Biomedical subjects

D R Sloan

Publications and source records attributed to D R Sloan.

18 recordsLinked to original sources

PubMed1995

Sodium requirement for broiler breeder hens.

Two experiments were conducted with Arbor Acres hens to determine their Na requirement. Sodium chloride was added to a corn-soybean meal diet to furnish daily intakes of 35, 65, 95, 125, and 150 mg per hen in Experiment 1. The 150 mg level was replaced with 180 mg in Experiment 2. The hens were maintained in floor pens with wood shavings used as litter. Experiment 1 was conducted for 9 wk and Experiment 2 for 12 wk. Egg production was significantly reduced during Week 4, when the hens had an intake of 35 mg Na/d. Egg production was reduced by Week 7 when the diet furnished 65 mg/d. Plasma Na was reduced and plasma K increased when the intake was 35 or 65 mg/d. Performance data from 6 to 9, and 6 to 12 wk were used in Experiments 1 and 2, respectively, to determine the daily Na requirement. The daily requirement for maximum production was 113.8 and 96 mg and the requirement for egg mass was 105 and 100 mg in Experiments 1 and 2, respectively.

Analysis of Variance↗

PubMed1994

The relationship of egg cholesterol to serum cholesterol, serum calcium, feed consumption, and dietary cholecalciferol.

Hy-Line W36 hens, 20 wk of age, were randomly assigned to one of three dietary treatments consisting of cholecalciferol at (0, 550, or 2,750 IU/kg of finished feed). Serum calcium and cholesterol, yolk cholesterol, and egg specific gravity were measured. Feed consumption, egg production, and egg weight measurements were also recorded. Feed consumption, egg production, and egg weights were initially reduced when cholecalciferol was omitted from the diet. These effects disappeared by the beginning of the fourth 28-d period. Egg cholesterol concentrations among treatments followed no consistent pattern. A positive correlation was noted between serum calcium and serum cholesterol.

Animals↗

PubMed1992

Research note: effect of removing salt from the diet of broiler breeder hens.

Two 28-day experiments were conducted utilizing 75-wk-old Arbor Acres broiler breeder hens to determine the effect of removing salt from the diet. Birds in Experiment 2 had been force-rested at 60 wk of age but were in production (65% hen-day) at experiment initiation. All hens received a corn-soybean meal diet either with or without added salt. Egg production was significantly reduced in both experiments by the end of the 4th wk for birds fed the diet with no added salt. However, egg production did not cease in hens receiving the diet with no added salt. Egg weights from hens receiving the diet with no added salt were significantly reduced by the end of Week 2 in Experiment 1 and Week 3 in Experiment 2. Specific gravity was only intermittently affected by dietary salt removal. Birds receiving no added salt lost 541 and 580 g in Experiments 1 and 2, respectively. Birds receiving added salt diets gained 55 and 23 g in Experiments 1 and 2, respectively. Removing salt from the diet was not an acceptable method of force-resting broiler breeder hens.

Animal Feed↗

PubMed1990

Energy supplementation of laying hen feed and drinking water.

Duplicate experiments were conducted with White Leghorn pullets (29 and 31 wk old) to determine the influence of sucrose additions to feed or drinking water upon performance and average daily energy intake. Treatments consisted either of 3.06 or 4.58% sucrose in drinking water or of 4.76% sucrose in the feed compared with a control diet containing 2,657 kcal ME/kg. In each experiment, six replicate pens of 5 individually caged hens received feed or water treatments ad libitum for 42 days. Egg production and body weight change were not affected in either experiment by sucrose addition. Feed intake was significantly reduced in association with either level of sucrose in the water. In Experiment 1, egg weights from hens receiving sucrose water were significantly below those of controls, probably because of lowered feed intake. Total energy consumed per gram of body weight was significantly higher in both studies for birds receiving the sucrose water.

Animal Feed↗

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↗

PubMed1975

Influence of hormonal extracts on hens producing eggs with non-calcified or partially calcified shells and factors associated with this condition.

1. Daily injection of hypothalameal extract (HE) and adenohypophyseal extract (AE) into hens aged 56 or 67 weeks for 14 d did not significantly influence the production of shell-less (SL) or ultra-thin-shell (UTS) eggs. 2. The injection of HE significantly increased hard-shell (HS) egg production in the younger hens. 3. Neither AE nor HE affected egg weight, serum calcium, gain in body weight or food consumption. 4. In a third experiment hens selected for poor egg production laid at a rate of 58% of which 36% were SL, 29% UTS and 35% HS eggs. Whereas the production rate of the good layers was 65% of which 1-4% were SL and 1-4% were UTS eggs. 5. Specific gravity of HS eggs, serum calcium, weight of ovary, oviduct, or adenohypophysis did not differ between good and poor layers. 6. Since SL and UTS eggs are easily overlooked the decrease in egg production with age may be as great as indicated by normal production records; the problem may be concerned more with the mechanism of shell formation.

Animals↗

PubMed1974