Biomedical subjects

J Brake

Publications and source records attributed to J Brake.

At least 19 recordsLinked to original sources

PubMed1995

Relationship of sex, strain, and body weight to carcass yield and offal production in turkeys.

Three strains of male and female market turkeys (British United Turkeys, Hybrid, and Nicholas) were grown under commercial contract production conditions and slaughtered at a range of BW (4,200 to 17,640 g) and age (13 to 22 wk) that covers the range of commercial market weights in use at the time of the study. During processing, the weight of blood, feathers, head, neck, feet plus shanks, heart, liver, gizzard, lungs, gastrointestinal tract, water uptake, hot and chilled carcass with fat pad, fat pad alone, tail, wings, drumsticks, thigh meat, Pectoralis major, Pectoralis minor, scapula meat, lower back, upper back with ribs, breast skin, thigh skin, thigh bone, and hind half (legs, thighs, and saddle) were determined. The data were subjected to least squares analyses using models that included strain and sex effects relative to live BW. Significant differences in yield between the sexes but not among strains were found for feet plus shanks, gizzard, hot and chilled carcass with fat pad, and scapula meat. Similarly, significant differences in yield among strains but not between sexes alone were found for blood, feathers, heart, and hind half. The relationships of live BW with all other variables showed both strain and sex differences in yield. Whereas whole carcass yield as a function of BW was affected by sex alone, most other components varied by both sex and strain. Thus, choice of strain, sex, and age at slaughter affect the projected production of edible carcass and offal components.

Animals↗

PubMed1995

Effects of strain and rearing dietary regimens on brown-egg pullet growth and strain, rearing dietary regimens, density, and feeder space effects on subsequent laying performance.

The objective of this experiment was to compare the growth and development of two brown-egg strains when grown on three different dietary regimens, i.e., a "normal" step-down protein (SDP) regimen, a step-up protein regimen with a low energy starter (SUPLES), and a step-up protein regimen with a high energy starter (SUPHES). The SUPLES and SUPHES feeding regimens resulted in significantly lower BW and feed conversion, shorter sternum length, and lower tibial breaking strength than the SDP regimen. The weights of the liver, spleen, and fat pad were not different among the three regimens. The high energy starter in the SUPHES regimen significantly reduced FC below that obtained with the SUPLES program. The SUPHES regimen significantly reduced total feed cost compared with the other two feeding regimens. Both step-up protein regimens reduced total protein, energy, Ca, P, lysine, and sulfur amino acid consumption. Because tibial breaking strength was also reduced by the step-up protein regimens, the data suggest that the levels of dietary Ca and P should be increased with these programs to compensate for the reduced consumption associated with them.

Animal Feed↗

PubMed1994

A harness and computer system to facilitate automated body temperature data collection in heat-stressed broilers.

An easy-to-use, low-cost system was developed that permitted nearly continuous, automated core body temperature (Tc) readings on 7-wk-old male broiler chickens via direct computer linkage to thermistor probes held in place by a specially designed harness. Elevated Tc was noted in heat stress studies following the replacement of expelled temperature probes in some hyperthermic birds. To demonstrate the usefulness of the data collection system described herein, three treatments with three to four birds per treatment were used to examine this observation. Birds were designated as handled only (HAN), handled to remove and replace the temperature probe (RPL), or left as nonhandled controls (CON). Treatments had no effect on subsequent Tc in experiments when the thermoregulatory capacity of the birds was not challenged. However, when the birds were sufficiently challenged, Tc of HAN and RPL birds increased within 4 min of the initiation of handling and remained above baseline for up to 45 min. The Tc of CON birds in that trial also increased, but to a smaller degree, within 5 min and remained above baseline for up to 20 min. This study indicates that Tc of hyperthermic birds can be superelevated by simulated manual placement of cloacal temperature probes and that fixed probes connected to an automated data monitoring and collection system is a relatively simple way to avoid this problem.

Animals↗

PubMed1994

Effect of age and presence of perches during rearing on tonic immobility fear reactions of broiler breeder pullets.

Broiler breeders were housed in pens in an all-litter house with an 8-h photoperiod from hatching to 20 wk of age. They were reared either in the presence or absence of perches (7 cm per bird) and on either a 14% or a 17% CP diet. The duration of the tonic immobility (TI) fear response was measured in 15- and in 20-wk-old birds; each pullet was tested individually and once only. There was an apparent age-related increase in the duration of TI, which was attenuated by the provision of perches during rearing. The results are discussed in terms of maturational and environmental influences on the development and alleviation of fear.

Age Factors↗

PubMed1994

Relationship between shell porosity, shell thickness, egg weight loss, and embryonic development in Japanese quail eggs.

Japanese quail eggs that hatched (H) or pipped (PIP) exhibited less weight loss through 15 d of incubation than did eggs that died late (LD), whereas eggs containing early dead (ED) embryos exhibited the greatest weight loss. The pore concentration at the large end of each egg was greatest in H eggs when compared with all other types. The pore concentration at the equator was greatest in H eggs and least in the eggs of the ED embryos. All other egg types lay statistically between these two types with regard to equator porosity. The small end pore concentration was similar in H, INF, and LD eggs and in the LD, PIP, and ED eggs. The least number was exhibited by the ED eggs and most by the H eggs. The thinnest shells at the small end were exhibited by H eggs, whereas thicker small end shells were exhibited by ED, LD, and PIP egg types. No differences were observed at the large end or equator. The data suggest that ED eggs exhibit excessive weight loss even though shell porosity was lower and shell thickness was similar to other egg types. This suggests that some functional component of the egg such as the shell membrane or albumen may contribute to this excessive weight loss. A similar statement can be made for LD eggs, which experienced greater weight loss through 15 d than did PIP or H eggs.

Animals↗

PubMed1993

Exclusion of broiler breeder females from male feeders with a male only grill. 1. Behavioral and technical aspects of design and development.

A series of experiments was conducted in order to develop a feeder grill that would allow broiler breeder males, but not females, to eat. Females are typically excluded from male feeders by increasing the height of the feeder. However, male feeder heights that exclude most females increase the time required for males to consume a given amount of feed 19 to 60%. Typical male feeder height from floor to feeder pan lip in commercial practice is 55 cm, which is about the distance from floor to the head of the male in an erect posture. Females measure about 40 cm in an erect posture. Because the necks of males (8.0 cm) are longer than those of females (6.3 cm), the lip of male feeder pans was extended horizontally 12.7 cm with a wire mesh on the assumption that females could not stretch their necks enough to reach the feed. However, the females learned quickly to perch on the extended lip and eat. Total exclusion of females from the male feeder, regardless of feeder height, was achieved by placing a horizontal upper mesh 5.6 to 10.2 cm above the extended lip, and connecting the upper mesh to the lower extended lip of the feeder with vertical bars spaced 5.1 cm apart. The horizontal upper mesh prevented perching by females and the 5.1-cm spacing of the vertical bars allowed males but not females to reach the feed by inserting their heads and necks up to their shoulders.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed1993

Relative bioavailability of L-ascorbyl-2-polyphosphate in broiler chickens.

Broiler chick diets and drinking water were supplemented with two sources of vitamin C: crystalline L-ascorbic acid (AsA) or L-ascorbyl-2-polyphosphate (APP) to provide 0, 25, 50, 100, 200, 400, 800, 1,600, and 3,200 ppm (mg/kg) AsA. The bioavailability of APP relative to AsA, as estimated by the change in plasma AsA concentration, was evaluated during 24-h periods of supplementation. When provided in the feed, no differences in dietary AsA content were attributed to vitamin source. In contrast, APP administration at 25 and 50 ppm, resulted in higher (P < .001) AsA values in drinking water when compared with AsA supplementation. Plasma AsA values were elevated (P < .05) above baseline when either AsA or APP were supplemented in the feed or water at a level of 400 ppm or greater. Plasma AsA concentrations, following supplementation of the diets, were higher (P < .05) in AsA-treated (800 ppm) chicks when compared with APP-supplemented chicks. During water supplementation, AsA (800 ppm) and APP (3,200 ppm) administration resulted in higher plasma AsA values when compared with their alternate vitamin source. At all other levels of water supplementation, no differences in plasma AsA were associated with vitamin source. The absence of a consistent difference in plasma AsA, relative to vitamin source, suggests that the isolated differences observed may be due to chance. It was concluded that APP was of similar bioavailability to that of AsA, as estimated by the ability to elevate plasma AsA concentrations in broiler chicks.

Animals↗

PubMed1992

Zinc-induced molt: evidence for a direct inhibitory effect on granulosa cell steroidogenesis.

Results from previous studies indicate that the use of dietary zinc may provide an effective means to initiate an induced molt in laying hens. Although much evidence indicates that high concentrations of zinc (10,000 to 20,000 ppm) cause the cessation of lay primarily by depressing feed intake, recent data suggest that lower concentrations (2,800 ppm) in a calcium-deficient diet may act via a direct action on the ovary. Therefore, a series of in vitro studies was conducted to evaluate whether zinc can affect granulosa cell progesterone production. Incubation of granulosa cells from the largest preovulatory (F1) follicle with zinc as zinc sulfate (.1 to 10 microM) had no effect on basal progesterone production. By contrast, ovine luteinizing hormone-stimulated progesterone production was inhibited (P less than .05) in a dose-related fashion by zinc in both the sulfate and acetate forms (1 to 10 microM). Furthermore, zinc attenuated oLH- and forskolin-induced cyclic adenosine monophosphate (cAMP) formation, and inhibited 8-bromo-cAMP- and calcium ionophore (A23187)-induced progesterone production. Such results indicate both pre- and post-cAMP sites of action for zinc's inhibitory actions on progesterone production in F1 granulosa cells. Finally, ovine follicle-stimulating hormone-stimulated cAMP accumulation and progesterone production in granulosa cells collected from 9- to 12-mm follicles (a stage of development representing the early, rapid growth phase) were suppressed (P less than .05) by co-incubation of cells with zinc.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Methyl-3-isobutylxanthine↗

PubMed1992

Molt induced by dietary zinc in a low-calcium diet.

Three experiments were designed to test the hypothesis that zinc has a specific effect independent of anorexia during induction of molt. In Experiment 1, hens were fed a low-calcium (.08%) basal molt diet to which was added 0, 110, 620, or 1,120 mg/kg (ppm) zinc as zinc sulfate heptahydrate (ZnSO4.7H2O) for 7 days and 0, 1, 400, 2,800, or 4,200 ppm zinc, respectively, for the following 14 days. In Experiment 2, hens were provided ad libitum access to the low-calcium basal molt diet with 2,800 ppm added zinc for 14 days during which a paired control hen received a similar amount of the low-calcium basal molt diet. In Experiment 3, hens were fed the low-calcium basal molt diet on a restricted basis amended with either 0 or 2,800 ppm zinc on a restricted basis for 10 days. In Experiment 1, all hens that consumed zinc had significantly fewer days to last oviposition as compared with control hens, and this occurred without significant differences in body weight or feed consumption for the lowest zinc group. When compared with the control group, higher levels of zinc did decrease body weight and feed consumption. In Experiment 2, the hens consuming the diet with 2,800 ppm zinc (Zn2800) reached last oviposition significantly sooner than control hens, although the Zn2800 hens actually consumed more feed. In Experiment 3, the Zn2800 hens lost more body weight than control hens due partially to earlier reproductive tract regression. Serum luteinizing hormone was increased in the Zn2800 hens.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

A mathematical model for estimation of broiler egg weight loss from physical dimensions and air cell size during incubation.

A formula was derived that will enable hatcheries to estimate percentage weight loss using the width, length, and air cell diameter of the egg. The formula was derived by fitting an equation to the shape of the egg and using this shape equation to obtain estimates of air cell volume and egg volume. These estimates were coupled with the principle that weight = density x volume to give the final formula as a function of air cell diameter divided by egg width. The formula was tested by comparing its estimated values with measured values from eggs set at two different incubation conditions chosen to cover the range of conditions found in commercial hatcheries. As the day of transfer approached, embryo size and distortion of the air cell caused inaccuracies to develop in the results of this equation. However, data suggest that the equation can be used to calculate percentage weight loss until approximately the 16th day of incubation.

Animals↗

PubMed1992

Research note: maintenance of duodenum weight during a molt induced by dietary zinc in a low-calcium diet.

The duodenal loop was excised from hens that had been induced to molt by a low-calcium diet containing 2,800 ppm zinc in the form of zinc sulfate heptahydrate. This was compared to that of hens pair-fed a layer diet. In Experiment 1, hens exhibited an increased duodenum weight after receiving the zinc diet for 14 days but no differences remained 14 days later. In Experiment 2, increased duodenum weight was noted after 4 days on the zinc diet and this persisted through 10 days. This greater tissue weight was observed whether expressed on a wet or dry weight basis. Thus, there was a persistency of tissue mass. The duodenum does not regress during a zinc-induced molt as it does during a fast-induced molt.

Animals↗

PubMed1991

Research note: lack of effect of a live yeast culture on broiler breeder and progeny performance.

Broiler breeders were fed corn and soybean diets containing 0, .1, .3, or .5% of a live yeast culture from 21 through 64 wk of age. In addition to assessing various breeder reproductive variables, chicks from each treatment level were grown to 17 days of age at 30, 40, 50, and 60 wk of breeder age. With the exception of a significant decrease in fertility at the .3% level, there were no effects on broiler breeder or progeny performance.

Animals↗

PubMed1991

Hydrogen peroxide as an alternative hatching egg disinfectant.

The present study examined the effectiveness of H2O2 at different concentrations to disinfect broiler hatching eggshell surfaces and to maintain hatching potential. Under pure culture conditions, .50% H2O2 yielded over a 6 log kill in 30 s of three potential eggshell bacterial contaminants. Under higher H2O2 demands, such as occurs on eggshell surfaces, H2O2 concentrations of 5% (vol/vol) were required to disinfect the shell surfaces (approximately 5 log reduction). Hatchability of fertile eggs from a 44-wk-old flock was significantly increased by 2% following spraying 5% H2O2 in comparison to untreated controls. Level of contaminated eggs and "early-dead" embryos were significantly reduced in the H2O2-treated eggs. In comparison with formaldehyde fumigation, no significant difference in hatchability due to H2O2 treatment was detected in eggs from a 30- or 56-wk-old flock. Eggshell permeability, as measured by egg moisture loss in an incubator, was not significantly affected by H2O2 (5%) or formaldehyde fumigation when compared with untreated or water-sprayed control eggs. These results demonstrated that H2O2 compared favorably to formaldehyde as a hatching egg disinfectant without adversely affecting hatching potential. Under some conditions, H2O2 actually improved the hatching potential of fertile broiler eggs compared with hatchability of untreated eggs.

Animals↗

PubMed1991

Retention of larvicidal activity after feeding cyromazine (Larvadex) for the initial 20 weeks of life of single comb White Leghorn layers.

Single Comb White Leghorn pullets were fed cyromazine (Larvadex) continuously at levels of 0, 25, 250, and 1,000 mg/kg diet (ppm) from hatch to 20 wk of age. Fresh manure was bioassayed for toxicity to housefly, Musca domestica, larvae beginning at the 6th wk after removal of cyromazine from the feed, and at weekly intervals thereafter. At 6 wk after removal of the feed additive there was 51.6% fly mortality at 25 ppm, 75.7% at 250 ppm, and 86.5% at 1,000 ppm relative to the 0-ppm control. Fly mortality decreased to less than 10.7% mortality at 13 and 15 wk postremoval for hens grown on 25 ppm and 250 ppm cyromazine, respectively. Hens grown on 1,000 ppm cyromazine produced manure that was still exhibiting more than 50% fly mortality 20 wk after removal of the feed additive. These data demonstrate retention of cyromazine in laying hens for up to 20 wk after feeding the chemical to the birds at 5 to 200 times greater than the maximum recommended rate for the initial 20 wk of life.

Administration, Oral↗

PubMed1990

Effect of feeding diets containing corn treated with a commercial mold inhibitor (Myco Curb) on broiler-breeder performance.

Corn purchased from commercial sources was split at delivery and was left untreated or treated with a commercial mold inhibitor. Feed was prepared from these two lots of corn from within 1 wk to as much as 20 wk after delivery over the course of two experiments. There was evidence of reduced mold growth due to the mold inhibitor, particularly in the second experiment where initial mold populations were higher. Mycotoxins were evident in feed samples, regardless of the corn treatment. There was no significant effect from the treatment of corn on growth, livability, egg production, feed conversion, egg weight, or the eggshell quality of broiler breeders. Treatment of corn with a mold inhibitor significantly increased hatchability of fertile eggs in both experiments. Fertility was also significantly improved in the second experiment. These data suggest that using corn treated with a mold inhibitor results in significantly better hatchability in broiler breeders than untreated corn, although there were no observed differences in the incidence of mycotoxins in the samples taken.

Animal Feed↗

PubMed1990

Effect of a quaternary ammonium sanitizer for hatching eggs on their contamination, permeability, water loss, and hatchability.

The present study tested the biocidal effectiveness of the quaternary ammonium Hatching Egg Sanitizer Spray (HES Spray) in disinfecting broiler hatching eggs and in terms of its effects on eggshell permeability, water loss, and hatchability. The application of HES at a 1.5% or a 3.0% concentration resulted in significant reductions in the total aerobic counts on the egg surface of 98.1% and 99.9%, respectively, within 30 min of application. Molds and yeasts were significantly reduced by 3.0% HES at 14 days of incubation. Significant reductions in total aerobic counts on the egg surface due to 1.5% and 3.0% HES were also observed on eggs that were allowed to "sweat." The 3.0% HES concentration also reduced coliforms on egg surfaces. Hatchability of fertile eggs from a 32-wk-old flock was significantly increased, over 6.0%, by spraying 1.5% or 3.0% HES in comparison to controls that were not sprayed, with no significant difference in hatchability due to treatment observed in eggs from flocks that were 36, 42, 46, or 62 wk of age. This change in hatchability associated with spraying HES may be due to a change in eggshell permeability (respiration) caused by an interaction of HES with the eggshell cuticle.

Animals↗

PubMed1990

Effect of four levels of added fat on broiler breeder performance.

Broiler breeders were fed corn-soybean diets and reared under 8 h of incandescent light. Birds were photostimulated with a mixture of incandescent light and daylight at 20 wk of age. Corn-soybean breeder diets with 0, 2, 4, and 6% added poultry fat were fed from 24 to 64 wk of age. Daily feed allocations were adjusted to provide comparable calculated protein intake at peak egg production; calculated ME intake was 413, 437, 461, and 484 kcal per bird per day for the 0, 2, 4, and 6% added fat diets, respectively. Feed was gradually reduced such that ME intake reached 400, 415, 429, and 422 kcal ME per bird per day from 57 to 64 wk of age for the respective diets. When compared with 0%, all levels of added fat significantly increased egg production and feed conversion. Fertility was increased significantly with the 4% added fat when compared with fertility at 2%; fertility with 0 or 6% added fat was intermediate. Female body weight increased in a dose-related manner in response to added fat. Chicks per hen was maximized at 4% added fat. Taken together, the data are interpreted to mean that 4% added fat is near the optimum for broiler breeders.

Animal Feed↗

PubMed1989

Selenium effects on glutathione peroxidase and the immune response of stressed calves challenged with Pasteurella hemolytica.

The present study was conducted to determine whether a marginal Se deficiency affects health, blood characteristics and the immune response of calves subjected to stresses associated with weaning, shipping (332 km) and Pasteurella hemolytica inoculation. Treatments were 1) -Se, 2) -Se/P. hemolytica, 3) +Se (.1 mg Se/kg feed) and 4) +Se/P. hemolytica. Previous Se intake was controlled; dams of -Se calves were fed diets marginally deficient in Se (.03 to .05 mg/kg), whereas dams of +Se calves received a s.c. injection of 30 mg Se (as sodium selenite) every 60 d. Calves were inoculated with P. hemolytica intratracheally on d 3 following weaning and transport. Inoculation with P. hemolytica increased (P less than .05) body temperatures, platelet counts, serum IgM concentrations and serum antibody titers and decreased serum albumin concentrations at 4 to 7 d postinoculation. Weight gains for the 21-d study were not affected by Se status, although whole blood and plasma glutathione peroxidase (GSH-Px) were higher (P less than .05) for +Se calves. Plasma GSH-Px increased (P less than .01) in calves showing signs of morbidity. Increases in plasma GSH-Px were correlated positively with body temperature. Serum IgM concentrations were higher (P less than .05) in +Se calves on d 17, but Se-supplemented calves had lower (P less than .05) anti-P. hemolytica titers on d 17 than -Se calves. Selenium status did not affect body temperatures, plasma creatine phosphokinase or serum IgG and albumin concentrations. These results indicate that Se status can affect IgM concentrations following stress.

Animals↗