scholarly journals The Lack of Response of 25-Hydroxy-Vitamin D3 on Egg Shell Quality or Other Criteria in Laying Hens

1976 ◽  
Vol 55 (5) ◽  
pp. 1983-1985 ◽  
Author(s):  
D.A. Roland ◽  
R.H. Harms
Keyword(s):  
Vitamin D3 ◽  
Laying Hens ◽  
Shell Quality ◽  
Egg Shell

Nutritional and environmental factors involved in egg shell quality of laying hens

1992 ◽  
Vol 33 (4) ◽  
pp. 781-794 ◽  
Author(s):  
J. Grizzle ◽  
M. Iheanacho ◽  
A. Saxton ◽  
J. Broaden
Keyword(s):  
Environmental Factors ◽  
Laying Hens ◽  
Shell Quality ◽  
Egg Shell

Assessing the response of hen weight, body composition, feather score, egg quality, and level of excreta nitrogen content to digestible balanced protein intake of laying hens

2018 ◽  
Vol 98 (4) ◽  
pp. 619-630 ◽  
Author(s):  
D. Kumar ◽  
C. Raginski ◽  
K. Schwean-Lardner ◽  
H.L. Classen
Keyword(s):  
Egg Production ◽  
Diet Composition ◽  
Laying Hens ◽  
Egg Quality ◽  
N Content ◽  
Shell Quality ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Egg Shell ◽  
Level Of Significance

Ideally balanced dietary protein is critical for laying hen egg production and feed efficiency, but also affects other important characteristics. This research was designed to study the nonegg production and feed intake response of Lohmann-LSL Lite hens to 550, 625, 700, 775, and 850 mg d−1 of amino acid balanced digestible lysine (Dlys) from 27 to 66 wk of age. Data collection included hen weight (HW), feather scoring, tissue weights, egg specific gravity, egg component weights, and excreta nitrogen (N) content. The experiment was a completely randomized design and level of significance was fixed at P ≤ 0.05. Hen weight (quadratic, Q), pectoralis muscle (absolute, % – Q), and abdominal fat (absolute – linear, L; % – Q) increased with increasing Dlys intake. Although gastrointestinal segment weights and lengths were affected by Dlys intake, interpretation of results was confounded by other aspects of diet composition. Hen feather score (L) and excreta N content (Q) increased, and egg shell quality (L) decreased with increasing Dlys intake. Absolute egg component weights increased with Dlys intake, but effects on proportional weights were Q and relatively minor. In conclusion, balanced Dlys intake affected a variety of practical nonproduction characteristics in laying hens.

scholarly journals Calcium particle size and feeding time influence egg shell quality in laying hens

2019 ◽  
Vol 41 (1) ◽  
pp. 42926
Author(s):  
Aliasghar Saki ◽  
Abbas Rahmani ◽  
Azam Yousefi
Keyword(s):  
Particle Size ◽  
Laying Hens ◽  
Feeding Time ◽  
Shell Quality ◽  
Egg Shell

scholarly journals The Response of Layer Hen Productivity and Egg Quality to an Additional Limestone Source when Offered Diets Differing in Calcium Concentrations and the Inclusion of Phytase

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2991
Author(s):  
Isabelle Ruhnke ◽  
Yeasmin Akter ◽  
Terence Zimazile Sibanda ◽  
Aaron J. Cowieson ◽  
Stuart Wilkinson ◽  
...  
Keyword(s):  
Egg Production ◽  
Laying Hens ◽  
Egg Quality ◽  
Nutrient Digestibility ◽  
Egg Mass ◽  
Shell Weight ◽  
Shell Quality ◽  
Ad Libitum ◽  
Egg Shell ◽  
The Impact

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). Egg weight, rate of lay, and egg mass were unaffected by dietary treatment (p > 0.05). Egg shell weight % (p < 0.001), shell thickness (p < 0.001), and shell breaking strength (p < 0.01) decreased in line with dietary Ca levels. In summary, dietary superdosing with phytase reduced the consumption of a separate limestone source in individually housed, early lay ISA Brown hens. Egg shell quality variables but not egg production worsened in line with lower dietary Ca levels.

scholarly journals Egg quality and age of laying hens: implications for product safety

2013 ◽  
Vol 53 (12) ◽  
pp. 1291 ◽  
Author(s):  
J. R. Roberts ◽  
Kapil Chousalkar ◽  
Samiullah
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Laying Hens ◽  
Egg Quality ◽  
Age Groups ◽  
Product Safety ◽  
Shell Quality ◽  
Low Correlation ◽  
Egg Shell ◽  
Scanning Electron

Eggs were collected from commercial caged layer flocks in early, mid, late and very late lay. Eggs were candled and scored for translucency. Cuticle cover was estimated using MST Cuticle Stain and a Konica Minolta hand-held spectrophotometer. Traditional measures of egg quality were determined using specialised equipment. Shell ultrastructural features were scored following plasma ashing of shell samples and viewing under a benchtop scanning electron microscope. Translucency score was significantly higher in late lay than for all other age groups. Shell quality declined with increasing flock age. However, the extent of cuticle cover on the egg shell was not significantly different among flock age groups. The incidence of shell ultrastructural features associated with good quality shells was lower for older flocks and incidence of ultrastructural features associated with poorer quality shells was higher for older flocks. Translucency score had a low correlation with the ultrastructural features of the mammillary layer.

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