فهرست مطالب
نشریه علوم دامی (پژوهش و سازندگی)
پیاپی 98 (بهار 1392)
- تاریخ انتشار: 1392/02/12
- تعداد عناوین: 8
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صفحه 2مطالعه ای برای بررسی تاثیر افزودن گلوتامین به جیره بر فعالیت آنزیمهای لاکتات دهیدروژناز، آلانین ترانس آمینازآسپارتات ترانس آمیناز پلاسما، پارامترهای خونی، تلفات و عملکرد به مدت 4 هفته در جوجه های گوشتی تحت آسیت القایی انجام شد. تعداد 160 قطعه جوجه نر گوشتی راس سویه 308 به طور کاملا تصادفی در2 تیمار با 4 تکرار و 20 جوجه در هر تکرار تقسیم شدند. جوجه های مورد آزمایش، برای القای سندرم افزایش فشار خون ریوی(آسیت) و، در دمای سرد طبق برنامه دمایی ویژه ای قرار گرفتند. 2 تیمار آزمایشی عبارت بودند: 1-از تیمار شاهد و 2-تیمار گلوتامین، که حاوی یک درصد گلوتامین در خوراک مصرفی به همراه جیره پایه بود. نتایج به دست آمده در این تحقیق نشان داد که تیمار گلوتامین به طور معنی داری (05/0 >P) سبب بهبود ضریب تبدیل در هفته پنجم و کل دوره شد. نتایج پارامترهای خونی نشان داد که تعداد گلبول قرمز، درصد هماتوکریت و مقدار هموگلوبین تحت تاثیر تیمارها قرار نگرفتند. فعالیت آنزیم های ASTوALT در روز 42، در تیمار گلوتامین به طور معنی داری کمتر از تیمار شاهد بود اماLDH پلاسما تحت تاثیر تیمارها قرار نگرفت. نسبت یطن راست به کل بطن ها (RV/TV)و میزان تلفات ناشی از آسیت در روز 42، نیز در تیمار گلوتامین به طور معنی داری کمتر از تیمار شاهد بود.
کلیدواژگان: آسیت، گلوتامین، فعالیت آنزیمی، عملکرد، پارمترهای خونی -
صفحه 11
در این تحقیق، اثر عوامل محیطی موثر بر پتانسیل تولیدی (تولید شیر، تولید چربی و درصد چربی) گاومیش های شیری استان خوزستان مطالعه شد. از اطلاعات متعلق به 129 گله گاومیش که طی 13 سال (1386-1374) توسط مرکز اصلاح نژاد دام کشور جمع آوری شده بود، استفاده شد. اثر عوامل محیطی سن زایش و فصل زایش با استفاده از نرم افزار SAS و رویه GLM با روش مدل خطی مورد بررسی قرار گرفت و تعداد روزهای شیردهی به عنوان متغیر کمکی در نظر گرفته شد. اثر عوامل مورد بررسی برای تمام صفات معنی دار بود. میانگین وخطای استاندارد صفات تولید شیر، چربی و درصد چربی به ترتیب،82/7 ± 56/2174 و 62/0 ± 80/138 کیلوگرم و 01/0 ± 28/6 درصد به دست آمد. گاومیش هایی که در فصل بهار زایش داشتند، بیشترین تولید شیر و تولید چربی را به خود اختصاص دادند و بیشترین درصد چربی در فصل بهار مشاهده شد. بیشترین شیر و چربی تولیدی در یازده سالگی مشاهده شد و بیشترین درصد چربی مربوط به دو سالگی بود.
کلیدواژگان: استان خوزستان، صفات تولید شیر، عوامل محیطی، گاومیش -
صفحه 18این آزمایش برای بررسی اثر زمان جایگزینی چربی اشباع با غیر اشباع جیره بر عملکرد جوجه های گوشتی انجام شد. برای این منظور از 700 قطعه جوجه گوشتی ماده یکروزه (سویه راس 308) در قالب طرح کاملا تصادفی با 7 تیمار، 5 تکرار و20 قطعه جوجه در هر تکرار استفاده شد. جوجه ها به مدت 6 هفته با جیره های حاوی 5 درصد چربی و سطوح انرژی و پروتئین یکسان در دوره آغازین (1 تا 21 روزگی) و رشد (22 تا 42 روزگی) تغذیه شدند. در این آزمایش روغن آفتابگردان به صورت هفتگی جایگزین پیه شد به طوری که جیره 1 در کل 6 هفته آزمایش حاوی پیه، جیره2 در 5 هفته اول حاوی پیه و در یک هفته آخر حاوی روغن آفتابگردان جیره3 در 4 هفته اول حاوی پیه و در دو هفته آخر حاوی روغن آفتابگردان، جیره4 در 3 هفته اول حاوی پیه و در سه هفته آخر حاوی روغن آفتابگردان، جیره 5 در 2 هفته اول حاوی پیه و در چهار هفته آخر حاوی روغن آفتابگردان، جیره6 در هفته اول حاوی پیه و در پنج هفته آخر حاوی روغن آفتابگردان و جیره7 در کل آزمایش حاوی روغن آفتابگردان بود. نتایج نشان داد که جیره های آزمایشی در دوره آغازین برافزایش وزن زنده تاثیر معنی داری نداشتند(05/0
P). بیشترین مصرف خوراک در دوره آغازین و کل دوره در جوجه های تغذیه شده با جیره دارای پیه دیده شد(05/0 >P). با افزایش زمان جایگزینی پیه با روغن آفتابگردان، مصرف خوراک در دوره آغازین و کل دوره پرورش کاهش یافت (05/0 >P) اما بر مصرف خوراک در دوره رشد اثر نداشت(05/0
P). بالاترین نقطه ذوب چربی محوطه بطنی در جوجه های تغذیه شده با جیره یک و پایین ترین آن در جیره های 5، 6 و 7 دیده شد(05/0 >P).
کلیدواژگان: منبع چربی، چربی محوطه بطنی، جوجه گوشتی -
صفحه 27این تحقیق با هدف اندازه گیری شاخص بهره وری کل عوامل تولید با دو رهیافت جدید در گاوداری های شیری صنعتی شهرستان شهریار صورت گرفت. داده های مورد نیاز از طریق تکمیل پرسشنامه از تعداد 51 گاوداری شیری که به روش نمونه گیری با طبقهبندی تصادفی انتخاب شده بودند، در سال 1388 جمعآوری گردید. نتایج نشان داد که میانگین درآمد ناخالص و هزینه کل تولید در گاوداری های کوچک و متوسط در مقایسه با گاوداری های بزرگ، کمتر بود. میانگین شاخصهای حقیقی و ظاهری بهرهوری کل عوامل تولید برای کل گاوداری های مورد مطالعه به ترتیب برابر 082/1 و 246/1 بود. اختلاف موجود، بخشی از درآمد ناخالص گاوداری های شیری است که گاوداران به عنوان سود در نظر گرفته حال آن که این مبلغ، هزینه غیرملموس است. نتایج همچنین نشان داد که با افزایش اندازه گله، میانگین عملکرد تولید شیر افزایش می یابد. ضمن این که رابطه مثبت و معنی داری(05/0
کلیدواژگان: بهره وری کل عوامل تولید، شاخص حقیقی، شاخص ظاهری، گاوداری شیری
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Page 2A study was conducted to investigate the effects of glutamine on blood parameters، plasma enzymes activity، performance in broilers with pulmonary hypertension syndrome (PHS) during 4 weeks. A total of 160 male broilers randomly were divided in 2 groups of 4 replicates and 20 chicks for any replicate. At day 14، temperature was reduced to amplify the incidence of Pulmonary Hypertension Syndrome. Two treatment groups were: 1: Control group and 2: Control group with 100g glutamine/ Kg feed. Average BW gain، average feed intake and average feed conversion ratio were measured weekly from week 3. Mortality was inspected to determine cause of death and diagnose of heart failure. Hematological، biochemical and pathological tests were used; total red blood cell (RBC)، hemoglobin (HGB)، hematocrit (HCT)، release of alanine transaminase (ALT)، aspartate transaminase (AST)، lactate dehydrogenase (LDH). At end of the experiment (wk 6)، 2 chicks from each replicate were randomly selected and slaughtered. The heart was removed; the right ventricle was dissected away from the left ventricle and septum then ratio of right ventricle weight to total ventricle weight (RV/TV) calculated too. The results indicated that glutamine significantly، (P≤0. 05)، improved feed conversion ratio at week 5 and total experiment period. None of RBC، Hct and Hgb was not affected by glutamine. Glutamine at day 42، significantly reduced Plasma enzyme actives ALT and AST، nonetheless، LDH activity was not affected by glutamine supplementation. It is also، glutamine significantly reduced RV/TV and mortality compared to Control.Keywords: Ascites, Blood paremetres, Performance, Enzyme activies, Glutamine
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In this study، the effect of environmental factors of production traits (milk yield، fat yield and fat percentage) were studied. Data collected from 129 buffaloes herd from Khuzestan province by Animal Breeding Organization of Iran during 13 years (1995-2008). Using linear model environmental factors on age at calving and season of calving analyzed by GLM procedure in SAS software. Lactation length considered as a covariance in model. The effect of all factors those studied were significant (P<0. 01). Means and standard errors of milk and fat yield and fat percentage were 2174. 56±7. 82kg، 138. 80±0. 62kg، 6. 28±0. 01% respectively. Buffalo calving in spring showed the highest milk yield and fat yield and highest fat percentage was showed in spring. Buffalo calving in 11 age was showed the highest milk yield and fat yield and the highest of fat percentage was showed in 2 age at calving.
Keywords: Khuzestan province, Milk production traits, Environmental factors, Buffalo -
Page 18This experiment was conducted to evaluate the time of the switch from a saturated (tallow) to an unsaturated (sunflower oil) dietary fat source on the performance of broiler chickens. A field experiment was carried out in which seven hundred (Ross hybrid female) broiler chicks were randomly distributed into seven groups with five replicates of 20 birds during a 6 week experiment. The birds were fed ad libitum with isocaloric and isonitrogenous diets containing 5 percent fat (tallow or sunflower oil) for two periods 1-21 and 22-42 days. Tallow was replaced by sunflower oil in the weekly diet of chicks (first treatment six weeks tallow، second treatment 5 weeks tallow followed by one week sunflower oil، and soon to the seventh treatment fed by sunflower oil for the whole six week). Results show that the dietary treatment for 1-21 days period had no significant effect on the body weight (p>0. 05). Further، birds fed diets supplemented with sunflower oil for 22-42 day and the whole period of experiment gained more weight compared to those fed diets supplemented with tallow (p<0. 05). Feed consumption was significantly higher for chicks fed tallow-supplemented diets in 1-21 days period and the whole period of the experiment (p<0. 05). The feed consumption decreased with replacing the type of fat from saturated to unsaturated (p<0. 05). however، in growing period diets had no significant effect on the feed consumption (p>0. 05). Chicks fed sunflower oil diet had the best value for feed conversion ratio (p<0. 05). The highest and the lowest melting points were observed in the first and the 5th-7th treatments، respectively (p<0. 05).Keywords: Fat source, Abdominal fat, Broiler chickens
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Page 27This study aims to measure total factor productivity by considering two new approaches in industrial dairy farms in Shahriar Township. The necessary data were collected through completion of questionnaire from 51 dairy farms by stratified random sampling method in the year 2009. The results showed that average gross income and total production cost were less in small and medium farms as compared to large farms. The average real and apparent total factor productivity index was 1. 082 and 1. 246 for whole studied dairy farms، respectively. Existing difference is part of gross income of dairy farms، which is not considered as a profit by cow-keepers، while، this amount is an intangible cost. The results also showed that average milk yield increases with increasing herd size. Meanwhile، there was not positive and significant relationship between herd size with real and apparent total factor productivity indices (p>0. 05).Keywords: Total factor productivity, Real index, Apparent index, Dairy farm
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Page 34Awareness of the animal carcass parts and fat-tail weight، in live animal can help to select and determine the optimum slaughtering age. For this purpose، live weight، phenotypic dimension of fat-tail as well as back fat thickness and eye muscle area were measured by ultrasound in 38 Moghani male lambs. Then، all sheep were slaughtered and after removal of their internal organs، carcasses were stored in cold temperatures for 24 hours at 4 °C. Then، each carcass was divided into two equal parts. Right sides of each carcass were cut in to، leg، shoulder، brisket، rack and neck and were weighed. Data analysis showed that body weight alone explains the 0. 85، 0. 43، 0. 56، 0. 70، 0. 52 and 0. 50 of the variations of half-carcasses، neck، shoulder، leg، rack and brisket، respectively. Residual standard deviation (RSD) in these equations was also very low and range from 0. 10 to 0. 50. Coefficient of determination of all equations were increased with adding variables measured by ultrasound in multivariate models except for neck weight، and were increased to 0. 86، 0. 43، 0. 59، 0. 73، 0. 58 and 0. 57، respectively. Coefficient of determination was 0. 78 for estimated fat-tail weight with the use of circumference، width and diameter of the fat-tail in step wise procedure. While، coefficient of determination with using full model increased to 0. 81. Based on results of this research، prediction of carcass cuts and fat tail weight is possible with high accuracy by using some phenotypic and ultrasound measurements.Keywords: Carcass parts, Ultrasound, Regression equations, Residual standard deviation
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Page 43The effects of lipogenic nutrients in a prepartum diet on production، reproduction and metabolic performance of cows in subsequent lactation period were studied. Twenty four pregnant multiparous cows were assigned randomly to 2 treatments in a completely randomized design. Cows were fed either a lipogenic diet (Lipogenic group) or a glucogenic diet (Glucogenic group) from week three prepartum and thereafter all cows were fed a similar glucogenic diet until 8 weeks postpartum. All cows were fed total mixed ration (TMR) ad libitum and were kept in individual stalls. Dry matter intake، body condition score، milk yield، milk composition and energy balance of animals were not affected by prepartum diet. Serum cholesterol and NEFA concentrations in Lipogenic group were significantly (P<0. 05) higher than those in Glucogenic group both during pre and postpartum periods. Prepartum diets had no significant effect on follicular populations in different classes. However، during the first 100 days in milk، the percentage of pregnant cows in Glucogenic group was about 14% higher، numerically. Results of this study confirmed relatively a positive effect of prepartum glucogenic diet on metabolic status and to some extant pregnancy rate.Keywords: Dairy cattle, Lipogenic diet, Glucogenic diet, Pregnancy
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Page 55This research was conducted to study the effect of heat-processed broiler litter (BL) in roughage based diet on the nutrients intake، microbial protein synthesis and nitrogen balance in sheep. In a completely randomized design، with four treatments (diets) and four replicates، 16 Moghani male sheep، with 63±2. 3 kg live weight، were allocated to four experimental diets including: control diet (mixture of wheat straw and alfalfa، 35:65 ratio)، and experimental diets; 1، 2 and 3 contained 80، 160 and 240 g BL (dry matter basis)، respectively. Results showed that average dry matter intake were 1200، 1506، 1735 and 1601; organic matter intake were 1082، 1350، 1541 and 1420 g/animal/d for the control and experimental diets 1، 2 and 3 respectively، that were significantly increased (P<0. 05) by inclusion of BL in the diet. The daily intake of ash free-neutral detergent fiber and crude protein intake were the lowest (respectively 624 and 123 g) for the control diet، whereas these variables were the highest (850 and 224g respectively) for the animals received 160 g/kg BL diet (P<0. 05). The total urinary purine derivatives excretion، microbial protein production and nitrogen retention were respectively 7. 10، 34. 50 and 5. 50 g/animal/d for the control diet but there were 9. 60، 47. 70 and 13. 30 g/animal/d for the diet contained 160g/kg BL that ranked the highest amounts (P<0. 05) between all diets In conclusion، supplementing roughage based diets with 160 g/Kg of BL could improve the nutrients intake and nitrogen metabolism in sheep.Keywords: Broiler litter, Microbial protein, Nitrogen balance, Sheep
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Page 64This experiment was conducted to evaluate the effects of tomato pomace (TP)، herbal oil sources and tallow on blood lipids، enzyme activity and antioxidant system of heat stressed broiler chickens. Seven hundred ninety-two one-d-old Arian broiler were randomly to 36 experimental units in the 9 dietary treatments (4 replicate with 22 birds each). The completely randomized design with factorial arrangement 3×3 (3 oil kinds: canola، soybean، tallow and 3 TP levels involved 0، 3، 5%) were used. The daily heat stressed schedule (33oC for 5 h) was applied from 29-42d. Canola and soybean oils decreased serum triglyceride and cholesterol in pre heat stressed (PHS) birds. In heat stressed (HS) birds، canola enhanced the HDL as compared to tallow diets. TP decreased the triglyceride، cholesterol and LDL and improved HDL. The oil type did not affect the enzyme activity of AST، ALT، ALP، LDH، CK and lipase in PHS and HS birds. The canola oil decreased the LDH in PHS and ALP and AST in HS birds. TP decreased the activity of ALP، AST، ALT and CK in PHS and HS birds. Tallow diet increased and decreased the GPx activity in PHS and HS respectively. Tallow and TP decreased TBARS index. The enzyme activity of GPx and SOD were enhanced by inclusion of TP. The oil kind and TP did not affect hematology parameters with the exception of H: L ratio. It is concluded that inclusion of canola oil and TP might decreased blood lipids، dehydrogenase enzyme activity and antioxidant system of heat stressed broiler chickens.Keywords: Oil, Tomato pomace, Blood metabolite, Antioxidant parameters, Heat stress