Physiological and behavioural parameters of broiler chicks grown under different heating systems

P.F.P. Ferraz¹*, E.T. Andrade¹, R.B. Vilas Boas¹, T. Yanagi Junior¹, R.R. Andrade², V. Becciolini³ and M. Barbari³

¹Federal University of Lavras, Agricultural Engineering Department, BR37200-000 Lavras, Minas Gerais, Brazil
²Federal University of Goiás, Department of Biosystems Engineering, College of Agronomy, BR74690-900 Goiânia, Brazil
³University of Florence, Department of Agriculture, Food, Environment and Forestry, Via San Bonaventura 13, IT50145 Firenze, Italy
*Correspondence: paricia.ponciano@ufla.br

Abstract:

This study aimed to compare the internal environment, physiological variables, and behavioural responses of chicks under two different heating systems. The experiment was performed in two commercial broiler houses located in Brazil, where 28,000 male Cobb chicks were housed during the first three weeks of life. One of the broiler houses was heated by an industrial indirect-fired biomass furnace (S1). In addition, another heating system consisting of two furnaces for indirect heating of the air using biomass (wood) as fuel, built by hand with bricks, mud, and dung on an iron structure (S2), was tested. Measurements of the dry bulb temperature (t_db), dew point temperature (t_dp), and relative air humidity (RH) were performed. Subsequently, the temperature-humidity index (THI) was calculated. In addition, the physiological variables of the respiratory rate (RR) and cloacal temperature (t_cloacal) were measured three times a day (8:00 am, 2:00 pm, and 6:00 pm) in four chicks. The behaviours were grouped by dendrograms, in which the similarity of these data was qualified. During the second and third weeks of life, the THI values were below the recommended range. The RR and t_cloacal data were below the recommended comfort values, which may be an indicator that the chicks were subjected to cold conditions. Regarding their behaviour, the chicks exhibited calm, feeding, and sleepy behaviours most of the time. Problems in the heating system inside the broiler house could be observed, possibly affecting the chicks’ thermal comfort and welfare, which consequently can result in productive and economic losses.

Key words:

behaviour, chicks, cloacal temperature, respiratory rate, thermal comfort

Additional concentrates do not affect feeding times of cows, but social positions of cows do

M. Soonberg¹*, M. Kass¹, T. Kaart², R. Leming¹ and D.R. Arney¹

¹Estonian University of Life Sciences, Department of Animal Nutrition, Fr. R. Kreutzwaldi 46, EE51006 Tartu, Estonia
²Estonian University of Life Sciences, Department of Animal Breeding and Biotechnology, Fr. R. Kreutzwaldi 46, EE51006 Tartu, Estonia
*Correspondence: maria.soonberg@student.emu.ee

Abstract:

In robotic milking dairy systems lack of control over intakes can be problematic for balancing the forage and concentrate portions of diets. This can lead to problems associated with high concentrate intakes and concomitant low forage intakes. To check this as a problem, the feeding behaviour of cows was observed: the number of daily visits to the feed barrier, the duration of these visits and actual feeding, of high and low yielding cows. The cows were robot-milked and fed a ration comprising, separately, concentrate feed from a robot and a feeder, and a grass/clover silage mix forage at the feed barrier. Individual variation in visiting times and times spent at the feed barrier were greater than the effect of level of production. There was no evidence that cows with higher milk yields are differentially motivated to feed from forage. But more dominant cows spent more time feeding than submissive cows.

Key words: