Trends in early life conditions of pigs and laying hens in order to prevent damaging behaviour: a GroupHouseNet update

Damaging behaviours in pigs and laying hens are among the most concerning current welfare issues. They are multifactorial in origin and difficult to stop once occurring. Prevention is crucial, and this is the focus of the COST Action project ‘GroupHouseNet’. In laying hens, feather pecking (FP) can best be prevented at the hatchery. The parental stock’s predisposition for FP can be assessed by epigenetic analysis, allowing careful stock selection. The fertilized eggs are then conventionally incubated in the dark, but studies show that light provision may reduce FP. Recent development of in-ovo sexing reduces chick handling, thus reducing stress. It further allows hatching with food and water provision, enabling on-farm hatching. Accessing feed right after hatching can be crucial for chicks to learn what to peck and eat. Artificial dark brooders, mimicking the mother hen’s wings, reduce fear, stress and FP. Matching the rearing and laying system through an all-in-all-out system reduces stress by eliminating catching, handling, transport and changing environment. In practice, multiple all-in-all-out barns can provide continuous egg output. A sustainable and circular system of feeding chickens insects grown using chicken manure seems feasible and positive in preventing FP. The use of pasture and supplementing hens whole grains are also being researched as potential strategies. Together, these trends can help in preventing damaging FP in laying hens. For pigs, early life factors can also influence later damaging behaviour, such as aggression, tail and ear biting. Aggressive biting is mainly reduced by socialisation (i.e. co-mingling) before weaning. Here, piglets learn to establish dominance relationships early in life which reduces fight duration when older. Tail biting, which is largely unrelated to aggression, is increased by early life undernutrition, social stress due to competition and cross-fostering. These factors are all influenced by litter size at birth. Familiar odours may contribute to reducing biting when pigs are moved from one environment to another by alleviating the level of stress associated with novelty. Tail and ear injuries pre-weaning may also occur due to mycotoxins from feed or straw, and can result in the affected piglet being bitten and the development of biters. Paying attention to tail and ear injuries pre-weaning is therefore recommended. Even though the barren environment of the pigs represents the major risk for expression of damaging behaviour, the pre-weaning environment should be optimized to reduce the likelihood of this problem. Foraging possibilities are essential for both laying hens and pigs. Providing pigs and poultry with the requirements for expressing natural behaviour and for reducing stress is therefore necessary to prevent damaging behaviour

Nutrient balance of layers fed diets with different calcium levels and the inclusion of phytase and/or sodium butyrate

In this study, Hisex Brown layers in lay were evaluated between 40 and 44 weeks of age to evaluate the inclusion of bacterial phytase (Ph) and sodium butyrate (SB) to diets containing different calcium levels (CaL). Performance, average egg weight and eggshell percentage, in addition to nutrient metabolizability and Ca and P balance were evaluated for 28 days. Birds were distributed according to a completely randomized experimental design with a 3x2x2 factorial arrangement, with three calcium levels (2.8, 3.3, 3.8%); the addition or not of phytase (500PhU/kg) and the addition or not of sodium butyrate (20mEq/kg), composing 12 treatments with eight replicates of one bird each. There was no additive effect of phytase or SB on the evaluated responses. Feed intake and feed conversion ratio were influenced by CaL, with the best performance obtained with 3.3% dietary Ca. Ca balance was positively affected by dietary Ca, and P balance by the addition of phytase. Ca dietary concentration, estimated to obtain Ca body balance, was 3.41%, corresponding to an apparent retention of 59.9% of Ca intake

Use of grit supplements by waterbirds: an experimental assessment of strategies to reduce lead poisoning

The ingestion of spent Pb shot due to confusion with grit or inadvertently with food particles causes Pb poisoning in a large number of waterbirds, this being one of the main causes of mortality for some species. Lead ammunition for hunting is being progressively banned in more countries, while grit supplementation has been proposed as a management measure to reduce the ingestion of deposited Pb shot. Studies of grit selection with waterfowl in semi- captivity and in the wild were undertaken to evaluate preferences in the colour and geochemical composition of grit, whether it was available dry or in water, its position within the wetland and the relationship between grit ingestion and feeding behaviour. Grit ingestion was higher when food was included in the treatments. In the absence of food, red grit was taken in higher amounts than grey in semi-captivity but not in the wild. Siliceous grit was taken in a higher amount than calcareous when offered dry, but not in water. No differences in the amount of ingested grit were found among different positions within the wetland. The number of feeding attempts in plots supplemented with grit was higher than in those without grit, although the highest numbers of feeding birds were found in plots supplemented with food. Grit ingestion in waterfowl is intimately associated with feeding behaviour. To optimize the effectiveness of grit supplementa- tion to reduce the risk of Pb poisoning in waterfowl, calcareous and siliceous grit may be combined and applied in feeding sites or mixed with bait to attract birds.This work was supported by a project funded by the Consejería de Medio Ambiente, Junta de Andalucía. P. Acevedo is funded by a Juan de la Cierva research contract awarded by the Ministerio de Ciencia e Innovación—Fondo Social Europeo. This study was also funded by MICINN (under CGL2007-62797).Peer reviewe