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 Effect of Claw and Beak Reduction on Growth Parameters and Fearfulness of Two Leghorn Strains

Commercial equipment used by the turkey industry at hatch sterilizes the germinal tissue of the claw with microwave energy and the beak tissue with infrared energy. This effectively trims the claws and beaks of the birds. Two strains of Leghorn chicks (1,200 each strain) were utilized to test this technique on chickens. Half were subjected to the claw reduction (RC) technique at hatch, and half retained intact claws (IC). The beaks of one-third of the birds in the claw treatments were reduced (BT) at hatch using the infrared technique, one-third were precision trimmed at 7 d, and one-third were not trimmed (IB). Body weight, weight gain, feed intake, feed conversion, mortality, and fearfulness were measured. Rearing followed standard commercial feeding and husbandry procedures. The RC birds had significantly lower BW, except from 3 to 6 wk, and had significantly lower feed consumption from 8 to 18 wk. The 1 d BT birds experienced significantly lower BW from 3 to 14 wk and ate less total feed by 4 wk. Mortality was less than 2.1% for all treatments. From 6 to 8 wk, fearfulness score (a subjective scale of 1 to 10) peaked at 8 to 10 for IC birds and 3 to 4 for RC birds. By 16 to 18 wk, fearfulness score subsided to 2 to 3 for RC and 6 to 8 for IC. Beak trimming and reduction of claw growth at hatch allowed pullets to be grown to sexual maturity on less feed and with a lower level of observed fearfulness using standard husbandry practices.

Group selection for adaptation to multiple-hen cages: selection program and direct responses

A selection experiment was initiated with a synthetic line of White Leghorns in 1982 to improve adaptability and well-being of layers in large multiple-bird cages by use of a selection procedure termed "group selection". With this procedure, each sire family was housed as a group in a multiple-bird cage and selected or rejected as a group. An unselected control, with approximately the same number of breeders as the selected line, was maintained for comparison and housed in one-third cages. Annual percentage mortality of the selected line in multiple-bird cages decreased from 68% in Generation (G)2 to 8.8% in G6. Percentage mortality in G6 of the selected line in multiple-bird cages was similar to that of the unselected control in one-bird cages (9.1%). Annual days survival improved from 169 to 348 d, eggs per hen per day (EHD) from 52 to 68%, eggs per hen housed from 91 to 237 eggs, and egg mass (EM) from 5.1 to 13.4 kg, whereas annual egg weight remained unchanged. The dramatic improvement in livability demonstrates that adaptability and well-being of these birds were improved by group selection. The similar survival of the selected line in multiple-bird cages and the control in one-bird cages suggests that break-trimming of the selected line would not further reduce mortalities, which implies that group selection may have eliminated the need to beak-trim. Corresponding improvements in EHD and EM demonstrate that such changes can also be profitable. The most surprising finding was the rate of which such improvement took place, with the majority of change in survival occurring by the third generation. However, EHD continued to improve at the rate of 4% per generation.

Group selection for adaptation to multiple-hen cages: beak-related mortality, feathering, and body weight responses

The hypothesis was tested that selection on the basis of family means for increased survival and hen-housed egg production, when sisters with intact beaks were kept together in multiple-bird cage, would cause adaptive changes in behavior. Specifically, it was posited that beak-inflicted injuries causing cannibalistic mortality and feather loss and damage would be reduced. Body weight effects were not predicted, but were examined. Three stocks were compared; the Selected (S), representing the seventh generation of selection, the Randombred Control (C) from which S was derived, and a commercial stock (X), known to be highly productive and peak-trimmed by commercial producers. Pullets were placed in single-bird (1H) as well as in 12-hen (12H) cages using a completely randomized block experimental design. Mortality from beak-inflicted injuries differed among stocks in total hens lost (P < 0.005). Of 576 per stock in 12H cages 287, 128, and 46 replacements were used from 17 to 44 wk in X, C, and S, respectively, to maintain group size. The C and S hens also differed from 44 to 59 wk and 17 to 59 wk. X hens were not included in comparisons of mortality beyond 44 wk. Relative incidence of mortality caused by vent-cloacal injuries differed with X > C = S (P < 0.005 for X vs C and S). For cages with > or = 1 cannibalistic death, X had twice (P < 0.025) and C 1.6 times (P < 0.10) as many with repeated losses as S. Means and variances of feather scores were different for 1H vs 12H cages, ages, and genetic stocks. Greater variances were observed in 12H cages and among older birds. Within 1H units, genetic stocks did not differ in general, but in 12H cages X and C were always more variable than S. In 12H cages, mean feather scores and body weights were decreased and S hens had better feathering than either C or X. The evidence supported the hypothesis.

Beak trimming effects on beak length and feed usage for growth and egg production

Two experiments were conducted to compare beak treatment effects on pullets of three genetic stocks. Within each stock, equal numbers were assigned to three treatments: no beak trimming (IN), beak trimming once (1X), and beak trimming twice (2X). Beak treatment, genetic stock, and age effects along with interactions among main effects were examined for production-associated traits during rearing and brief periods of early egg production. Beaks of 1X and 2X pullets remained shorter than those of IN pullets through final measurements at 36 and 32 wk of age in Experiments 1 and 2, respectively. However, differences in beak length decreased as age increased. Upper beaks of 2X pullets remained shorter than those of 1X pullets, but lower beaks of 1X and 2X pullets did not differ by 20 wk in Experiment 2. Weight gains, feed usage, and efficiency of growth were affected by beak treatments. Beak trimming reduced gains, feed eaten, feed wasted, and total feed used, and 2X pullets used their feed more efficiently for weight gain and egg production. A general decrease occurred in differences among beak treatments for weight gains, feed eaten, feed wasted, and efficiency of gains with increasing age during rearing. Nevertheless, significant differences in feed consumed, feed wasted, and efficiency of feed used for egg production indicated an economic advantage in favor of beak trimming.