Effects on plumage condition, health and mortality of dietary oats/wheat ratios to three hybrids of laying hens in different housing systems

Individual production differences do not explain cannibalistic behaviour in laying hens

1. Sixty-three laying hens were collected from 5 commercial farms experiencing outbreaks of cannibalism. It is known that cannibalistic behaviour varies strongly between hybrids and between individuals of the same hybrid. The aim of this study was to test specific hypotheses about the causation of cannibalism by comparing matched individuals varying in their cannibalistic behaviour. 2. To investigate feed efficiency, egg production and feed consumption, data were collected over 30 d. Nutrient deficiencies have been associated with outbreaks of cannibalism and we hypothesised that cannibals are more feed efficient than their flock mates and, therefore, more susceptible to transient nutrient deficiencies or imbalances that trigger cannibalistic behaviour. 3. Video recordings were made of victims of cloacal cannibalism and their matched controls during oviposition. Victims were expected to have longer oviposition durations and a higher incidence of short-term cloacal prolapses than controls, because the starting point for cannibalism is often suggested to be pecking at the red mucosa of the victim during, or just after, oviposition. 4. Oviduct swab samples were taken from surviving victims of cloacal cannibalism and their matched controls 4 weeks after the cannibalistic attack. If peck wounds provide a route for subsequent bacterial invasion of the reproductive tract, victims would be expected to have greater bacterial colonisation of the oviduct. 5. Mortality within each matched trio was recorded over a 23-month period after the cannibalistic attack. Victims that survived a cannibalistic attack were expected to have reduced longevity compared to controls and cannibals. This could occur if they developed secondary infections as a result of the cannibalistic attack, or if they had poorer health even before the attack. 6. No significant differences were found between cannibals, victims and controls in feed efficiency or any of the production variables measured. Victims of cloacal cannibalism did not expose their cloacal mucosa more, or for longer, than matched control hens during oviposition, and had no more bacteria in their oviduct. Victims tended to die sooner than their matched cannibals or cannibals during a 23-month period after a cannibalistic attack.

The effect of organic diets on the performance of pullets maintained under semi-organic conditions

The effects of organic diets, with or without supplements of betaine, saponin, fructo-oligosaccharide and methionine, on the health, performance and gut flora of pullets were investigated. A comparison was also made between birds fed organic diets and those fed a non-organic diet. Day-old Lohmann Tradition pullets were reared in 24 groups of 64 chicks indoors until 11 weeks, and then in 48 groups of 24 to 27 chicks with access to range until 17 weeks of age. Groups of birds were fed one of eight diets, a conventional rearing diet with supplementary amino acids, an organic basal diet, organic basal plus methionine and organic basal supplemented with one of the test ingredients. At most stages of growth the birds fed the conventional diet and those fed the basal diet with methionine performed better than those that had no supplemental methionine. Other dietary treatments had no consistently significant effect on growth, the microbial populations within the gastro-intestinal tract of the birds or the number of parasite eggs excreted. After 5 weeks with access to range, the birds that were fed three out of five diets regarded as deficient in sulphur amino acids achieved similar weights (P > 0.05) to birds that received diets adequate in sulphur amino acids. Health and welfare of birds fed organic diets was not adversely affected; however, an investigation of birds housed in larger flocks and taken into the laying phase, when physical demands on birds are greatest, is required.