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Pale, soft, and exudative meat in turkeys treated with succinylcholine.

Rapid post-mortem metabolism concomitant with the early onset of rigor mortis can lead to the development of pale, soft, and exudative (PSE) meat. However, a reliable, nonlethal method for induction of this syndrome for the ante-mortem identification of abnormal turkeys has not been identified. The present study was conducted to evaluate the potential use of succinylcholine for inducing PSE meat in susceptible turkeys. Four-week-old Nicholas toms were either uninjected (controls) (n = 44) or injected with succinylcholine and butorphanol (n = 76) in combination. Post-mortem tissue samples were taken from the Pectoralis at 15 min, 2 h, and 4 h, for pH and R-value (the ratio of inosine to adenosine) determination. L*values were evaluated at 4 and 24 h post-mortem and drip loss and cook loss were determined. Means for pH, R-value, L*value, drip loss, and cook loss did not differ due to injection treatment. When Pectoralis were grouped as normal (L* < 53) or pale (L* > 53), pale fillets had lower pH and higher R-values than normal birds by 15 min post-mortem. Decreased water-holding properties were evident as drip loss and cook loss were increased in the pale group. The observed frequency of pale birds was 21.6% in the population, and the occurrence of pale birds was highest in the butorphanol-treated group. These findings suggest that although butorphanol did not affect overall treatment means for the test parameters, more turkeys in the treated group exhibited PSE meat.

Analgesics, Opioid↗

Influence of preslaughter stunning on turkey breast muscle quality.

Pectoralis muscle quality was evaluated from 18-wk-old tom turkeys after electrical stun, carbon dioxide stun, or no stun methods were applied. Color was measured on raw muscle and cooked meat using a colorimeter. Muscle pH was measured 15 min post-mortem (initial), 24 h post-mortem (final), and after cooking. The right Pectoralis muscle of each carcass was excised for m-calpain analysis within 4 min post-mortem. After 24 h of storage at 4 C, the left Pectoralis muscle was excised to determine cook loss and shear force measurements. No significant difference was found in initial muscle pH (15 min) from turkeys receiving electrical or carbon dioxide stunning, 6.36+/-0.15 and 6.20+/-0.14, respectively. However, initial muscle pH for birds that were not stunned (5.99+/-0.08) was lower (P < 0.05) than the muscle pH of birds stunned using either of the two stunning methods. Stunning method had no effect on the final muscle pH, raw muscle color, cooked meat pH, cooked meat color, cook loss, or shear force. Cook loss was found to positively correlate with initial muscle lightness (r = 0.53), and cooked meat lightness (r = 0.48), but to negatively correlate with cooked meat yellowness (r = -0.48) and shear strength (r = -0.43). m-Calpain activity declined with the stunning methods in the following order: electrical > carbon dioxide > no stun. In addition, m-calpain activity was found to correlate with initial muscle pH (r = 0.95) and with cooked meat shear force (r = -0.43). The results of this study show that electrical stunning, carbon dioxide stunning, and no stunning methods provide comparable cooked turkey breast meat quality with no consistent differences after aging on the carcass for 24 h.

Abattoirs↗

Thermal and rheological properties and textural attributes of reduced-fat turkey batters.

Currently, modified potato and tapioca starches are used as functional additives in formulating reduced- and low-fat frankfurters. However, cornstarches may serve as alternative sources for comminuted meat systems. Meat batters formulated with ground turkey, 2% sodium chloride, 25% distilled-deionized water (ice), and 4% starch, including acid-thinned dent corn (ATDC), cross-linked waxy maize (XLWM), cross-linked dent corn (XLDC), modified potato (MP), acid-thinned dent corn with xanthan gum (ATDCG), or modified tapioca (MT) were compared. Thermal and structural properties of the batters were evaluated using differential scanning calorimetry (DSC) and dynamic rheological testing. Cooking loss, reheating loss, and texture profile analysis (TPA) were determined for cooked turkey batters. The DSC peak temperatures ranged from 57.5 to 74.9 C, which correlated positively to onset temperatures of the storage moduli (G') for XLWM starch. Incorporation of XLWM, XLDC, MT, or MP starch into turkey batters resulted in significant reductions in cooking and reheating losses. The TPA results showed that 9.42, 8.57, and 8.48 kg of force were required for 75% compression of cooked batter segments containing MP, XLDC, and XLWM starches, respectively. Segments prepared with ATDCG starch were the least firm and most springy of all starch-containing segments.

Animals↗

Effects of amino acid restriction during starter and grower periods on subsequent performance and incidence of leg disorders in two strains of male large white turkeys.

Male turkeys of two commercial Large White strains (Nicholas 88, BUT 6) were subjected to growth restriction by means of reducing amino acid (AA) content of diets to a minimum of 75% of NRC (1994) suggested levels. There were three periods when diets containing 75% of NRC recommended AA for that age period were fed ad libitum: 0 to 3 wk, 0 to 6 wk, or 6 to 12 wk. A fourth (control) group was not restricted in AA content at any time. When turkeys were not fed the AA-restricted diets they were fed diets formulated to meet a minimum of 100, 110, or 120% of NRC (1994) AA recommendations, which resulted in a 3 x 4 factorial arrangement of treatments with three AA levels by four restriction times. Four pens of 12 males each were fed each AA by restriction time combination. At 18 wk, all birds were scored individually for leg condition and representative samples of turkeys were processed for parts yield. Birds fed restricted diets from 0 to 6 or 6 to 12 wk had significantly lower BW at 18 wk than control birds. Birds fed the restricted diets from 0 to 3 wk did not differ significantly in 18-wk BW compared to control birds but the magnitude of difference was similar to that observed at the end of the restriction period. Feed utilization was not improved by early AA restriction. Restricting early growth resulted in a significantly higher incidence of birds with no leg disorders and a lower incidence of birds with moderate leg disorders than control birds. Feeding higher AA levels during realimentation resulted in a greater severity of leg disorders. Breast meat yield was depressed significantly as severity of early restriction increased. Increasing dietary AA above NRC (1994) recommended levels generally improved performance during realimentation but was not able to compensate for reduced gains during restriction.

Amino Acids↗

Sex differences in the resistance of turkeys to Escherichia coli challenge after immunosuppression with dexamethasone.

Five-week-old male and female commercial turkeys were immunosuppressed with two levels of dexamethasone (DEX) and challenged by airsac inoculation with 100 cfu of Escherichia coli. Mortality and airsacculitis (AS) scores were significantly higher in challenged birds treated with DEX and marginally higher in males than in females. Male mortalities had significantly higher AS scores than females. Recovery of E. coli from blood and tissues was significantly higher in challenged birds treated with DEX, marginally higher in males (P = 0.09), and significantly higher in male mortalities than in female mortalities. The low level of DEX seemed to have a protective effect against bacterial challenge in males, whereas the high level of DEX had a more adverse effect in males than in females. Body weights 2 wk postchallenge were significantly decreased by both DEX and E. coli, challenge. Relative liver and heart weights were increased by both DEX and E. coli, challenge, whereas bursal:spleen ratios were decreased by both treatments. Total leukocyte counts and relative heterophil counts from blood samples taken 24 h postinfection were significantly higher in DEX-treated birds and in unchallenged DEX-treated females than in males. The DEX treatment resulted in significantly higher heterophil:lymphocyte ratios, but there was no difference between sexes. Males had significantly lower serum levels of uric acid, total protein, albumin, aspartate aminotransferase, and lactate dehydrogenase than did females. Dexamethasone treatment also resulted in lower levels of total protein, albumin, and aspartate aminotransferase. These data suggest that male turkeys may be more susceptible to colisepticemia than female turkeys, especially when under severe stress.

Animals↗

Variation in resistance to Pasteurella multocida among turkey lines.

Previous research has shown that a line (F) of turkeys selected long-term for increased 16-wk body weight was more susceptible to challenge with washed Pasteurella multocida than a randombred control line (RBC2), the base population of F. A previous study also indicated that the mortality of the F line following challenge with P. multocida was similar to that of sire lines from two of the three major primary breeders. The purpose of the present study was to compare the resistance of the sire line from the third major primary turkey breeder (C) not previously studied with that of the F and RBC2 lines to determine whether there is variation in resistance among the sire lines from three major primary breeders. The sire lines from all three primary breeders were used in the production of commercial turkeys. Body weights of the F line were greater than those of the C line at the time of challenge with P. multocida. Both the C and F lines were heavier than the RBC2 line. The birds were challenged at 6 wk of age with a field isolate of washed P. multocida (1.2 x 10(7) organism per bird of capsular serogroup A and somatic serotype 3,4). Mortality was recorded daily for 14 d. Mortality following challenge with P. multocida was higher in the F line than in the C line, and both large-bodied lines had higher mortality than the RBC2 line. Based on the present results and those published in the literature, there may be variation in resistance among commercial sire lines from the three major primary breeders.

Animal Husbandry↗

Ontogeny of luteinizing hormone and estradiol secretion in turkey hens exposed to different photoperiods from hatch to sixty weeks of age.

Changes in concentrations of plasma luteinizing hormone (LH) and estradiol-17beta in turkey hens were measured during development utilizing stimulatory and nonstimulatory lighting treatments. All hens were maintained under 24 h light (L) from hatch to 3 wk of age, then 16L:8 dark (D) to 10 wk of age. From 10 wk of age, three lighting treatments were used: 1) 16L:8D from 10 to 60 wk of age (Treatment LD); 2) 6L:18D from 10 to 60 wk of age (Treatment SD); and 3) 16L:8D from 10 to 20 wk of age, 6L:18D from 20 to 30 wk of age, and then 16L:8D from 30 to 60 wk of age (Treatment SD-LD). Measurements of plasma LH and estradiol-17beta concentrations were based on weekly blood samples. Similar patterns of LH were observed in all treatments before 24 wk of age. The concentrations of LH were high at hatch then declined to low levels at 10 wk of age and rebounded to high levels at 18 wk of age before declining to low levels at about 24 wk of age. Low concentrations of LH were then maintained for hens on all treatments but were slightly higher in hens on Treatment SD from 35 to 60 wk of age. A transitory increase in LH, lasting about 3 wk, occurred for hens on Treatment SD-LD after photostimulation. The concentrations of estradiol-17beta were low and stable for hens on all treatments when they were not laying but were elevated about 2 wk prior to and during egg laying. All hens on Treatments LD and SD-LD laid eggs; no hens on Treatment SD laid eggs to 60 wk of age. It was concluded that 1) changes in plasma LH and estradiol-17beta were age related before about 24 wk of age, 2) turkey hens may not be photorefractory at hatch and can lay without juvenile exposure to SD photoperiods, and 3) LD photoperiods after about 20 wk of age are necessary for initiation of egg production in turkey hens before 60 wk of age.

Aging↗

Developmental regulation of proteoglycan synthesis and decorin expression during turkey embryonic skeletal muscle formation.

To delineate the role of proteoglycans in turkey skeletal muscle development, proteoglycan expression was examined in pectoral muscle from 14-, 20-, and 25-d-old embryos. Proteoglycans were separated by DEAE (diethylaminoethyl cellulose) anion exchange and molecular sieve chromatography. Glycosaminoglycan composition was measured by enzyme digestion and nitrous acid deamination. The proteoglycan decorin was analyzed at each of these stages of development for core protein size by polyacrylamide gel electrophoresis and for spatial distribution by immunohistochemistry. Chondroitin sulfate-containing proteoglycans were the predominant proteoglycans found throughout turkey embryonic skeletal muscle development. However, in 20- and 25-d-old pectoral muscle, higher levels of heparan and dermatan sulfate were observed compared with their values at 14 d. Two decorin core protein bands with molecular weights of 45 and 46 kDa were detected. Immunostaining for decorin showed that, as the connective tissue layers developed, decorin was localized in the perimysium and epimysium. These data indicate that turkey embryonic skeletal muscle proteoglycan expression is dynamic and changes from a matrix that is rich in a large chondroitin sulfate proteoglycan to one containing dermatan sulfate, heparan sulfate, and chondroitin sulfate proteoglycans, and suggests the presence of two forms of decorin.

Animals↗

Association of fatty acid synthase gene and malic enzyme gene polymorphisms with fatness in turkeys.

A candidate gene approach was carried out on a commercial line of turkeys to assess the association between fatness variability and polymorphisms of genes involved in lipid metabolism. Four restriction fragment length polymorphisms (RFLP) were typed on the fatty acid synthase gene (MspI/pF5), on the malic enzyme gene (HindIII/em), as well as on the acetyl coenzyme A carboxylase and delta9 desaturase genes. Fatness level was estimated in vivo by an ultrasonic instrument. Fat yield was assessed after slaughter by calculating the ratio of the leg skin plus subcutaneous fat weight to the whole leg weight. Finally, the lipid content was determined by extraction from the boneless leg. The 84 female turkeys sampled were full and half-sibs born from eight sires, seven of which were heterozygous for MspI/pF5 or HindIII/em RFLP and one of which was double homozygous at these loci. The analyses of variance used to compare the genotypes at each RFLP suggested a major role associated with the fatty acid synthase gene polymorphism in the explanation of fatness variability. One homozygous genotype for MspI/pF5 was about 1.5 standard deviations leaner than the other two homozygous genotypes. An analysis of the average effects of gene substitution confirmed the association between leanness and one allele of the fatty acid synthase polymorphism. It also identified a significant association between leanness and one malic enzyme RFLP allele, congruent with a strictly additive determinism for the effect associated with this polymorphism. This experiment provided new evidence of the association between both fatty acid synthase and malic enzyme gene polymorphisms and fatness variability in turkeys.

Animals↗

Inhibition of pink color development in cooked, uncured turkey breast through ingredient incorporation.

Nonmeat ingredients were tested for their ability to inhibit pink color (which consumers associated with undercooking) in turkey breasts with and without added pink color generating agents (1.0% nicotinamide; 20, 100 ppm nitrite). Nonmeat ingredients included: trans 1,2-diaminocyclohexane-N,N,N',N' tetraacetic acid monohydrate (CDTA), diethylenetriamine pentaacetic acid (DTPA), ethylenedinitrilotetraacetic acid disodium salt (EDTA), and nonfat dried milk (NFDM). Ingredients were evaluated at two (1%, 2% NFDM) or three different levels (50 ppm, 100 ppm, 200 ppm; EDTA, DTPA, and EDTA), over three storage times (1, 4, 21 d), and after 2 min of exposure to light and air. Whole muscle turkey strips were injected with a 20% treatment solution. Product was tumbled and heat processed to an internal temperature of 80 C. Turkey muscle strips containing ingredients without pink color generating agents were less red and lighter than controls. In most cases, 50 ppm of added EDTA, CDTA, or DTPA was sufficient to reduce pinking. Ingredients were more effective against nicotinamide- than nitrite-generated pink. Overall, ingredients delayed onset of pink color associated with storage time. In general, DTPA was the most effective of the test ingredients. However, as NFDM is both effective at reducing the pink defect and approved as a nonmeat ingredient, processors can incorporate this ingredient for the benefit of reducing this defect. Future studies should determine how NFDM achieves this reduction.

Animals↗

Measuring sperm:egg interaction to assess breeding efficiency in chickens and turkeys.

Systems used to measure fertility in poultry have themselves presented a major impediment to progress in maintaining or improving fertility. Generally, these systems have been time-consuming, quantitatively inadequate, or both. A simplistic illustration of the basis of the problem is that if six fertile eggs were laid by a turkey hen during 1 wk after insemination, then all we know is what happened to six sperm: they fertilized the eggs. If 100 million sperm were inseminated, then information on the other 999,999,994 is missing. A better approach for quantitating breeding efficiency is to estimate the numbers of sperm that interact with the egg in the infundibulum. These can be identified in laid eggs, as sperm in the outer perivitelline layer (OPVL sperm), or holes produced by sperm in the inner perivitelline layer (IPVL holes). Eggs can contain up to 250,000 OPVL sperm, so the scale improves on binary estimation of fertilization status. The number of spermatozoa interacting with the perivitelline layer is related to the artificial insemination (AI) dose, the number of oviducal sperm, and the probability of fertilization, not just for one egg, but for subsequent eggs laid by the same hen. Practical applications of sperm:egg interaction measurements include: replacement of fertility trials for evaluation of semen; general fertility evaluation; and monitoring breeding efficiency of commercial turkey and broiler breeders. Furthermore, studies of sperm transfer into eggs raise interesting questions about the efficiency of turkey hens' response to AI or mating frequency of broiler hens in commercial flocks.

Animal Husbandry↗

Rapid postmortem pH decline and delayed chilling reduce quality of turkey breast meat.

Effects of rapid postmortem metabolism and delayed chilling on turkey breast meat quality were assessed using color measurements, protein extractability, and gelation characteristics. Based on 15 min postmortem breast muscle pH, tom turkey carcasses were classified as rapid glycolyzing (RG), pH < 5.80, or normal glycolyzing (NG), pH > 6.00. Two carcasses per group with similar ultimate pH values were selected on four occasions for a total of 16 carcasses. One half of each carcass was immersion-chilled at 20 min postmortem, the other half was maintained at body temperature for 110 min and then chilled. Breast meat from RG carcasses had higher carcass temperature (15 min) and lower protein (sarcoplasmic and myofibrillar) extractability than breast meat from NG carcasses. Delayed chilling increased all breast meat color values (L*, a*, b*), and decreased protein extractability and cook yield compared to breast meat from immediately chilled carcass halves. The true strain of cooked gels was reduced for RG carcasses. Delayed chilling reduced both true strain and stress of meat gels. There were no interactions between the rate of postmortem pH decline and initiation of chilling, indicating that reductions in meat quality due to delayed chilling were independent of the carcass classification for rate of postmortem glycolysis. Results indicate that factors that affect both rate of postmortem glycolysis and carcass temperature decline are important to turkey breast meat quality.

Animals↗

Efficacy of neomycin sulfate water medication on the control of mortality associated with colibacillosis in growing turkeys.

The objective of this investigation was to evaluate the efficacy, safety, and toxicity of neomycin sulfate (Neomix 325) water medication to control mortality associated with colibacillosis (Escherichia coli) in growing turkeys. One efficacy trial was conducted at five locations; each location included 2,880 sexed 21-d-old turkey poults that were naturally challenged with litter from turkey flocks that had colibacillosis. Between 5 and 7 d after challenge, and when mortality had reached 0.5%, poults were randomized within sex into three treatment groups of 0, 11, or 22 mg neomycin sulfate/kg body weight. In each location, each treatment was replicated 12 times with 40 poults per sex per replicate. All treatments were administered in the drinking water for 5 d. The pivotal decision criterion was mortality. Mortality was defined as 1) supported mortality (SM): positive microbial culture for E. coli and gross lesions, 2) diagnosed mortality (DM): diagnosed as associated with E. coli but not supported by lesions or positive microbiological cultures, 3) overall mortality (OM): mortality associated with E. coli or other microorganisms and miscellaneous reasons such as accidents (trampling or suffocations). Performance data (growth and feed utilization) also were measured and are reported without statistical analysis. Results from this efficacy study clearly demonstrated the effectiveness of neomycin sulfate against E. coli as measured by a reduction in mortality. In the target animal safety and toxicity study (done in conjunction with the efficacy study), neomycin sulfate in the drinking water at 66, 110, or 220 mg/kg per d for 15 d had no observable adverse effects on poult performance, as measured by feed or water consumption, body weight, gross pathology, or mortality.

Animal Nutritional Physiological Phenomena↗

Photostimulation of turkey eggs accelerates hatching times without affecting hatchability, liver or heart growth, or glycogen content.

The objective of the current study was to determine the effects of incubating turkey eggs in the presence of incandescent light on hatching times, as well as liver and heart growth and function of the hatched poult. In each of two independent trials, 180 commercial turkey eggs were incubated either in a 12-h incandescent light:dark schedule or continuous darkness throughout the incubation period (n = 360). Hatching time was observed at 8-h intervals following 25 d of incubation. Hatchability was calculated as a percentage of total eggs set, and was also calculated as a percentage of fertilized eggs. Poult weights, blood glucose, liver weights, and heart weights were measured at hatch. Liver and heart glycogen concentrations were analyzed, and comparisons were made of light-treated hatchlings and controls exposed to continuous darkness. The photostimulation of eggs accelerated hatching times (P < or = 0.01) without affecting hatchability or poult weight at hatching. Neither organ weights nor organ glycogen contents of photostimulated poults differed significantly from controls incubated in the dark. Results of this experiment indicate that the incubation length of turkey eggs may be shortened by photostimulation of eggs during the incubation period without significantly affecting embryonic survival, liver or heart growth, or glycogen content.

Animals↗

Effect of dry honey on oxidation in turkey breast meat.

The effect of adding dry honey to turkey breast meat on oxidative stability was measured using TBA, volatile headspace, and oxidative stability index. Ground turkey breast meat was mixed with different concentrations of dry honey (0, 1, 5, 10, 15, and 20%) then cooked in polyethylene bags to 72 C. Oxidative stability measurements were taken for raw meat and cooked meat and for cooked meat after 48 h of storage at 4 C. The proximate composition of the raw meat was 73.9% moisture, 23.2% protein, and 1.3% fat. Gas headspace analysis determined hexanal to be the most abundant volatile compound. Hexanal content decreased as the amount of added honey increased in both freshly cooked meat and in meat stored for 48 h at 4 C. The TBA values also decreased with increasing levels of added honey in the freshly cooked and 48-h-stored meats. The percentage inhibition of oxidation for the 5, 10, 15, and 20% samples increased from 50 to 76% for the freshly cooked meat and from 34 to 88% for the 48-h-stored meat. The oxidative stability index increased with increasing concentrations of honey from 0.28 h (control) to 7.73 h (20% honey). Addition of up to 15% honey inhibited the development of oxidative compounds in cooked turkey meat, with little further inhibition observed compared to 20% honey.

Aldehydes↗

Effect of dietary phosphorus, calcium, and phytase on performance of growing turkeys.

Female and male turkeys were fed 110, 73, 52, and 30% of the NRC (1994) nonphytate P (NPP) requirement without and with 500 phytase units (FTU)/kg during 4 to 14 or 16 wk of age, respectively. At 110% P (control; also 110% of NRC Ca), phytase was without effect. At 73% of NPP (100% Ca), without phytase, performance was similar to the control; with phytase, performance was equivalent, and in some stages, superior to the control. At 52% of NPP (90% Ca), performance was inferior without phytase and was variably similar or poorer than the control with phytase. At 30% NPP without phytase, poults gained poorly and showed a high incidence of leg disorder at 8 wk when they were removed from experiment; poults gained better with 80% NRC Ca compared with 110%. At 30% NPP with phytase, turkeys performed remarkably well, although suboptimally, at 80 or 110% NRC Ca. Phytase at 400, 300, and 200 FTU/kg with increasing age periods performed as well as 500 FTU/kg with 73% of NRC NPP (100% Ca) and 52% NRC NPP (90% Ca). These lower phytase levels were not as sufficient as 500 FTU/kg with 30% of NRC NPP; this inadequacy was more severe with higher dietary calcium. Phytase was effective in reducing dietary P requirements of growing turkeys when the NPP levels were below NRC (1994) requirements.

6-Phytase↗

Antibody responses to sheep red blood cell and Brucella abortus antigens in a turkey line selected for increased body weight and its randombred control.

Turkeys from a randombred control line (RBC2) and its subline (F) selected for increased 16-wk BW were tested for primary and secondary antibody responses to SRBC antigen and Brucella abortus antigen (BA). Previous studies have shown that the F line was more susceptible to Pasteurella multocida and Newcastle disease virus than was the RBC2 line. Individuals from the RBC2 and F lines were intravenously injected with 1 mL 5% SRBC antigen or 0.1 mL undiluted BA at 4 and 6 wk of age; blood samples were collected at 0, 4, 7, and 10 d post-immunization. Total, IgG, and IgM titers were measured by agglutination assays. Compared with the RBC2 line, the F line had generally higher total anti-SRBC titers; the differences were significant at 14 d postprimary immunization (PPI) (females); at 10 d postsecondary immunization (PSI) (males); and 4, 7, and 10 d PSI (females) (P < or = 0.05). The F line also had higher IgM titers at 14 d PPI (females) and at 10 d PSI (males) (P < or = 0.05). For IgG titers, a line difference was evident in females at 4 and 10 d PSI (P < or = 0.05); the F line had higher titers than did the RBC2 line. For the antibody response to BA in males, the F line had lower total and IgM titers at 10 d PPI (P < 0.05) than did the RBC2 line. No significant line differences in response to the BA were found in total and IgM titers in female turkeys or in IgG titers in both sexes at any time. These results suggest that selection for fast growth rate of turkeys might have resulted in changes in humoral immunity to the SRBC antigen and BA.

Animals↗

Effect of ultraviolet radiation on the performance of intact male turkeys.

Ultraviolet (UV) sensitivity in birds has been shown to be intrinsically involved in the selection of mates; UV may, therefore, also play a role in the establishment and maintenance of social hierarchies in intensively housed turkeys. Cereal seeds and straw are known to reflect UV, and turkeys may use these cues for foraging and exploratory behaviors. A series of trials was conducted to see if supplementation of the photoperiod (12 h at various white light intensities) with UV radiation (0.06 to 0.16 W/m2 at floor level) and regular supplies of straw to the litter allow a better recognition of individuals within a flock, enrich the environment by the provision of new pecking material and of radiation across the whole range of avian sensitivity, and, as a consequence, reduce the incidence of injurious pecking in male turkeys that have not been beak-trimmed, detoed, or desnooded. Body weight gain, feed intake, feed conversion efficiency, and leg integrity were generally not significantly affected by UV supplementation and environmental enrichment. In contrast, the provision of UV radiation, simultaneous with a 12-h photoperiod of white light at intensities of <70 lx to 5 wk and of 10 lx to 20 wk, and the regular addition of straw to the litter, significantly reduced the incidence of culling because of injurious pecking. However, complex interactions among UV supplementation, white light intensity, and material environmental enrichment precluded a simple recommendation to solve the problem of injurious pecking.

Animal Nutritional Physiological Phenomena↗