Behavior evaluation of four different rustic, hillbilly chicken strains grown in an intensive system^

Modern science has shown evidence that many animals have the ability of thinking and feeling, and that their behavior is the result of intelligent, consistent processes. Ethology is the science that has helped us to understanding how animals behave and, on this bases, recognize more broadly the responsibility of humans to promote animal welfare. Concerns about farm animal welfare have ethical implications considering, in addition, its potential effects on food quality and quantity (Hötzel and Machado Filho, 2004).
In the poultry industry, the behavior possibilities are prone to alterations depending on the production system. Animal behavior allows for the evaluation of the temperature preference of birds, i.e., it is possible to evaluate the frequency of visiting drinkers and feeders, and even the frequency of given behavioral conducts can be evaluated as thermal comfort indicators (Salgado et al., 2007). Controversy exists about the motivations and behavior abilities existing in the various genetic strains (Stupak et al., 2008). The purpose of this study was to evaluate the behavior of hillbilly (synonyms: hake, slow-growing, alternative, country-type, rustic) chickens under an intensive production system.

The study was conducted in an experimental house, Parauapebas Exposition Park, State of Pará, Brazil. Three hundred and eighty (384) hillbilly chickens were used in this 90-day study. The birds were randomly distributed among 36 pens of 16 birds each, reared under an intensive system, at a stoking density of 6.4 birds/m². The treatments (T) were defined in accordance with each strain, as follows:

T1) Feathered-neck French gray rolled (in Portuguese: Caipira Francês Barré; in French: Barre Gris Cou Plume);

T2) Naked-neck, French stone-gray rolled (in Portuguese Caipira Francês Pedrês;  in French: Gris Barre Cou Nu); 

T3) Feathered-neck French gray master exotic (in Portuguese: Caipira Francês Exotico; in French: Master Gris Cou Plume);

T4) Naked neck, French Redbro red (in Portuguese: Caipira Francês Vermelho; in French: Redbro Cou Nu),

Feed was distributed ad libitum and all birds received the same the same feed. Each pen had a pressure drinker and a hanging round feeder. Climate was characterized using a mercury thermometer, and one max/min thermometer, both placed in the center of the house, at an approximate height matching chickens' body center.
For the behavior analysis, the birds were individually identified with  a non-toxic ink on the back. Evaluations were made for 12 consecutive hours, including 3 different aspects.
In the first evaluation, the time dedicated by the birds to the following behaviors, as per the methodology recommended by Santos (2009) and Silva et al. (2006): a) Walking: the bird moving between two points; b) Drinking: water intake at drinker; c) Eating: eating or picking at feed in the feeder; d) Resting: a bird at resting, with both the breast and the head on the litter; e) Standing: the behavior when the bird is not moving at all or does not fit any of the above-mentioned behavior descriptions; f) Sitting: a bird with the breast resting on the litter, head up, alert.
In the second evaluation, the frequency with which the birds performed the behaviors, and they were grouped as follows: a) Ingestion behavior: eating, drinking; b) Resting behavior: standing, laying down, sitting; c) Exploratory behavior: seeking, walking, picking at feathers or litter; d) Comfort behavior: extend the wings, self grooming, extending legs, shake.
In the third evaluation, the presence of agonist behaviors was included (aggression, combat, threating, submission, escape, interaction with other birds). In order to evaluate behavioral times, an analysis of variance with 5% probability was conducted, using the SAEG (System for Statistical and Genetic Analysis), UFV (2007). The differences among means of the variables studied were compared using Tukey´s test, at the level of 5%. For all other evaluations, data was tabulated using electronic spreadsheets, then charts were prepared.

The highest mean temperature value (35°C) was recorded at 14:00 hours, while the lowest temperature point (22°C) was recorded at 08:00 hours. The broadest thermal amplitude occurred at 11:00 hours. According to Nääs et al. (2007) the environmental conditions including high temperature, high relative humidity, and low speed winds can cause prostration and aggressive behaviors in the broilers.
Mean behavior expression times in the morning and afternoon periods are shown in Table 1. In the morning, the strain in T3 (Gray Master) showed the highest significant value (P<0.05) for the behaviors walking and drinking as compared to all other treatments. Regarding the behavior resting, T3 showed the highest value, with a significant difference (P<0.05) with T4 (Redbro). About the resting behavior in groups T1 and T4 no significant differences were found between themselves, but both were different from T3.
During the afternoon period, T3 (French Exotic) showed a higher value in the behavior walking, different from T4 (Redbro), but not different when compared to the other treatments. T3 also showed a higher water intake value, with significant difference (P<0.05) over all other treatments.
The feed intake behavior was higher in T2 (French Pedres), with a significant difference (P<0.05) when compared to T4 (Redbro), but not so when compared to all other treatments. T4 had a significantly higher value (P<0.05) in terms of the behavior resting and a lower value in terms of the behavior sitting, different from T3 that showed the highest sitting behavior but with no difference with regard to T3 (Gray Master) or T2. Sevegnani et al. (2005) evaluated the behavior of Ag Ross broilers (21, 28, 35, 42 and 49 days of age) subjected to heating stress, and found that the higher the ambient temperature, and the older the birds, the higher the water intake and the lower the feed intake.

Table 1. Men time of behavior expressions in four hillbilly chicken genotypes grown in an intensive system

Mean behavior expression times in these strains in terms of day times showed no statistical differences (P>0.05) for the behaviors of walking, drinking, resting, standing and sitting at any observation times. Nevertheless, the behavior eating was higher at 09:00, differing only from that at 14:00 and at 15:00 hours, that showed a significantly lower feed intake behavior (P<0.05). opposite to our results, Pereira (2007) evaluated various broiler house covers and found no differences in feed intake at the different day times studied.
The results of behavior frequency are shown in Table 2. The French Exotic, Gray Master  genotype (T3) showed higher values in the behaviors eating and resting, while the Redbro (T4) revealed a higher exploring behavior. Then highest index of comfort behavior was seen in the French Gray rolled genotype (T1) followed by the Gray Pedrés (T2). The Gray Pedrés (T2) showed the highest agonistic behavior value (58.0%).

Table 2. Frequency of expression of the behaviors observed in all 4 billhilly strains grown in an intensive system

Nazareno (2008) studied two different production systems (confinement and semi-confinement) with Cobb 508 broilers (from 1 to 42 days of age), and found that the chickens under the semi-confinement system with 3 m²/bird showed the best opportunities to express their natural behaviors and exploring the area surrounding out of the production module, thus enhancing animal welfare.

The French Exotic, French Master strain showed the highest eating/resting behavioral values, while the Redbro showed the highest exploring behavior value. Naked neck birds showed highest indexes of agonistic behavior.

Hötzel MJ & Machado Filho LCP. 2004. Bem-estar animal na agricultura do século XXI. Rev. de Etologia 6(1):03-15.

Nazareno AC. 2008. Influência de diferentes sistemas de criação na produção de frangos de corte industrial com ênfase no bem-estar animal. Dissertação (Mestrado em Engenharia Agrícola) - Universidade Federal Rural de Pernambuco. Departamento de Tecnologia Rural.

Pereira CL. 2007. Avaliação do conforto térmico e do desempenho de frangos confinados em galpões avícolas com diferentes tipos de cobertura. Dissertação de Mestrado, Faculdade de Zootecnia e Engenharia de alimentos, USP- Pirassununga.

SAEG - Sistema para Análises Estatísticas e Genéticas. 2007. Versão 9.1: Fundação Arthur Bernardes-UFV- Viçosa.

Salgado D, Nääs IA, Ferreira DF, Moura DJ. 2007. Modelos estatísticos indicadores de comportamentos associados a bem-estar térmico para matrizes pesadas. Eng. Agríc. 27(3):619-629.

Santos MJB. 2009. Sistemas de produção de frango de corte caipira com piquetes enriquecidos e sua influencia no bem estar animal e no desempenho zootécnico. Dissertação de mestrado do Programa de pós-graduação em engenharia agrícola da UFRP.

Sevegnani KB, Caro IW, Pandorfi H, Oliveira IJ, Moura DJ. 2005. Zootecnia de precisão: análise de imagens no estudo do comportamento de frangos de corte em estresse térmico. Revista Brasileira de Engenharia Agrícola e Ambiental 9(1):115-119.

Silva IJO, Barbosa Filho JAD, Silva MAN, Piedade SMS. 2006. Influência do sistema de criação nos parâmetros comportamentais de duas linhagens de poedeiras submetidas a duas condições ambientais. Rev. Bras. Zootec. 35(4):1439-1446.

Stupak EC, Molento CFN, Lecheta MP. Outubro/2008. Motivação em frangos de corte de alta taxa de crescimento. Livro de Resumos do 16º Evento de Iniciação Científica da UFPR.