Use of Particulate Limestone or Oyster Shell in the Dietary Regimen of White Leghorn Hens

Abstract

Three experiments, initially containing 6912 or 8192 Single Comb White Leghorn pullets from 9 or 40 genotypes, were carried out to determine the effects of replacing a portion (28%) of the dietary calcium from pulverized limestone (LS) with hen-size particulate LS (Experiment 1) or supplementing 3.2% calcium-containing diets with oyster shell (OS) (Experiments 2 and 3) during the first laying cycle (Experiments 1 to 3) and second laying cycle (Experiment 3). The hens were housed either 1 or 3 hens/cage in Experiment 3 and 1 hen/cage in Experiments 1 and 2.Replacing a portion of the pulverized LS with particulate LS produced an increase in egg specific gravity compared to 3.3% calcium-containing control diet but had little effect on egg production and weight, viability, body weight, or interior egg quality. Supplementary OS also increased specific gravity, particularly of eggs produced in the latter part of the laying cycle (450 and 900 days), but viability was decreased due to kidney disorders, and egg weight decreased in Experiment 3 compared to the control. While feed intake was lower and egg production higher for the OS-supplemented than nonsupplemented hens in Experiment 2, the reverse occurred in Experiment 3 during both the first and second laying cycles. There were few interactions between dietary calcium treatment and genotype of hen or housing density. The average total calcium intake was 5.2 g/day for the hens that received OS and about 3.4 g/day for the nonsupplemented hens in the first laying cycle of Experiments 2 and 3. For the second laying cycle of Experiment 3, the total calcium intakes were 5.9 and 3.4 g/hen/day for the OS-supplemented and nonsupplemented hens, respectively. Further studies are needed to establish the economic importance of the improvement of shell quality when the diets of hens housed at more than 1 bird/cage are supplemented with OS because of the decreases in egg yield, viability, and production efficiency. (

Eggshell Quality as Influenced by Sodium Bicarbonate, Calcium Source, and Photoperiod

“…Haugh units were significantly higher (P<.01) when limestone was provided as the only Ca source and the photoperiod was restricted to 16 hr (Table 4). These findings are similar to those of Hamilton et al, (1985) who reported lower Haugh units from eggs when hens were provided oyster shell. A significant increase (P<.01) in yolk pigmentation when dietary NaHC0 3 was provided (Tables 4 and 5) is similar to the findings of Bushong et al (1972), but contrary to those of Ernst and Hendershott (1977).…”

“…Scott et al (1971) reported that oyster shell particles accumulated in the gizzard during the day and dissolved slowly throughout the night, thus maintaining elevated blood Ca levels during nonfeeding periods. Different aspects of shell quality were reported to be improved by partial replacement of limestone with oyster shell in the diet (Moran et al, 1970;Scott et al, 1971;Brister et al, 1981); Duke, 1981 andHamilton et al, 1985). Additional support is provided by the results of this study.…”

Effect on Layer Performance and Shell Quality of Switching Limestones with Different Solubilities

“…In the present study, the substitution of oyster shell for limestone of equal particle size showed no beneficial effect on shell quality. Anderson et al (1982) and Hamilton et al (1985) reported a similar finding when equal particle sizes were used.…”

Calcium from limestone meal and grit in laying hen diets - effect on performance, eggshell and bone quality

“…The effect of LG and oyster shell at 100 % substitution for limestone meal on performance, eggshell and bone quality was generally similar and confirms the findings of Hamilton et al (1985).…”