مجله تحقیقات دام و طیور
سال یکم شماره 4 (1391)

The aim of this study was to determine the effects of adding different levels of superoxide dismutase (SOD) and reduced glutathione (GSH) antioxidants before freezing on motility, total progressive motility, viability and positive response to hypo-osmotic swelling test (HOST) parameters after Bull semen was frozen. In this study, four bulls aged 4-5 years were used and 20 times the semen collection (5 ejaculates per bull) was performed. The samples were frozen, after addition of the superoxide dismutase (100 and 150 IU / ml) and GSH (5 and 7.5 mM) antioxidants was added to Tris - egg yolk extender. After thawing samples, the total and progressive motility, sperm viability and positive response to the HOST parameters were determined at zero and 2 hours of incubation. Adding superoxide dismutase and GSH antioxidant levels did not reveal significant differences between treatments in any of the semen parameters in the initial hour of incubation after thawing. 2 h incubation of post-thawed semen samples containing superoxide dismutase (100 IU/ml) significantly improved total motility, viability and membrane integrity of the sperm (P< 0.05). Also, in samples containing superoxide dismutase (150 IU/ml), sperm membrane integrity was maintained (P<0.05). In the semen samples with antioxidant GSH (5 mM), total motility and membrane integrity of the sperm are considerably improved after tawing (P< 0.05). This study showed that using of superoxide dismutase and GSH antioxidants as freezing semen extender additives can be used to improve post-thawed bull semen quality.

This experiment was carried out to evaluate nutritional behavior and nutrient digestibility in lactating dairy cows. Three Brown Swiss dairy cows (average milk yield of 22 kg/d and 200±20 days in milk) were used in a latin square design (3×3) for a three periods. The experimental treatments were 1. TMR with mash concentrate, 2. TMR with pellet concentrate and 3. TMR in a cubic form. Diets chemical composition were similar but were were different physically. The experimental diets were delivered to the animals twice daily at 0800 and 2000. Each experimental period consisted of 21 days; 14 days for adaptation period and 7 days for sampling. The results indicated that average length of eating, rumination and chewing total over 24 hours, and per 1kg consumed NDF and dry mater intake was significantly lower (P<0.05) for cows fed with cube diet. However, it was not significant between mash and pellet diets.. Total apparent digestibility was not significantly affected by the experimental diets. Therefore, Dry matter intake was higher in TMR with pellet concentrate and on 2h after feeding (for mash,pellet and cube diets were:5.03,7.82 and 5.03 kg resoectively). Plasma glucose and urea nitrogen increased as significant (P<0.05) in diet with pellet concentrate. It seems that decreasing feed particle size in cubic diet decreased chewing activity. It is concluded, when particle size increased, chewing activity increased but no effect on digestibility of DM, OM,CP and NDF.

This study was carried out to the determination of nutritive value of Safflower seeds (untreateated and treated with 120º C heat) using in situ nylon bag and in vitro gas production techniques in Gizel sheep. Two fistulated Gizel sheep with average BW of 50.5±2.5 kg were used in a complete randomized design. The gas production was measured at 2, 4, 6, 8, 12, 16, 24, 36, 48 and 72 h and ruminal DM and CP disappearance were measured 0, 4, 8, 12, 16, 24, 36 and 48 h. Dry matter degradabilities of Safflower untreateated and treated seeds at 48 h were 54.30 and 50.90%, there were higher and lovier respectively, that showed significant differences (p<0.05). Crude protein degradabilities of Safflower untreateated and treated seeds at same times were 47.89 and 44.25 respectively that showed significant differences (p<0.05). The gas production of Safflower untreateated and treated seeds at 72 h were 161.39 and 328.12 ml/g DM that showed significant differences (p<0.05).

This study was conducted in a factorial arrangement in complete randomized design (4×2) with 320 one-day old Ross broiler chickens for investigation effect of different level of olive pulp and enzyme on performance and nutrients digestibility for 42 days. The treatments were included: 4 levels of olive pulp (0, 5, 10 and 15% dry matter) and two levels of supplemented enzyme (0 and 0.5% DM) with 4 replicates for each treatment and 10 birds in each replicate. The olive pulp caused to significant increased of intake and gain of broilers (P<0.05). The broilers fed 10% olive pulp had highest intake and gain. The enzyme supplementation significantly decreased feed intake in grower phase (22-42 days) and whole trial period (0-42 days). Interaction of olive pulp and enzyme on feed intake in the starter phase was significant (P<0.05). Treatment content olive pulp plus enzyme and 10% olive pulp plus 0% enzyme had least and most feed intake, respectively. In starter phase olive pulp significantly affected feed conversion ratio (P<0.05). The best feed conversion ratio was for treatment content 5% olive pulp. The supplementation enzyme had significant effect on feed conversion ratio in the starter (P<0.05). Therefore, olive pulp can be used in broiler diets and enzyme improves the nutritional value of olive pulp.

This work was conducted to study the effects of organic selenium, vitamin E and garlic as different dietary antioxidants on the performance parameters, immune system and carcass fat deposition of broilers. The experiment was conducted using a total of 192 day-old male broiler chicks (Ross 308). Birds were randomly allotted to one of dietary treatments and three replicates of sixteen chicks per pen in a completely randomized design. The birds were assigned to receive dietary treatments as follow: a commercial basal diet which contained no feed additive was used as a Control treatment. Treatment 2 was control diet plus 15 g/kg of garlic powder. Treatment 3 was formulated by supplementing the control diet plus 0.3 g/kg organic selenium. Treatment 4 enriched with 2 g/kg of vitamin E (Alpha-tocopherol acetate). To evaluate the performance, chicks of each pen were weighed and feed intake was recorded every week. On day 42, three birds from each pen were killed and dissected to evaluate the abdominal fat. To evaluate the immune system and determine the antibody production against sheep red blood cells of micro-hem agglutination were used to titerat. The results indicated significant reduction in carcass fat and increase in body weight of broilers due to the influence of dietary supplementation of garlic powder. Selenium and vitamin E in compared with the control treatment showed a significant increase in antibody titers, against SRBC and immune system of broilers

This investigation was carried out to characterize the effect of Satureja khuzistanica (SkEO), on cholesterol content and fatty acids composition of breast and thigh meat in broiler chicken. A total of 720 one-day-old Cobb 500, broiler chicks were used to study the effect of six experimental treatments in 6 replicate of 20 birds each, in a 42 days trial. Treatments included continual adminstration of 0 (control-), 200, 300, 400 and 500 mg/ L SkEO or 500 mg/ L Tween-80 (at 1:1 ratio v/v; control+) into drinking water. The fatty acid composition and cholestrol content of breast and thigh muscles were assessed on 12 samples per treatment. The fatty acid composition of the breast meat was significanlty differed from that of thigh meat (P>0.05). Supplementation of broielr water with SkEO did not affect fatty acid composition of breast and thigh meat (P>0.05). The cholestrol content in thigh meat was significanlty greater by approxmatly two folds than breast meat (P<0.05) and in either was affected by SkEO treatemnt (P<0.10). It was concluded that, SkEO ehxibit cholesterol-reducing effect in breast and thigh meat in broiler chickens. No indication, However, was found to verify fatty acid-modulating effect for SkEO in broiler meat.

In order to investigate of environmental factors that affect some growth traits in Lori-Bakhtiari sheep, 7721 records of birth weight, 6462 records of one month weight, 7275 records of weaning weigh, 5745 records of 6 month weight, 3326 records of 9 month weight and 3088 records of yearling weight collected in Shahrekord sheep breeding station during 1989-2012 for Lori-Bakhtiari sheep were used. The SAS statistical software was used to determine the effect of environmental factors. The results of this study showed that environmental factors like birth year, sex, type of birth, and the age of mother have significant effect on all traits. Also the interaction between the sex of lamb-type of birth was significant for traits birth weight, weaning weigh, 6 month weight and 9 month weight (p<0.01). The interaction between the age of mother and type of birth was significant for birth weight (p<0.01) and the interaction between the age of mother and sex of lamb was significant for 6 month weight (p<0.01) and weaning weight (p<0.05). The significant effects of deliberated environmental factors could be altering the incidence of phenotypic growth traits. So if these factors have been not considered in estimating of breeding value of animals, could be biased the estimation significantly. Consequently the calculated values of genetic trend would be very far from reality.

In order to study the effect of sperm type (internal and external) and cow genotype (grade and pure) on probability of milk fat depression (MFD), a number of 938,047 test day records belonging to 108,077 first-parity Holstein cows calved during 1995-2009 in 427 herds were used. For data analysis, statistical methods of Pearson's chi square and logistic generalized linear model were utilised. In the model, fixed effects of production season, sperm type used for dam insemination, first calving age, herd, animal genotype, calving year, and stage of lactation as well as random effect of sire were included. Based upon fat to protein ratio for each test day record and with respect to threshold point of -0.12, dependent variable was defined as a binary (zero code for lack of MFD and unit code for incidence of MFD) character. Incidence of MFD was not significantly associated with sperm type while it was significantly related to the cow genotype. Estimate of odds ratio (OR) for the grade as compared to the pure cows was found to be 0.949 indicating that the former are less sensitive to MFD.