نوع مقاله : مقاله پژوهشی
نویسندگان
1 بخش بهداشت و بیماریهای طیور، گروه علوم درمانگاهی دانشکده دامپزشکی، دانشگاه شهید چمران اهواز، اهواز، ایران.
2 گروه علوم دام و طیور،دانشکده علوم دامی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران
3 بخش علوم دامی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان گلستان، سازمان تحقیقات، آموزش و ترویج کشاورزی، گرگان، ایران
4 گروه علوم دام و طیور، دانشکده فناوری کشاورزی، دانشگاه تهران، پاکدشت، ایران
5 بخش تحقیقات تغذیه دام و طیور، مؤسسه تحقیقات علوم دامی کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction: The feed restriction program is one of the main techniques in growth curve manipulation for increasing production efficiency in broiler chicken .Quantities and qualitative feed restriction are procedures that can be used to manipulate the feeding strategies of poultry in order to decrease growth and metabolic rate to some extent and so alleviate the incidence of some metabolic diseases such as ascites, lameness, mortality, and sudden death syndrome and so improving feed conversion and reducing feed cost. Also to produce a leaner bird and reduce the unfavorable effects of fat on human health, and to reduce fat deposition in broiler carcasses using of feed restriction programs can be profitable in broiler chickens production. This article surveys new findings in feed restriction of broilers and evaluates the application of feed restriction methods to broiler chicken production. Arian broiler is one of the meat strains that originated in Iran and considering that several decades have passed since the arrival of Arian line in the Iran country, It is necessary to carry out Time nutritional experiments to more accurately meet the requirement of them with regard to optimizing growth, FCR, carcass efficiency and increasing tissue by increasing the density of nutrients such as AA. Therefore, the objective of this study was to investigate the effect of commercial strain type and feeding methods on performance, intestinal morphological parameters, and immune system of broiler chickens.
Materials and Methods: The experiment was conducted for 45 days using 600 broiler chicks in a 2 × 3 factorial arrangement under a completely randomized design. The factors included two commercial strains (Arian and Ross 308) and three feeding methods (free access, intermittent feed restriction, and time feed restriction), with 6 treatments, 5 replicates and 20 birds per replicate. The diets of experimental included T1: Arian strain broilers with free access to feed, T2: Arian strain broilers with intermittent access to feed, T3: Arian strain broilers with time feed restriction method, T4: Ross 308 strain broilers with free access to feed, T5: Ross 308 strain broilers with intermittent access to feed, T6: Ross 308 strain broilers with time feed restriction method. At 45 days of age, 6 bird from each replicate were randomly selected, weighed, and killed). Feed intake of experimental units was calculated from the fraction of feed consumed at the end of the period from the feed allocated at the beginning of the period, based on chick days. At the end of 45 weeks, maturation parameters including body weight and length, neck length, wing length, shank length and diameter were measured. To determine blood parameters, 12 birds were selected from each dietary treatment (2 birds /pen), and blood samples of approximately 5 ml were obtained from the wing vein after a 2-hour feeding withdrawal. At the end of the experiment (45 days of age), the weighed broilers were cut using the cervical dislocation method and then plucked and eviscerated. The internal organs (heart, digestive tract, and fat tissue) were also weighed and expressed as percentages of the slaughter weight of broiler. Immediately after bird euthanasia, a 3-cm sample of the liver and middle portion of the jejunum (midpoint between the bile duct entry and Meckel's diverticulum) was collected, opened longitudinally, washed with PBS, and fixed in 10% formaldehyde and phosphate buffer 0.1 M with pH 7.3. The data obtained from the experiment were analyzed in the form of a completely randomized design using SAS software version 9.4 (2024) with the general linear model (GLM) procedure. The respective means were compared with Tukey's test at the probability level (P < 0.05).
Results and Discussion: The feed conversion ratio (FCR) of Arian strain broilers improved throughout the entire period when using the free feeding method, compared to Ross 308 strain broilers under the intermittent feed restriction method (P<0.05). Time feed restriction in Arian broilers led to an increased shank thickness, compared to intermittent feed restriction in Arian broilers and free feeding in Ross 308 broilers (P<0.05). The villus height to crypt depth ratio increased using the time-restricted feed method compared to the free access to feed method in Ross 308 strain broiler chickens (P<0.05).
Conclusion: Based on these findings, Arian strain with time feed restriction and Ross 308 strain with free feeding showed the best weight performance. Overall, the time feed restriction method in Arian broiler chickens improved body physical parameters, intestinal morphometry, and enhanced immune system (decreased heterophil to lymphocyte ratio) and productive performance throughout the experimental period.
کلیدواژهها [English]
©2025 The author(s). This is an open access article distributed under Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source.
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