Current methods and techniques of beak trimming laying hens, welfare issues and alternative approaches

Beak trimming is used in the egg industry to prevent mortality from cannibalism and minimise injurious pecking, vent pecking, aggressive pecking at the head and all forms of feather pecking, although the practice does not completely reduce the damage. There are alternatives to beak trimming, but they have not been reliable in preventing injurious pecking. However, beak trimming should not be used without providing birds enriched indoor and outdoor environments. Even when birds are beak trimmed, providing enriched facilities is recommended. The two main methods of beak trimming are hot blade (HB) and infrared beak treatment (IRBT). HB trimming removes the beak tips and cauterises the beak stump. The IRBT method uses heat from an infrared lamp to treat the outer beak and the underlying tissue. Initially, the tips of the beak remain intact and then soften and wear as the bird uses its beak. In contrast, the HB method results in an open wound that takes 3 weeks to heal. Two major welfare issues arise from beak trimming. The first is loss of sensory input because of removal of or heat treatment of sensory receptors in the beak. The second issue is the potential for acute and chronic pain from severing or heat treatment of nerves. HB trimming initially results in acute pain but there is limited evidence for beak sensitivity in IRBT birds. The development of neuromas in the beak have been implicated as a cause of chronic pain after HB trimming. When birds are HB trimmed (one-half of upper beak; one-third of lower) in the first 10 days of life, neuromas will develop, but they will resolve, compared with birds trimmed at older ages. However, neuromas will not resolve in 10-day old birds if more than one-half of the beak is HB trimmed. While HB trimming is performed according to accreditation standards by removal of one-half the upper beak and one-third of the lower beak is considered excessive, it prevents beak regrowth and the need to subject birds to re-trimming and a second bout of acute pain from the beak wound. Current levels of IRBT to treat half of the beak using the vendors quality-assurance protocol have been implemented worldwide to ensure that neuroma formation is prevented; however, if severe levels of IRBT are used, acute pain and subsequent neuromas may persist. The main impact of beak trimming is how the bird uses its beak when it eats, drinks and pecks at other birds and the environment. Reduced feed intake after HB trimming indicates pain associated with pecking or difficulty in eating. HB-trimmed birds initially show an increase in listlessness and guarding behaviours and increased inactivity, which indicates pain. IRBT and HB-trimmed birds have fewer aggressive pecks at the head, and there is a reduction in severe feather pecking and better feather scores, which results in a large reduction in mortality. Depending on the severity of IRBT and HB trimming, the advantage of using IRBT is improved welfare.

Different effects of infrared and one-half hot blade beak trimming on beak topography and growth

This study examined the effects of infrared beak treatment (IR-BT) and hot blade beak trimming (HB-BT) on beak length and production in laying hen pullets. Seventy-two 1-d-old birds were randomly assigned to the HB-BT, IR-BT, or control group. Birds were pair housed by treatment, and beak images and production indices were obtained posttreatment at fixed intervals for 10 wk. Immediately after treatment, HB-BT beaks were shorter than control or IR-BT beaks (P < 0.01), whereas control and IR-BT beaks remained comparable in length until the onset of tissue degeneration and erosion of the IR-BT beaks at 1 to 2 wk posttreatment. At wk 2 posttreatment, beaks were longest in control birds, intermediate in IR-BT birds, and shortest in HB-BT birds (P < 0.01). Thereafter, an increase in beak length in all treatments was observed over time (P < 0.01), but HB-BT beaks had the greatest regrowth. The beak length of birds in the HB-BT group was similar to that of birds in the IR-BT group from wk 3 to 8, and then grew longer at wk 9 and 10 posttreatment (P < 0.01). The effects of treatments on BW emerged at d 5 posttreatment. The BW of birds in the HB-BT group was suppressed up to and including wk 9 posttreatment compared with that of control birds (P < 0.05) and was significantly lower than that of birds in the IR-BT group between 2 and 4 wk posttreatment (P < 0.05). Birds in the IR-BT group did not differ from control birds after wk 3 posttreatment (P < 0.05). By the final week of the study, differences in BW across treatments were no longer apparent (P > 0.05). For the most part, feed intake was higher in control birds, intermediate in birds in the IR-BT group, and lowest in birds in the HB-BT group until wk 9 posttreatment (P < 0.05). Similarly, feed waste was generally higher in control birds and least in birds in the HB-BT group (P < 0.05). The IR-BT treatment appeared to be more effective at inhibiting beak regrowth, with a less pronounced effect on feed intake than the HB-BT treatment in laying hen pullets.

The Effects of Different Beak Trimming Techniques on Plasma Corticosterone and Performance Criteria in Single Comb White Leghorn Hens

DeKalb XL chicks were given a beak trim at 6 d of age (6DP) with a 2.8-mm gauge and a beak trim at 11 wk (11WB) with a block cut approximately 2 mm anterior to the nasal openings. Corticosterone (CS) levels of the 6DP treatment were (P < or = 0.01) elevated above nontrimmed CS levels at 2 h posttrim; and BW and feed consumption (FC) of the 6DP were depressed until 8 wk of age. At 11 wk of age, CS of the 11WB treatment was (P < or = 0.02) elevated above controls at 1, 2, 8, and 5 wk posttrim. The 11WB treatment resulted in a decrease in FC and a reduction in BW at 12, 14, and 16 wk of age, whereas there were no differences among treatments in livability during the pullet phase. At 72 wk of age, FC of the nontrimmed controls was greater than both beak trimmed treatments, and both beak trimmed treatments had greater hen housed eggs, percentage hen day egg production, and percentage livability. Both beak trimmed treatments resulted in better egg income, feed cost per hen, and net income (NI). The 6DP and 11WB beak trim treatments resulted in an improvement of NI per hen of 1.48 dollars and 1.86 dollars, respectively. In addition, both beak trimmed treatments exhibited better feather score and Hansen's test (fearfulness). It was concluded that pullets and hens could adapt to the physiological stress of beak trimming and out perform, during a lay phase, controls whose beaks were not trimmed.

Improving animal well-being through genetic selection

This paper reviews the possibilities of adapting laying hens to cages by means of genetic selection. By selecting separately for rate of lay and longevity using a kin selection method, a strain of laying hen has been developed that shows much less feather pecking and cannibalism than a control strain, and with no decrease in productivity. This experimental strain enjoys a higher level of welfare in cages because it does not require beak trimming.

The effect of beak trimming on two strains of commercial tom turkeys. 2. Behavior traits

The influence of beak trimming of two strains of commercial male turkeys (Strains A and B) on behavior during the growing period was investigated. Poults were either left with beaks intact or arc beak trimmed at hatching. Strain by beak treatment interactions were generally lacking, indicating that these two strains responded similarly. Beak trimming did not influence tameness (as measured by response to a novel object at 16 wk), fearfulness (as measured by tonic immobility response at 18 wk), or resting behavior from 3 to 15 wk of age. When compared to birds with intact beaks, birds with trimmed beaks spent more time standing during the week of hatching and were observed eating more often at 2 wk of age. Strain B birds were more tame, less fearful, and rested more at 8 and 11 wk of age than Strain A birds. Results of the current study indicate that the influence of arc beak trimming at hatching on behavior of male turkeys at hatching did not appear to have a lasting negative impact on their well-being.

Group selection for adaptation to multiple-hen cages: production traits during heat and cold exposures

A selected line of White Leghorns that has shown improved survivability and productivity and reduced feather loss in multiple-hen cages was evaluated for production traits under both stressed and unstressed conditions. It was hypothesized that hens selected for adaptation to multiple-bird cages would react less intensely to stressors and therefore lay more eggs and have lower mortality under stressed conditions. Three lines of chickens (selected, control, and commercial) were housed in either single-hen (1 hen) or multiple-hen cages (12 hens, social competition) at 16.7 or 17.1 wk of age. They were subsequently subjected to cold exposure at 33 wk of age and heat exposure at 44 wk of age. The selected line of chickens in multiple-hen cages showed an increased resistance to heat exposure, as indicated by lower mortality, when compared to the control and commercial lines housed in multiple-hen cages. Egg production 8 d prior to, during, and 8 d following either cold or heat exposures indicated that the selected line of chickens withstood social, handling, and environmental stressors better than the control line and, in some cases, the commercial line of chickens. It was concluded that the selected line of Leghorns showed evidence of stress resistance through lowered mortality and improved production.

The effect of beak trimming on two strains of commercial tom turkeys. 1. Performance traits

Two commercial strains (Strains A and B) of tom turkeys were either beak trimmed or left with intact beaks. These strains responded similarly to beak trimming for performance traits, with the exception of a higher incidence of beak-inflicted injuries among Strain B toms with intact beaks. Turkeys with trimmed beaks had higher body weights at 8, 12, and 16 wk. Feed efficiency was better in beak-trimmed birds from 4 to 8 wk, 12 to 16 wk, and 0 to 18 wk. Beak treatment did not effect mortality. Leg abnormalities caused the majority of culling or resulted in death or culling from beak-inflicted injuries. Beak trimming seems to be a beneficial practice in tom turkeys because feed efficiency of beak-trimmed toms was improved and injuries were reduced in a strain that tended to exhibit a high degree of beak-inflicted injuries. The results suggest that the need for beak trimming tom turkeys may be reduced when feed efficiency of toms with intact beaks is improved.

Review: welfare perspectives on hens kept for egg production

The wild ancestors of chickens, along with those of most other farm animals, were preadapted to domestication because their lack of specialized requirements allowed them to adapt to a wide variety of environments provided by humans. Currently most commercial chickens kept for table-egg production are incubated, reared, and maintained as productive adults in high-density, artificial environments. Nevertheless, there are limits to adaptability as indicated by behavioral, physiological, immunological, and individual productivity indicators when environmental conditions become extreme. However, with the exception of obvious injury, no single criterion is likely to be adequate. Multiple indicators are required to obtain reliable evaluation of whether husbandry practices and environmental conditions reduce hens' welfare significantly. Concern for the well-being of hens has led to the phasing out of cages in two European countries. Although cages are known to be associated with some problems of well-being, it is known also that they have some welfare advantages for hens over alternative systems of production and they have definite economic advantages for producers. Therefore, it is doubtful whether the use of cages should be denied without exploring further the possibilities of cage modification or genetic selection aimed at improving the well-being of hens in such environments. Ethical perspectives relative to animals have been evolving since the time of Aristotle more than 300 yr B.C. Recent developments include divergence of welfare concerns between utilitarian and animal rights based philosophies. The utilitarians generally agree that animals may be used for human benefit if unnecessary pain and suffering are avoided and humane care and management criteria are met. Fundamentally, rights-oriented groups reject such exploitation. The general public exhibits a continuum of attitudes towards animals. However, there are indications that they are moving towards a protectionist attitude toward farm animals. Many requirements for good husbandry are known. However, uncertainty prevails in some areas, particularly with the necessity of routine procedures such as beak trimming and the amount of space needed, optimal group size, and whether nests, roosts, litter, and other quality of environment features are necessities or luxuries in terms of hens' welfare. Floor and feeder space and group size seem to be of paramount importance, and space that is adequate for well-being seems to be greater than that which yields the greatest net income. Genetic solutions to several behavior-related problems that compromise hens' well-being seem to be feasible and worthy of greater emphasis by commercial poultry breeders.

Research note: genetic adaptation to multiple-bird cage environment is less evident with effective beak trimming

Selection of hens with intact beaks for high performance in multiple-bird cages has produced a stock that clearly exceeds its unselected control when hens have intact beaks but shows less advantage when comparisons involve effectively beak-trimmed birds. The selected stock performed at about the same level as a stock recently derived from a commercial source (but with two generations of relaxed selection) when birds had intact beaks but at a lower level when birds had their beaks trimmed. Relative incidences of deaths from cannibalistic pecking were partially responsible for the results obtained.

Selection and beak-trimming effects on behavior, cannibalism, and short-term production traits in White Leghorn pullets

Pullets of stocks derived from the North Central Randombred White Leghorn population without selection (C) or selected (S) on family performance when kept with beaks intact in multiple-hen cages were compared. Pullets had intact, one-fourth, or one-half of the beak removed (IN, 1/4R, and 1/2R, respectively). No stock differences were detected for behavior traits or other measures during the rearing period. However, beak-trimmed pullets were more inactive and feeding behavior was depressed in 1/2R pullets 1 wk after beak trimming. At 16 wk, 1/4R pullets' beaks had regrown but 1/2R pullets' beaks continued to be shorter than IN pullets' beaks. No differences in fearfulness were found between genetic stocks or among beak length treatments early in the laying period. Deaths from beak-inflicted injuries accumulated steadily from 18 wk until the study was ended at 40 wk. Cannibalistic deaths occurred less frequently in S as compared with C pullets within each beak treatment. As the amount of beak removal increased, beak-inflicted mortality decreased. The S pullets had earlier sexual maturity, lighter egg weights, and greater hen-housed egg production and egg mass than C pullets, and 1/2R pullets had greater egg production than 1/4R and IN pullets. Genetic stock by age and beak treatment by age interactions were present for hen-housed production and egg mass, and the interactions appeared to result primarily from increased mortality from cannibalistic pecking with increased age.

Beak trimming effects on behavior patterns, fearfulness, feathering, and mortality among three stocks of White Leghorn pullets in cages or floor pens

White Leghorn pullets of the Y1, Y2, and North Central Randombred (NCR) experimental stocks were used. Half of the birds of each stock had half of the upper and less of the lower mandible removed at 4 wk of age by making a V-shaped cut as viewed from the side (BT), whereas the other half retained their beaks intact (IN). Pullets were moved from growing pens to a layer house at 18 wk of age. Seventy-two cages and 30 floor pens were filled with 6 and 20 birds per unit, respectively. Pullets within a cage or floor pen were all of the same genetic stock and beak treatment. All measurements were performed within 10 wk after housing, except for mortality in cages. When kept in cages, genetic stocks did not show behavioral differences. However, in floor pens, stock differences were detected in feeding, crouching, and nonaggressive pecking. When kept in cages, the stocks also differed in 24-wk body weight, weight gain from 18 to 24 wk, and certain measures of fearfulness in both cages and pens, and in feather condition at 21 and 22 wk. Mortality from cannibalism and hen-days survival of caged IN pullets differed among genetic stocks. Mortality from cannibalism was absent among pullets kept in experimental floor pens. In cages, BT pullets were less active, gained less weight, and had lower incidence of cannibalism than IN pullets. Also, BT pullets were less nervous and had better feather condition than IN pullets. However, trimming beaks to prevent cannibalism was less effective in NCR pullets than in Y1 or Y2 pullets. In floor pens, BT pullets showed less activity and reduced feeding frequency and less fearfulness as indicated by duration of induced tonic immobility. Agonistic behaviors were not different between BT and IN pullets. From these results, beak trimming could be interpreted as having either stressful or stress-alleviating effects, depending on the criteria used. However, proper beak trimming appears beneficial when cannibalistic pecking is likely to be a problem. The relative benefits of beak trimming vary among genetic stocks.