Status of the Digestive System and Tibiae of Cropectomized Hens at Night

1981

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Four experiments were conducted to determine the effect of time of dietary calcium intake on shell quality. Hens in Experiments 1 to 3 were fed one or more diets containing the following calcium levels: 3.4% (daily); 6.4 and .4% (on consecutive days, in a 2-day feeding cycle); and 9.4, .4, .4% (on consecutive days, in a 3-day feeding cycle) such that each group received essentially 3.4% calcium over a 1-, 2-, or 3-day period, respectively. In Experiment 2, hens were also fed a 3.4 and .4% calcium diet on consecutive days in a 2-day feeding cycle. Three treatment groups were used in Experiment 4; the control group was fed a 3.4% calcium diet from 6 am to 8 pm; the other two groups were fed a .4% calcium diet over the same time period except that they were dosed with 3.0 g calcium at 8 am or 4 pm daily.Hens receiving diets containing an average of 3.4% calcium or approximately 3.4 g calcium per day over 2-or 3-day periods could not maintain shell weight, egg specific gravity, or serum calcium at levels comparable to that of control hens fed 3.4 g calcium daily. Hens fed the calcium-deficient diet also tended to overconsume feed when compared to controls. Hens dosed with 3.0 g calcium at 8 am consumed significantly less feed and had significantly lower shell weight and egg specific gravity than control hens, whereas dosing hens with 3.0 g calcium at 4 pm had no significant adverse effect on feed consumption or shell weight.It was concluded that time of dietary calcium intake had a significant effect on the ability of the hen to maintain shell quality. (

Section: Methodsmentioning

confidence: 99%

The Influence of Time of Dietary Calcium Intake on Shell Quality

Lennards

1981

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“…Samples were ground to uniform particle size, ashed at 600 C for 8 hr, and dilutions made using lanthanum oxide solutions as final diluent. Calcium content was determined by atomic absorption spectrophotometry (Stonerock et al, 1975).…”

Section: Methodsmentioning

confidence: 99%

Reproductive Performance of Laying Hens on Outbound and Return Sides of Automatic Feeders with Different Chain Speeds

Paulus

1986

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Experiments were conducted in six industry layer houses to determine the influence of hen position along the feeder on productive performance of laying hens. All hens were fed a commercial corn-soy mash diet with part of the limestone supplied in the form of pullet size particles of CaC0 3 . Four types of feeders, with six feeder speeds ranging from 2.5 to 27.3 m/ minute, were tested. Treatments consisted of birds on the outbound and return sides of feeder lines, with each treatment replicated six times. Criteria studied were egg production, body weight, feed consumption, egg weight, egg specific gravity, and body-checked and cracked eggs. Calcium content of the feed collected at different feeder positions was also determined.Results indicated that hens on the return sides of the feeder had twice as many cracked and 50% more body-checked eggs than hens on the outbound side. With the exception of two houses, the incidence of cracked and body-checked eggs was significantly greater on return than outbound feeder lines regardless of type of feeder or feeder speed. Hens on the return side consumed significantly more (8%) feed when fed ad libitum than hens on the outbound side. There were no significant differences in dietary calcium levels taken at different feeder locations or in egg specific gravity between treatments. There were no significant differences in egg production, egg weight, or body weight between treatments. Because the increase in shell breakage and body-checked eggs was not due to differences in shell quality (specific gravity), it is hypothesized that shell quality problems were the result of higher activity levels of hens on return lines. (

“…After weighing, the samples were ground to uniform particle size, ashed at 600 C for 6 hr, dissolved in concentrated HC1, and appropriate dilutions were made using lanthanum oxide solution as final diluent. Calcium content was determined by atomic absorption spectrophotometer as described by Stonerock et al (1975).…”

Section: Methodsmentioning

confidence: 99%

Influence of Dietary Ingredients on Calcium Utilization in the Laying Hen

Farmer

1986

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Experiments were conducted to evaluate the benefit of calcium supplementation with or without other dietary ingredients on egg shell quality. A total of 250 Hyline hens, 44 weeks of age, were randomly divided among five treatments (Experiment 1). The dietary treatments were as follows: Treatment 1, controls (C) were fed a 3.5% calcium diet ad libitum; Treatment 2, hens were fed a .08% calcium diet (LC); Treatment 3, hens were intubated with limestone following 24-hr consumption of .08% calcium diet (LCI); Treatment 4, feed removed for 24 hr (NF); Treatment 5, feed removed for 24 hr and hens then intubated with limestone (NFI). All diets were restored to the control calcium level after 48 hr. Experiment 2 was identical to Experiment 1 except Dekalb XL hens, 50 weeks of age, were used. Eggs were collected daily for 5 days for egg specific gravity, egg weight, and shell weight determinations. Forty hens were sacrificed in Experiment 2 at 48 hr into the experiment to measure calcium distribution in the gastrointestinal (GI) tract and feces. Results indicated that hens fed the LCI treatment produced eggs with significantly higher specific gravity and heavier shells than hens given limestone with an empty GI tract. The calcium analysis of the GI tract revealed that much of the calcium supplement did not move beyond the gizzard in hens fed the NFI treatment. It was concluded that hens not only needed other nutrients for maximum utilization of dietary and skeletal calcium, but other nutrients or dry matter may also be needed to facilitate the passage of calcium from the gizzard.