scholarly journals Effect of Dietary Calcium Level, Calcium Lactate and Ascorbic Acid on the Egg Production of S.C. White Leghorn Hens

1962 ◽  
Vol 41 (5) ◽  
pp. 1596-1602 ◽  
Author(s):  
T.W. Sullivan ◽  
J.R. Kingan
1960 ◽  
Vol 55 (1) ◽  
pp. 137-140 ◽  
Author(s):  
Susan E. Kent ◽  
T. F. Reid ◽  
Alastair N. Worden

1. Three completed series of laying trials involving the incorporation of calcium lactate in the diet are reported.2. The addition of 1 or 2% calcium lactate to a layers mash results in a significant increase in egg production and/or the efficiency of the ration in terms of numbers of eggs per unit weight of food consumed. This effect has been obtained in birds at the onset of lay and also in birds that have been in lay for some 5 months.3. The incorporation of 0·5% calcium lactate appears to be inadequate.4. There is no evidence to date that the effect is attributable to dietary calcium, but the mechanism of action is unexplained.5. Egg-weight, but not egg-quality, as judged by routine candling, is slightly lowered by feeding calcium lactate.


1963 ◽  
Vol 22 (2) ◽  
pp. 501-505 ◽  
Author(s):  
L. A. Menahan ◽  
P. A. Knapp ◽  
W. G. Pond ◽  
J. R. Jones

Author(s):  
C. Pandian ◽  
A. Sundaresan ◽  
A. V. Omprakash

The present study was conducted to assess the effect of supplementation of Multi-enzymes with lysophospholipids on production performance of pure line White Leghorn layers. Body weights before and after the experiment did not differ significantly across the experimental diets. Irrespective of the dietary treatments, the birds gained 3.83 per cent of live weight relative to its initial body weight. Mean per cent Hen housed egg production was significantly (Pis less than 0.05) higher in diet supplemented with 0.10 MEC-L than other groups. Mean egg weight and average daily feed consumption during 25 to 35 weeks of age indicated no significant effect of enzyme supplementation. Average daily feed consumption per bird in control, 0.05 % and 0.1% multi-enzyme supplemented groups was 108.13, 105.66 and 107.67 g respectively and birds offered control diet recorded numerically more feed intake than enzyme supplemented groups. Comparatively low feed per egg was observed in 0.10 per cent group followed by 0.05 per cent group which offers economic benefits than control diets. However, the egg quality traits between different dietary enzyme supplementation groups showed no significant difference.


2018 ◽  
Vol 63 (No. 6) ◽  
pp. 230-236 ◽  
Author(s):  
J.O. Rosa ◽  
G.C. Venturini ◽  
T.C.S. Chud ◽  
B.C. Pires ◽  
M.E. Buzanskas ◽  
...  

This study estimated the genetic parameters for reproductive and performance traits and determined which ones can be used as selection criteria for egg production in laying hens using the Bayesian inference. The data of 1894 animals from three generations of White Leghorn laying hens were analyzed for fertility (FERT), hatchability (HATC), and birth rate measurements at 60 weeks of age (BIRTH), body weight at 16 and 60 weeks of age (BW16 and BW60), age at sexual maturity (ASM), egg height/width ratio, weight, and density at 28, 36, and 40 weeks of age (RHW28, RHW36, RHW40, WEGG28, WEGG36, WEGG40, DENS28, DENS36, and DENS40, respectively) traits. The genetic parameters were estimated by the Bayesian inference method of multi-trait animal model. The model included the additive and residual genetic random effects and the fixed effects of generation. The a posteriori mean distributions of the heritability estimates for reproductive traits ranged from 0.14 ± 0.003 (HATC) to 0.22 ± 0.005 (FERT) and performance from 0.07 ± 0.001 (RHW28) to 0.42 ± 0.001 (WEGG40). The a posteriori mean distributions of the genetic correlation between reproductive traits ranged from 0.18 ± 0.026 (FERT and HACT) to 0.79 ± 0.007 (FERT and BIRTH) and those related to performance ranged from –0.49 ± 0.001 (WEGG36 and DENS36) to 0.75 ± 0.003 (DENS28 and DENS36). Reproductive and performance traits showed enough additive genetic variability to respond to selection, except for RHW28. This trait alone would have little impact on the genetic gain because environmental factors would have a higher impact compared to those from the additive genetic factors. Based on the results of this study, the selection applied on the BIRTH trait can be indicated to improve FERT and HATC of eggs. Furthermore, the use of the WEGG40 could improve egg quality in this population.


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