Gisele A. Felix

Feeding behavior and crop damage caused by capybaras (Hydrochoerus hydrochaeris) in an agricultural landscape

This study aimed to assess the yield loss caused by capybaras in rural areas of Dourados-MS, their feeding periods, crop preferences and the landscape characteristics of farms that may affect the occurrence of capybaras herds. Semi-structured interviews in 24 different farms were done during a period between April 2010 and August 2011. Field observations were held at different times of the day, and also during the night in order to record peaks of the feeding behavior in six farms. Direct counting of capybaras along with the group of animals reported as seen by the farmers during the interviews was used to estimate the size of herds. Data was analyzed using the Principal Components Analyses and the Analytic Hierarchy Process. The average number of capybaras found in a regular herd was 18.8 ± 7.90 animals. The average number of capybara herd by farms was of 1.38 ± 0.92 while the average number of capybaras by farms was 32.33 ± 27.87. Capybaras selected rice (Oryza sativa) when it was available (14.5% of devastation in 1.18% of total planted area); however, the most eaten crop was corn (Zea mays) with 38.55% of loss rate in 16.17% of the total planted area. Capybaras ate mostly in the evening and during the night. The availability of water resources in the rural area predisposed the occurrence of capybaras herds.

Impact of exposure to cold on layer production

Infrared thermographic images were used to evaluate the effect of the exposure of layers to cold. In this trial, 540 Isa Brown® layers with an average age of 69 weeks were housed in a conventional layer house typically used in Brazil during a period of cold environmental temperatures. Environmental and heat-transference data were recorded between July 13-16, 2010. It was verified that layers under cold stress conditions lost four times more energy that the recommendations trying to maintain their body temperature. Due to their reduced feed intake capacity, hens are not capable of increasing the availability of the metabolic energy required to maintain their body temperature and egg production, consequently resulting in economic losses.

Influence of genetic strain and season on back scratch lesions in broilers

This study aimed at evaluating the influence of genetic strain, sex, and season on the incidence of back scratches during the rearing period. Male and female broilers of two genetic strains reared during the hot or cold season were evaluated. This meta-analysis included 894 samplings in 351 broiler houses of contracted farms located in the state of Mato Grosso do Sul, Brazil, in 2010. Broilers of all ages (1 to 43 days) were sampled, capturing 2% of the birds in the house at each sampling. Each flock was evaluated twice, in 21-day intervals. Broilers were reared as single-sex flocks; there were no straight-run flocks. Scratch lesions were classified as present or absent. Strain A broilers presented lower scratch rates (p < 0.05) than strain B birds. During the starter period (1 a 21 days), males presented higher scratch rates (p < 0.05) than females, and the incidence of these lesions was lower during the hot season compared with the cold season. It was concluded that different management practices can be adopted to minimize back scratches in broilers of different sexes and strains during hot and cold seasons, such as reducing weight control frequency and the period of chick containment in brooder circles.