Infra-red beak trimming influences, pecking stone consumption, feed intake, feed and nutrient selection in free range laying hens

Beak trimming can have serious consequences on hen welfare, health and production. However, compared to hot blade trimming, the infra-red technique has resulted in more uniform beak length and symmetry (Dennis et al., 2009). Pecking stones (Analysed Values: 20.50% calcium, 4.30% phosphorus, 5.0% sodium and 2.50% magnesium) have been used in Europe and are reported to blunt hens’ beaks and alter pecking behaviour (Glatz and Runge, 2017). The objective of the current study was to evaluate the impact of infra-red beak trimming, pecking stone usage and hen age on feed intake and nutrient selection as well as the evaluation of relationships between beak length and pecking stone consumption, feed intake and nutrient selection.

A total of 18 flocks (Farm A, n = 10 flocks, infrared red beak trimmed hens, 20,000 /flock; Farm B, n = 8 flocks, non-beak trimmed hens, 2000 /flock) were examined. On each farm, hen placement was performed in 2 identical sheds at the same time. Each flock was randomly assigned to either a control group (no pecking stones) or a treatment group (1 pecking stone/1000 hens/10 weeks). At each time point (every 10 weeks from 16 until 66 weeks of age), 10 hens were randomly selected from each flock and individually confined in a holding pen (each holding pen housed 20 hens individually in each flock) amongst their peers. Each holding pen was equipped with 250g of mash feed and ad libitum water. Beak length was measured prior to placement while individual body weights were measured prior to and after 24 hours of placement in these holding pens. Feed samples prior to placement and feed residues from each hen were weighed before and after the 24 hour evaluation period and used for feed intake calculation and proximate analyses. Data were analysed in a 2 × 2 factorial arrangement (non-trimmed/ infrared trimmed beaks × pecking stones/no pecking stone availability) using a general linear mixed model. Spearman’s rho correlation coefficients were used to examine the relationship between beak length and other measured variables.

Farm type showed trend towards an effect (P = 0.057) on feed intake and a significant effect (P= 0.04) on crude protein consumption. A significant farm × pecking stone effect was observed on aluminum mineral consumption (P = 0.03), similarly a significant effect of farm × age was observed on copper (P = 0.007), sodium (P = 0.01), magnesium (P < 0.01), phosphorus (P=< 0.01), and zinc (P < 0.01) intake. Beak length was positively correlated with crude protein (r = 0.275, P = 0.008), sodium (r = 0.221, P = 0.035) and phosphorus (r = 0.284, P = 0.006) consumption. In addition, beak length was strongly correlated to pecking stone consumption (r = 0.563, P < 0.001) indicating hens with longer beaks consumed significantly more pecking stones.

Although infrared beak trimming is a non-invasive technique it altered the pecking behaviour and nutrient selection.

ACKNOWLEDGEMENTS: This research was conducted within the Poultry CRC (sub-project 2.1.13) supported by DSM Nutritional Products Singapore.