Increasing stocking density of Egyptian laying hens: 1- antioxidants &live yeast
Abstract: A study was designed to increasing stoking density of Egyptian laying hens from 8 to 12 birds / m2. Also, to investigate the ability of supplemental antioxidants mixture (0.3 mg Selenium + 2g Ascorbic acid + 50.000 IU vitamin A + 100 mg Tocopherol /kg feed) or live yeast (Saccharomyces cerevisiae 5 xl012 CFU/g) to avoid the detrimental effects of increasing stocking density to 12 birds / m2. A total of 330 pullets and 30 cocks of Dandarawy at 20 wks of age were randomly chosen. Birds were allocated into six groups. The 1st , 2nd and 3rd groups were placed in 8 birds / m2 to achieve hen densities of 834 cm2/ bird However, the 4th , 5th and 6th groups were placed in 12 birds / m2 to achieve hen density of 834 cm2 / bird. Every stocking density category was fed either basal diet, plus I g antioxidants mixture / kg diet, or plus 1 g live yeast / kg diet, respectively.
Results indicated that increasing stocking density from 8 to 12 birds / m2 significantly reduced body weight gain, egg laying rate, total egg mass, feed consumption. Besides, mortality rate and erythrocyte cells were significantly increased and feed conversion was not affected Conversely, supplementing the laying diet with either antioxidants mixture or live yeast considerably improved (P<0.05) live weight gain, mortality rate, feed consumption, feed conversion, egg laying rate and egg mass due to both densities or in overall mean, indicating that the two supplements could alleviate the negative effects of increasing stocking density. Egg weights were not significantly influenced by either densities or supplemental diets.
Supplementary antioxidant mixture caused (P<0.05) higher Haugh units, shell thickness and yolk index only whereas; yeast did not affect egg quality in any term. Both supplementations had a positive effect (P<0.05) on fertility and hatchability percentages. Supplementary antioxidants or yeast to layers diet increased (P<0.05) plasma concentration of total protein as well as albumin and globulin, in opposite glucose were decreased (P<0.05), while T3 ALT or AST values did not change. A significant raise in heterophil cells number, together with a corresponding significant reduction in lymphocyte cells number also, significant increase in Heterophils Lymphocytes ratio. and appearance of monocyte cells were observed with increasing stocking density. Conversely, a significant decrease (P<0.05) in Heterophil cells number, significantly (P<0.05) increase in Leucocytes, attribute to increase lymphocyte cells (immunity improvement), also (P<0.05) decrease of H/L ratio, and disappear monocyte cells were detected due to increasing stoking density with both types of supplementations as compared to their control, indicating that both supplementations could be attenuate haematological stress of increasing stocking density. Summarily, supplementation of antioxidants and live yeast to laying hens could be considered as a potential protective management practice in preventing or ameliorating the detrimental effects of increasing stocking density of laying hens from 8 to 12 birds / m2 and assurance this alternative and that does not lead to excessively poor bird welfare.
Publication year 2008
Pages 575-598
Availability location معهد بحوث الانتاج الحيوانى- شارع نادى الصيد- الدقى - الجيزة
Availability number
Organization Name
City الاسكندرية
serial title Egyptian Poultry Science
ISSN 1110-5623
Author(s) from ARC
Agris Categories Animal physiology - Nutrition
AGROVOC
TERMS		 Aflatoxins. Antioxidants. Ascorbic acid. Layer chickens. Retinol. Selenium. Stocking density. Tocopherols. Yeasts.
Publication Type Journal
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