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

Abstract

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.

Calcium and Phosphorus Metabolism and Eggshell Formation of Hens Fed Different Amounts of Calcium

“…Also, for any given level of P, when hens were fed diets low in Ca, feed intake was depressed (Roush et al, 1986). This decrease in feed intake may also be related to the elevated concentrations of P in plasma reported by Miles et al (1984). Although plasma P was not measured, apparent P retention (Table 3) indicates that hens fed 2.5% Ca retained less grams total P on SF days compared tained.…”

The effect of different feeding schedules on egg quality, blood, and bone parameters in broiler breeders

“…93, 6.17, 6.79 mg/dl; P = 0.0811; Table 4. Miles et al (1984), after performing experiments, reported that the average of P content in plasma at the time of oviposition for hens fed in the morning or afternoon was 3.95 and 4.10 mg/dl, respectively. On the other hand, higher values from 4.91 to 5.90 mg/dl were obtained from the plasma of hens which blood was collected 21 h after oviposition.…”

“…The hens were marked with dye and 21 h after oviposition, blood samples were collected once again (Miles et al, 1984;Junqueira et al, 2002). Blood samples from each treatment were placed in tubes and packed in ice.…”

Effects of an Induced Molt and Shell Quality on the Physical Dimensions and Mineral Composition of Eggs and Intrauterine pH ,

“…The thicker shells of HS eggs collected at 0700 vs. 1100 hr appear to be related to increased shell phos-phorus rather than shell calcium, magnesium, or manganese content. The decrease in plasma phosphorus observed in hens laying afternoon eggs as compared to morning eggs (Miles et al, 1984) may be due to increased transport of phosphorus from the blood to the shell gland, thus explaining the higher shell phosphorus content of HS eggs collected at 0700 hr as compared to those collected at 1100 hr.…”