Increasing stocking density of Egyptian laying hens by using:2 - enzymes &tranquilizers
Abstract: A study was conducted to increasing stoking density of Egyptian laying hens from 8 to 12 birds / m2. Also, to investigate the ability of supplemental Enzymes (Avizyme) or Tranquilizer (Diazepam) to alleviate the deleterious 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 first three groups were housed as 8 birds / m2 to achieve hen density of 1250 cm2/bird. The other three groups were housed as 12 birds / m2 to achieve hen density of 834 cm2/ bird. Every category was fed the basal diet, fortified with 1 gm avizyme / kg diet or 2 ppm diazepam, respectively. .
Results indicated that increasing stocking density (12 birds / m2) significantly reduced body weight gain, egg laying rate, total egg mass, feed consumption and lymphocyte cells number (L). Besides, mortality rate and erythrocyte cells were significantly increased but feed conversion was not affected. Conversely, in response to avizyme or diazepam supplements, live weight gain, mortality rate, feed consumption, feed conversion, egg laying rate and egg mass were improved (P<0.05) in both densities or overall means, indicating that the two supplements alleviate the negative effects of increasing stocking density to 12 bird/m2. Egg weights were not significantly influenced by either densities or dietary supplements. Except for yolk index which altered (P<0.05) with enzyme supplementation, none of the egg quality parameters, fertility, hatchability, average values of relative hatched chick weight and absolute chick weight were affected by either dietary supplementations or both stocking densities. Diazepam supplementation reflected (P<0.05) higher T3 hormone and total protein as well as albumin and globulin, in both densities; however none of metabolic profile parameters were affected by the avizyme addition. A significant raise in heterophil cells (H) number, together with a corresponding significant reduction in lymphocyte cells (L) number also, significant increase in Heterophils / Lymphocytes ratio, and appearance of monocyte cells were observed with increasing stocking density. Conversely, both types of supplementation caused (P<0.05) decrease in Heterophil cells number, also (P<0.05) increase in leucocytes which attribute to increase lymphocyte cells (P<0.05), Heterophils / Lymphocytes ratio was significantly (P<0.05) lower, and disappear of monocyte cells, indicating that the dietary supplementation could partially ameliorate haematological stress of increasing stocking density. The results would suggest that increasing stocking density from 8 to 12 birds / m2 with avizyme or diazepam supplementation increased egg productivity and minimizing the physiological stress without worsen egg quality. Seemingly, the new aspects could be applicable to achieve sharp decreases (50%) in the housing, wages and labor, and equipment costs per hen subsequently maximizing profits and economic returns of layer farms and assurance the alternative of increasing stocking density to 12 birds / m2 and that does not lead to excessively poor bird welfare.
Publication year 2008
Pages 553-574
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		 Enzymes. Layer chickens. Stocking density.
Proposed Agrovoc Enzymes Stability;Tranquilizing drugs;
Publication Type Journal
↑