Behavior characteristics of Rhea americana in captivity submitted to different photoperiods and relations male:female / Características comportamentais de emas em cativeiro submetidas a diferentes fotoperíodos e relações macho:fêmea

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Researches has revealed that animal welfare is determinant on economic and technical viability of animal production systems. In this way the understanding of animal behavior will be a useful tool for detection of problems that interferes in the animal confort and promove damages to the producer. The animals behave according determined standards. Those standards are defined as an organized segment of attitudes that have a special function. It can be an unique act or a serie of activities that represent an answer of the animal to some environmental stimulus. A change in the environment usually produces more than one comportamental answer, but the animal learns to use that one more efficient. As the imposed environmental challenges occur in regular cycles, the animals exhibit their standard of behavior in cycles too. By example, bovines in pasture system answer to the natural cycle clear-dark, grazing, pondering and resting at the same schedules. The experiment was conducted in the Poultry Sector of the Federal University of Viçosa (UFV), located in the Farm Boa Vista de Cachoeira de Santa Cruz, town of Viçosa, Minas Gerais State. The behavior data were analysed statisticaly by descriptive method, through comparison by frequency of evaluated characteristics, for the evaluated treatments. 21 Rhea americana were used, being 15 females and 06 males, with average of two and a half years old (after first oviposition). The animals were lodged in shed, arrenged in three stalls with differents photoperiod, being weighed before and after each experimental period. It was adopted the use of colorful collars to facilitate the identification of the animals. The photoperiods were based on the parallels 21 (Viçosa, MG), 25 (Ponta Grossa, PR) and 52 (extreme South of Argentina). Being respectively 10.5h of light/day in the stall 1 (6:45am to 5:15pm), 13.5h of light/day in the stall 2 (5:15am to 6:45pm) and 16.5h of light/day in the stall 3 (3:45am to 8:15pm). The lightbulbs used in the stalls 2 and 3 were of the fluorescent kind, being used 6 bulbs of 20W in stalls of 200m2 each (that area of the shed was sub-divided in stalls with area of 15 meters of length for 5 of width totalling up 75 m2 by stall). The lights were turned on in April of 2006, with gradual increase during six days. The data collection of oviposition and brooding was made in the beginning and the end of each cycle. The photoperiod experiment was devided in four phases, with distinct collect of information: a) In the first phase the animals were subdivided in two groups/photoperiod, being one group constituted of a male and two females and the other one of a male and three females. That means stall 1A (1M:3F)(10.5h light/day), stall 1B (1M:2F)(10.5h light/day); stall 2A (1M:3F) (13.5h light/day), stall 2B (1M:2F)(13.5h light/day); stall 3A (1M:3F)(16.5h light/day), stall 3B (1M:2M)(16.5h light/day). The data were collected between October 10th and 27th of 2006 and performed analysis between differents photoperiod but with the same ralation M:F, that means between stalls A (1A, 2A and 3A) and stalls B (1B, 2B and 3B) in the morning and afternoon. The statistical analysis for the scan method was descriptive, making comparisons of the comportamental data in categories (position, consumption, social, reproductive and others) between the stalls with differents photoperiod but with the same relation M:F, that means comparisons between stalls A (1A, 2A, 3A) and stalls B (1B, 2B and 3B) in the morning and afternoon. It was verified that the perception of the light trouhg the cranial way interfers in the reproduction and in the behavior of the Rhea americana and that the photoperiod and the different relations male:female change the behavior of the animals and their egg production, libido and social behaviors. b) 2nd Phase (Animals in stalls B with the head painted) In the second phase all tha animals in the stalls B (1M:2F) of each photoperiod had they head painted with black ink, with the objective of inhibit the light. The observations were conducted between November 3rd and 20th of 2006. The percentage of the interactions male:female was verified according the duration of the photoperiod, that means that how much bigger the photoperiod is, bigger will be the interactions at the morning. In this way can be concluded that the perception of the light trough the cranial way interfered in the reproduction and in the social and ingestive behavior of Rhea americana; the different photoperiods and relations M:F changed the behavior of the animals, their egg production and libido. All animals with the head painted showed photo-refractoriness and changed their reproductive behavior (mating, display and oviposition) after some weeks. c) 3rd Phase (Trade the males of the stalls A with the ones in the stalls B) In the third phase was made the trade of the males of stalls A (heads with no ink) with the males of stalls B (heads painted) in each photoperiod. For example, the male from stall 1A (1M:3F)(10.5h light/day) was traded with the male from stall 1B (1M:2F)(10.5h light/day). The obsevations were made from November 27th to December 14th of 2006. Can be concluded that the perception of the light though the head interfered in the reproduction and behavior of the animals. Males with the head painted had less matings than the ones with head not painted even in different photoperiods. The females with head painted also showed photorefractoriness and changed they reproductive behavior, including ceasing the oviposition. d) 4th Phase (inversion of treatments) In the fourth phase the males traded in phase 3 were put back to their inicial stalls. However, the animals from stalls 1A and 1B that were never displayed to the photoperiod, were traded with the animals from stalls 3A and 3B, that had a longer photoperiod (16.5h light/day). The observations were made from January 10th to 27th of 2007. The statistical analysis for both methods (focal and scan) were realized in the descriptive form, like made in the phases 2 and 3. In this phase had no presence of brooding during the period observed. The percentage of interactions male:female was verified according the duration of the photoperiod, that means that how much bigger the photoperiod is, bigger will be the percentage of interactions male:female in the morning time. In this way can be concluded that the perception of the light trough cranial way interfered in the reproduction and in the social and ingestive behaviors of the Rhea americana; and the different photoperiods and relations male:female changed the behavior of the Rhea americana and their egg production, libido and social behavior.

ASSUNTO(S)

producao animal environmental aspects rhea americana rhea americana aspectos ambientais comportamento ema (ave) performance register registro de desempenho behavior

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