scholarly journals Influence of supplemental phytase on calcium and phosphorus utilization in laying hens

1998 ◽  
Vol 77 (2) ◽  
pp. 290-294 ◽  
Author(s):  
R.W. Gordon ◽  
D.A. Roland
Keyword(s):  
Laying Hens ◽  
Phosphorus Utilization ◽  
Calcium And Phosphorus

scholarly journals Prolonged Dark Time Within A 24-h Light Regime Improves Eggshell Quality by Enhancing Calcium Deposition in Laying Hens

2020 ◽  
Author(s):  
Qian Xin ◽  
Jingpeng Zhao ◽  
Hongchao Jiao ◽  
Haifang Li ◽  
Xiaojuan Wang ◽  
...  
Keyword(s):  
Feed Efficiency ◽  
Egg Production ◽  
Laying Hens ◽  
Light Regime ◽  
Calcium Deposition ◽  
Eggshell Quality ◽  
Dark Time ◽  
Calbindin D28k ◽  
Calcium And Phosphorus ◽  
Calcium Transporter

Abstract Background: The absorption and transportation of calcium and phosphorus is mainly relied on their corresponding transporters. Eggshell is mainly formed during dark time in one egg cycle. The aim of this study was to determine the effect of different light regime on eggshell quality and the expression of the relevant calcium and phosphorus transporters in laying hens. Seventy two 56-week-old laying hens were randomly divided into two groups and subjected to the following treatments: 16 h light: 8 h dark (control) and 9 h light: 15 h dark (LDP). The expression of phosphorus transporters type IIb Na/Pi co-transporter NaPi-IIa (NPt2a) and NaPi-IIb (NPt2b), calcium transporter calbindin-D28k (CaBP-D28k), and plasma membrane Ca ATPase 1b (PMCA1b) were measured in small intestine, kidney, and eggshell gland. Results: The results showed that the feed intake (P < 0.001) and egg weight (P = 0.05) was decreased by LDP treatment, while laying rate, egg production, and feed efficiency were not significantly influenced (P > 0.05). Compared to control, eggshell hardness was increased (P < 0.05) by LDP treatment whereas eggshell thickness and eggshell percentage were not significant changed. Eggshell calcium (Ca) and phosphorus (P) contents were elevated in LDP-hens, compared to control birds. Compared to control birds, serum Ca (P < 0.01) and P levels (P = 0.079) at dark time were increased in LDP-hens while and alkaline phosphatase (ALP) activity was lowered (P < 0.05). The protein expression levels of CaBP-D28k and PMCA1b were not influenced in duodenum but were decreased at light time in jejunum of LDP hens. In kidney, the expression of CaBP-D28k, PMCA1b and NPt2a were not changed by LDP treatment. In eggshell gland, however, the expression of CaBP-D28k and osteopontin (OPN) were relative higher in LDP hens compared to control birds, whereas the PMCA1b expression was not altered. Conclusions: The result indicates that the increased circulating Ca and P concentrations in dark time are favorable for the deposition of calcium and phosphorus in eggshell. The result offers an alternative strategy for the laying hen with a worse eggshell problem.

scholarly journals Laying performance and eggshell quality in laying hens fed diets supplemented with prebiotics and organic acids

2010 ◽  
Vol 55 (No. 7) ◽  
pp. 294-306 ◽  
Author(s):  
S. Świątkiewicz ◽  
J. Koreleski ◽  
A. Arczewska
Keyword(s):  
Organic Acids ◽  
Egg Production ◽  
Volatile Fatty Acids ◽  
Laying Hens ◽  
Feed Additives ◽  
Egg Mass ◽  
Positive Effects ◽  
Eggshell Quality ◽  
Laying Performance ◽  
Calcium And Phosphorus

The aim of the study was to evaluate the effect of organic acids and the prebiotic fructans on egg production and eggshell quality when added to the layer diet with different levels of calcium and phosphorus. The experiment was carried out on 168 Bovans Brown hens, allocated to 14 groups of 12 replications. Each hen (replication) was kept in an individual cage 40 cm &times; 40 cm in size. A 2 &times; 7 factorial arrangement, with two dietary levels of calcium and phosphorus (normal &ndash; 3.70% Ca, 0.65% P, and reduced &ndash; 3.25% Ca, 0.60% P) and with diets supplemented by selected additives (none, 0.75% inulin, 0.75% oligofructose, 0.50% volatile fatty acids (VFA), 0.25% medium chain fatty acid (MCFA), 0.30% VFA + 0.20% MCFA, 0.75% inulin + 0.50% VFA) was used. The experiment was carried out over 34 weeks, from the age of 26 to 70 weeks. There were no statistically confirmed effects of the factors studied in this experiment on egg performance, i.e. laying rate, egg mass, feed intake and feed conversion. Reducing the dietary levels of Ca and P significantly decreased eggshell percent, thickness, density and breaking strength. The additives used had a considerable effect on eggshell quality at 46, 58 and 70 weeks of age, and these positive effects were most pronounced in the case of inulin and MCFA. There was no significant interaction between Ca and P dietary levels and the additives used. It was thus concluded that selected feed additives which lower the pH of the diet and intestinal content can beneficially influence eggshell quality in older high-producing laying hens. &nbsp;

A critical study of the failure of a long-term calcium and phosphorus balance experiment with laying hens

1960 ◽  
Vol 54 (1) ◽  
pp. 131-139 ◽  
Author(s):  
N. K. Jenkins ◽  
C. Tyler
Keyword(s):  
Laying Hens ◽  
Systematic Errors ◽  
Critical Study ◽  
Short Term ◽  
Phosphorus Balance ◽  
Long Term Experiments ◽  
Calcium And Phosphorus

A long-term calcium and phosphorus balance experiment with laying hens is described.The cumulative balances of calcium and phosphorus over a whole year were seen to be physiologically impossible.Results from other workers using short term balances could be equally impossible and a similar situation has recently been noted in balance experiments with ruminants.The techniques employed in the experiment were, therefore, investigated in detail.Only systematic errors could be responsible and it was found that the most likely source of such errors was (a) the spilling of food on to the floor or into the water bowl, and (b) failure to collect all the droppings.These errors only become apparent in long-term experiments and are more pronounced when diets containing high levels of calcium and/or phosphorus are fed.

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