavior of the fattening rabbits, subject to different treatments in which the variation factors were placing objects, cage size, number of animals per cage and the density. In behavioral studies two more variables were analyzed: the effect of the age of the animals and the time of day. One hundred eighty hybrid (New Zealand x Californian) animals of both sexes were used. The rabbits were controlled from 35 days (weaning age) to 70 days (age at slaughter). Throughout the test the photoperiod was of 12 hours of light daily (08:00h to 20:00h). The animals were randomly distributed by 8 treatments considered and housed in cages. The following variables were considered: placement or not objects in the cages (empty cans of soft drinks and wood sticks), number of animals per cage (1, 2 or 4 rabbits/cage), cages size (large: 0.3 m2 and small: 0.15 m2) and density (7 rabbits / m2 and 13 rabbits / m2). Animal individual weight and food consumption were performed on a weekly basis to determine the productive performances. The behavior of the rabbits was recorded weekly by a video camera (Canon EOS 450 Digital) during the whole fattening period. Each cage was shot 4 times a day, held at 8: 30h, 11: 30h, 15: 30h and 18: 30h and each film had a duration of 2 minutes. Environmental enrichment with objects and the density had no significant effect on productive performances. The size of the cage did not influence significantly the body weight and feed efficiency. However, there was a higher daily gain in the second period (56-70 days) in small cages compared with the large cages (43.6g and 46.7, respectively) and increased daily intake in the first period (35-49 days ) in large cages compared to the small cages (118.4 and 111.0g / day, respectively). The number of rabbits per cage did not significantly affect the body weight, but the daily gain in first period (35-49 days) was superior to the cage with 2 rabbits and lower to the cage with 1 rabbit (43.1 and 38.1g, respectively ). The feed efficiency in the first period (35-49 days) was also superior to the cage 2 and lower for rabbit cages with 1 rabbit (0.383 and 0.335, respectively). The behavior "lying on alert" was performed more often by animals housed in cages without objects than in enriched cages (46.17 and 40.03%, respectively). In small cages behavior "sleep" was performed more frequently and in large cages the behavior "can play" was the more frequent. In cages with 4 rabbits behaviors performed more often were the "eat" and "play can" and less frequent behavior were "sleeping" and "gnaw wood." In cages with 1 rabbit the behavior "sleep" and "gnaw wood" were performed more frequently while the behavior "can play" was less frequent. In cages enriched with objects with different size and with different numbers of animals per cage no abnormal behavior were observed. The "fast-moving" was more observed in low density cages than in high density cages (0.59 and 0.24%, respectively), which is an abnormal behavior and the behavior "can play" was more observed in high density cages compared to low density cages (0.25 and 0.08%, respectively).According to these results there is greater interaction with cans of soft drinks in different treatments than with those of wood chips. It was also not observed any signs of aggressive behavior among animals throughout the fattening period. In conditions where did the study and considering the entire period of fattening, environmental enrichment did not affect growth performance of rabbits and their animal welfare do not appear to significantly improved.
The aim of this work was to study productive performances and behavior of the fattening rabbits, subject to different treatments in which the variation factors were placing objects, cage size, number of animals per cage and the density. In behavioral studies two more variables were analyzed: the effect of the age of the animals and the time of day. One hundred eighty hybrid (New Zealand x Californian) animals of both sexes were used. The rabbits were controlled from 35 days (weaning age) to 70 days (age at slaughter). Throughout the test the photoperiod was of 12 hours of light daily (08:00h to 20:00h). The animals were randomly distributed by 8 treatments considered and housed in cages. The following variables were considered: placement or not objects in the cages (empty cans of soft drinks and wood sticks), number of animals per cage (1, 2 or 4 rabbits/cage), cages size (large: 0.3 m2 and small: 0.15 m2) and density (7 rabbits / m2 and 13 rabbits / m2). Animal individual weight and food consumption were performed on a weekly basis to determine the productive performances. The behavior of the rabbits was recorded weekly by a video camera (Canon EOS 450 Digital) during the whole fattening period. Each cage was shot 4 times a day, held at 8: 30h, 11: 30h, 15: 30h and 18: 30h and each film had a duration of 2 minutes. Environmental enrichment with objects and the density had no significant effect on productive performances. The size of the cage did not influence significantly the body weight and feed efficiency. However, there was a higher daily gain in the second period (56-70 days) in small cages compared with the large cages (43.6g and 46.7, respectively) and increased daily intake in the first period (35-49 days ) in large cages compared to the small cages (118.4 and 111.0g / day, respectively). The number of rabbits per cage did not significantly affect the body weight, but the daily gain in first period (35-49 days) was superior to the cage with 2 rabbits and lower to the cage with 1 rabbit (43.1 and 38.1g, respectively ). The feed efficiency in the first period (35-49 days) was also superior to the cage 2 and lower for rabbit cages with 1 rabbit (0.383 and 0.335, respectively). The behavior "lying on alert" was performed more often by animals housed in cages without objects than in enriched cages (46.17 and 40.03%, respectively). In small cages behavior "sleep" was performed more frequently and in large cages the behavior "can play" was the more frequent. In cages with 4 rabbits behaviors performed more often were the "eat" and "play can" and less frequent behavior were "sleeping" and "gnaw wood." In cages with 1 rabbit the behavior "sleep" and "gnaw wood" were performed more frequently while the behavior "can play" was less frequent. In cages enriched with objects with different size and with different numbers of animals per cage no abnormal behavior were observed. The "fast-moving" was more observed in low density cages than in high density cages (0.59 and 0.24%, respectively), which is an abnormal behavior and the behavior "can play" was more observed in high density cages compared to low density cages (0.25 and 0.08%, respectively).According to these results there is greater interaction with cans of soft drinks in different treatments than with those of wood chips. It was also not observed any signs of aggressive behavior among animals throughout the fattening period. In conditions where did the study and considering the entire period of fattening, environmental enrichment did not affect growth performance of rabbits and their animal welfare do not appear to significantly improved.
Descrição
Dissertação de Mestrado em Engenharia Zootécnica
Palavras-chave
Produção animal , Fatores ambientais , Comportamento animal , Desempenho animal , Coelho (oryctolagus)