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Biomedical subjects

E T Moran

Publications and source records attributed to E T Moran.

At least 19 recordsLinked to original sources

Effect of glutamic acid on broilers given submarginal crude protein with adequate essential amino acids using feeds high and low in potassium.

Broiler males were examined for their response to feeds containing CP 1 to 2% below levels advocated by NRC (1994) and when supplemented with L-glutamic acid. Crude protein and glutamic acid treatments were imposed in starting, growing, and finishing feeds over 7 wk with K at high and low levels likely to occur in practice (0.80 vs 0.65 to 0.55%). All feeds were formulated to be isocaloric (3.20 kcal ME/g) and satisfy NRC (1994) essential amino acid (EAA) minimum requirements. Improved live weight gain occurred during the first 6 wk with supplementation of glutamic acid to the low CP feed but not when intact protein per se was used to increase CP. A similar advantage in growth was obtained from glutamic acid in response to its addition at equivalence of 1 to 2% CP as well as when dietary adjustments maintained low CP. Response to altered K could not be interpreted because of concurrent differences in glutamic acid and AMEn intakes. High glutamic acid levels did not decrease abdominal fat unless CP increased concurrently, whereas carcass back bruising and drumstick deformations were relieved by supplemental glutamic acid independent of CP. Increased weight gain from glutamic acid was only evident with drumsticks and debris that included the back when carcasses were cone-deboned. Supplemental glutamic acid is believed to improve the rate of connective tissue formation during rapid growth.

Amino Acids, Essential

Carcass yield and weep loss from fast-food cuts after processing broilers using extremes in stunning current and slush-ice chilling.

Six-week-old broilers were compared in yield and weep loss when stunned using either 25 or 125 mA current followed by slush-ice chilling where resultant carcasses were either held static for 4 h or subjected to 45 m of tumbling. Treatments were factorially arranged among the populations of 32 pens (24 birds per pen) that had been reared under common conditions. Tumbling increased chill water uptake, abdominal fat content, and yield of whole carcasses, whereas no differences occurred as a result of the stunning treatments. Carcasses were separated into a nine-piece cut immediately after chilling. All parts lost weight from weepage during the subsequent 24 h, and weep from total parts was greater when carcasses had been tumbled than held static. Keel portion breasts and drumsticks continued a weight advantage from water uptake with tumble chilling, but wings, thighs, and split breast lost this additional water and were similar to those respective parts static chilled. High stunning current led to an increased amount of keel portion breast, regardless of chilling treatment, with subsequent weep not being affected. Alterations in yield that occur because of chilling procedure are substantial and not equivalent among parts, whereas stunning has little impact and is focused on the breast.

Absorption

Lighting programs for broilers that reduce leg problems without loss of performance or yield.

This study tested the effects of light schedules on performance and yields of broiler chickens. In Experiment 1, light treatments during Days 1 to 49 of age were: 1) 23 h light (L):1 h dark (D); 2) 16L:8D;3) 16L: 3D:1L:4D; and 4) 16L:2D:1L:2D:1L:2D. In Experiment 2, Light Treatments 1 and 2 were the same as Treatments 1 and 4, respectively, in Experiment 1; 3) 23L:1D Days 1 to 7, 16L:8D Days 8 to 14, the light period was increased by 2 h/wk during Days 15 to 35, and 23L:1D Days 36 to 42; and 4) 23L:1D Days 1 to 7, 16L:8D Days 8 to 14, 16L:3D: 2L:3D Days 15 to 21, 16L:2D:4L:2D Days 22 to 28, 16L: 1D:6L:1D Days 29 to 35, and 23L:1D thereafter. In Experiment 1, BW was greater in Treatment 4 than Treatment 2 at 22 (708 vs 642 g) and 49 d (2,948 vs 2,797 g), percentage leg problems was lower in Treatments 2 to 4 (9, 10 and 6%, respectively) than in Treatment 1 (20%), and percentage Grade A was greater in Treatment 4 than Treatment 2 (60 vs 46%) at 49 d. In Experiment 2, BW was greater in Treatment 1 (692 g) than Treatments 3 (617 g) and 4 (620 g) at 21 d, and the incidence of tibial dyschondroplasia was lower in Treatment 2 (3.1%) than Treatment 3 (15.3%) at 42 d. There were no differences for mortality among treatments in either experiment.

Animals

Response of broiler strains differing in body fat to inadequate methionine: live performance and processing yields.

Ross x Arbor Acres (RxAA) and Steggles x Arbor (SxAA) chicks were given all nutrients as advocated by NRC (1984) except for methionine. Corn and soybean meal were the sole CP sources, and both strains were compared when feeds were adequate and deficient in methionine (0 to 3 wk, .65 vs .42% with 24.2% CP and 3.20 kcal AME/g; 3 to 6 wk, .54 vs .46% with 20.7% CP and 3.21 kcal AME; and 6 to 8 wk, .35 vs .30% with 17.8% CP and 3.19 kcal AME, respectively). Cystine exceeded NRC (1984) recommendation with all feeds. Live weights of RxAA broilers were heavier throughout the experiment, but SxAA had the advantage in feed conversion. Adverse effects of low methionine on weight gain were apparent only during the first 6 wk, and SxAA responded to the deficiency more than RxAA from 0 to 3 wk. The SxAA birds had less abdominal fat when processed at both 6 and 8 wk than RxAA. Low methionine increased fat proportions at 6 wk but not at 8 wk. Percentage chilled carcass yield without abdominal fat was similar for each strain and decreased as a result of low methionine at both ages. Low methionine also reduced proportions of skinless boneless breast meat but only at 6 wk and particularly in SxAA birds. The increased ability of RxAA birds to deposit fat enabled additional feed intake, in turn, minimizing repercussion of inadequate methionine.

Adipose Tissue

Continuous submarginal phosphorus with broilers and the effect of preslaughter transportation: carcass defects, further-processing yields, and tibia-femur integrity.

Broiler males were given a series of feeds from 0 to 8 wk having all nutrients advocated by the NRC (1984) and were compared with birds offered feeds with available P continuously 10% below recommendation. At termination, birds in pens were divided for cooping, and coops were either subjected to 6 h of truck transportation and 4 h of preslaughter rest or held stationary for 10 h. High summer temperatures existed throughout experimentation, and low dietary P reduced body weight gain through the first 6 wk, whereas an advantage in feed conversion and mortality occurred from 6 to 8 wk. Weight loss increased when birds were subjected to transportation, regardless of P nutriture, and a portion of the loss was recovered during processing as gain in relative chilled carcass yield. Proportions of abdominal fat and skinless boneless meats from chilled carcasses were unaltered, regardless of treatment. Increased incidence of deformed drumsticks occurred because of low P as did drumstick bruising, which was further accentuated when birds had been transported. Back bruising was prominent when P was adequate and birds were held stationary, whereas the converse occurred with transportation. Tibia length was reduced as a consequence of low P, whereas the femur suffered in terms of decreased mineral density at the epiphyses and resistance to Instron-applied stress. Although transportation in itself did not affect any bone measurement, inadequate P weakened the skeleton to increase likelihood of carcass defects during preslaughter stress.

Animal Husbandry

Lack of interactions between dietary lysine or strain cross and photoschedule for male broiler performance and carcass yield.

The purpose of this study was to test interactions of dietary lysine or strain crosses provided increased lysine with photoschedule on broiler performance and carcass quality. In Experiment 1, treatments were factorially arranged as two lysine levels [control grower and finisher (NRC, 1984) or control grower and finisher plus .15% L-lysine HCl] and two photoschedules [23 h light (L):1 h dark (D) or 14L:10D]. All birds received a control starter feed and dietary treatments were initiated at 22 d of age. In Experiment 2, treatments were factorially arranged as two strain crosses [Peterson x Arbor Acres (PAA) or Ross x Ross (RR)] and two photoschedules (23L or 16L). All birds received standard starter and standard grower and finisher plus .15% L-lysine HCl. There were no lysine by photoschedule or strain cross by photoschedule interactions in this study. The high-lysine diet increased BW, improved feed efficiency, increased lean carcass weight and yield of breast meat, and decreased abdominal fat and yield of thighs. The PAA strain cross had better feed conversion, fewer Grade A carcasses, more back bruises and breast blisters, greater yield of wings and drumsticks, and less yield of breast meat than RR. The 23L had greater BW, better feed efficiency, fewer breast blisters, greater carcass weight (Experiment 1), more abdominal fat (Experiment 2), lower yield of wings (Experiment 1), drumsticks, and thighs, and greater yield of breast meat than the treatments with shorter photoschedules. Increased dietary lysine did not compensate for decreased breast meat yield associated with 14L (Experiment 1).

Animals

Lysine supplementation of low-protein diets for broiler breeder males.

Two experiments were conducted to assess the impact of supplemental L-lysine HCl on N balance in broiler breeder males fed 8% CP corn-based diets (3,220 kcal MEn/kg; .15% supplemental DL-methionine; .24% basal lysine). In Experiment 1, 78-wk-old males were fed the basal diet with either 0, .05, .10, or .25% supplemental L-lysine HCl. Birds were allowed to eat for 1 h each day to a maximum intake of 325 kcal MEn per bird per day. Total excreta were collected for 8 consecutive days. Nitrogen retention and balance were not different among treatments (P greater than .05) and responded neither linearly nor quadratically to dietary lysine level. Removing the variation due to differences in N intake with analysis of covariance did not change the response. In Experiment 2, 30-wk-old males were fed the same basal diet with supplemental lysine levels of 0, .15, .30, .45, .60, and .75% L-lysine HCl for 5 consecutive days. Nitrogen balance and retention were different among diets, and both variates responded linearly to increases in dietary lysine. Removing the variation due to differences in N intake removed treatment effects, however, suggesting that at least part of the difference was the result of variable levels of intake. Regression analysis indicated a significant linear increase in both N balance and retention with increasing dietary lysine level (R2 = .82). These results suggest that young broiler breeder males can make better use of the protein of corn if supplemental lysine is provided. However, older birds do not demonstrate improved N balance as a result of supplemental dietary lysine.

Analysis of Variance

Strain-cross response of heavy male broilers to dietary lysine in the finisher feed: live performance and further-processing yields.

A total of 2,560 male broilers from eight commercial strain-crosses were growth to 42 days of age on common starter (1 to 21 days; 23.06% CP, 3,217 kcal ME/kg) and grower (21 to 42 days; 20.14% CP, 3,224 kcal ME/kg) rations. All strain-crossed subsequently received finisher diets (17.95% CP; 3,186 kcal ME/kg) containing either .85 or .95% lysine from 42 to 53 days of age. Further-processing yields were determined on 12 birds per pen, selected within +/- 10% of the replicated pen (8 pens per strain-cross, 40 birds per pen) average weight. The strain-crosses differed significantly (P less than .05) in BW (1, 21, 42, and 53 days), weight gain (WG), feed:gain ratio (1 to 21 and 21 to 42 days), and mortality rate (1 to 21 days). The lysine effect during the finisher period was significant for 53-day BW and WG from 1 to 53 days. Chilled carcass (CC) and abdominal fat (AF) weights, CC yield (percentage, excluding AF), AF yield (percentage of CC weight), Pectoralis major, Pectoralis minor, total deboned breast (TDB), drumstick, thigh, wing, and residual "cage" and skin yields varied among the strain-crosses. A significant weight and yield response to lysine was observed for TDB. Variation observed among strain-cross in live performance, further-processing yields, and response to additional lysine is attributed to differences in rate of growth and degree of maturity at market age. Furthermore, the lysine requirement during the finisher period for optimum breast meat yield may be higher than that recommended by the National Research Council in 1984.

Adipose Tissue

Response of male turkeys hatched from first-cycle and force-molted breeder hens to a regimen providing progressive feeds by weight and the value of increased lysine prior to marketing.

Male poults originating from 41- and 85-wk-old Nicholas Large White breeder turkey hens were compared using a six-feed system provided on the basis of weight. Each source of poult was compared further in its response to lysine at .65 and .80% in the final feed (14.5% CP and 3.40 kcal AMEn/g) before marketing at 18 wk of age. Poults from 85-wk-old hens were heavier at placement than those from 41-wk-old hens. Equalization of body weights occurred once the allotment of starting feed had been consumed and for the most part remained similar thereafter. Increasing lysine content of the final feed did not improve body weight of both sources of birds at marketing (P < .13). Feed conversions included accrued mortality, and treatment differences were not apparent. Commercial processing of the flock and measurements on sample birds indicated no ready differences in chilled carcass yield nor proportions of parts occurred among treatments. The overall effects of breeder age with the progeny were negligible, and the .65% level of lysine that presently serves as the 1984 National Research Council minimum requirement when associated with 14% CP and 3.30 kcal/g appears to be adequate for the Nicholas strain of turkey from 16 to 18 wk of age.

Animal Feed

Performance of broiler breeder males given low protein feed.

One hundred and eight 24-wk-old broiler breeder males were arranged into 18 groups of six birds of equal average BW. Six groups were killed for carcass evaluation at 24 wk of age; the other 12 groups were divided between two dietary treatments. One treatment was a typical breeder-recommended male broiler breeder ration (standard, or ST; 12% CP, 3,160 kcal ME/kg), whereas the other was a low-protein, corn-based diet (all corn, or AC; 8% CP, 3,220 kcal ME/kg) formulated to approximate minimum amino acid requirements for positive nitrogen balance. All birds were fed at a rate of 325 kcal ME/day per bird to 68 wk of age. Body weight, semen volume, and sperm concentration were evaluated weekly. All birds remaining at 68 wk were killed for carcass evaluation. Feed and age effects on BW were highly significant (P less than .001). However, birds did not respond similarly to treatments with increasing age. Birds fed ST were heavier and surpassed breeder-recommended BW by 38 wk of age, whereas birds given AC were lighter and remained below breeder-recommended weights throughout the study. Semen production was measured by semen volume, sperm concentration, total sperm yield, and proportion of males producing semen; values were similar for treatments at all ages. Birds given the AC feed had more carcass fat than ST-fed birds at 68 wk of age, but ST-fed birds had the same proportion of fat at 68 wk as birds killed at 24 wk. Results suggest that the amino acid levels provided by the AC diet were less than adequate for optimal BW gain, but adequate for semen production.

Amino Acids

Cup versus tray excreta collections in metabolizable energy assays.

A cup-and-harness excreta collection device was compared with a traditional tray-type excreta collection method in an ME study. The AME and AMEn were determined for two different diets (12% CP, 3,160 kcal ME/kg, and 23% CP, 3,160 kcal/kg). Twenty-four broiler breeder males were used with methods and diets arranged in a 2 x 2 factorial design. A standard AME feeding and collection protocol was followed. There were no differences in any measured variables attributable to method of excreta collection. However, dietary differences were readily apparent with both methods. Data suggest less variability in collection-related variables for the cup collection procedure. Ease and rapidity of changing containers makes the cup collection method a viable alternative when large numbers of birds are involved. Excreta can be stored in the same containers in which it is collected. Additionally, contamination of excreta with feathers, feed, scale, and vomit are avoided.

Animals

Influence of whey and probiotic-supplemented withdrawal feed on the retention of Salmonella intubated into market age broilers.

Broilers (6 wk of age) were crop-intubated with a nalidixic acid-resistant strain of Salmonella typhimurium and given four withdrawal feeds: 1) control feed (corn and soybean meal base, 18% CP and 3,200 kcal ME/kg); 2) control plus 5% whey (61% lactose); 3) control plus probiotic (6.8 x 10(6) cfu of Bifidobacterium pseudolongum, Bifidobacterium thermophilium, and Lactobacillus acidophilus); and 4) control plus 5% whey plus probiotic. In Experiment 1, male broilers received 9.8 x 10(7) cfu of S. typhimurium per bird midway through a 20-h fast. The withdrawal feeds were continuously offered through a subsequent period of 6 to 7 days. Live performance of broilers during this time was similar among treatments. Ceca from birds consuming whey were significantly (P less than .05) increased in weight and distended with gas. Recovery of S. typhimurium from the ceca was low with all treatments, and the effects of whey or probiotic at reducing the organism could not be determined. In Experiment 2, female broilers received the same four experimental feeds for 48 h. Salmonella typhimurium was intubated 24 h after feed access (1.2 x 10(7) cfu per bird). Again, no differences (P greater than .05) in performance occurred, but the inclusion of whey led to increased cecal weight and size (P less than .05). Large numbers of S. typhimurium were recovered from the ceca 24 h after intubation, but the levels were similar among treatments. Whey and probiotic in the withdrawal feed did not appear to affect the Salmonella level in ceca when the organism was consumed prior to marketing.

Animal Feed

Effects of egg weight, glucose administration at hatch, and delayed access to feed and water on the poult at 2 weeks of age.

Eggs from a 42-wk-old small-type turkey breeder flock were weighed and divided into heavy, medium, and light categories relative to the population average. Poults from each category were sexed, then given .5 mL of 50% glucose in saline by either crop intubation (CI) or subcutaneous injection at the neck (SC). Controls did not receive glucose. One-half of the birds from each treatment were immediately given access to feed and water in pens of brooder batteries; the remainder were held 3 days in transportation boxes before placement in other pens of the same batteries. Poult weight at hatching and 3 days later paralleled egg weight. Improvement in 3 day BW occurred after glucose administration and was greater by SC than CI, but these advantages were only apparent when feed and water had been accessible during the interim. Egg weight effects on BW and gain persisted to 2 wk of age, as did the depression from delayed nutrient access; however, the advantage from glucose with poults having early access to nutrition disappeared. Alterations in the proximate compositions of livers and carcasses among treatments were small. Total mortality increased with egg weight when poults received feed and water early after hatching, while the converse occurred when delayed. Deaths were not altered by either glucose or fasting (P greater than .05).

Administration, Oral

Effects of posthatch glucose on poults fed and fasted during yolk sac depletion.

The advantage of glucose administration after hatching was examined in terms of poult performance and body changes 3 days after administration. A .5-mL dose of 50% glucose in saline was either subcutaneously (sc) injected in the neck or intubated into the crop. Controls did not receive glucose nor were they handled. Controls and poults given glucose were divided into two groups and either brooded with feed and water or kept in transportation boxes and fasted. Poults that were fasted lost weight, and glucose treatments did not alter this loss; however, access to feed and water led to a gain in weight. Those poults given glucose had greater weight gains and feed consumption than controls. Liver, yolk sac, and carcass contained increased moisture in response to glucose when feed and water had been provided, whereas only the carcass expressed this change when the birds were fasted. Most changes to glucose were greater from sc than oral dosing, and neither egg weight of origin nor sex influenced the extent of poult response.

Administration, Oral

Metabolic changes in pectoral muscle and liver of turkey embryos in relation to hatching: influence of glucose and antibiotic-treatment of eggs.

Small type turkey eggs were pressure differential dipped in an antibiotic solution (spectinomycin 3,000 ppm) with or without glucose (10%) and incubated. Pectoral muscle and liver samples taken from the embryos at the knocking, pipping, and posthatch stages of development were studied. Muscle glycogen decreased between pipping and posthatch. Liver glycogen decreased progressively between knocking and posthatch. Whereas liver free fatty acids decreased as the embryo completed the hatching process, muscle levels were less subject to change. Providing the embryo with antibiotic plus glucose improved overall glycogen in both tissues and reduced muscle lactate. Results from treatment with antibiotic alone resembled those in the first treatment with regard to liver glycogen and muscle lactate but to a lesser degree. Results support the hypothesis of an extensive muscle involvement in the hatching process and need for glucose through the perihatch period.

Animals

Subcutaneous glucose is more advantageous in establishing the posthatch poult than oral administration.

Poults have been shown to have low carbohydrate reserve after hatching, and glucose at this time improves early performance. Present experimentation examined the effects of .5 mL of 50% glucose in saline 2 h after subcutaneous injection (s.c.) at the base of the head or given as an oral gavage. Timing of administration and slaughter corresponded to when poults would encounter antibiotic-vitamin injection at the hatchery and the subsequent stress of transportation. Live weight after treatments was greater for poults given s.c. glucose than those untreated, whereas oral dosing led to a loss in weight. This weight loss could be wholly attributed to decreased carcass moisture. The s.c. glucose increased yolk sac resorption, and s.c. and oral glucose improved accretion of crude protein and ether extract by the yolk sac and liver-free carcass. Liver glycogen and blood glucose increased to a greater extent from s.c. than from oral glucose. Loss of body water after oral glucose and the poults' reduced efficacy in improving carbohydrate status might be attributed to an immature intestine.

Administration, Oral