1. Research focused on lower light intensity levels is required to set minimum standards appropriate for production and welfare of intensively housed broilers. The objective of this research was to study light intensity (0.1 to 10 lx) effects on Ross × Ross 308 and 708 genotypes. 2. Three experiments (35 d each) using 18 720 broilers were conducted with the initial experiment using two replicates of 0.1, 1, 5 and 10 lx. The second and third experiments examined 0.5, 1, 5 and 10 lx with treatments replicated twice in each experiment in a randomised complete block design with experiment acting as a block. In each experiment, mixed sex broilers from each genotype were housed in 6 equally sized pens per room. 3. In Experiment 1, the introduction of 0.1 lx at d 7 caused high levels of mortality and poor growth rate from d 7 to 14 and was discontinued. 4. In Experiments 2 and 3, increasing light intensity increased body weight gain (0-35 d) and feed intake (0-35 d) in a quadratic and linear fashion, respectively. Similarly, mortality corrected gain to feed ratio (FCR, 0-35 d) demonstrated a quadratic response with a maximum at 5 lx. Carcass, breast meat and skin, abdominal fat and drum skin, as a percentage of live weight, increased while drum bone and wing yield decreased in a linear fashion with increasing light intensity. Total carcass composition was unaffected by light intensity. 5. Genotype effects were numerous. No interactions were found between genotype and light intensity. 6. Ocular dimensions and the incidence of foot pad lesions decreased in a quadratic and linear fashion, respectively, with increasing light intensity. In contrast, welfare-associated gait score and mortality levels were not affected by light intensity. 7. It was concluded that performance, breast meat yield and bird welfare improved with increasing light intensity. The data support 5 lx as a minimum light intensity in broiler production.

Laying hens continue to improve in egg production (EP) and feed efficiency (FE), and therefore, it is relevant to re-examine their digestible balanced protein (BP) requirements. From 27 to 66 wk of age, hens (Lohmann-LSL Lite) were fed diets designed to provide 550, 625, 700, 775, or 850 mg hen −1 d −1 of amino acid balanced digestible lysine (Dlys). Response criteria included EP, egg weight (EW), feed intake (FI), mortality, egg mass (EM), egg size classifications, FE (kg feed kg −1 EM), and lysine efficiency (LE; mg Dlys g −1 EM). The experiment was a completely randomized design, and data were analyzed using regression analysis. Differences were considered significant if P ≤ 0.05. Hen-day (HD) EP, EW, EM, FI, and LE increased and FE and mortality decreased in a quadratic fashion with increasing Dlys intake, while the proportion of cracked eggs increased linearly. Egg size classifications increased linearly (jumbo, extra-large) and quadratically (large) or decreased in a quadratic manner (medium, small) with increasing Dlys intake. Maximum HDEP, EW, and EM, and minimum FE were achieved at 769, 903, 836, and 839 mg hen −1 d −1 intake of Dlys, respectively. In conclusion, the digestible BP requirement of laying hens varies with response criteria.

Ideally balanced dietary protein is critical for laying hen egg production and feed efficiency, but also affects other important characteristics. This research was designed to study the nonegg production and feed intake response of Lohmann-LSL Lite hens to 550, 625, 700, 775, and 850 mg d−1 of amino acid balanced digestible lysine (Dlys) from 27 to 66 wk of age. Data collection included hen weight (HW), feather scoring, tissue weights, egg specific gravity, egg component weights, and excreta nitrogen (N) content. The experiment was a completely randomized design and level of significance was fixed at P ≤ 0.05. Hen weight (quadratic, Q), pectoralis muscle (absolute, % – Q), and abdominal fat (absolute – linear, L; % – Q) increased with increasing Dlys intake. Although gastrointestinal segment weights and lengths were affected by Dlys intake, interpretation of results was confounded by other aspects of diet composition. Hen feather score (L) and excreta N content (Q) increased, and egg shell quality (L) decreased with increasing Dlys intake. Absolute egg component weights increased with Dlys intake, but effects on proportional weights were Q and relatively minor. In conclusion, balanced Dlys intake affected a variety of practical nonproduction characteristics in laying hens.

Two trials were conducted to study the effect of feeding barley silage on the behaviour and performance of beak-trimmed laying hens. In each trial, 20 hens and 2 roosters were housed in each of eight group-housed enriched cages, with four cages provided a laying hen diet and four cages additionally given free access to barley silage. Egg production and quality, and hen behaviour were assessed throughout the trials (Trial One 20-30 weeks; Trial Two 19-28 weeks). Data were analysed using Proc Mixed of SAS 9.4 and differences were significant when P ≤ 0.05. Silage-fed hens consumed 41 (13.9 g DM) and 50 (13.5 g DM) grams of silage per hen per day in Trials One and Two, respectively, while consuming less layer diet. Birds fed silage spent less time expressing aggressive and feather-pecking behaviours and in nest boxes, and more time feeding than control birds. Egg production, egg quality, and bird weight were not affected by treatment; yolk colour was darker for the silage treatment. Feathering quality was improved in silage-fed birds compared to control birds. It was concluded that providing hens with access to barley silage can improve welfare indicators without negatively affecting the egg production and egg quality.Key words: welfare, wet feeding, environmental enrichment, foraging, feather condition.Résumé : Deux expériences ont été effectuées pour étudier l'effet d'alimenter les poules pondeuses débécquées à l'ensilage d'orge sur leurs comportements et performances. Dans chaque expérience, 20 poules et 2 coques ont été logés en groupe dans huit cages aménagées, avec quatre cages offrant une diète standard pour les poules pondeuses et quatre cages qui offraient en plus l'accès libre à l'ensilage d'orge. La production d'oeufs et leurs qualité ainsi que le comportement des poules ont été évalués tout au long des expériences (Expérience un: 20 à 30 semaines; Expérience deux: 19 à 28 semaines). Les données ont été analysées au moyen de Proc Mixed de SAS 9.4 et les différences jugées significatives lorsque P < 0,05. Les poules nourries à l'ensilage consommaient 41 (13,9 g matières sèches [DM -« dry matter »]) et 50 (13,5 g DM) grammes d'ensilage par poule par jour dans les expériences un et deux, respectivement, tout en consommant moins de la diète pour poules pondeuses. Les oiseaux nourris à l'ensilage passaient moins de temps à exprimer des comportements agressifs et de picage de plumes, moins de temps dans les nichoirs et plus de temps à manger que les oiseaux témoins. Il n'y a pas eu d'effet du traitement sur la production d'oeufs, la qualité d'oeufs et le poids de l'oiseau. La couleur du vitellus (jaune) était plus foncée chez celles sur le traitement d'ensilage. La qualité du plumage était améliorée chez les poules nourries à l'ensilage par rapport aux témoins. Il a donc été conclu qu'offrir l'accès à l'ensilage d'orge peut améliorer les indicateurs de bien-être sans effet négatif sur la production et la qualité des oeufs. [Traduit par la Rédaction]

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