Egg Shell Quality and Bone Status as Affected by Environmental Temperature, Ca and Non-Phytate P Intake and in vitro Limestone Solubility in Single-Comb White Leghorn Hens (original) (raw)
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Egyptian Poultry Science Journal, 2020
This research examined the inspiration of different proportions of large and small particles of limestone on egg production, eggshell quality and breaking strength of tibia from 32 to 44 weeks of age in Golden Montazah layers diets. Chickens were randomly allocated to four groups-32 pullets per group were divided into four replicates. Limestone consisting of fine (F > 0.6 mm) and large (L>2.8mm-4.5mm). All chickens obtained a basal diet of the similar formula. Variations between four equal groups depends on the ratio of fine pulverized limestone by larger particle size limestone. Significantly higher eggshell breaking force (31.69N), shell weight (5.65 g), and shell thickness (0.46 mm) were obtained for eggs from the fourth treatment of hens than (29.46 N; 5.33 g ; 0.37mm respectively) for eggs from the control group. Tibia breaking strength was significantly higher for the fourth group (350.66 N) vs. (252.82 N) respectively than those in control group. The conclusion of our study present some chances of eggshell quality enhancement by the use of larger limestone particles as a Ca supplement in layer diets. From 60% to 100% replacement of small size by large particle of limestone given helpful results on eggshell and tibia bone qualities.
Misr journal of agricultural engineering, 2019
This study investigated the influence of different particle sizes of limestone in Golden Montazah layers diets on physical and mechanical properties of egg production, eggshell quality and breaking strength of tibia from 32 to 44 weeks of age. Limestone consisted of fine (F> 0.6 mm) and coarse (C>2.8mm-4.5mm). All hens take a basal ration of the same composition. The differences between the four equal groups were in the replacement percent of fine pulverised limestone by granular limestone, of coarser particle size. The control group takes the basal diet with only pulverised limestone as a calcium supplement. In the diet ration of the second group, 60% of the pulverised limestone was replaced with granular limestone, in the third group percent 80 % and in the last group 100% of fine limestone replaced with coarse particles of limestone. Significantly higher breaking force (31.69N), shell weight (5.65 g), shell thickness (0.46 mm) were found for eggs from the fourth group of hens than for eggs from the control group (29.46 N; 5.33 g ; 0.37 respectively). Tibia breaking strength was significantly higher (350.66 N) than those in control group (252.82 N). The results obtained in our investigation showed some possibilities of eggshell quality improvement using limestone of coarser particle size as a Ca supplement in the hen diet. Replacing 60-100% of fine limestone by coarser particle size limestone had positive effects on eggshell quality.
Limestone particle sizes and lighting regimens on egg and bone quality of laying hens
Pesquisa Agropecuária Brasileira, 2015
The objective of this work was to evaluate the effect of limestone particle sizes in the diet and of lighting regimes on the egg and bone quality and on the performance of commercial laying hens. Three hundred Hissex White layers, at 18 weeks of age, were distributed in a completely randomized design, in a 5×2 factorial arrangement (coarse limestone in the diet at 0, 25, 50, 75, and 100%; with or without artificial light), with five replicates of six birds. No significant interaction was observed between particle sizes and lighting regime for the evaluated parameters. There was no significant effect of coarse limestone level in the diet on the performance and egg quality of hens; however, bone deformity (3.23 to 4.01 mm), strength (5.19 to 6.70 kgf cm-2), and mineral matter (51.09 to 59.61%) improved as the proportion of coarse limestone increased. For lighting regime, the treatment with artificial light yielded higher Haugh unit values (87.17 vs. 85.54) than that with natural light only. Greater limestone particles improve bone quality of laying hens, and the use of artificial light can benefit the albumen quality of the eggs.
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.
Effect of the levels of calcium and particle size of limestone on laying hens
Revista Brasileira de Zootecnia, 2011
This experiment was conducted to evaluate the effect of levels of calcium (Ca) and particle size of limestone (LS) for laying hens. It was used 216 Dekalb White laying hens at 25 to 49 weeks of age in a completely randomized design in a 3 × 2 factorial arrangement, composed of three levels of calcium (3.92, 4.02 and 4.12%) and two particle sizes of limestone (thin - 0.60 mm; and thick - 1.00 mm), resulting in 6 treatments with six replicates of six birds. There was no significant effect of levels of calcium and limestone particle size neither of the interaction calcium × particle size for feed intake, egg weight, specific gravity, shell thickness, shell percentage, Haugh unit, calcium and phosphorus digestibility and percentage of digestive tract. Production, mass, conversion by mass and conversion by egg dozen had their best results with 4.12% of calcium in the diet. Percentage of gizzard and feed intake observed at 3:00 p.m. improved as limestone granulometry improved from 0.60 to...
Limestone was crumbled into fine particles (LF) of 0.1-0.4 mm or to a particulate grit (LG) of 2-4 mm. One hundred and eighty individually kept Hy-Line Brown laying hens were used in the experiment and divided into 10 groups. Diets containing 8.1% of LF or LG substituted for LF at a proportion of 10, 20, 40, 50, 60, 80 and 100% were compared with diet containing 8.1% oyster shells. At moderate substitution levels, the particulate limestone grit increased the thickness of eggshells in the first laying period (60-80% LG), improved yolk pigmentation (20-100% LG) and enlarged calcium deposition in eggshells (10-100% LG). Partial (20-90%) and complete substitution of LG for LF increased eggshell breaking strength, but improvement of tibia bone strength was observed only at 20% LG limestone. Analysis of feed refusals suggests that the limit value of voluntary intake of grit particles LG is 5.5 g daily per hen.
Comparative use of oyster shell and limestone as sources of calcium in the diet of laying chickens
Nigerian Journal of Animal Production, 2020
Egg producers primarily use oyster shell or limestone as supplemental sources of dietary calcium. This study was conducted to investigate the efficiencies of limestone (CaCo3 ) and oyster shell as calcium sources in the diets of laying hens. Ninety, 58 weeks old Golden Comet Hubbard laying birds were randomly allotted to three treatments of three replicates. Each replicate had 10 birds per replicate. Three different rations were formulated for the study. To include Diet 1 as the control, a diet with bone meal (46%) and oyster shell (54%). Diet 2 had oyster shell and bone meal supplying 82% and 18% of the dietary calcium while Diet 3 had 82% and 18% of the dietary calcium supplied by limestone and bone meal respectively. Feed and water were provided ad-libitum. The parameters measured include: Feed intake (g/d); Hen day production (%); Efficiency of feed utilization (kg); Egg and shell weight (g); Bone weight (g); Ash content of bone (%) and Calcium content of bone (%). The study las...
Animals
Laying hens require substantial quantities of calcium (Ca) to maintain egg production. However, maintaining recommended dietary Ca through inclusion of limestone may impede nutrient digestibility, including that of other minerals. It was hypothesized that providing a separate source of dietary Ca in the form of limestone grit would preserve Ca intake of hens offered diets containing suboptimal Ca concentrations. Furthermore, the impact of dietary phytase at a “superdosing” inclusion rate on the voluntary consumption of limestone grit was evaluated. One hundred and forty-four laying hens (19 weeks of age) were assigned to one of six dietary treatments in a 3 × 2 factorial arrangement comprising three dietary Ca concentrations (40, 30, and 20 g/kg) and ±dietary phytase (3500 FYT/kg diet) on an ad libitum basis for six weeks. Limestone grit (3.4 ± 1.0 mm) was provided to all hens ad libitum. Hens offered diets containing phytase consumed significantly less limestone grit p = 0.024). Eg...
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 Journal of Applied Poultry Research, 2012
A commercial diet (CM diet; 17.4% CP and 4.37% Ca) was compared with a diet with 35% replacement of limestone by a CaSO 4-zeolite mixture (5.76% CaSO 4 and 1.18% zeolite) and a 0.4 percentage units reduction in protein content (RE diet) in laying hens. Apparent N retention, egg production, egg composition and excreta pH were measured. Previous studies demonstrated that the RE diet reduced ammonia emissions by 48%. Laying hens (192 total; 48 replicate cages per diet with 2 hens per cage; 1441 ± 135 g initial BW) were fed experimental diets from 33 to 49 wk of age. Apparent N retention averaged 48.2% (P > 0.05). Egg production (83.6%) and number of shell-less eggs (0.18%) were not affected by the diet. Eggs tended to be heavier (59.4 vs. 58.8 g/egg, P = 0.06) and yolk percentage (29.7 vs. 29.0%, P = 0.013) was greater with the RE diet. At 48 wk of age, the total solids content per egg was also greater from hens fed the RE diet (13.2 vs. 12.6 g/egg, P = 0.032). Other egg components were not influenced by diet (58.1% of albumen and 9.04% of shell). Feeding the RE diet resulted in a higher specific gravity (1.0786 vs. 1.0656 g/g, P = 0.014) only when hens were 44 wk-old. At the end of the experiment, excreta were collected from all cages (excreta from 3 cages were mixed and pooled; 16 pools of excreta per diet). At collection, excreta of hens fed the RE diet had lower pH (5.89 vs. 6.54, P < 0.001) and higher moisture content (74.0 vs. 70.9%, P < 0.001) than those of hens fed the CM diet. After 7 d of storage, excreta pH of hens fed the RE diet continued to be lower (6.30 vs. 8.36, P < 0.001). A slight reduction in dietary protein and replacing a portion of the Ca from CaCO 3 with CaSO 4 did not affect egg production nor did it impair shell quality. Feeding the RE diet to laying hens resulted in a reduction in excreta pH, even after 7 d of storage, as compared with laying hens fed the CM diet.