Biomedical subjects

R J Buhr

Publications and source records attributed to R J Buhr.

At least 19 recordsLinked to original sources

PubMed2003

Effects of stunning and decapitation on broiler activity during bleeding, blood loss, carcass, and breast meat quality.

Four experiments were conducted to determine the effects of electrical stunning and decapitation on bird activity as well as carcass and meat quality. In Experiment 1, broilers were subjected to one of four stunning and killing methods: no stun and neck cut, stun and neck cut, no stun and decapitation, and stun and decapitation. Birds were scored for severity of physical activity on a scale of 1 to 4 with 1 being no activity and 4 being severe wing flapping and muscular contractions. Carcasses were also scored for red wing tips and broken bones. In Experiments 2 to 4, all birds were stunned prior to neck cut or decapitation. Carcasses were scored as described in Experiment 1 as well as measurements of blood loss, feather removal, and breast meat pH, color, cook loss, and tenderness. Based on carcass activity in Experiment 1, decapitation following stunning was similar to a conventional stun and unilateral neck cut, except there was almost no late activity (after 60 s) observed in the decapitated birds. Decapitation following stunning did not result in any consistent carcass quality defects compared to conventional killing in the four experiments. No differences were found in 24-h lightness values, yellowness, cook yield, tenderness, and ultimate pH between conventionally killed and decapitated birds. Blood loss and breast meat redness were inconsistent. These results indicate that high frequency stunning and decapitation may be an acceptable alternative to conventional slaughter based on carcass and meat quality and by ensuring an irreversible loss of consciousness.

Abattoirs↗

PubMed2002

Microbiological consequences of skin removal prior to evisceration of broiler carcasses.

The objective of this project was to determine if removal of skin prior to evisceration lowers the number of bacteria that can be recovered by whole carcass rinse or sponge sampling. Four experiments were conducted, two with each type of sampling (rinse or sponge). New York dressed carcasses obtained from a commercial broiler processing plant were aseptically skinned or left with skin intact. The carcasses were then aseptically eviscerated by hand. Carcasses were rinsed in 100 mL sterile water or sampled by moist sponge. When sampled by rinse, significantly fewer Campylobacter and total aerobic bacteria were recovered from carcasses that had been skinned prior to evisceration. When sampled by sponge, significantly fewer Campylobacter, Escherichia coli, coliform and total aerobic bacteria were recovered from the outer surface of carcasses without skin. No differences were noted for bacterial counts recovered from internal surfaces by sponge sampling. Similar trends were observed when carcasses were subjected to an inside and outside washing step after evisceration. Removal of skin and washing the carcass led to significantly less Campylobacter being recovered by whole carcass rinse compared to carcasses that were washed with the skin on. When sampled by sponge, incidence of Campylobacter and level of total aerobic bacterial counts were lower on the outer surface of skinned and washed carcasses than on washed carcasses with intact skin. Like the unwashed carcasses, no differences were noted for bacterial counts recovered from internal surfaces by sponge sampling. Although not commercially practical, it is possible to lower the level of Campylobacter on the outside of broiler carcasses by removal of the skin prior to evisceration.

Animals↗

PubMed2002

Reducing airborne pathogens, dust and Salmonella transmission in experimental hatching cabinets using an electrostatic space charge system.

Electrostatic charging of particles in enclosed spaces has been shown to be an effective means of reducing airborne dust. Dust generated during the hatching process has been strongly implicated in Salmonella transmission, which complicates the cleaning and disinfecting processes for hatchers. Following two preliminary trials in which dust reduction was measured, four trials were conducted to evaluate the effectiveness of an electrostatic space charge system (ESCS) on the levels of total aerobic bacteria (TPC), enterobacteriaceae (ENT), and Salmonella within an experimental hatching cabinet. The ESCS was placed in a hatching cabinet that was approximately 50% full of 18-d-old broiler hatching eggs. The ESCS operated continuously to generate a strong negative electrostatic charge throughout the cabinet through hatching, and dust was collected in grounded trays containing water and a degreaser. An adjacent hatching cabinet served as an untreated control. Air samples from hatchers were collected daily, and sample chicks from each hatcher were grown out to 7 d of age for cecal analysis in three of the trials. The ESCS significantly (P < 0.05) reduced TPC and ENT by 85 to 93%. Dust concentration was significantly reduced (P < 0.0001) during the preliminary trials with an average reduction of 93.6%. The number of Salmonella per gram of cecal contents in birds grown to 7 d of age was significantly (P < 0.001) reduced by an average log10 3.4 cfu/g. This ionization technology is relatively inexpensive and could be used to reduce airborne bacteria and dust within the hatching cabinet.

Air Microbiology↗

PubMed2002

Carbohydrate-based cocktails that decrease the population of Salmonella and Campylobacter in the crop of broiler chickens subjected to feed withdrawal.

The efficacy of various carbohydrate-based cocktails in reducing the number of enteropathogens in the crops of broilers subjected to feed withdrawal was examined. Market-aged broilers that had been orally challenged with Salmonella typhimurium were provided the cocktails during a 12-h feed withdrawal. After feed withdrawal, the broilers were processed, and their crops were aseptically removed and weighed. Crops were then blended in distilled water, and the pH of the suspensions was measured electronically. Populations of S. typhimurium, Campylobacter, and lactic acid bacteria in the crop suspensions were enumerated. Findings indicated that significantly fewer S. typhimurium and Campylobacter were recovered from the crops of broilers that had been provided cocktails supplemented with sucrose than from the (Key words: crop, carbohydrate, feed crops of broilers provided cocktails supplemented with equal concentrations (wt/vol) of glucose. Furthermore, significantly fewer S. typhimurium were recovered from the crops of broilers provided cocktails supplemented with 2 to 10% sucrose than from the crops of broilers provided water or cocktails that were not supplemented with carbohydrates. The pH of the crop contents of broilers provided carbohydrate cocktails were lower than the pH of the crops of broilers provided water or cocktails that were not supplemented with carbohydrates. Consumption of the cocktails did not produce significant changes in the crop weights. Findings indicate that altering the composition of carbohydrate-based cocktails provided to broilers during feed withdrawal may affect the efficacy of cocktails in reducing the number of enteropathogens recovered from the crops of broilers.

Animal Feed↗

PubMed2001

Unheated water in the first tank of a three-tank broiler scalder.

Scalding with unheated water in the first tank of a simulated three-tank scalder was tested to determine whether carcass bacteria, efficiency of feather removal, and cooked breast meat tenderness are affected as compared with carcasses scalded at the same temperature (57 C) in all tanks. This experiment was performed on 3 d using 6-wk-old broilers. On each day, eight birds per treatment were processed. During the first 40-s scalding period, one carcass was placed in approximately 24 C water. The other carcass was placed simultaneously in a scalder unit containing approximately 2,050 L of water at 57 C. Carcasses were then held out of the water for 15 s, after which both were placed for 40 s in opposite ends of the scalder containing water at 57 C. After the second scalding period, both carcasses were again removed from the water for 15 s, followed by another 40 s in the 57 C water. Total scald time was 2 min for each treatment. After picking, carcasses were rinsed with 200 mL of sterile 0.1% peptone water for 1 min. Aerobic bacteria and Escherichia coli were enumerated and incidence of salmonella was determined by standard methods. After rinsing, carcasses were eviscerated by hand and chilled for 30 min in ice slush. All carcasses were scored for the presence of feathers, and the appearance and condition of the skin were noted. Four hours postmortem, breast fillets were removed from carcasses and chilled overnight at 2 C. The next morning, breast fillets were cooked to an internal endpoint temperature of 75 to 80 C. Warner-Bratzler shear values were measured to determine tenderness. No differences were found in numbers of aerobic bacteria and E. coli, incidence of salmonellae, tenderness of cooked breast meat, or number of feathers left on carcasses.

Animals↗

PubMed2001

Effects of age, sex, and duration of postmortem aging on percentage yield of parts from broiler chicken carcasses.

The objective of this study was to evaluate effects of age, sex, and postmortem carcass aging duration on parts yield from broiler chickens. Two hundred twenty-four mixed-sex broilers were reared under commercial-like conditions for various periods between 37 and 51 d, slaughtered, packed in ice, and then aged for 0, 2, 4, or 6 h. Mean percentage yield of thighs, drumsticks, forequarters, wings, breasts, and filets were evaluated for each rearing period, sex, and postmortem aging duration. Yield of meatier parts such as thighs, forequarters, breasts, and filets increased with birds' ages. Female carcasses produced higher percentage yields of forequarters, breasts, and filets but lower yields of drumsticks. Carcasses aged 2 h or more postmortem tended to have lower yields of forequarters, breasts, and drumsticks than did carcasses aged for shorter durations. No statistically significant interactions among age, sex, or postmortem aging duration that affected yield of parts were detected. This information is useful to integrated poultry firms wishing to optimize yield of the most commercially valuable parts.

Age Factors↗

PubMed2001

Influence of age and postchill carcass aging duration on chicken breast fillet quality.

Breast fillet quality was evaluated from 37-, 39-, 42-, 44-, 46-, 49-, and 51-d-old broilers after post-chill (PC) aging of the carcass 0, 2, 4, or 6 h and deboning. Fillets were vacuum sealed in cooking bags and heated to an internal temperature of 72 C by submersion in a 95 C water bath. Cook yield was determined as the weight percentage of the fillet remaining after cooking. Texture of the cooked fillets was measured using a Warner-Bratzler (W-B) shear device. Fillet cook yield and shear force values were significantly affected by bird age at slaughter, and PC carcass aging duration before deboning. Bird gender significantly affected cook yield, whereas the interaction between age and PC aging duration significantly affected W-B shear. Fluid lost during cooking was greater for fillets aged 0 h PC and decreased when PC aging was 2 h or greater. Overall, W-B shear values decreased (more tender) when fillets were aged on the carcass at least 2 h PC, with the exception of fillets from 51-d-old broilers. After 2 h of PC aging on the carcass, shear force values for fillets from older broilers (49- and 51-d-old) were in the "very tough" portion of a texture scale (>12.60 kg), whereas textures of fillets from 42- and 44-d-old broilers were in the "slightly tough to slightly tender" portion of the scale (8.5 and 7.2 kg, respectively). These data show that if poultry processors harvest fillets earlier than usual (<2 h PC aging), the fillet texture will be more tender if it originates from younger broilers (42- or 44-d-old) instead of older broilers (49- or 51-d-old).

Age Factors↗

PubMed2001

Broiler carcass contamination with Campylobacter from feces during defeathering.

Three sets of experiments were conducted to explore the increase in recovery of Campylobacter from broiler carcasses after defeathering. In the first set of experiments, live broilers obtained from a commercial processor were transported to a pilot plant, and breast skin was sampled by a sponge wipe method before and after defeathering. One of 120 broiler breast skin samples was positive for Campylobacter before defeathering, and 95 of 120 were positive after defeathering. In the second set of experiments, Campylobacter-free flocks were identified, subjected to feed withdrawal, and transported to the pilot plant. Carcasses were intracloacally inoculated with Campylobacter (10(7) CFU) just prior to entering the scald tank. Breast skin sponge samples were negative for Campylobacter before carcasses entered the picker (0 of 120 samples). After defeathering, 69 of 120 samples were positive for Campylobacter, with an average of log10 2.7 CFU per sample (approximately 30 cm2). The third set of experiments was conducted using Campylobacter-positive broilers obtained at a commercial processing plant and transported live to the pilot plant. Just prior to scalding, the cloacae were plugged with tampons and sutured shut on half of the carcasses. Plugged carcasses were scalded, and breast skin samples taken before and after defeathering were compared with those collected from control broilers from the same flock. Prior to defeathering, 1 of 120 breast skin sponge samples were positive for the control carcasses, and 0 of 120 were positive for the plugged carcasses. After passing through the picker, 120 of 120 control carcasses had positive breast skin sponge samples, with an average of log10 4.2 CFU per sample (approximately 30 cm2). Only 13 of 120 plugged carcasses had detectable numbers of Campylobacter on the breast skin sponge, with an average of log10 2.5 CFU per sample. These data indicate that an increase in the recovery of Campylobacter after defeathering can be related to the escape of contaminated feces from the cloaca during defeathering.

Animals↗

PubMed2001

Presence and level of Campylobacter, coliforms, Escherichia coli, and total aerobic bacteria recovered from broiler parts with and without skin.

This study was undertaken to determine if broiler chicken parts without skin are less contaminated with Campylobacter than those with skin. Samples were taken in a commercial plant from defeathered carcasses before evisceration. Bacterial counts from rinse of aseptically removed meat samples were lower than those from stomached skin samples. No Campylobacter were recovered from meat collected from the breasts or thighs, and only 2 of 10 drumstick meat samples had detectable levels of Campylobacter. However, 9 of 10 breast skin, 10 of 10 thigh skin, and 8 of 10 drumstick skin samples were positive for Campylobacter, with between 2 and 3 log10 CFU/g of Campylobacter. Breasts, thighs, and drumsticks were removed from broiler carcasses following evisceration before entering the chill tank. There was a significant difference (50 to 90%) in the levels of Campylobacter on breasts, thighs, and drumsticks with and without skin. Similar trends were noted for coliform, Escherichia coli, and total aerobic bacterial counts from samples collected in the plant. Broiler part samples were also collected at retail outlets. These samples were either skin on and skinned in the laboratory or skin off at purchase. Aseptic removal of skin from broiler breasts, thighs, and drumsticks did not cause change in Campylobacter, coliform, E. coli, or total aerobic counts recovered from the skinned part. Likewise, parts purchased without skin did not have different bacterial counts than paired parts purchased with the skin on. Consumers should not expect to significantly lower the number of bacteria present on a chicken breast, thigh, or drumstick by removing the skin.

Animals↗

PubMed2000

Reduction of Salmonella in the crop of broiler chickens subjected to feed withdrawal.

Broilers were challenged with 10(9) Salmonella typhimurium and then were provided a glucose-based cocktail supplemented with 0 to 15% glucose during feed withdrawal in battery cages or in pens on litter. After feed withdrawal, broilers were processed, and their crops were aseptically removed and weighed. Crops were then stomached in distilled water, and the pH of the suspension was measured electronically. Salmonella typhimurium, Enterobacteriaceae, and lactic acid bacteria in the crop suspensions were enumerated on the appropriate bacteriological medium. Findings indicated that fewer S. typhimurium and other Enterobacteriaceae were recovered from the crops of broilers provided the cocktail supplemented with 7.5% glucose than from the crops of broilers provided either water or cocktails supplemented with lower or higher concentrations of glucose. Inhibition of the growth of S. typhimurium and other Enterobacteriaceae in the crops of broilers provided the cocktail supplemented with 7.5% glucose was generally associated with increased growth of lactic acid bacteria and decreased crop pH. Providing the cocktail to broilers before shipping to processing plants may reduce the number of food-borne pathogens that poultry carry into processing plants.

Animals↗

PubMed2000

Physical, chemical, and microbiological changes in the crop of broiler chickens subjected to incremental feed withdrawal.

Trials were conducted to determine the effect of feed withdrawal on the weight, pH, native bacterial flora, and Salmonella typhimurium persistence in crops of broilers. Six-week-old broilers were provided medicated or unmedicated feed and were subjected to feed withdrawal for 0 to 24 h in transportation crates or on litter. After feed withdrawal, broilers were stunned, bled, scalded, and picked. Crops were aseptically removed and weighed. Crops were then blended in 20 mL distilled water, and pH values of the suspensions were measured. Aerobic bacteria, Enterobacteriaceae, S. typhimurium, and lactic acid bacteria in the suspension were enumerated on appropriate bacteriological media. Feed withdrawal produced significant decreases in the crop weights. Crop pH increased by 1.0 unit within 6 h of feed withdrawal. Enterobacteriaceae and S. typhimurium populations generally decreased during the first 12 h of feed withdrawal and remained unchanged or increased during the final 12 h of the 24-h feed withdrawal period. The number of lactic acid bacteria recovered from the crop usually decreased as the duration of feed withdrawal increased. Changes in crop weights, pH, native microflora, or the recovery of S. typhimurium from the crop were similar in broilers subjected to feed withdrawal on litter or in crates and in broilers provided medicated or unmedicated feed before initiating feed withdrawal. Findings indicate that a decrease in the number of lactic acid producing bacteria in the crop and an increase in crop pH may be related to the reduction of anti-Enterobacteriaceae activity in the crop during extended feed withdrawal.

Animals↗

PubMed2000

Campylobacter recovery from external and internal organs of commercial broiler carcass prior to scalding.

Campylobacter is a human pathogen commonly found on live broilers and processed carcasses. To plan effective intervention strategies, it would be helpful to know which Campylobacter populations are associated with the external and internal organs of broilers. Six carcasses were collected after exiting the bleed tunnel at a commercial broiler plant on each of three visits (n = 18). Carcasses were placed individually into sterile plastic bags, sealed, and covered with ice for transport to the laboratory. Five locations were sampled aseptically from each carcass: breast feathers (hand picked from the sternal tracts); breast skin, including the sternal tracts; crop; ceca; and colon. Samples included adhering contamination or lumen contents and were covered with phosphate-buffered saline and blended. Serial dilutions were made for examination of Campylobacter, coliform, Escherichia coli, and total aerobic bacterial populations. Average sample weights (grams) were as follows: feathers, 1.5; skin, 6.5; crop, 5.1; ceca, 7.8; and colon, 3.1. Campylobacter populations (mean log10 colony-forming units per gram of sample) found were feathers, 5.4; skin, 3.8; crop, 4.7; ceca, 7.3; and colon, 7.2. Coliform/E. coli populations observed were feathers, 6.4/6.0; skin, 5.3/4.9; crop, 4.3/3.7; ceca, 6.6/6.2; and colon, 5.8/5.3. Total aerobic bacterial populations found were feathers, 7.9; skin, 7.1; crop, 5.8; ceca, 6.8; and colon, 6.4. On a per gram basis, ceca and colon are the internal organs that if ruptured could cause the highest number of Campylobacter to be leaked onto the carcass. The crop also contained more Campylobacter per gram than did the skin, and if compromised may increase the numbers on the surface of the carcass. However, even with no contamination from an internal organ, a substantial population of Campylobacter is already resident on broiler skin as the carcass enters the early stages of processing.

Abattoirs↗

PubMed2000

Influence of flooring type during transport and holding on bacteria recovery from broiler carcass rinses before and after defeathering.

Four trials were conducted to determine whether conventional solid or elevated wire mesh flooring, during transport and holding of broilers prior to slaughter, influenced the number of bacteria recovered from feathered and defeathered carcasses. After 4 h off feed, 7-wk-old broilers were placed at commercial density into a modified commercial transport dump-coop on either fiberglass sheeting or 2.54x2.54 cm wire mesh flooring that allowed feces to fall through. Broilers were transported for 1 h and then held for 13 h under a covered shed before processing. Broilers were killed by electrocution, and the vents were plugged to prevent escape of feces. External carcass rinses were obtained twice (from the same carcass) from eight broilers per flooring treatment per trial, before scalding and defeathering and again after defeathering and removal of the head and feet. Greater numbers of total aerobes, coliforms, and Escherichia coli were recovered from feathered carcasses than from defeathered carcasses. Campylobacter count was also less for defeathered than feathered carcasses from the solid flooring treatment but did not significantly decrease following defeathering of carcasses from the wire flooring. The incidence of Campylobacter-positive carcasses was reduced following defeathering for both flooring treatments, but the percentage of Salmonellae-positive carcasses remained constant. Coliform (log10 6.20 vs. 5.63 cfu/mL of rinse) and E. coli (log10 5.93 vs. 5.36) counts in the feathered rinses were significantly higher for the solid flooring compared with wire flooring, respectively. After defeathering, the number of coliforms (log10 3.12) and E. coli (log10 2.91) recovered did not differ between flooring treatments. Aerobic plate count (log10 7.06 and 4.02), Campylobacter count (log10 2.49 and 1.80), and the incidence of Campylobacter-positive (44 and 11%) and Salmonellae-positive (52 and 50%) carcasses for feathered and defeathered rinses, respectively, did not differ between flooring treatments. These results indicate that although broilers transported and held on solid flooring had noticeably dirtier breast feathers and higher coliform and E. coli counts prior to scalding and defeathering, bacteria recovery from external carcass rinses did not differ between the solid and wire flooring treatments after defeathering.

Animals↗

PubMed2000

Physical, chemical, and microbiological changes in the ceca of broiler chickens subjected to incremental feed withdrawal.

Trials were conducted to determine the effect of feed withdrawal on the weight, pH, native bacterial flora, and the persistence of Salmonella typhimurium in the ceca of market-age broilers. Broilers were provided medicated or unmedicated feed and then were subjected to feed withdrawal for 0 to 24 h in transportation crates or on litter. After feed withdrawal, broilers were stunned, bled, scalded, and picked. One cecum from each bird was aseptically removed and weighed. The cecum was then blended in 20 mL of distilled water, and the pH of the blended suspension was measured. The number of total aerobes, Enterobacteriaceae, S. typhimurium, and lactic acid bacteria in the suspension were enumerated on the appropriate bacteriological media. Results indicated that up to 24 h of feed withdrawal produced no significant change in cecal weight and that cecal pH varied by up to 0.3 units during feed withdrawal. There were significant increases in the population of Enterobacteriaceae during feed withdrawal in Trials 2 and 3, and there was a significant increase in the population of cecal aerobes in Trial 3. Feed withdrawal produced significant decreases in the population of lactic acid bacteria in all trials, but no significant change in the population of S. typhimurium occurred during feed withdrawal. There were no significant differences in cecal weight, pH, native bacteria populations, or S. typhimurium populations between broilers that were subjected to feed withdrawal on litter or in crates. Findings indicate that feed withdrawal does not always effectively evacuate the contents of the ceca and that the ceca of broilers subjected to feed withdrawal can remain a source of foodborne bacterial pathogens.

Animal Feed↗

PubMed2000

Effect of electrical stimulation and polyphosphate marination on drip from early-harvested, individually quick-frozen chicken breast fillets.

Individual and combined effects of electrical stimulation and polyphosphate marination on drip and other quality attributes of early-harvested, individually quick-frozen chicken breast fillets were evaluated. Broiler chickens were slaughtered, half conventionally processed and half with electrical stimulation. Fillets were harvested 1 h postmortem and marinated in either NaCl solution or NaCl plus polyphosphate solution. Marinade absorption, pH, drip, cooking loss, and shear values were observed. Electrical stimulation had no direct effect on pH, cooking loss, or shear values, whereas polyphosphate increased pH and decreased cooking loss. Polyphosphate treatment caused fillets from unstimulated carcasses to absorb more marinade and yielded more drip that those from stimulated carcasses. Fillets from stimulated carcasses marinated in NaCl solution without polyphosphate yielded less drip than those from unstimulated carcasses. Polyphosphate reduced drip of fillets from unstimulated carcasses but not of those from stimulated carcasses. Results support previous reports indicating interactions between polyphosphates and processing parameters that can affect ultimate quality of poultry meat products.

Animals↗

PubMed1999

Effect of polyphosphate treatment and electrical stimulation on postchill changes in quality of broiler breast meat.

The objective of this study was to assess effects of treating electrically stimulated broiler forequarters with polyphosphates after various aging periods on quality. Ninety-six mixed sex broilers were electrically stunned and slaughtered. Half the carcasses were electrically stimulated during bleeding and half were not. Forequarters were harvested immediately after chilling and after 2, 4, and 6 h postchill. Left forequarters were marinated in salt solution and right forequarters in salt solution plus sodium tripolyphosphate. After marination, the quarters were cooked. Yield and meat pH were evaluated immediately after marinating; and color, yield, and cooking loss were evaluated after cooking. Electrical stimulation resulted in a decline in muscle pH for the 0 postchill group. The pH of muscles from unstimulated and stimulated carcasses from the remainder of the postchill times were equivalent. Phosphate treatment increased pH at all postchill times. Electrical stimulation of the marinated quarters increased cooking loss and decreased yield regardless of marinade composition. Both cooking loss and yield were superior for forequarters harvested at 0 or 2 h postchill compared to those harvested at 4 or 6 h postchill. The phosphate improved moisture binding regardless of electrical treatment or time of harvest. Color values of cooked muscles were unaffected by marination time, but the phosphate-treated muscles had higher b* (yellowness) values than controls. Shear values of unstimulated carcasses that received phosphate treatment were 35% greater than those that received no phosphate treatment. When the carcasses were electrically stimulated, the toughening effect of the phosphate was eliminated.

Animals↗

PubMed1999

Subcutaneous temperature profile, skin appearance, and picking efficiency of immersion and spray scalded broiler carcasses.

To compare immersion and spray scalding temperature profiles, thermocouples were positioned beneath the skin of broiler carcasses in eight separate locations. The locations were as follows: 1 and 2) the upper left and right breast, 3 and 4) middle of the left and right thigh, 5 and 6) beneath the left and right wing, 7) the lower back above the pygostyle, and 8) the upper back between the wings. Standard immersion scalding at 52 or 56.5 C for 2 min or a prototype spray scalder at 60, 65, or 70 C for 1 min were used to monitor s.c. temperature during scalding. Immersion scalding resulted in an exponential profile with the lower temperature having less temperature deviation for the monitored locations. Among sampling locations, the spray scald temperatures were divergent among locations and the highest temperatures were recorded when thermocouples were within the spray patterns. As with the immersion scalded carcasses, lower temperatures for the spray scalding demonstrated less deviation among the monitored locations and a closer grouping of the final temperatures. The only spray scald temperature tested at which s.c. temperatures approached those of the immersion scalded carcasses was 70 C. Additional carcasses were scalded, picked, and examined for skin appearance and picking efficiency. All carcasses spray scalded for 60 s had a "cooked appearance" when evaluated. When spray scald times were reduced to 30 s, skin appearance improved, but with the exception of the 70 C trial, picking efficiency was poorer.

Animals↗

PubMed1999

Subcutaneous feather tract denervation does not alter feather retention force ante- and postmortem in broilers.

To determine whether feather retention force (FRF) in 6-wk-old commercial broilers was influenced by the presence or absence of cutaneous innervation, nerve trunks for the pectoral and sternal feather tracts were severed unilaterally (left side) in Trial 1. In Trial 2, the sternal subcutaneous nerve trunk was severed either unilaterally (left or right side) or bilaterally. Four days postdenervation, FRF was determined bilaterally either antemortem (immediately prior to stunning) or 2 min after stunning and bleeding (postmortem). In Trial 1, the pectoral feather tract ante- and postmortem FRF values did not differ significantly for innervated or denervated tracts. In this trial, the sternal feather tract ante- and postmortem FRF values were 13% higher (44 g) for the denervated (left side) than for the innervated (right side) treatments. Partitioning this difference into the effects of sample side or innervation could not be attained because only the left side was denervated (left-denervation or right-innervated) in Trial 1. In Trial 2, both the left and right sternal feather tracts were represented in equal numbers for the innervated and denervated treatments, and there were no significant differences in FRF related to innervation, left and right side, or ante- and postmortem sample times. The presence or absence of cutaneous nerve innervation does not appear to influence FRF ante- or postmortem. This finding indicates that treatments disabling the central nervous system antemortem may lower FRF indirectly by altering cutaneous metabolism and therefore have been consistently unsuccessful in substantially altering postmortem FRF.

Animals↗