Behaviour requirements within a cage environment

Dietary Inositol Reduces Fearfulness and Avoidance in Laying Hens

Simple Summary

Brain inositol is known to affect memory, and the incidence of depression, anxiety, and obsessive-compulsive disorder in mammals. Phytate, a naturally occurring inositol ester in plants, binds other nutrients, making them unavailable for digestion. The addition of phytase, the enzyme capable of hydrolyzing phytate, to diets increases the release of both inositol and nutrients for absorption in the chicken digestive tract. In this study, we assessed how dietary phytase or pure inositol affected laying hen behaviour, fearfulness, aggression, and stress levels. To increase the probability of seeing effects, hens were not beak treated and were fed two balanced protein levels differing in digestible amino acid sufficiency. Inositol did not affect stress levels, as measured by heterophil-to-lymphocyte ratio, or the number of hen comb or skin lesions. However, regardless of the source, pure inositol or phytase derived inositol reduced the number of feathers in the vent area, suggesting an increase in feather pecking. Pure inositol reduced fearfulness in laying hens, but phytase-derived inositol did not.

Abstract

Myo-inositol (inositol) affects memory, and the incidence of depression and anxiety in mammals. An experiment was designed to determine if pure inositol (0.16%), or high levels of phytase (3000 FTU/kg) affect the behaviour of fully beaked Lohmann LSL lite hens fed amino acid sufficient (19% crude protein (CP)) and deficient diets (16% CP), from 19 to 59 weeks of age. The data collected included live-scan behaviour observations and novel object (NO) tests (both at 1, 10 and 40 weeks of the trial); heterophil-to-lymphocyte (H/L) ratios (week 1 and week 40 of the trial); end of trial feather cover, and comb and skin lesions; and daily mortality. Reducing CP increased sitting by 2.5%. Inositol, but not phytase, reduced the latency to peck at the NO by 300 sec. Inositol reduced vent feather cover by 12% and tended to increase mortality by 13%. No effects on H/L ratio, and comb or skin lesions were found. In conclusion, regardless of the source, inositol reduced vent feather cover, while it tended to increase mortality. Only pure inositol reduced fearfulness in laying hens.

Effects of cage height and stocking density on the frequency of comfort behaviours performed by laying hens housed in furnished cages

Spatial restriction and low cage height can reduce the rate at which comfort activities, such as wing flaps, stretching, body shakes and tail wags, are carried out by laying hens in conventional wire cages. In this study we investigated the performance of these activities in laying hens housed in furnished cages with perches and nest boxes, similar to those required in EU legislation from 2012. We compared the behaviour of groups of eight hens at a stocking density of 762 cm2 per bird with that of pairs of hens housed at a lower stocking density of 3048 cm2 per bird at two minimum cage heights of 38 cm and 45 cm. The rates of wing/leg stretches (0.80 stretches per hen per hour), tail wagging (0.76), body shaking (0.48), wing raising (0.19) and feather raising (0.05) were low, whilst full wing flaps were not observed during the study. Hourly rates of performance of wing/leg stretches (0.45 vs 1.06) and tail wags (0.34 vs 1.25) were significantly lower in eight-bird cages than in two-bird cages. We conclude that reducing the number of hens in furnished cages increases opportunities to perform certain comfort activities, but that, even at low stocking densities, comfort activities are rarely observed.

O Comportamento das Aves

Os estudos sobre o comportamento das aves, principalmente as galinhas, datam de 1912, quando o gênero Gallus passou a ser estudado com mais intensidade na área da Genética. Tais estudos eram simplesmente filosóficos até o início da década de 80, quando uma nova era da produção industrial avícola surgiu, objetivando um maior volume de produção econômica em todas as áreas de exploração. Esse objetivo reativou de maneira científica os estudos de comportamento das aves face à tecnologia de produção empregada nos sistemas de exploração, tornando-os mais acentuados já na década de 90, culminando com um simpósio internacional realizado nos Estados Unidos onde foram traçados os objetivos ou linhas de pesquisas na exploração avícola. O intuito era evitar problemas com os movimentos ambientalistas, traçando novos rumos para uma produção eficiente sem interferir no comportamento das aves já no início do novo milênio. Esta revisão, tem como objetivo principal uma análise científica e filosófica sobre o comportamento das aves em diversos métodos de exploração.

Ability of laying hens to negotiate horizontal perches at different heights, separated by different angles

1. This paper describes how birds move between horizontal perches at different heights with different angles separating them, using the time to complete the task and the number of birds failing to indicate ability. 2. For the first experiment, 4 groups of 15 birds (ISA Brown) were subjected to each of the experimental treatments (using three perches with angles of 0 degree (horizontal control), 30 degrees, 45 degrees or 60 degrees between them). The birds were required to move upward between the perches for each treatment and then to move downward between the perches, as a second part of the experiment. 3. Birds moving up between the perches took significantly longer at 60 degrees than at any other angle. No birds failed to complete the task. 4. For birds moving downward between the perches, the median time to complete the task increased significantly with angle. Furthermore, the number of birds failing to complete the task increased with angle. 5. A second experiment was conducted to test whether the vertical or horizontal component of distance affected birds' ability to negotiate perches separated by different angles. 6. For the second experiment 4 groups of 10 Lohmann Brown laying hens were subjected to each of the following treatments: two horizontal perches separated by 30 degrees or 60 degrees and either directly, horizontally or vertically separated by a set distance of 50 cm. Birds were required to move both up and down between perches. 7. Birds negotiated horizontally-separated perches more successfully at 30 degrees than at 60 degrees. However, when the vertical distance between the perches was 50 cm there was no significant difference in the ability of birds to move downward at 30 degrees or 60 degrees. For birds moving upward, 60 degrees was easier to negotiate than 30 degrees. 8. The vertical and horizontal separations, as well as the different angles affected the ability of birds to move between perches. There was a general decreasing trend in ability with increasing vertical separation between perches. 9. The findings are important in terms of arrangements of perches to improve bird welfare. To minimise the risk of injury, the angle between perches at different heights should be no more than 45 degrees, and the horizontal and vertical distances between these perches minimised, to allow the birds to be able to move downwards more easily.

Applications of behavior to poultry management

The application of poultry behavior to management is discussed with examples of behavior-management interactions relating to commercial poultry husbandry practices. Behaviors that are important for the adaptation of poultry to husbandry include: social behavior, aggression, sexual behavior, feeding, broodiness, cannibalism, nest site selection, and comfort behaviors.