مجله علوم دامی ایران
سال چهل و سوم شماره 3 (پاییز 1391)

This study was conducted to compare the effects of different illumination programs on the cellular and humoral immune system using 320 one day–old male broilers (Arian 386) in a completely randomized design of 8 replications (10 birds each). The four assayed lighting schedules were comprised of: 1- continuous lighting (control), 2- decrease then sudden increase of lighting, 3- decreasing-gradual increasing lighting and 4- intermittent lighting (1 light: 3 dark periods). Humoral immune responses were assessed following immunization by Sheep Red Blood Cells (SRBC) and Newcastle virus (ND) vaccine. Increase in skin thickness due to Dinitrochlorobenzen (DNCB) contact was utilized to assess the cellular immune response: Total antibody against SRBC was lower in the sudden increase in lighting program as compared with the other programs (P<0.05). During the first immunization treatment the 2-mercaptoethanol resistant anti-SRBC antibody was decreased in the intermittent program as compared with control (P<0.05). The 2-mercaptoethanol sensitive anti-SRBC antibody was significantly lower in gradual as well as in sudden increase programs in comparison with control and intermittent groups (P<0.05). Anti-ND antibody was the highest in gradual increasing group as compared with control and other lighting programs (P<0.05). The skin thickness response to DNCB increased in intermittent and gradual increasing programs compared to control (P<0.05). Heterophil to lymphocyte ratio decreased in all lighting schedules as compared with continuous lighting of control group (P<0.05). Weight of bursa was increased in sudden increasing schedule as compared with control and other lighting programs (P<0.05). It could be concluded that introduction of some limitation in lighting hours is a practical tool for improvement of immune system. The observed results emphasized the application of decreasing-gradual increase lighting program could modulate the cellular as well as and humoral immune responses in Arian broilers.

The objective of this study was to determine the effect of calcium borogluconate injection 24, 48 hours prepartum and immediately postpartum on Dry Matter intake at day of calving, milk yield, and as well on blood metabolites during the first 21 days of postpartum in cows fed anionic diets. Thirty six lactating dairy cows were arrenged by parity (1, 2, 3+) and allocated to three subcutaneous injection treatments of 15.2 gr calcium as borogluconate at different times of pre and postpartum ot the expected calving date control. Along with a Treatment 1 consisted of cows (n= 9) receiving no treatment before or after parturition. Treatment 2 consisted of cows (n= 9) receiving 15.2 gr of ca as borogluconate immediately postpartum. Treatment 3 consisted of cows (n= 9) receiving calcium borogluconate 24 h prepartum. Treatment 4 consisted of cows (n= 9) receiving calcium borogluconate 48 h prepartum. Dry matter intake in treatments 1, 2, 3 and 4 were recorded as 10.87, 15.03, 12.63 and 12.32 kg in the first 24 h after calving, respectively and indicating significant differences among treatments. Milk yields in treatments 1, 2, 3 and 4 were recorded as 36.03, 40.35, 38.9 and 38.77 kg/ d in the first 21 days in milk, respectively with the yield in treatment 2 being significantly greater than that in the control. Serum calcium concentrations in treatments 1, 2, 3 and 4 amounted to 7.77, 9.31, 8.67 and 8.41 mg/ dl, respectively so, the concentration in treatment 2 was significantly than those in the other treatments. Blood glucose concentrations in treatments 2, 3, and 4 were significantly higher than that in treatment 1.There were no differences observed in the concentrations of serum Ca, Mg, β-hydroxybutyrate and cortisol among treatments. Overall, it was proved that calcium borogluconate injection immediately postpartum can improve performance and many other health indicators than the case when non-injected.

The present experiment was carried out to investigate the nutritive value of banana tree leaves and stems silage by use of in vitro gas production and as well in situ nylon bag techniques. Experimental treatments were comprised of: 1- Stems and leaves of banana trees (control), 2- Stems and leaves of banana trees’ silage without addition of any additive, 3- Stems and leaves of banana trees’ silage + 15% refusal dates, 4- Stems and leaves of banana trees’ silage + 5% wheat straw and 5- Stems and leaves of banana trees’ silage + 15% refusal dates + 5% wheat straw. After two months, silages were opened up while pH and apparent characteristics of silage materials determined. Then, evaluated were: the chemical compositions by standard method, dry matter degradability through in situ nylon bag methods and organic matter digestibility as well as metabolisable energy through in vitro gas production techniques. Results revealed that addition of refusal dates decreased NDF while increasing WSC, indicating that it improved the quality of silage. Dry matter degradability in banana tree residues with 15% refusal dates plus 5% wheat straw silage treatment was the highest, while banana tree residues with 5% wheat straw silage treatment was of the lowest degradability (p<0.05). In gas production trial, the highest gas production volume, organic matter digestibility and metabolasable energy beloged to Banana tree residues plus 15% refusal dates silage treatment (p<0.05). As a whole, the results indicated that banana tree residues plus 15% refusal dates silage was the most suitable treatment as compared with other treatments and can be recommended for being used in animal nutrition (sheep and goats).

The objective of the present study was to investigate the effects of bacterial additives on chemical characteristics and ruminal degradability of Alfalfa silage. In this experiment the treatments consisted of: 1-untreated alfalfa silage (control), 2-treated with Ecosyl (EC), 3- Lacticil Maize (LM), and 4- a combination of both additives, EC and LM, at half level of treatments 2 and 3. Silos were opened up on day 40 the following ensiling. Silages quality were assessed. Degradibility parameters were estimated through tests carried out on 3 fistulated Holstein dry cows. EC treatment exhibited the lowest Dry Matter (DM) among treatments (P <0.05). Lacticil maize decreased pH in both treatments 2 and 3 while LM bore the lowest pH in comparison with the other treatments. (P <0.05). Treatment 3 and 4 bore higher degradability and “a” fraction than treatments 1 and 2 at zero time of incubation (P <0.05). LM decreased the” a”,”a+b”fraction and effective degradibility of cell wall as compared with the other treatments (P <0.05) while the highest '”a” fraction was recorded for EC (P <0.05). Treatment 4 had the highest cell wall degradability at 72 hours of ruminal incubation (P <0.05). Ecosyl increased protein degradability at 12, 48 and 72 hours of ruminal incubation. The results finally indicated that Lacticil Maize can be utilized in alfalfa silage as a suitable additive because it reduces the pH and increases “a” fraction of dry matter in the aforementioned silage.

This experiment was designed to evaluate the effects of different levels of full fat canola seed (either with or without any enzyme addition) on broiler productivity. Four hundred and thirty two male broilers were employed in a completely randomized design of 2×6 factorial arrangement involving 2 levels of enzyme (either with or without), and 6 levels of canola seed (0, 5, 10, 15, 20, 25%). Experimental diets were fed in the grower (14-21) and finisher (21- 42) periods. The results indicated that by inclusion of 5% of canola seed (with and without enzyme), weight gain and FCR were more appropriate than the other levels of canola seed (P<0.05) without any significant difference with control. Increased level of canola seed caused decrease in feed intake (P<0.05). Higher levels of canola seed (25%) caused the decreased percentage of carcass and abdominal fat as well as higher liver weight, but did not exert any significant effects on gastrointestinal tract. Effects of canola seed levels at 26 days of age on T3, AST and creatinine were significant(P<0.05), but at 42 days of age no significant effect was observed (except for creatinine), indicating decreased anti- nutritive effects of canola seed by age. The added enzyme did not improve the performance parameters. In conclusion, the results indicate, that up to 5% of canola seed could be added to broiler rations without any need for enzyme addition.

To assess the effects of different fat supplements (palm oil, soybean oil or complete roasted soybean) to the transition period diets on Holstein dairy cows, 30 multiparous Holstein cows (fourth parity) with 794±41 kg of body weight and 250±10 days of pregnancy were, randomly, attributed to experimental diets including palm oil (treatment 1), soybean oil (treatment 2) or roasted whole soybean, as on oil containing supplement (treatment 3). following 14 days of adaptation to experimental pens, the animals were started to have free access to experimental diets within a period of 3 weeks following to 3 weeks after calving. Daily Dry Matter Intake (DMI), milk production and composition, animal weight changes, energy balance and nutrient digestibility coefficients of diets were determined. Obtained data were analyzed while applying a completely randomized design. At prepartum, treatment 3 exhibited a higher DMI (14.2 kg) as compared with treatments 1 and 2 (13.5 and 13.7 kg, respectively). At postpartum, DMI for treatment 3 (38.7 kg) was recorded higher (P<0.01) than that for treatment 1 (40.3 kg). The percentages of milk fat and lactose were similar among the experimental groups (P>0.05), but protein was differ (P=0.04). Treatment 1 exhibited a higher gross feed efficiency as compared with treatments 2 and 3 (P<0.01). Apparent digestibility of dry matter, organic matter and NDF were highest in treatment 2, while the lowest in treatment 3 (P<0.01). Overall, feeding diets containing palm oil (in Holstein dairy cows) improved feed intake and energy balance, but caused a higher negative change in body weight. On the other hand, the addition of soybean oil increased diet digestibility as well as feed efficiency and without any negative effect on milk production and composition.

This experiment was carried out to study the effects of different levels of canola meal of different fat sources on the egg quality, performance as well egg yolk cholesterol during the first 12 weeks of age in laying hens (Hy-line W-36). Throughout the experiment a total of 432 hens were employed in a completely randomized design in a factorial arrangement of 3×4, with three levels of canola meal (0, 7.5 and 15%) and different fat sources (soybean oil, canola oil, poultry tallow and fatty acid), with three replicates (n=12). The results showed that Egg weight (g), egg production (%), egg mass (g), feed consumption (g), feed conversion ratio, and egg quality traits including, egg gravity, shell weight (g), haugh unit, shell thickness (mm) and egg yolk cholesterol were not significantly affected by levels of canola meal and by fat sources. The egg production was increased by addition of soybean oil to diets containing 15% canola meal (p<0.05). Feeding of 15% canola meal + soybean oil, increased egg production (p<0.05). Layers which consumed canola oil bore a higher yolk index. Feed cost per kilogram of egg mass decreased significantly in the treatment of 15% canola meal, and poultry fat. The replacement of 15% canola meal and poultry tallow supplementation as a fat source in diets should be useful in decreasing of feed costs.

Fifteen Holstein male calves (416 ± 35 kg initial BW; mean ± SD) were employed in a replicated 3 × 3 Latin square test to investigate the effect of partial replacement of barley grain by Wheat Factory Sewage (WFS) within three 22-d periods including 16 d of adaptation and 6 d of data collection. The basal diet (WFS0) consisted of 42.5% (DM basis) barley grain, partially replaced with either 23.5% WFS (WFS10) or 47% WFS (WFS20). Calves were fed ad-libitum once a day as total mixed ration with free access to water. Feeding WFS decreased dry matter intake as compared with WFS0 (10.0, 9.2 and 9.2 kg/d in WFS0, WFS10, and WFS20, respectively) but there was no difference observed between WFS supplemented diets. Body weight changes per period and average daily gains were not affected by dietary treatments but feed efficiency increased in calves fed WFS20 as compared with others. Including WFS increased nutrient digestibility coefficients as compared with WFS0 but there was no difference observed between WFS supplemented diets. Feeding WFS did not affect blood plasma metabolites expect for plasma insulin concentration which was decreased. Results indicated that partially replacing barley grain with WFS in male’s calves finishing diets reduced dry matter intake, but increased nutrient digestibility and thereby feed efficiency. In general, using wheat factory sewage as by-product replaced for grain in finishing diets can be justifiable on both productivity and from on economical point of view.

Seventy four 9-month-old Fars indigenous roosters were randomly divided into three equal groups. The first group was exposed to 14 hours light and 10 hours darkness. The second group was exposed to the same lighting schedule as the first one and supplemented with 3 mg/kg of body weight edible melatonin daily. The third group was finally exposed to 24 hours of constant light. Semen was collected four times at 20 day intervals through abdominal massage the semen samples of every 8 roosters in each group, being pooled. The pooled semen samples of the first group were supplemented with either 4 vs. 8 mg/ml of vitamin E or 3 vs. 6 mM of melatonin, respectively. The pooled semen samples were frozen, and then thawed after 2 weeks past. Semen characteristics including pH, sperm motility, sperm viability, sperm membrane integrity and Malondialdehyde (MDA) concentration were evaluated before freeze and after thawing. The interaction between the treatment and freezing process was significant (P<0.05) only for MDA concentration and sperm viability. Supplementation of semen with melatonin significantly decreased the sperm viability as compared with the control. Vitamin E (at a concentration of 4 mg/ml) increased sperm viability following thawing as compared with the control. Maximum vs. minimum concentrations of MDA were observed at 6 mM melatonin vs. 4 mg /ml) vitamin E supplementation, respectively. In conclusion, it could be said that vitamin E supplementation in indigenous rooster semen, (as compared with melatonin supplementation) decreases lipid peroxidation in frozen sperm, improvig semen quality following thawing.

The objective followed in this study was to compare six software packages (DFREML, WOMBAT, ASReml, MATVEC, DMU and Thrgibbsf90) as based on some such features as being user friendly, easing computational facilities as well as accuracy and precision of the estimated genetic vs. environmental parameters. For conduction of the study, simulated and field data (Birth weights and weaning weight of Baluchi lambs) were utilized. In all the softwares, except for Thrgibbsf 90, estimates were obtained with restricted Maximum likelihood method via AI algorithm, but in Thrgibbsf 90, the estimates were obtained using Bayesian Gibbs Sampling. The results showed that the choice of software depends on user interest and the goal followed in the research. Since the estimated parameters come out to be similar, even in confidence intervals, there seems no concern to exist in estimation of genetic and environmental parameters (for continous variables) using linear models,and through an application of different softwares.

This study was carried out to investigate the effect of selection on the reduction of fat-tail size in Lori-Bakhtiari lambs. The study lasted for five years at the Development and Breeding center of Lori-Bakhtiari Sheep Station. Estimation of fat-tail weight, using external fat-tail dimensions was obtained from regression procedure at 6 month age. Soft tissue depth at the point 12 cm from the midline dorsal body on 12th ribs at the age of six months (using an animal model of Scanner Device 480) was determined. Components of (co) variance and genetic parameters were estimated using multivariate animal model and a restricted maximum likelihood approach. Selection as based on economic selection index of multiplying a vector of breeding value traits by vector of economic values of traits was conducted. Coefficients of 1 and -4 for the economic value of body weight and estimation of fat-tail weight traits were applied. Phenotypic and genetic trends were obtained through regression means of phenotype while breeding values on year of birth for each trait being predicted. The results showed that average of fat-tail weight (estimated at the age of six months) in lambs amounted to 2.37 kg. The estimates of heritability and standard error fat-tail amounted to 0.33 ± 0.05. Genetic trend of body weight at the six months of age was 160 gr. The genetic trend of fat-tail weight was estimated as -40 gr, with a high coefficient of determination of 0.94. Depth of soft tissue from ultrasound and at six months of age was accompanied by a negative genetic trend (-0.024 mm). Change of phenotype of body weight and ultrasound soft tissue depths were estimated as positive and more than genetic variations. However, phenotypic trend reduction of fat-tail weight as compared with the genetic trend stood at a lower level.

The present research was conducted to analyze the genetic structure of egg quality traits in Japanese quail. External and internal egg quality traits were assessed on 1706 eggs of laying Japanese quail. Eggs were collected for 4 days at the quaits 10 weeks of age. The investigated traits were analyzed through univariate as well as multivariate animal models employing restricted maximum likelihood method. Heritability of external of eggs quality traits consisting Egg Weight(EW), Egg Length(EL), Egg Width (EWI), Egg Shape Index (ESI), Shell Weight (SW), Shell Thickness (ST) and Shell Yield (SY) were between 0.09 (SY) to 0.41 (EW). Heritability of internal egg quality traits consisting Yolk Weight (YW), Yolk Height (YH), Yolk Index (YI), Yolk Diameter (YD), Albumen Weight (AW), Albumen Height (AH), Albumen Index (AI) and Internal Quality Unit (IQU) were recorded from 0.06 (IQU) to 0.33 (YW). Negative genetic correlations were found between EW with ST and SY (-0.33 and -0.64, respectively). The results indicated that increasing egg weight will reduce egg shell thickness, genetically. YW showed favorable genetic correlations with YH (0.32), YD (0.96), AW (0.85) and AH (0.87). Therefore, selection based on yolk weight will improve internal egg quality in Japanese quail. Genetic correlations of EW with most of the internal egg quality traits were positively high (from 0.77 to 0.99). Based on present results, selection for higher egg weight is enough to increase internal egg quality traits. To improve both external and internal egg quality traits, it is necessary to involve have egg shell thickness together with egg weight in the selection index.

Body Weight (BW) is a complex and important economic trait that may benefit from the implementation of Marker Assisted Selection (MAS). The objective followed in this study was to identify QTLs associated with BW at different ages as distinct traits based on an experimental half-sib cross of Japanese quails divergently selected for BW at 4 weeks of age. The body weights at hatch, and as well at one, two, three and four weeks of age were assessed in the F2 population. A total 220 F2 individuals were genotyped for 6 informative microsatellite markers located on chromosomes 1, 2 and 9. The interval mapping was conducted to identify putative QTLs. A QTL for BW at hatch while another at 1 wk of age were identified as significant on chromosome 2 (P<0.01) which may include 1.25% vs. 1.63% of the phenotypic variance, respectively. A QTL for BW at 3 wk of age can be susggested on chromosome 1. As for BW at 4 wk of age, one QTL was recognized as significant on chromosome 1 (P<0.01) while two suggested on chromosomes 2 and 9. A significant QTL explains 1.13% of the phenotypic variance. In conclusion, the results introduced some regions as harboring significant QTLs that affect BW traits. This study provided a potential for further work(s) on candidate gene(s), and Marker Assisted Selection for Body Weight traits.

Data utilized in this study were 6800 records of lambs’ life longevity, and survival rate from 263 sires and 1839 dams collected from 1989 through 2009, from the Lori-Bakhtiari flock at Shooli Station in Shahrekord. The data were analyzed, using Linear and Hazard Ratio models along with Weibul function. These models included such non genetic factors as year and month of birth, sex of lamb, type of birth, age of dam and lambs birth weight as linear and quadratic covariates. Results revealed that the overall mean of lamb’s life longevity and cumulative survival rate, up to yearling, were 301.60 days vs. 78.68%, respectively. The effect of non genetic factors on survival rate resulted from linear model were almost the same as hazard ratio model of Wiebull function. The effect of year and month of birth, sex of lamb and lamb’s birth weight as quadratic covariate were significant (p<0.05). But the effect of age of dam and type of birth were not significant (p>0.05) on the longevity of lamb’s life as well as survival rate. The survival rate and hazard ratio of lambs born in the first vs. the second months were higher vs. lower than those in the third month respectively. The male lambs suffered from a lower survival rate and higher hazard ratio than the females. Lambs with medium birth weight benefited from a higher survival rate and lower hazard ratio than lambs with either too low or too high birth weights. Although, lambs born from younger and older dams suffered from lower survival rates and higher hazard ratios, but they did not any significant differences with lambs born from middle aged dams. Twin lambs suffered from lower survival rates and higher hazard ratios than single lambs, but the differences were not significant. According to the results obtained in this study, the effect of non genetic factors on lamb’s survival rate to yearling age, achieved from liner and non linear models were similar and to increase the survival rate by correcting the non genetic factors, one could use the results obtained from either linear or non linear models.