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Biomedical subjects

B L Hughes

Publications and source records attributed to B L Hughes.

At least 19 recordsLinked to original sources
PubMed1991

Effects of exposing broiler breeders to nicarbazin contaminated feed.

Ten-mo-old broiler feeds were fed nicarbazin (NCZ) at 0, 25, 50 and 100 ppm of their diet for 2, 4, or 6 days to simulate accidental contamination of their feed with the medicant. Reduced egg production was observed in all treatments except 25 and 50 ppm NCZ for 2 days. A consistent reduction in egg weight occurred only at the maximum treatment level of 100 ppm for 6 days. Reduction in hatchability was generally evident by Days 5 and 6 of the experiment except for the lowest treatment of 25 ppm NCZ for 2 days. Due partially to the low number of eggs set, no statistically significant reduction in hatchability was seen for the group receiving 50 ppm NCZ for 4 days, but hatchability had dropped over 17 percentage points (from 93.3 to 75.5%) by Days 5 and 6 of the experiment, and continued to drop to a low of 31% on Days 11 and 12 of the experiment. Shell pigmentation was the most sensitive characteristic measured, with significant depigmentation occurring after only 2 days of feeding 25 ppm NCZ. Generally, the severity and duration of effects were in proportion to medicant concentration and length of treatment time. Fertility was not influenced by the medicant.

Animal Feed↗
PubMed1990

The amylase gene-enzyme system of chickens. II. Biochemical characterization of allozymes.

The chicken amylase allozymes, AmyF and AmyS, were extracted from pancreatic tissues of AmyF/F and AmyS/S individuals and purified. Activities were measured under various reaction conditions (= treatments) to assess whether the allozymes were functionally different. The amylases had properties typical of alpha-amylases, i.e., both were inhibited by ethylenediaminetetraacetate and alpha-amylase inhibitor from wheat, had pH optima between 7.0 and 8.0, and could utilize a variety of substrates containing alpha 1,4 linkages. The amylases were also found to be inhibited by potassium phosphate buffer and p-chloromercuribenzoate. In terms of substrate specificity, both amylases could utilize all of the substrates tested with activity observed in the following order: amylopectin greater than potato starch greater than dextrin greater than glycogen greater than amylose. Statistical analysis indicated significant functional differences between the two allozymes in terms of specific activities, substrate specificities, and inhibitor sensitivities. AmyF had a significantly lower specific activity than did AmyS. The amylases responded differently to the substrate amylose, with AmyF better able to digest this substrate. AmyS was less sensitive than AmyF to alpha-amylase inhibitor from wheat.

Amylases↗
PubMed1990

Reproduction responses of broiler-breeders to anticoccidial agents.

Two experiments were conducted to determine the effects of anticoccidial agents on production and reproduction of broiler breeders. In Experiment 1, nicarbazin (NCZ) was fed at 20, 50, and 100 ppm. There was no depression in egg production, egg weight, or fertility from feeding these levels. As level of NCZ increased, there was a linear decrease in hatchability. The amount of 4,4'-dinitrocarbanilide (DNC) in the egg yolks increased linearly as the levels of NCZ went up; the degree of egg-shell depigmentation was directly related to the level of NCZ fed starting at 50 ppm. Experiment 2 utilized a different strain of broiler breeders. Halofuginone (3 ppm), maduramicin (5 ppm), monensin (100 ppm), narasin (70 ppm), NCZ (125 ppm), robenidine (33 ppm), and salinomycin (60 ppm) were fed to broiler breeders at the levels listed. Only NCZ reduced egg production. Narasin induced a reduction in egg weight. Both narasin and salinomycin caused a significant drop in hatchability. Feeding NCZ also induced a rapid and more severe decrease in hatchability. Monensin was the only anticoccidial agent that reduced fertility. Halofuginone, maduramicin, and robenidine had no biologically significant effect on henday production, egg weight, hatch of fertile eggs, or shell depigmentation. Feeding NCZ at 125 ppm caused a complete bleaching of brown-shell eggs by the 3rd consecutive day of treatment; but 7 days after NCZ was withdrawn from the feed, pigmentation returned to the pretreatment level.

Animals↗
PubMed1990

Production and egg-quality responses of White Leghorn layers to anticoccidial agents.

Two studies were conducted to determine the effects of anticoccidial agents on the production and reproduction of White Leghorns. In Experiment 1, nicarbazin (NCZ) was fed at 0, 20, 50, and 100 ppm. Hen-day egg production, egg weight, the egg-yolk DNC (4-4'-dinitrocarbanilide) level, and egg-yolk mottling were affected by the treatments. When response was evidenced, the relationship between those variables and the level of NCZ was basically linear. Decreased egg production occurred from Days 5 and 6 of the treatment through Days 1 and 2 of withdrawal. On Days 9 and 10 of treatment, the control hens peaked at 92% hen-day production, while hens fed 20, 50, and 100 ppm of NCZ peaked late--at 90, 82, and 80%, respectively. Compared to the controls, egg weight was reduced linearly as the level of dietary NCZ increased. The egg-yolk DNC level increased from Days 3 and 4 of treatment through Days 9 and 10 of withdrawal. Egg yolk mottling generally increased along with the level and duration of feeding NCZ. If the NCZ was mistakenly fed to White Leghorn layers, ill effects would be alleviated within 10 days after drug withdrawal. In Experiment 2, halofuginone (3 ppm), maduramicin (5 ppm), monensin (100 ppm), narasin (70 ppm), nicarbazin (125 ppm), robenidine (33 ppm), and salinomycin (60 ppm) were fed to White Leghorn hens at the levels specified in parentheses. Nicarbazin reduced egg production, depressed egg weight, reduced shell thickness, and caused egg-yolk mottling; but internal egg quality, as measured by Haugh Units, was unaffected. Halofuginone, maduramicin, monensin, narasin, robenidine, and salinomycin did not have a meaningful effect on the variables measured when fed to White Leghorn layers.

Animal Feed↗
PubMed1988

The amylase gene-enzyme system of chickens. I. Allozymic and activity variation.

Amylase allozymic and activity variation was studied in three flocks of chickens (Gallus domesticus). Individuals from one flock were studied to assess the effects of sex, tissue, and genotype on amylase activity. Additionally, the allozymes were purified and their specific activities compared. Variation was observed within and among the flocks. Two alleles were found to be segregating in the flocks, one flock being polymorphic and the other two monomorphic. Mean amylase activities among the three flocks were significantly different. The relationship of this activity variation to regulatory variation is discussed. There were no significant effects of sex or genotype on amylase activity and, in most cases, no correlation between activities in the various tissues. However, in heterozygotes one of the alloamylases had much lower activity than the other.

Amylases↗
PubMed1988

Comparison of primary rabbit kidney and MRC-5 cells and two stain procedures for herpes simplex virus detection by a shell vial centrifugation method.

By using a conventional tissue culture method as a standard, four shell vial centrifugation culture (SVC) formats were compared for herpes simplex virus (HSV) detection in 300 clinical samples. Both MRC-5 and primary rabbit kidney (PRK) cells were used in the conventional and SVC systems. In addition, both a direct monoclonal fluorescent antibody to HSV (MAb-FA; Syva Corporation, Palo Alto, Calif.) and an indirect HSV polyclonal antibody-horseradish peroxidase stain (poly-HRP; Difco Laboratories, Detroit, Mich.) were used to stain shell vials of both cell types. Conventional tubes were incubated for up to 7 days with daily examination for cytopathic effect, which was confirmed as HSV by staining with an MAb-FA. Shell vials were inoculated, centrifuged, incubated for 16 to 24 h, and stained directly with MAb-FA or indirectly with a poly-HRP stain. Of the 300 specimens examined, 82 (27%) were HSV positive by conventional tissue culture. PRK cells detected 81 (99%) positive specimens, compared with 74 (90%) specimens detected with MRC-5 cells. Of the 82 positive specimens by conventional culture, the SVC formats detected 68 by MRC-5 and MAb-FA, 74 by MRC-5 and poly-HRP, 64 by PRK and MAb-FA, and 77 by PRK and poly-HRP. Therefore, PRK stained by an indirect method with poly-HRP was the most sensitive of the SVC formats tested, detecting 94% of the positive specimens.

Animals↗
PubMed1986

Frequency and structure of macrophages and abnormal sperm cells in guinea fowl semen.

Semen from young and old guinea fowl was examined for macrophages and abnormal sperm cells. Large numbers of macrophages were found in the semen from both groups. However, there were significantly more abnormal sperm cells in the semen of the young males. The abnormal cells consisted of large coiled cells, bent spermatozoa, and round-headed cells. The predominant abnormality in the young males was bent sperm, although their semen also contained large round cells. The large round cells were identified as abnormal spermatids by electron microscopy and were more prominent in the older males. The abnormal spermatids were pleomorphic and exhibited various stages of intermediate and late spermatid development. The macrophages were activated cells that exhibited phagocytosis of large number of normal spermatozoa but were never observed to engulf abnormal cells. Their ultrastructure consisted of numerous lipid droplets, vesicles of ingested spermatozoa, lysosomal structures, residual bodies, and undigested remnants of spermatozoa. The presence of macrophages and abnormal spermatids in semen has been associated with lowered fertility in other species; thus, semen with exorbitant numbers of these cells should not be used for artificial insemination of the guinea fowl.

Acrosome↗
PubMed1986

Effects of temperature on reproduction in guinea fowl.

The effects of four temperature regimens on the onset and maintenance of semen and egg production, fertility, hatchability, and feed consumption by guinea fowl were examined. Temperatures of 26.7 and 21.1 C hastened the onset of egg and semen production in guinea fowl. However, egg and semen production rates of guineas exposed to ambient or 15.6 C minimum temperatures eventually increased to the level of those exposed to the higher temperatures. This suggests that it may be possible to initiate production by exposure to a warm environment and then reduce the environmental temperature after egg and semen production has been well established. There were no statistically significant differences in fertility or hatchability. Differences seen in feed conversion were mainly due to delayed onset of egg production in the lower temperature regimens. Thus, it appears that proper winter management of guinea breeders would involve exposure to a warm temperature for some period of time.

Animals↗
PubMed1985

High-density winter brooding in a solar facility.

Broilers were brooded under high-density and low ventilation conditions in a solar facility to 25 days of age and then moved to conventional facilities for growout. Nonstatistical comparisons were made on the performance of these birds to that of broilers grown under conventional conditions starting at day-old. Body weight differences during the brooding phase were primarily due to density with birds in the solar house weighing an average of 10.2% less than those brooded in a conventional house. Growth depression continued during the growing phase but was reduced in magnitude to 3% at Day 46. During the brooding phase no definite trends were seen with regard to effects of ventilation or density on feed conversion. Compared with conventionally-housed birds, feed conversion of the birds in the solar facility was slightly poorer at the end of the brooding period. This trend was reversed in the growing phase due to compensatory growth, giving the solar brooded birds an overall advantage at the end of the study. Mortality during the 46-day study was within the expected range for both the solar-brooded (3.1%) and conventionally-brooded (3.0%) birds. Energy consumption for supplemental heat and ventilation in the solar facility (.76 kWh/bird) was similar to that reported for energy efficient, environmentally-controlled houses and about half that for conventional facilities. Litter moisture in the solar facility was excessive due to the high bird density, low ventilation rates, and the use of a concrete slab floor.

Animal Feed↗
PubMed1984

Phospholipid and cholesterol profiles from chicken seminal components during in vitro storage at 5 C.

Two experiments were conducted with undiluted chicken semen to determine if fluctuations in endogenous phospholipids and cholesterol might relate to loss of fertilizing capacity which accompanies in vitro storage for 24 hr at 5 C. The following parameters were monitored quantitatively: individual seminal plasma and spermatozoal phospholipids, spermatozoal cholesterol to phospholipid molar ratios, and spermatozoal cholesterol mole percent. After storage for various periods, total lipids were extracted with chloroform:methanol (2:1, v/v). Total phospholipids were obtained by precipitation with cold acetone and further resolved into individual components by thin layer chromatography. All phospholipids and cholesterol were quantitated spectrophotometrically. Spermatozoal phospholipids, the spermatozoal molar ratio of cholesterol to phospholipid, and the spermatozoal mole percent of cholesterol remained essentially the same throughout the 24-hr storage period. Seminal plasma phosphatidylethanolamine also did not fluctuate significantly during the storage period. However, the phosphatidylcholine and the phosphatidylserine-inositol fractions from the seminal plasma appeared to increase with time.

Animals↗
PubMed1984

Catabolism of phospholipids by chicken seminal components after storage.

The possibility of an activation of chicken spermatozoal phospholipase A2 during in vitro storage of undiluted semen was investigated. After storage for periods up to 24 hr at 5 C, the ability of semen to catabolize added phosphatidylcholine labeled on the 2nd carbon of glycerol with 14C oleic acid was assessed. Neither spermatozoa nor plasma from undiluted chicken semen was found to be capable of catabolizing added 14C labeled phosphatidylcholine, regardless of the storage period. No enzyme activity was evident when fresh semen was incubated under various assay conditions to determine the influence of cholic acid, calcium, and the type of phospholipid substrate on phospholipase A2 activity. The influence of spermatozoal protease activation on phospholipase A2 activity from undiluted chicken semen and from Naja naja naja was also investigated and found to have no influence on phospholipase A2 activity.

Animals↗
PubMed1983

Bone fragility in broilers as affected by pen height, sex, and a comparison of left and right humeri.

Humeri and tibiotarsi breaking strengths were determined for broilers raised in pens of varying heights. Five hundred forty-four broilers were reared in conventional floor pens or wire cages on the floor with overhead restrictions of 20, 30, 40, or 60 cm. No significant differences were noted on growth, feed conversion or tibiotarsi breaking strength. Height-restricted broilers had significantly weaker humeri than did the controls. A significant linear relationship (P less than .05) was noted in height-restricted broilers in that as pen height increased so did humeri strength. Further studies were conducted to test for significant differences between male and female humeri strength and between right and left humeri on the same bird. Forty-six pairs of female and male humeri were obtained, tagged for identity, and broken on the Instron Model 1122. Males had significantly stronger humeri than females and right humeri were significantly stronger than left humeri in both sexes.

Animals↗
PubMed1982

Ultrastructure of the guinea fowl (Numidia meleagris) spermatozoon.

The ultrastructure of guinea spermatozoa was characterized by transmission and scanning electron microscopy. The average lengths and widths (measured at the widest points) of the segments were as follows: acrosome, 1.8 x .47 mu; nucleus, 12.8 x .49 mu; midpiece, 3.9 x .59 mu; flagellum, 59 x .52 mu. Thus, the guinea sperm cell is slightly smaller than the chicken or turkey spermatozoon. The ultrastructure of the guinea spermatozoon was similar to that of the chicken and turkey with two exceptions: 1) the mitochondria had cristae aligned parallel and oblique with respect to the outer limiting membrane and 2) there was no proximal centriole, the distal centriole projected into the implantation fossa with "arms" of the nonstriating connecting piece extending laterally from the centriole to the implantation fossa.

Animals↗
PubMed1982

Seminal plasma free amino acids and seminal and blood plasma proteins of the guinea fowl (Numidia meleagris).

Glutamic acid was the major free amino acid in guinea seminal plasma, representing 90.00% of the total amino acids. Threonine comprised 3.74%, aspartic acid 3.23%, and serine 1.50%. Others were detected at less than .50% of the total free amino acids. Blood plasma protein concentration and SE were 2.68 +/- .35 g/100 ml, and the proteins were fractionated by disc acrylamide electrophoresis into seven major bands: albumin, alpha-1, a dense beta fraction, and four postbeta, or gamma, proteins. Seminal plasma protein concentration and SE were .45 +/- .03 g/100 ml, and the proteins separated into nine fractions: albumin, alpha-1 and -2, beta-1, -2, and -3, and three postbeta, or gamma, bands.

Amino Acids↗
PubMed1982

The effects of red and white light during the prebreeder and breeder periods on egg production and feed consumption in Large White turkey.

Large White turkey hens were conditioned with 5 lx of white or red incandescent light from 20 to 32 weeks of age. Hens from both of these groups were given white or red incandescent light at two intensities (approximately 85 and 160 lx) during a 20-week breeder period. Feed consumption was greatest for hens no white light during the prebreeder period (P less than or equal to .01), but hens on red light consumed the greatest amount of feed during the breeder period. The only consistent finding concerning egg production was the hens exposed to high intensity (160 lx) white light, regardless of whether the prebreeder light was white or red, had the poorest egg production (P less than or equal to .01). It is concluded that red light during the prebreeder or breeder periods is not beneficial for egg production over that achieved with low intensity white incandescent light, and that bright white incandescent light is deleterious to egg production.

Animals↗
PubMed1982

The effect of reverse protein and low protein feeding regimens in the rearing period on pullet growth, subsequent performance, and liver and abdominal fat at end of lay.

Four brown egg strains were used to study the effect of rearing diets on growth and performance. The treatments were arranged in a 4 x 3 factorial with two replicates of 45 birds. The control diet was formulated and fed to National Research Council recommendations. Birds on reverse protein (RP) were fed diets with 13, 16, and 19% protein and those on low protein (LP) regimen received a 13.5% protein diet with amino acids adjusted on a megacalorie basis to approximate the control diet. At 20 weeks of age pullets were caged and fed a standard layer diet. Logistic curves were fitted to the growth data by a nonlinear least squares method and the parameters of each curve analyzed. No significant strain x diet interactions were observed. There were significant differences among strains in weight gain and feed intake. Dietary regimens had no significant effect on total gain and feed intake. However, diets significantly altered age at one-half maximum growth or inflection point (alpha) and mean growth rate (rho). Inflection point of the growth curve was significantly delayed in birds fed RP and LP diets. Although apparent conversion was not affected by diets, the partition coefficients at any time (t) for maintenance (beta mt) and gain (beta gt) were altered. Neither strain nor dietary regimens affected abdominal fat or organ weights at the end of the rearing period. No significant effect of rearing dietary regimens was detected in age at 50% production or peak production, feed conversion, feed intake, livability, liver fat, abdominal fat, or shell strength. The reverse-protein regimen significantly depressed egg weight. The results of the study indicate that 1) the rearing dietary regimens were adequate for strains of different body weight and egg output characteristics; 2) dietary alteration of growth curve parameters failed to influence production, feed intake, mortality, shell strength, livability, liver fat, or abdominal fat during the production period.

Abdomen↗
PubMed1981

An evaluation of gelatin as a diluent component for storage of chicken semen.

This study was conducted using a gelatin-Beltsville Poultry Semen Extender (BPSE) mixture to determine whether or not gelatin aids in the preservation of chicken semen stored at temperatures of 4 to 12 C. Two experiments were conducted designed to determine 1) the optimum gelatin-extender ratio and 2) the optimum in vitro conditions (storage temperature, semen-gas ratio, stopper type, holding temperature, and semen-diluent ratio) for BPSE only and for the best gelatin-BPSE mixture as determined in Experiment 1. Varying the gelatin concentration in BPSE from 15 mg/ml to 30 mg/ml had no significant effect upon either fertility or hatchability. Varying the storage temperature, semen-air ratio, or stopper type had no significant effect upon fertility regardless of the presence or absence of gelatin. However, a significant interaction was noted between the stopper type and the diluent. Cooling semen diluted 1:1 with BPSE at a rate of 1 C/min to 10 C prior to storage and then transporting the post-stored semen at 10 C had a detrimental effect on fertility. Increasing the dilution rate above 1:2 had a significant negative effect upon fertility, with a significant interaction noted between the diluent and the semen-diluent ratio. When comparing BPSE only against the BPSE-gelatin mixture (30 mg/ml), the BPSE-gelatin mixture yielded significantly lower fertility in most instances and had no significant augmenting effect on fertility in those instances where it was not harmful. Therefore, under the in vitro conditions provided in this study, gelatin, in conjunction with BPSE, served no potentiating function in enhancement of fertility of stored chicken semen.

Animals↗