Biomedical subjects

N B Anthony

Publications and source records attributed to N B Anthony.

At least 55 records · Page 3Linked to original sources

PubMed1994

Effect of a urease inhibitor and ceiling fans on ascites in broilers. 1. Environmental variability and incidence of ascites.

A low ventilation model to induce ascites was introduced and characterized. In addition, the effect of supplemental air mixing via ceiling fans (CF) and the feeding of a urease inhibitor (0, 125, and 250 ppm) on incidence of ascites were investigated. Twelve environmental chambers were utilized in the trial; six were fitted with CF. Each dietary treatment was replicated twice per CF treatment. One hundred and twenty day-old male commercial broilers were reared per chamber. Atmospheric O2, CO2, and NH3, temperature, and humidity, as well as weekly litter moisture and pH, were monitored. Chamber CO2 levels increased immediately then stabilized. Chamber NH3 levels increased between 2 to 4 wk of age and rapidly declined when ventilation rates were increased to 1 cfm per bird. The CF and dietary treatments had little effect on air or litter variables except for NH3. Supplementing the diet with urease inhibitor resulted in a greater than 50% reduction in cumulative mortality due to ascites and a slight reduction in weekly BW gains. The CF treatment had no effect on production variables such as weekly feed intake, gain, and feed to gain ratio, or survivability due to ascites.

Ammonia↗

PubMed1994

Effect of a urease inhibitor and ceiling fans on ascites in broilers. 2. Blood variables, ascites scores, and body and organ weights.

Restricted ventilation was used to experimentally induce ascites in commercial male broilers. The role of a dietary urease inhibitor (0, 125, and 250 ppm) and ceiling fans to reduce ascites was investigated. At 6 wk of age, birds were bled, euthanatized, weighed, scored for ascites, and heart, liver, and small intestine weights were obtained. Random samples were analyzed for intestinal ammonia. Blood samples were analyzed for blood gases, hemoglobin, red blood cell count, blood urea nitrogen, ammonia, and uric acid. Birds fed 125 and 250 ppm urease inhibitor were significantly (P < .001) lighter at 6 wk, when compared with controls. Urease inhibitor (125 and 250 ppm) significantly decreased large intestine ammonia. Urease inhibitor significantly increased small intestine (250 ppm) and liver weights (125 and 250 ppm), whereas urease inhibitor at 125 ppm decreased right ventricular heart weight. Urease inhibitor had no effect on ascites scores, blood gases, or blood ammonia, but hemoglobin, blood urea nitrogen, red blood cell count, and uric acid were significantly (P < .05) decreased by 125 ppm urease inhibitor.

Animals↗

PubMed1994

Genetic analysis of antibody responses of turkeys to Newcastle disease virus and Pasteurella multocida vaccines.

Heritability (h2) of 16-wk BW and primary and secondary antibody responses and genetic and phenotypic correlations among these traits were estimated for 931 male and female turkeys vaccinated with Newcastle disease virus (NDV) and Pasteurella multocida. Turkeys from a line selected for 22 or 23 generations for increased 16-wk BW were vaccinated at 6 and 12 wk of age with blood samples collected 3 wk postvaccination. Antibody titers were determined using an ELISA method and transformed to log(e) for analysis. Heritability estimates for primary and secondary antibody responses to NDV were .380 +/- .070 (SE) and .296 +/- .063, respectively. For primary and secondary antibody responses to P. multocida, h2 estimates were .458 +/- .075 and .333 +/- .066, respectively. Heritability estimate for 16-wk BW was .404 +/- .071. The genetic correlation between primary and secondary antibody responses to NDV was .491 +/- .150. There was no genetic correlation between primary and secondary antibody responses to P. multocida. Although the genetic correlation between primary antibody responses to NDV and P. multocida was .292 +/- .159, the genetic correlation between secondary responses to the two antigens did not differ from zero. There were no genetic correlations between antibody responses and 16-wk BW. Similar results were observed for phenotypic correlations. Based on heritability and genetic correlation estimates, it would be possible to improve antibody responses to either NDV or P. multocida singularly; however, to improve antibody responses to both antigens, selection would have to be applied for each antigen.

Animals↗

PubMed1993

Divergent selection for body weight and yolk precursor in Coturnix coturnix japonica. 9. Evaluation of traits associated with onset of sexual maturity.

An experiment was conducted to compare traits associated with onset of sexual maturity in Japanese quail lines. Lines divergently selected for high and low 4-wk BW (HW and LW), and high and low total plasma phosphorus at beginning of lay (HP and LP) were compared with a randombred line (RBC1) that served as the base population for HW, LW, HP, and LP. The HW sublines (HW-HP and HW-LP) and LP subline (LP-HW) were also compared to their respective line of origin. Most of the differences observed for males selected for a single trait were found for weight-selected rather than for phosphorus-selected lines. The patterns of significance closely followed differences expected due to the extreme diversity in BW for the HW and LW when compared with RBC1. Females generally matured approximately 2 wk later than males for HW, HP, and LP. Line LW females matured approximately 4 wk later than LW males. Differences were observed for variables associated with onset of sexual maturity for HW, LW, and HP when compared with RBC1. Observed changes in carcass variables for sublines were generally associated with reductions in BW for HW-HP, and HW-LP versus HW and for increases in BW for LP-HW versus LP. The differences were likely due to the fact that two-trait selection (BW for males and total plasma phosphorus in females) has allowed weights to diverge when compared with lines selected for single traits.

Age Factors↗

PubMed1992

Interaction between step-up versus step-down lighting from four to sixteen weeks on growth and development in turkey hens from two commercial strains.

British United Turkeys (BUT) and Nicholas (NIC) hens were exposed to a step-up (10 to 16 h/day) or a step-down (16 to 10 h/day) light program from 4 to 16 wk of age. Lights were increased or decreased by .5h/wk. From 1 to 20 wk, weekly BW data were used to calculate growth curve parameters according to the Gompertz equation. Compared with BUT hens, the slope of the growth curve was greater, but the BW and age at the point of inflection (POI) was decreased in NIC hens. The step-down light program significantly increased the slope of the growth curve, but decreased the BW and age at POI compared with the step-up program. A sample of hens from each strain and program was processed at 16 wk. The relative weight of the Pectoralis minor (P. minor) was increased in BUT hens compared with NIC hens. The absolute and relative weights of the Pectoralis major and the absolute weight of the P. minor were increased in hens from the step-down program compared with the step-up program. The step-up program significantly increased the relative weight of the abdominal fat pad compared with the step-down program, and NIC hens had more abdominal fat than BUT hens. Total carcass lipid was significantly increased by the step-up program, compared with the step-down program, and NIC hens had significantly more carcass lipid than BUT hens.

Abdomen↗

PubMed1992

Progeny performance when dams and chicks are fed supplemental zinc.

Three consecutive trials involving approximately 700 to 800 broilers (0 to 28 days) were conducted to examine effects on growth and immunity of chicks after supplementing dams with inorganic Zn versus organic Zn. Offspring from hens fed a basal diet (72 mg Zn/kg) or diets with 152 mg Zn/kg supplemented with ZnO or organic Zn-Met were randomized across four battery brooders. Chicks were fed a starter diet without supplemental Zn containing 100 mg Zn/kg or diets supplemented with 40 mg/kg Zn from ZnO and DL-Met or Zn-Met containing 140 mg Zn/kg. No differences among treatments (P greater than .05) were found in feed conversion or average BW. Supplemental Zn-Met in hen diet increased (P less than .06) cellular immune response in progeny. Embryonic bone weights were higher (P less than .05) in progeny when dams were fed Zn-Met. Zinc as Zn-Met in diets of dams and progeny enhanced primary antibody titers to Salmonella pullorum antigen.

Animals↗

PubMed1991

Comparison of growth curves of weight selected populations of turkeys, quail, and chickens.

The pattern of growth from hatch to sexual maturity was measured in quail, chicken, and turkey females using the Gompertz equation. Quails and chickens were selected for high or low immature BW and turkeys were selected for high BW. Quail and turkey species also included their respective randombred control populations. The chicken species included an F2 of the selected lines. Thus, there were considerable differences in BW not only among species but between lines within species. Differences were evident at hatch as hatch weights relative to asymptotic BW were greater for quail than chickens and turkeys. Age and BW traits associated with point of inflection (POI) were variable. Species differences appeared to be influenced by the selection scheme applied to the populations. Slope at POI was greatest in quail and the same for turkeys and chickens. Age at 90% of the asymptotic BW was generally greatest for chickens, intermediate for turkeys and lowest for quails. Selection age in relation to age at POI may contribute to the timing and magnitude of growth response observed.

Age Factors↗

PubMed1991

Research note: Influence of body weight selection on the growth curve of turkeys.

The growth curve of a population of turkeys selected for increased 16 wk BW (Line F) and a randombred control population (RBC2) was determined. It was concluded that the Gompertz equation best described the growth pattern of Lines F and RBC2 regardless of sex. Line F had higher BW at hatching, BW and slope at point of inflection (POI), and asymptotic BW than Line RBC2. Age at POI and asymptote were achieved later for Line RBC2 than for Line F. Male turkeys had higher BW and age at POI and BW and age at asymptote than females. Slope at POI was greater for females than for males.

Age Factors↗

PubMed1991

Genetic association of selection for increased leg muscle and increased shank diameter with body composition and walking ability.

Body compositions of a randombred control population (RBC2), a line selected for increased 16-wk BW (F), a line selected for increased shank diameter (FL), and a line selected for increased leg muscle mass (FM) were compared at 16 wk of age. The F line originated from the RBC2 population and the FL and FM lines were developed as sublines of the F line. The F and FL lines were developed through mass selection of BW and shank width, respectively. The FM line was developed through family selection for leg muscle mass. Selection for BW in the F line has resulted in an increase in the proportion of breast muscle and a decrease in the relative amount of leg bone in comparison with the RBC2 population. Selection for increased shank width in the FL line has increased not only shank weight but has produced concomitant increases in the weight of the tibiotarsal and femur bones. Although FL line has also shown a correlated increase in BW in association with increases in shank width the increase in leg bone weight was relatively greater than the increase in BW. Therefore, the relative weights of leg bones in the FL line increased such that they were more similar to the RBC2 population than to the F line. Although the amount of leg muscle increased slightly in the FM line, the relative proportion of leg muscle did not increase significantly. The selection program used was probably ineffective in increasing the proportion of leg muscle because of the high percentage (low selection intensity) of families selected and small family size for estimating family means.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Genetics of growth and reproduction in the turkey. 11. Evidence of nonadditive genetic variation.

A commercial sire line (C) and an experimental population selected solely for increased 16-wk BW (F) were reciprocally crossed to produce crossbred F1 and F2 progeny. The F1 and F2 crosses were used to evaluate the presence of nonadditive genetic variance for growth and reproductive traits. The crosses demonstrated improved growth performance as indicated by heterosis for 16- and 20-wk BW. The difference in BW was, however, reversed at maturity as indicated by negative heterosis for BW at maturity. The F1 and F2 crosses also exhibited heterosis for walking ability. Heterosis for reproductive traits was greater than for growth. The F1 crosses produced approximately 20 eggs more in a 180-day production season than the parental populations. This difference was halved in F2 generation hens. Improved egg production was achieved both through an increase in the rate of egg production and through a reduction in broodiness. The present experiment indicates that there is potential for significant heterosis for growth and reproduction in some crosses in the domestic turkey. The results also indicate that heterosis can be considerable, even in crosses of lines which do not differ greatly in BW or reproductive performance.

Animals↗

PubMed1991

Genetics of growth and reproduction in the turkey. 12. Results of long-term selection for increased 180-day egg production.

A line of turkeys selected 28 generations for increased 180-day egg production (E) was compared through regression analysis with the randombred control population (RBC1) from which it originated. The only curvilinear trends observed for RBC1 were for egg weight and 8-wk (both sexes) and 16-wk (males) BW. Linear declines in egg production and rate of lay through 84 and 180 days of lay, the number of clutches during the 180-day production period, effective days of egg production, and 16-wk (females) and 20-wk (both sexes) BW were observed for RBC1. The RBC1 turkeys had linear increases in the percentage of broody hens during the first 84 and 180 days of production, the average length of the broody period, and the total number of days lost to broodiness during the 180-day period. When expressed as a deviation from RBC1, positive quadratic curvilinear changes were observed for E turkeys for number of clutches and broody periods, and days lost to broodiness during the first 180 days of production. Percentage hatch of fertile eggs at 8 and 12 wk of production also exhibited a positive quadratic change with generation. Linear increases in egg production, rate of lay, clutch length (average and maximum), number of effective days of production, and percentage hatch of fertile eggs 12 wk into production were observed for E turkeys. There were linear declines in number of days from photostimulation to the production of first egg, number of clutches, and number, average length, and days lost to broodiness for E line turkeys.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Research note: lack of an effect of high levels of menadione on tumor development in Japanese quail females.

The objective of the experiment was to study the influence of a high but nontoxic dietary level of menadione (vitamin K3) on the incidence of leiomyomas and leiomyosarcomas in the oviduct of females from various lines of Japanese quail. Analyzed values of vitamin K3 per 1,000 kg of feed were 7.37 g in the control diet, and 149.6, 1,722, and 3,722 g for the experimental diets from 0 to 4, 5 to 8, and after 8 wk of age, respectively. Females were killed after they had been in production for 158 days. Females from three large-bodied lines had a greater incidence of smooth muscle tumors than those from a smaller randombred control line. The high dietary level of vitamin K3 had no influence on tumor development.

Animals↗

PubMed1990

Secretory pattern of growth hormone, insulin, and related metabolites in growing male turkeys: effects of overnight fasting and refeeding.

The effect of an overnight fast on the secretory profile of growth hormone (GH), insulin, and related metabolites [glucose, nonesterified fatty acids (NEFA) and triglycerides (TG)] was determined in two separate experiments with 8- and 9-wk-old male turkeys. Toms were provided feed ad libitum or were fasted 20 h prior to sampling. Blood samples (.6 to .7 mL) were collected every 10 min for 8 h from the toms showing a positive weight gain between cannulation and the initiation of the experiment. Overall and baseline, GH levels were higher for the fasted birds versus the fed birds. The GH peaks for the fasted birds were of shorter duration than those for the fed birds, but were more frequent. The plasma NEFA levels of the fasted birds were higher than those of the fed birds. Plasma TG was lower for the fasted than the fed group. Insulin, which was secreted in a pulsatile fashion, was lower for the fasted versus the fed birds. Fasting produced no change in plasma glucose. A separate group of fasted males was refed after 4 h of sampling; the plasma levels of GH, insulin, and metabolites returned to those observed in birds given feed ad libitum within 30 min of refeeding. There appeared to be no relation between the pulsatile release of GH and the circulating levels of NEFA.

Animal Feed↗

PubMed1990

Divergent selection for body weight and yolk precursor in Coturnix coturnix japonica. 8. A summary of correlated responses.

Correlated response data accompanying 19 generations of selection for increased (HW) or decreased (LW) 4-wk BW and increased (HP) or decreased (LP) total plasma P were summarized. Similarly, 11 generations of selection of sublines derived from the original Lines HW and LP were also analyzed. Sublines were maintained through selection of males for increased 4-wk BW and females for the respective high or low plasma P. The randombred control (RBC1) was stable for BW early in egg production, BW change from early to late in production, wet and dry liver weights, 120-day egg production, and ova weight. A linear decrease in BW was found for the RBC1 line late in egg production, egg and respective component weights, and ova number. Body weight early and late in the production period for original Lines HW and LW was different from the RBC1 line. Wet liver weight increased for the HW line while dry liver weights declined in the original Lines LW, HP, and LP. Egg weights were greater in Line HW and lower in Lines LW, HP, and LP than in the RBC1 line. Yolk weight increased in Line HW and decreased in Lines LW and LP. Albumen weight was reduced in Line LP while shell weight was increased in Line HW and decreased in Line HP. Egg production, from onset to 120 days, decreased in Lines HW and LW when compared to the RBC1 line. Line LP had more follicles in rapid development than Line RBC1. The sublines responded similarly to their line of origin differing only in the magnitude of response. This was a reflection of the mating scheme, which placed selection pressure on BW of males and plasma P in females.

Animals↗

PubMed1990

Pattern of growth and plasma growth hormone secretion in turkeys selected for increased egg production.

Male and female turkeys of a slow-growing line selected for increased 180-day egg production (Line E) and its faster growing randombred control (RBC1) were sampled weekly for BW and plasma growth hormone (GH) content. Hatching weights were higher for RBC1 than Line E poults, but no difference was observed between sexes. The pattern of growth of the two lines, as described by the Gompertz equation, was different in magnitude of growth [BW at point of inflection (POI) and asymptote] but not in form (slope and age at POI and age at asymptote). Males achieved higher weights at POI and asymptote but took longer to reach these weights. Slope at POI was greater for females than for males. Plasma GH was higher in Line E than in RBC1 at hatching but higher in RBC1 than in Line E from Weeks 7 to 28. Males had higher concentrations of circulating plasma GH than females at all ages. The GH pool size was maximal at 5 wk for females and 10 wk for males. Maximal concentrations of circulating GH preceded maximal GH pool size by several weeks.

Animals↗

PubMed1988

DNA, RNA and total protein content of leg and breast muscles of White Rock chickens selected for 56-day body weight.

Pectoralis and gastrocnemius muscles from White Rock chickens divergently selected for 29 generations for high or low 56-day body weight were analyzed for DNA, RNA and protein (mg/g) content at 12 ages between hatch and 273 days of age. Dimorphism between lines was maximum at day 18 for both muscle types and then declined with age. High-line chickens generally deposited relatively more muscle tissue than those from the low line. Although nonadditive genetic variation was evident for absolute muscle weights, it was more frequent for muscle weight relative to body weight. For both muscle types, DNA unit number, as measured by DNA content (mg/g), was larger for the high line than the low immediately after hatch and smaller in the high than in the low line from day 10 to 56 after which lines were similar. RNA and protein/g muscle were similar for both lines at most ages. Between days 4 and 56, a period of rapid muscle growth, DNA unit size (protein/DNA) of both muscle types was larger in the high than in the low line. Heterosis was positive for protein, DNA unit number and size, and negative for RNA content. While weight of pectoralis muscle was similar to that of one gastrocnemius muscle on day 1, by day 273 its weight was over 3-fold greater. DNA unit number was higher in pectoralis than gastrocnemius muscle from hatch to day 4, similar on days 7 and 10 and lower for pectoralis muscle beyond day 10. RNA content was similar at all ages except 4, 7 and 10 days. DNA unit size followed the same pattern as DNA unit number; however, greater nuclei number at hatch for the high line corresponded with low DNA unit size. This pattern suggests a higher rate of cellular filling for pectoralis than gastrocnemius muscle.

Aging↗

PubMed1987

Divergent selection for body weight and yolk precursor in Coturnix coturnix japonica. 7. Influence of genetic changes in body weight and yolk precursor on egg production.

Japanese quail lines were started from a randombred control by selecting for high (HW) or low (LW) 4-week body weight and high (HP) or low (LP) total plasma phosphorus (P), a measure of yolk precursor. In the 9th generation, 2 sublines were initiated from Line HW based on high (HW-HP) or low (HW-LP) level of P in females while males were continually selected for HW. A subline (LP-HW) was started from Line LP in the 9th generation by selecting the males for HW while continuing to select the females for LP. All lines were maintained with 36 parental pairs. Realized heritability (h2) values for 4-week body weight were .38 +/- .02 in Line HW and .32 +/- -.02 in Line LW for 15 generations. Respective h2 were .32 +/- .01 and .34 +/- .01 for P in Lines HP and LP. Although P increased in Line LW, there was no change in Line HW. Body weight of Lines HP and LP declined slightly, but significantly. Egg production decreased significantly in Lines HW, LW, HP, HW-HP, and LP-HW, but did not change in Lines LP and HW-LP. Decrease in egg production of Line HW-HP was greater than that of Lines HW or HP. These results suggest that if both body weight and P are selected for simultaneously, then egg production will decrease more than if selection pressure is applied on either trait alone, even though the two traits do not appear to be genetically closely correlated.

Animals↗

PubMed1987

Growth hormone status and growth characteristics of Japanese quail divergently selected for four-week body weights.

A randombred line of quail (R1) and two lines selected for either increased (HW) or decreased (LW) 4-wk body weight were used to examine the relationship of growth to circulating growth hormone (GH) levels during growth. Differences in GH between males and females were not detected. Growth hormone was low at hatching in all lines but then increased to relatively high levels by the first post-hatching sample (3 to 7 days). A decline in GH then occurred in all lines, with low adult levels detected earlier in lines HW and R1 than in LW. The patterns of GH secretion and growth characteristics of lines HW and R1 were similar while those of LW were unique.

Age Factors↗