Studies on egg shells. IV.—The site of deposition of radioactive calcium and phosphorus

Tyler, C.

doi:10.1002/jsfa.2740050706

Cited by 33 publications

(6 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If the digestive system contains decreased levels of calcium, the skeletal system becomes a very important source of calcium for the forming shell. Tyler (1954) assumed from several studies that there was a period in the early morning hours when absorption of dietary calcium from the previous day's food ends and calcium for egg shell formation is supplied largely from the skeleton. Histological studies of medullary bone by Bloom et al (1958) and Stringer (1962) confirmed Tyler's assumption.…”

Section: Introductionmentioning

confidence: 99%

Plasma Phosphorus at 0, 6, and 21 Hours Postoviposition in Hens Laying in the Morning or Afternoon

1984

View full text Add to dashboard Cite

Two experiments were conducted using White Leghorn hens. Blood samples were collected immediately following oviposition (0 hr) or 6 or 21 hr postoviposition from hens laying in the morning or afternoon. Plasma phosphorus was determined at each time period. In Experiment 1, plasma phosphorus at oviposition was essentially the same for hens laying in the morning or afternoon (3.95 and 4.10 mg/dl, respectively). At 6 hr postoviposition plasma phosphorus was lower than that observed at 0 hr (3.22 and 3.15 mg/dl, respectively). When comparing plasma phosphorus levels at 21 hr postoviposition of hens laying in the morning or afternoon a higher (P less than or equal to .05) phosphorus level was observed for hens that laid in the morning (5.90 vs. 4.91, respectively). In Experiment 2, plasma phosphorus levels at 0 and 6 hr postoviposition were 3.32 vs. 3.18 and 2.81 vs. 2.74 mg/dl for hens laying in the morning and afternoon, respectively. At 21 hr postoviposition, phosphorus values of 5.30 vs. 3.65 mg/dl were reported for hens laying in the morning and afternoon, respectively. Data also indicated that on the day a hen does not lay an egg, plasma phosphorus does not rise. An hypothesis is offered to explain the difference in egg shell quality between eggs laid in the morning or afternoon.

show abstract

Section: Introductionmentioning

confidence: 99%

Plasma Phosphorus at 0, 6, and 21 Hours Postoviposition in Hens Laying in the Morning or Afternoon

1984

View full text Add to dashboard Cite

show abstract

“…The reason for this is unknown. Tyler (1954) concluded that there was a period in the early hours of the morning between the time when absorption of di-etary calcium from the previous day's food ends and absorption from the current day's food begins when calcium for shell formation comes largely from the skeleton. This conclusion was later supported by the results of histological studies of the medullary bone of laying hens at different stages of egg shell calcification (Bloom et al, 1958;and Stringer, 1962).…”

Section: Discussionmentioning

confidence: 97%

Calcium Metabolism in the Laying Hen

Roland¹,

Sloan²,

Harms³

1973

Poultry Science

View full text Add to dashboard Cite

Forty-four mature hens were used in two experiments to determine the total amount, rate of passage and absorption of feed and calcium in the digestive system at night. The hens were fed 3.6 and S.l percent calcium on a dry weight basis in experiments 1 and 2, respectively. Birds were sacrificed at intervals throughout the night. Each segment of the digestive system was examined and contents removed and analyzed for calcium.In experiment 1 the percent calcium in the small intestine was significantly lower at 6 a.m. than at 8 p.m. The birds absorbed 48 percent of the contents and 61 percent of calcium in the digestive system from 8 p.m. to 6 a.m. In experiment 2, the content of feed in the digestive system at 8 p.m., 12 midnight and 4 a.m. was 35.5, 22.3 and 15.2 grams, respectively. The hens absorbed 30 percent of the contents and 43 percent of calcium from 8 p.m. to 12 midnight. During the next four hours they absorbed only 11 percent of the content and 15 percent of the calcium. Fifty-three percent of the content in the crop at 8 p.m. was metered out by 12 midnight and 48 percent of the content at 12 midnight was metered out by 4 a.m. These results indicate that the digestive system of the hen has less total calcium during the early morning hours (4-6 a.m.) than the late afternoon (8 p.m.).at Oakland University on June 10, 2015 http://ps.oxfordjournals.org/ Downloaded from

show abstract

“…Hertelendy, 1961), no information is available on the dynamic equilbria between absorbed dietary Ca, skeletal Ca and the blood Ca pool from which material for the shell is drawn. From observations on the shell, following the feeding of 45Ca, Tyler (1954) has concluded that the supply of Ca to the shell gland may be made up entirely of Ca from the food, or from the bone, or from varying proportions, depending upon the time of day. T o study these relationships and to determine the quantitative contribution of diet and skeleton, a double radioisotope labelling technique was used with Shaver Starcross 288 hens fed on a diet containing 3 % Ca.…”

Section: The Interrelationship Between Food and Water Intake And Egg mentioning

confidence: 99%

Abstracts of Communications

1968

Proc. Nutr. Soc.

View full text Add to dashboard Cite

The development of high-lysine maize has raised wide interest. This paper considers the possible value of a high-lysine barley for animal feeding if resources were used successfully in developing one.A least-cost mixture for young bacon pigs had lysine as one cost-limiting factor when computed so that the quantity containing 70 Ib 'total digestible nutrients' also contained at least 0.69 lb Ca, 0.51 Ib P, 17 Ib protein, 0.82 lb lysine, o.571h 'methionine+cystine', 0.66 lb isoleucine and fixed levels of six further amino acids. T h e following ingredients (with prices, &'ton) were used in this calculation : standard barley (22 for UK or 30 for EEC countries), fish meal (72)' soya meal (M), DL-rnethionine (~oo), L-lysine hydrochloride (560, a likely future price), CaCO, (a) and CaHPO, (44). Opportunity prices (i.e. maximum prices for additional ingredients at which they would be brought into the least-cost formula) were then computed for barleys of different composition. Expressed as percentages of the price of standard barley (117; of protein containing 3'4% lysine), they are: Standard barley at Ezzlton Standard barley at A30/ton 105 107 rog 122 IOI 102 104 112Calculations for a 14% protein mix for older pigs, with individual amino acids reduced in proportion, gave essentially the same results; nor were they changed significantly by removing the specification for total protein content. Including synthetic L-lysine hydrochloride at its current price of Lgoojton changed results by no more than z percentage units.Normally, high-protein barleys have a lower lysine (expressed as % of protein).If a realistic target for a high-lysine barley were I 5 7;) of protein, still containing 4% lysine, our type of calculation indicates that for use in pig rations it could conirnand a price pr-mium of not more than 9% in the UK over standard barley.

show abstract

Studies on egg shells. IV.—The site of deposition of radioactive calcium and phosphorus

Cited by 33 publications

References 6 publications

Plasma Phosphorus at 0, 6, and 21 Hours Postoviposition in Hens Laying in the Morning or Afternoon

Plasma Phosphorus at 0, 6, and 21 Hours Postoviposition in Hens Laying in the Morning or Afternoon

Calcium Metabolism in the Laying Hen

Abstracts of Communications

Contact Info

Product

Resources

About