Responses of laying hens to induce molting procedures using cassava meal of variable length with or without recovery period
| Autor: | Kanokporn Saengkudrua, Nirat Gongruttananun |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Meal Cassava Albumen quality 0402 animal and dairy science 04 agricultural and veterinary sciences Anatomy Biology Egg albumen Molting Variable length 040201 dairy & animal science Feed conversion ratio lcsh:S1-972 03 medical and health sciences Recovery period 030104 developmental biology Animal science Eggshell ultrastructure lcsh:Agriculture (General) General Agricultural and Biological Sciences Laying hen Moulting |
| Zdroj: | Agriculture and Natural Resources, Vol 50, Iss 5, Pp 400-407 (2016) |
| Popis: | The effects were determined of varying the length of the recovery period on postmolt performance in laying hens induced to molt by cassava meal. The hens were randomly assigned to one of five groups: group 1 (NC), the control group, whereas groups 2 (IM 0 ), 3 (IM 1 ), 4 (IM 2 ) and 5 (IM 3 ) were subjected to an induced molt program. The procedure included a 14 d stress period, during which the birds were induced to molt with cassava meal, and recovery periods varying from 0 wk to 3 wk. Hens in the IM 0 , IM 1 , IM 2 and IM 3 groups had recovery periods of 0 wk, 1 wk, 2 wk and 3 wk, respectively, during which they were fed a pullet developer diet. During the early postmolt period, the egg production of the IM 0 group was significantly lower than that of the control group. The IM 1 hens consumed significantly more feed and had a significantly higher feed conversion ratio than the control birds. The albumen height was significantly improved by the IM 0 and IM 1 treatments. No consistent differences were observed among treatments for any parameter of postmolt performances, except for improved albumen weight and mortality rate, which were observed in the IM 3 group. Scanning electron microscopy illustrated evidence of erosion in the mammillary layer of the shell in the control hens. The density of the mammillary knobs in all molted groups was significantly lower than that of the control group. The mammillary knob diameter of the IM 2 group was significantly greater than that of the control group. |
| Databáze: | OpenAIRE |
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