فهرس المقالات feed restriction

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  1 - Influence of Feed Withdrawal for Three Hour Time Period on Growth Performance and Carcass Parameters Later Stage of Male Broiler Chickens
  P.H.G.J. De Silva A. Kalubowila
  Feed restriction strategies are proven to be effective in increasing the growth performance and carcass parameters of broiler chickens. The objective of the present experiment was to evaluate the effects of feedremoval for three hour time periodon growth performance and أکثر

  Feed restriction strategies are proven to be effective in increasing the growth performance and carcass parameters of broiler chickens. The objective of the present experiment was to evaluate the effects of feedremoval for three hour time periodon growth performance and carcass parameters of relatively older male broiler chickens. Twenty days old male broiler chickens (n=80) were allocated into 16 floor pens. Birds in eight pens were fed ad libitum while those in other eight pens were fasted for 3 hours per day (13.00-16.00) during 21-42 d experimental period. There was a slight feed intake reduction (P<0.01) due to feed restriction during 21-25 d, but not thereafter. When feed was offered after three hours of deprivation, birds consumed significantly (P<0.01) higher amount of feed within first two hours, compared to the feed intake of ad libitum group during the same time period. Birds fed ad libitum were heavier (P<0.05) on day 42 but not on days 25, 30 and 35. Feed restriction significantly reduced the weight gain between 35-42 d (P <0.01) and the total weight gain (P<0.05) from day 21-42. Feed conversion ratio (FCR) between 30-42 d was significantly (P<0.05) lower under ad libitum feeding, and also overall FCR from 21-42 d was affected by the feeding regimes. Restricted feeding increased the total giblet weight (liver+heart+gizzard) (P<0.10), the carcass weight (P<0.01) and dressing percentage (P<0.05) while reduced (P<0.01) the length of the small intestine relative to carcass weight. Restricted feeding tended to reduce (P<0.10) the percentage of abdominal fat. The results conclude that feed restriction for three hours per day from days 21-42 increased dressing percentage while reducing abdominal fat content of matured male broiler chicken. تفاصيل المقالة
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  2 - The Effect of Limiting the Time of Feed Access during the Growing Phase on the Performance of Broilers
  A. Ranjbar B. Navidshad M.R. Asadi F. Mirzaei Aghjehgheshlagh A. Kalantari Hesari
  This study was carried out to investigate the effect of feed restriction during the first week of the grower period on the performance, intestinal morphology, and some blood parameters of broilers. Seventy five one-day-old Ross 308 male broilers were used in a completel أکثر

  This study was carried out to investigate the effect of feed restriction during the first week of the grower period on the performance, intestinal morphology, and some blood parameters of broilers. Seventy five one-day-old Ross 308 male broilers were used in a completely randomized design with 3 treatments, the control group and groups with feed restriction program at the first week of the grower phase for 6 or 12 hours (6HR or 12HR). In the grower phase, the 12HR program reduced feed intake and daily weight gain. The feed conversion ratio during the grower phase decreased by feed restriction. In the finisher phase and whole the experimental period, no difference was observed in the performance traits. Serum cholesterol levels decreased in the 12HR group compared to the HR group. Serum malondialdehyde levels decreased in both groups with dietary restriction compared with the control group. The aspartate transaminase activity was higher in the 12HR group than in the 6HR group. In the duodenum, a significant decrease in the height of the villi was observed due to feed restriction. The lowest crypt depth at the duodenum was also observed in the 12HR group. The ratio of villi height to crypt depth in the duodenum was lower in the 12HR group than in the other two groups. In the jejunum, the highest villi height was recorded in the 12HR, control, and 6hr groups. In the ileum, like in the jejunum, the highest height of villi was observed in the 12HR group, and the difference with the control group was significant. The diameter of villi in the Ileum was also not affected by feed restrictions. The depth of the crypt increased due to feed restriction. The results of this study suggest that 6 hours of dietary restriction in the first week of the grower period did not affect the production traits of broilers and 12 hours of dietary restriction in the mentioned period, although reduced feed intake and growth in the grower period, at the end of rearing period sufficient compensatory growth occurred. On the other hand, it seems that the 12-hour diet restriction in the first week of growth has positive effects on the morphology of the small intestine by increasing the absorption surface and also has a positive effect on the peroxidative state of the body, which needs further research. تفاصيل المقالة
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  3 - اثر شدت و مدت گرسنگی به همراه پدیده رشد جبرانی بر عملکرد رشد، خصوصیات لاشه و ترکیب شیمیایی گوشت بره های گوسفند نژاد لری
  بهروز یاراحمدی محسن محمدی ساعی علیرضا چگنی
  این تحقیق به ‌منظور بررسی اثر شدت و مدت گرسنگی به همراه پدیده رشد جبرانی بر عملکرد رشد، خصوصیات لاشه و ترکیب شیمیایی گوشت بره‌های نر گوسفند نژاد لری با 54 رأس بره ی نر 30 کیلوگرمی انجام شد. فاکتورهای مورد آزمایش شامل مدت گرسنگی با دو سطح (35 روز و 45 روز) و شدت گرسنگی ب أکثر

  این تحقیق به ‌منظور بررسی اثر شدت و مدت گرسنگی به همراه پدیده رشد جبرانی بر عملکرد رشد، خصوصیات لاشه و ترکیب شیمیایی گوشت بره‌های نر گوسفند نژاد لری با 54 رأس بره ی نر 30 کیلوگرمی انجام شد. فاکتورهای مورد آزمایش شامل مدت گرسنگی با دو سطح (35 روز و 45 روز) و شدت گرسنگی با سه سطح (حد اشتها، 80 درصد و 60 درصد) بوده که بر اساس آزمایش فاکتوریل با طرح پایه کاملاً تصادفی (3×2) با سه تکرار انجام شد. در پایان آزمایش میزان افزایش وزن روزانه، وزن نهایی، ضریب تبدیل غذایی و خوراک مصرفی محاسبه ‌شد. همچنین خصوصیات لاشه به همراه هزینه تولید برای هر کیلوگرم افزایش وزن لاشه و گوشت لخم محاسبه شد. جهت تعیین ترکیب شیمایی گوشت درصد ماده خشک، خاکستر، چربی خام و پروتئین خام تعیین شد. نتایج نشان داد بین افزایش وزن روزانه، ماده خشک مصرفی و ضریب تبدیل خوراک در پایان دوره محدودیت تفاوت معنی‌دار وجود داشت (05/0 >p ). در پایان رشد جبرانی گروه‌های محدودیتی با 35 روز گرسنگی افزایش وزن روزانه بیشتری نسبت به سایر تیمارها داشتند (05/ 0>p ). در دوره رشد جبرانی ضریب تبدیل خوراک در تیمارهای محدودیت خوراک نسبت به تیمار شاهد کاهش داشت (05/0 >p ). نتایج صفات لاشه در دوره محدودیت خوراک نشان داد که میانگین اکثر صفات لاشه در تیمارهای شاهد بالاتر از گروه‌های محدودیت بود (05/0 >p ). در این بین وزن دنبه، درصد دنبه و چربی کل لاشه در تیمارهای شاهد بالاتر از کلیه گروه‌های محدودیت بود.در این مورد گروه‌های محدودیت خوراک 35 و 45 روز گرسنگی بالاترین درصد گوشت لخم لاشه را در دوره محدودیت و رشد جبرانی داشتند. این مطالعه مشخص نمود بره‌های تحت محدودیت 60 درصد خوراک با 35 روز گرسنگی به دلیل افزایش وزن بالاتر، ضریب تبدیل خوراک مناسب‌تر و صفات لاشه مناسب‌تر همچنین درصد گوشت لخم بیشتر نسبت به سایر تیمارها ارجحیت داشتند. تفاصيل المقالة