Effect of Diets with Various Calcium and Boron Levels in Prelaying Period on Growth, Bone Ash and Subsequent Performance and Shell Quality of Laying Hens (original) (raw)
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The influence of supplemental calcium given in flour or granular form and calcium intake on bone properties and egg characteristics of brown-egg laying hens was investigated at sexual maturity and at end of lay. Physical and mechanical bone characteristics were determined using 3-point and torsional tests. There was no effect of calcium source on the measured bone characteristics at sexual maturity. Bone breaking strength was positively correlated with both stiffness and total calcium intake. At 72 weeks, birds which had been offered additional calcium of either source exhibited considerably higher bone breaking strength than did control birds. Bone stiffness of birds offered limestone granules was significantly higher than control birds. Regression analysis showed strong relationships between calcium intake, bone stiffness and breaking strength. Shell quality was significantly better for birds consuming limestone in a granular form than for control birds. Shell quality for birds given limestone flour was intermediate between the other two groups. It is concluded that calcium supplementation increases egg quality, mechanical properties of the bone and as a consequence, may be able to reduce the risk of broken bones at the end of laying period. These effects are independent of the form of the supplemented calcium.
Poultry Science, 2008
A total of 1,152 Lohmann Brown laying hens were used to study the influence of level (3.5 and 4.0%) and source (coded FIN, COA, and OYS) of Ca in the diet on productive performance and egg quality from 58 to 73 wk of age. The FIN diet contained all the Ca carbonate as fine limestone (LIM). In the COA and OYS diets, 40% of the fine LIM was substituted with either coarse LIM or oyster shell. Each treatment was replicated 8 times (24 hens). Productive performance and egg quality traits were recorded every 4 wk, and tibia characteristics and shell quality traits were determined at 73 wk of age. An increase in Ca intake from 4.08 to 4.64 g/hen per day improved egg production (71.2 vs. 74.9%; P < 0.001), egg mass (49.0 vs. 51.4 g; P < 0.05), and feed conversion ratio (2.43 vs. 2.30 kg of feed/kg of egg; P < 0.001). In addition, an increase in Ca intake improved shell weight (9.98 vs. 10.20%; P < 0.05), shell thickness (0.342 vs. 0.351 mm; P < 0.01), and shell density (82.0 vs. 83.8 mg/cm 2 ; P < 0.001). Calcium source had no effect on productive performance, tibia characteristics, or egg quality except for shell density, which was greater for hens fed COA than for hens fed FIN, with hens fed OYS being intermediate (81.9 vs. 84.0 vs. 82.7 mg/cm 2 , respectively; P < 0.05). It was concluded that Brown egg-laying hens in the late phase of production require more than 3.5% Ca in the diet (4.08 g of Ca/hen per day) and that the substitution of 40% of fine LIM with COA or OYS does not affect productive performance and has little impact on shell quality and tibia characteristics.
The Effect of Different Dietary Calcium Levels on Calcium Metabolism in Laying Hens
“Agriculture for Life, Life for Agriculture” Conference Proceedings, 2018
The experiment was carried out on four groups of Hy-Line var. Brown hens (n = 350 each) fed on diets which provided 2.49, 3.07, 3.78 and, respectively, 4.15 g% calcium (Ca) during the laying period. Consequently, mean daily Ca intake was 2.74, 3.38, 4.16 and 4.60 g/cap., respectively. Ca metabolism was assayed at 20 weeks of age (start of the laying), 36 weeks of age (the peak of the laying) and 68 weeks (the end of the laying period). A significant part of the ingested Ca was not absorbed. The percentage of Ca exonerated by feces was higher at the start of the laying and lowers in the peak of laying and at the end of the laying period. The amount of Ca exonerated as unabsorbed Ca increases as the amount of ingested Ca increases inside of each age level. It was found also an increase of the Ca content of the egg shell according the Ca intake statistically significant (P<0.05) in 36- and 68-wk.-old hens, but not in 20-wk.-old hens. Blood plasma Ca showed significantly higher value...
South African Journal of Animal Science, 2010
In this study dietary boron at different doses (0, 25, 50, 100 and 200 mg/kg feed) was supplemented to layers from 4 to 64 weeks of age. There was no significant difference between treatments with respect of mortality, egg production, egg weight, egg mass and cracked eggs. Significant increases were observed in body weight as age rose. Body weight was not affected by dietary boron supplementation at 16 and 40 weeks of age. At 64 weeks of age boron additions of 50, 100 and 200 mg/kg to the diet resulted in significant lower body weights than that of the control group. Egg quality parameters; albumen height and Haugh units, were improved when 25 or 50 mg boron/kg diet was supplemented above the other treatments. Shape index, shell thickness, shell breaking strength were not affected by treatments, though 25 mg boron/kg diet tended to increase shell breaking strength. Tibia bone strength and phosphorus content in the tibia and femur were not affected by boron supplementation. Boron supplementation at 25 and 50 mg/kg significantly increased femur bone strength, and ash and calcium content of the tibia and femur bones. Concentration of boron in bone increased with the increase in dietary boron.
Effect of Dietary Calcium Sources on Laying Hens Performance and Egg Quality
Journal of Animal Production Advances, 2013
This study was designed to investigate the effect of feeding two different (oystershell and limestone) sources of calcium to layer hens (Bovan) on performance and egg shell quality. The experiment extended for 4 weeks during which 24 Bovan layers at 24 weeks were used. Birds were divided into two groups (12 bird/ treatment) with four replicates in each battery cage. Traits measured were egg production, feed intake, feed conversion ratio,, body weight change, egg weight, egg height, egg diameter, albumen weight, albumen height, yolk weight, shell weight, and shell thickness. Results showed that the source of calcium (oystershell versus limestone) significantly affected (P<0.05) egg production(59.82 Vs 76.19), feed intake(139.53 Vs142.02), feed conversion ratio(4.67 Vs 2.99) and body weight change (-4.67 Vs 8.91). On the other hand, the source of calcium had no significant effect (P<0.05) on egg weight, egg height, egg diameter, albumen weight, yolk weight, shell weight, shell thickness and shell ash. The results suggest that the inclusion of lime stone in layers ration as calcium source is more beneficial than oystershell.
The objective of this study was to determine the influence of limestone particle size in the diets with different contents of Ca on the biomechanical and geometrical measurements of tibia and femur bones, digestibility of nutrients, and selected biochemical blood variables. The experiment was conducted with 108 laying hens, allocated to 9 treatments of 6 replicates (cages), with 2 layers in each cage. A 3×3 factorial arrangement, with 3 dietary concentrations of Ca (3.20, 3.70, and 4.20%) and 3 levels of dietary substitutions (0, 25, and 50%) of fine particles of limestone (FPL; diameter, 0.2 to 0.6 mm) with large particles of limestone (LPL; diameter, 1.0 to 1.4 mm), was used. The hens were fed with experimental diets from 25 to 70 wk of age. At wk 45 a balance experiment was conducted, and after termination of the experiment, i.e., at wk 70, tibia and femur bones, and blood samples, were collected for analysis. Neither dietary Ca concentration nor limestone particle size had an effect on dry matter, organic matter, ether extract, N-free extracts, crude fiber, and crude ash digestibility, and P retention and excretion; however, Ca excretion increased linearly and Ca relative retention decreased linearly with increasing Ca dietary concentration (P<0.05). No effect of limestone particle size on tibia and femur biomechanical and geometrical measurements, tibia and femur mineralization, serum alkaline phosphatase activity, and serum Ca and P concentration, was observed. Increased dietary Ca concentration enhanced linearly tibia and femur bone breaking strength, yielding load, stiffness, and Ca concentration (P<0.05). Serum alkaline phosphatase activity decreased linearly with increasing Ca dietary concentration (P<0.05). In conclusion, the results of this study demonstrated that a content of 3.20 to 3.70% Ca in a layer’s diet is not sufficient through the entire laying cycle to maintain optimal bone quality; however, partial substitution of fine- with large-particle limestone does not improve Ca and P retention and bones quality variables.
Biological and economic optimum level of calcium in white leghorn of second cycle laying hens
Agrociencia, 2006
Calcium is important for optimum performance and eggshell formation, since inadequate levels in the diet of laying hens may affect shell quality and egg production. An experiment with 250 Leghorn Hy-Line® W-98 was conducted to evaluate the effect of five calcium levels (2.74, 3.48, 4.06 and 5.19% and three laying periods (79 to 87, 88 to 96 and 97 to 105 weeks of age) on egg production and shell quality. There was no interaction between calcium level and laying period, but the main effects showed that: the calcium level of the diet affected (p≤0.05) daily feed and calcium intake, egg weight, eggshell thickness but not egg mass, feed conversion and egg specific gravity. There were differences among periods (p≤0.05) in all productive performance and eggshell quality as the age of the hens advanced, except in egg weight. The biological optimum levels for maximum egg mass and shell thickness were 3.17 and 4.02 g hen1 d1, and the economic optimum level was 3.17 g hen1 d1.
Arch. Anim. Breed., 58, 301-307, 2015
The objective of this study was to evaluate the effect of particle size of a dietary Ca source on egg production and eggshell quality when added to hens’ diets that have different levels of calcium. The experiment was carried out on 216 ISA Brown hens (25 to 70 weeks of age), allocated to 9 groups of 12 replicates (cages), with two birds in each cage. A 3 x 3 factorial arrangement was used, with three dietary levels of calcium (3.20, 3.70 and 4.20 %) and three levels of dietary substitutions (0, 25 and 50 %) of fine particles of limestone (FPL, diameter 0.2–0.6 mm) with large particles of limestone (LPL, diameter 1.0–1.4 mm) as a Ca source. The level of Ca in the diet had no effect on egg production, mean egg weight, feed intake, feed conversion ratio or eggshell quality parameters (P>0:05). Substitution of FPL with LPL did not affect laying performance indices or eggshell quality at 30, 43 and 53 weeks of age (P>0:05); however, it increased (P<0:05) eggshell percentage, thickness, density and breaking strength in older hens (69 weeks of age). In conclusion, the results of this study demonstrated that a level of 3.20% Ca in a layer’s diet is sufficient through the entire laying cycle to maintain good egg production and eggshell quality and that partial (25 or 50 %) substitution of fine- with large-particle limestone can, irrespective of the level of Ca in the diet, improve eggshell quality in aged laying hens.
Effect of Calcium Sources and Particle Size on Performance and Eggshell Quality in Laying Hens
Turkish Journal of Agriculture - Food Science and Technology, 2014
An experiment was conducted to determine the effect of different combination calcium sources and particle size on performance and egg shell quality in layer hens. In the experiment, 198 brown laying hens at 44 week of age were randomly assigned into 11 treatments groups. The experimental diets consisted of different calcium sources (Fine limestone, large limestone, large oyster shell and large egg shell) and their different combination. The experimental unit consisted of a groups of three hens, thus each treatment was replicated six times. Different calcium sources and particle size addition to the laying hens diet had no significantly effect on body weight gain, egg production, egg mass, feed intake, feed conversion ratio, egg specific gravity, egg shell weight, egg shell thickness and egg shell breaking strength but egg weight had significantly affected by the treatments. The significantly highest egg weight was found in laying hens fed with 50 % fine limestone and 50 % large lime...
The effect of dietary inclusion of meat and bone meal on the performance of laying hens at old age
South African Journal of Animal Science, 2004
The effect of the inclusion of meat and bone meal (MBM) in the diet of old laying hens on their egg production and the quality of their eggs was investigated. Meat and bone meal containing a high concentration of ash and a low concentration of crude protein was included at levels of 2.0, 4.0 and 6.0% in the diets and fed for 20 weeks. Forced moulted 84-week old laying hens (Brown-Nick) were divided randomly into four treatment groups of 120 hens each. The inclusion of 2.0% MBM to the layer diet increased hen-day egg production significantly, whereas inclusion in excess of 2.0% MBM had no additional beneficial effect on egg production. However, the inclusion of dietary MBM at all three levels depressed egg weight. There were no significant effects of dietary treatments on egg weight, feed intake and feed conversion ratio of the hens. The specific gravity of the eggs from hens fed the control diet was significantly lower than from those receiving the diets containing 2.0 and 4.0% MBM. The Haugh Unit value of eggs in the 6.0% MBM treatment was significantly higher than the other treatments. There were no significant effects of MBM inclusion on yolk colour score, yolk height, eggshell thickness, eggshell weight and eggshell strength. However, MBM inclusion in a diet had a significant beneficial effect on eggshell quality. The eggshell ratios of the 2.0, 4.0 and 6.0% MBM treatments were significantly higher than in the control diet, while the cracked/broken egg ratio was significantly lower. In conclusion, inclusion of MBM containing a high ash and low crude protein content to conventional maize-soya bean diet improved egg production performance of laying hens. The dicalcium phosphate level in the diet could also be reduced without any adverse effects on egg production and egg quality.