نوع مقاله : مقاله پژوهشی
نویسندگان
گروه پرورش و مدیریت طیور، دانشکده کشاورزی، دانشگاه تربیت مدرس، تهران، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
This study was conducted to investigate the effect of different levels of alkaline hydrolyzed feather meal (AHFM) on the performance, intestinal morphology, and meat oxidation of Arian broiler chickens from d 15 to 42. A total of 480 one-day-old chickens of two sexes (equal ratio) were randomly distributed among 24 pens (20 chicks per experimental unit). The four experimental diets contained different levels of feather meal (0, 2, 4, and 5 %), which were replicated six times. During the grower period, daily weight gain decreased and the feed conversion ratio increased at 4 and 5 % AHFM levels (P<0.05), also feed intake increased in birds fed on a 5 % AHFM diet (P<0.05). In the overall experimental period feeding 4 % AHFM decreased the body weight gain compared to control (P<0.05) and the feed intake was reduced in birds fed on 2 % AHFM (P<0.05). The feed conversion ratio has not been influenced by the level of AHFM 15-42 d. Diets with AHFM decreased the jejunum villi height, while this reduction in the ileum was observed at 4 and 5 % AHFM, and goblet cell density increased at 5 % AHFM (P<0.05). With the increase in the level of AHFM, the concentration of malondialdehyde in fresh breast, and thigh meat decreased so that the group receiving five percent of AHFM had the lowest concentration of malondialdehyde (P<0.01). The level of 5 % AHFM reduced the litter moisture (P<0.05) and the levels of AHFM did not affect the concentration of the litter ammonia. None of the mortality, production efficiency index, and feed cost per kilogram of live weight were significantly affected by experimental treatments. As a general conclusion, the use of AHFM reduced the body weight and increased the feed conversion ratio of Arian broilers without affecting the mortality rate and production efficiency index, although meat oxidative stability improved.
کلیدواژهها [English]
Extended Abstract
Introduction
Considering feed cost as a principal item in broiler production, seeking alternative low-cost and nutritious feed ingredients is an attractive research field in practical poultry nutrition. Feathers serve as body cover in living boilers, which will convert to waste as soon as the chicken is slaughtered. Feathers are of limited nutritional value, due to low digestibility and improper amino acid profile in relation to broiler requirements. This perishable by-product needs to be processed as soon as possible to avoid environmental pollution. Traditionally feathers were cooked under heat and steam pressure in specialized high-pressure cookers, which require a plenty amount of energy and equipment and often produce heat-damaged feather meal. We introduce an alkaline hydrolysis method enable to convert the raw feathers into an almost soluble amino acid-rich product, namely alkaline hydrolyzed feather meal (AHFM). The used processing method is fast, easy, and affordable and doesn’t need high-temperature/ pressure equipment, just needs water and sodium hydroxide as consumable materials. There is no data on optimum inclusion rate of AHFM in broilers’ diets. This experiment was an attempt to test the effects of feeding AHFM levels on Arian broilers' growth performance, intestinal morphometry, meat lipid stability, and litter quality.
Materials and Methods
Alkaline hydrolyzed feather meal was produced in the first part of the experiment and its chemical composition was described in terms of crude protein, amino acids profile, ash, and some of the minerals. A total of 480 Ross 308 one-day-old broilers (straightforward) were randomly divided into 24 floor- pens furnished with wood trash (2*1 m) and raised for the first 14 d under the same condition. The four experimental diets were fed from 14 to 42 d. The control diet was formulated with 0 AHFM, while the three other diets were formulated to have 2, 4, and 5 % of levels of AHFM, respectively. Birds have free access to feed and water, and temperature and illumination were set as the Arian hybrid guidelines. Growth performance criteria (body weight gain, feed intake, feed conversion ratio, and mortality) were analyzed in 14-35, 36-42, and 15-42 d. At the end of the experiment on day 42, a chicken from each replicated pen was randomly selected to be sampled for meat (breast and thigh), and intestine. The malon-di-aldehyde content of fresh/oxidation-induced meat samples was determined as a marker of lipid oxidation. Sections of the small intestine parts were processed to cut 5 µm thickness to measure the villi dimensions. Data were analyzed in a completely randomized design (four treatments and six replicates). Means were separated using Duncan test and the linear-quadratic contrasts were set to test the regression of dependent variables from the AHFM dietary inclusion levels (P<0.05).
Results and Discussion
During the grower period, daily weight gain decreased and the feed conversion ratio increased at 4 and 5 % AHFM levels (P<0.05), also feed intake increased in birds fed on a 5 % AHFM diet (P<0.05). In the overall experimental period feeding 4 % AHFM decreased the body weight gain compared to control (P<0.05) and the feed intake was reduced in birds fed on 2 % AHFM (P<0.05). The feed conversion ratio has not been influenced by the level of AHFM 15-42 d. Diets with AHFM decreased the jejunum villi height, while this reduction in the ileum was observed at 4 and 5 % AHFM, and goblet cell density increased at 5 % AHFM (P<0.05). With the increase in the level of AHFM, the concentration of malondialdehyde in fresh breast, and thigh meat decreased so that the group receiving five percent of AHFM had the lowest concentration of malondialdehyde (P<0.01). The level of 5 % AHFM reduced the litter moisture (P<0.05) and the levels of AHFM did not affect the concentration of the litter ammonia. None of the mortality, production efficiency index, and feed cost per kilogram of live weight were significantly affected by experimental treatments.
Conclusion
As a general conclusion, the use of AHFM reduced the body weight and increased the feed conversion ratio of Arian broilers without affecting the mortality rate and production efficiency index, although meat oxidative stability improved.
)