Journal of Animal Production, Print ISSN: 2008-6776., Online ISSN: 2382-994X

Abstract The aim of the present study was to investigate the performance of the hybrids obtained by crosses of the six Japanese silkworm lines named IRA1, IRA3, IRA5, IRA7, IRA9, and IRA11 and six Chinese silkworm lines named IRA2, IRA4, IRA6, IRA8, IRA10, and IRA12. The new hybrids derived from these lines along with available commercial hybrids (as control groups) for six traits including cocoon weight, cocoon shell weight, cocoon shell percentage, best cocoon weight, pupation rate and best cocoon pupation rate were measured and recorded in spring 2020. The IRA7×IRA6 and IRA7×IRA12 hybrids had more performance in comparison with commercial hybrids in terms of productive traits including cocoon weight and cocoon shell weight (p<0.01), but, when productive and viability traits (pupation rate and best cocoon pupation rate) were considered together in an evaluation index, they were not among the selected hybrids. Commercial 31×32 hybrid in terms of cocoon shell weight and cocoon shell percentage had more performance in comparison with the other hybrids (new and commercial) (p<0.01). Hybrids had a significant difference for pupation rate and best cocoon pupation rate (p<0.01), and the IRA5×RA12, IRA1×IRA10 and IRA11×IRA6 hybrids showed the lowest mean for both traits in comparison with other hybrids (p<0.01). The obtained results showed that seven hybrids including IRA9×IRA2, IRA11×IRA2, IRA3×IRA6, IRA3×IRA2, IRA7×IRA4, IRA7×IRA10 and IRA7×IRA8 were greater than the minimum set for every six traits. Among these hybrids, some will be chosen in the commercial production line based on their performance in the field and regional experiments to supply the country's required silkworm eggs.

Abstract In the current research, immune system responses against sheep red blood cells (SRBC) and Newcastle disease virus (NDV) in two sexes of both wild and Italian speckled quails were investigated. To compare phenotypic differences of two sexes for humoral immune responses a one-way analysis was applied, and a simple animal model using the MCMCglmm package of R software was used for genetic analysis, assuming variance components between the two sexes are different. Phenotypic comparison between males and females did not show a significant difference in any of the strains. In both strains, heritability of humoral immunity in males was higher than females. Results showed, in wild strain, heritability of IgT in males (0.187), and IgY in females (0.177) were higher than other estimates. The highest heritability was related to the NDV, which was estimated to be 0.214 and 0.268 in males and females, respectively. Therefore, genetic selection for IgN can be expected to improve the performance of the birds’ humoral immune system. Likewise, according to the higher estimates of immune responses in males, genetic selection of humoral immune responses for IgN, leads to higher genetic progression.

Abstract To investigate the interaction effects between season and dietary forage particle size on milk yield and composition, one hundred early lactating Holstein were allocated. Dietary forage particle size included long (7.7 mm) and fine (4.4 mm), were adjusted as an experimental treatment per season. The results showed that raw milk yield, protein, lactose and total solid percentage of milk were higher within spring compared to summer (p< 0.01). Milk yield and milk lactose percentage for cows fed fine forage particle size trended to be higher than cows fed long forage particle size. Also, the amount of dry matter consumed within two hours after feeding for summer was higher than spring. Totally results revealed that cows fed with fine forage particle size had more homogeneous feeding behavior pattern within both studied season than cows fed long forage particle size.

Abstract Effect of Saccharomyces cerevisiae on growth performance, health index, nutrient digestibility, serum metabolites and feed consumption behavior of infant calves using 18 Simmental infant male calves aged about 20 days and initial body weight 47±2.4 kg was studied in a completely randomized design with three treatments and six replications. Treatments included: 1- control group (without yeast), 2- treatments containing 2.5 grams of Saccharomyces cerevisiae yeast per day and 3- Treatments containing five grams of Saccharomyces cerevisiae yeast per day. The trial period was 60 days, which included a seven-day acclimatization period. Dry matter intake and daily weight gain were measured and feed conversion ratio was calculated. Digestibility of nutrients and blood metabolites were measured. Calves receiving five grams of yeast had higher weight gain and better conversion ratio (P <0.05). Blood glucose, cholesterol, triglyceride and nitrogen urea concentrations were not affected by experimental treatments. Dry matter digestibility was higher in calves consuming 5 g of yeast than the control group (P <0.05). According to the results of this study, the use of yeast improves daily weight gain and improves feed conversion ratio as well as significantly increases dry matter digestibility, so it is possible to use Sacromycis cerevisiae in the diets of suckling calves, Used at a level of five grams per day.

Abstract The effect of Betaplus probiotic levels in the diet on growth performance and histomorphometry of Japanese quail jejunum was investigated by using 288 broiler chicks with six treatments of four replications and 12 birds per each in a completely randomized design from one to 42 days of age. Treatments included: control group (without additives); three diets containing levels of 0.5, 1 and 1.5 g/kg of Betaplus probiotic; diet with deficient in protein, and diet with deficient in protein and contained 1 g/kg of Betaplus. Feed intake, body weight and increase body weight were measured weekly and conversion factor was calculated. At 42 days of age, two birds were randomly selected from each replicate and the traits related to carcass dissection were assessed. For histomorphometrical evaluation of the intestine, the jejunum samples were collected. The utility of betaplus probiotic at level 1 g/kg improved food intake, weight gain, conversion factor and some histomorphometrical parameters of jejunum (p <0.05), In birds were feed with level of 1.5 g/kg Betaplus, the villi thickness and crypt diameter and number of the goblet cells were decreased (p <0.05). According to the results, the use of Betaplus probiotic at level 1 g/kg in the diet improves the growth performance and histological parameters of the jejunum in Japanese quail.

Abstract This study was performed to investigate the relationship between apparent digestibility of magnesium (Mg) with body weight, feed intake and phytase enzyme with 120 individual B-line Arian male broilers. Birds were assigned two standard diets and a diet supplemented with one gram of phytase (FTU / 500 kg). Daily feed intake, weekly weight gain, feed conversion ratio during rearing and Mg digestibility were measured at 28 to 30 days. Using Gompertz model, growth rate (c), initial weight (b) and maximum growth potential (m) were analyzed. Growth rate and maximum growth potential were higher in the group consuming phytase enzyme (P <0.05). Weight gain and feed conversion ratio improved under the effect of phytase supplemented diets (P <0.05). Magnesium digestibility was higher in phytase enzyme diets than standard basal diets (P <0.05). The results showed that the modeled growth rate affected the Mg digestibility so that birds with higher growth rate (faster growth potential) had more potential for Mg digestion (P <0.05). The relationship between Mg digestibility and body weight gain was positive and the higher the Mg digestibility, the greater the weight gain (P <0.05). Birds with higher growth potential have the ability to digest more of the mineral Mg, and this digestibility is increased by the use of the phytase enzyme. Therefore, in the breeding programs of Arian chickens, more attention can be paid to the relationship between the use of magnesium and the growth rate parameter.

Abstract The effects of valine supplementation on performance, immunity and behavoural indices of broiler chickens reared under heat stress condition was evaluated. Total of 420 male and female Ross-308 broiler chickens were allocated to 6 treatments with 5 replicates in a completely randomized design. Experimental groups were as fallows: positive control (fed basal diet and reared under Ross-308 recommended rearing temperature), Nagative control (fed basal diet and reared under heat stress (HS)), and four treatment groups fed basal diet supplemented with 5, 10, 15 and 20 percent valine above the Ross-308 valine recommendation and reared under HS. Heat stress significantly decreased feed intake, body weight and European production efficiency factor (EPEF), antibody titer against NewCastle, lymphocyte percentage, serum total protein concentration and alkaline phosphatase and lactate dehydrogenase activities and increased heterophile percentage, heterophile to lymphocyte ratio, rectal temperature and tunic immobility of broiler chickens (P < 0.05), but 5% valine supplementation improved BW of broiler chicken at the end of grower and BW and EPEF at the end of total period; 10% valine supplementation increased relative weight of breast and thigh muscle and 15 and 20% valine supplementation increased lymphocyte and decreased heterophile percentage as compared to control group (P < 0.05). In conclusion, 5% valine supplementation improved final body weight and feed convertion ratio of heat-stressed broiler chikens and 15 and 20% valin inclusion improved blood immune cell percentages but had no effect on humoral immune response and tunic immobility test of HS broiler chickens.

Abstract Effect of different levels of calcium (0.6 and 0.3%), phytase (0 and 1500 FTU/kg), and citric acid (0 and 1%) in diets containing 0.15% of non-phytate phosphorus, on growth performance, carcass traits, and bone chemical properties were investigated using 882 10-day-old male broilers from 11 to 40 days of age in 2 × 2 × 2 factorial arrangements based on a completely randomized design including nine treatments (positive control and eight diets without any inorganic P) and seven replications. phytase supplementation increased average daily gain and gain to feed ratio, but the effect of phytase was more apparent in broiler chickens received diets containing 0.6% calcium at 25 to 40 days of age (P <0.01). Reducing dietary calcium levels decreased average daily gain (11 to 24 days) and gain to feed ratio (11 to 24 and 25 to 42 days). Also, the inclusion of citric acid in diets containing 0.3% calcium had a negative effect on these traits (P <0.01). The combination of phytase and citric acid in diets containing 0.6% Ca increased the feed efficiency compared to the 0.3% diet (P <0.01). Phytase supplementation increased toe ash and bone sodium percentage and decreased bone calcium and phosphorus concentration (P<0.01). Bone phosphorus decreased by reducing dietary calcium levels and phytase supplementation (P <0.01). The relative heart and pancreas weight decreased with phytase supplementation (P<0.05). Reducing dietary calcium levels increased the relative liver and pancreas weight and decreased abdominal fat and heart percentage (P<0.05). According to the results, the combination of phytase and citric acid in diets containing 0.6% calcium was more effective in improving growth performance of broilers fed diets containing low non-phytate phosphorus.

Abstract In order to investigate the effects of different periods of thermal manipulation during embryogenesis on thermotolerance, hatchability and blood parameters of Ross (308) broilers strain, 608 fertile eggs were used in a completely randomized design of 4 treatments with 4 replicates. Experimental groups with different thermal manipulation (for control (0 h), 6, 12 and 18 hours) where incubated at 65% humidity and 39.5°C from 7 to 16 days of incubation. At 7 d of incubation, the infertile and undeveloped eggs were removed after the candling. The result showed that thyroid hormones and facial surface temperature, as metabolism and thermotolerance index, decreased significantly in 6-, 12- and 18-hour-treated groups compared to the control group (P < 0.05). The hatchability was higher in the eggs exposed to zero (control), six- and 12-hour thermal manipulation than in the other groups (P < 0.05), and a reduction of hatchability was observed in the 18-hour treatment group. Hatching time increased significantly in the thermal-treated groups (P < 0.05), whereas treatments did not have any significant effects on the body weight, body length, and quality of chickens (P > 0.05). Yolk sac percentage was higher in the treated groups than in control (P < 0.05). Increasing the length of thermal treatment increased the female sex ratio (P < 0.05) significantly. The blood concentration of uric acid and total protein significantly decreased in 6-, 12- and 18-hour treatment groups compared to the control group (P < 0.05). In conclusion, based on the results of this study, 6 and 12 hours of thermal manipulation induced thermotolerance without adverse effects on hatchability.

Abstract The aim of this study was to investigate the changes in some blood parameters in 15 Lori ewes during pregnancy and compare it with one month before pregnancy and lactation. Blood samples were taken from the jagulur vein before normal mating as a control, at the end of every three months of pregnancy and two weeks after delivery during lactation, and the complete blood cell count of each sample was evaluated by a veterinary cell counter. In extensions, Giemsa staining and differential white blood cell count were performed and total plasma protein values were evaluated by refractometry. The number of red blood cells and the percentage of hematocrits during lactation were significantly reduced compared to pregnancy (P˂0.05). Mean cellular volume was reported in all periods in one spectrum. Decreases in mean hemoglobin levels of red blood cells, mean hemoglobin concentrations in red blood cells and platelet count in pregnancy were observed compared to before mating. The number of leukocytes and neutrophils increased around delivery and decreased after delivery. During pregnancy, the number of eosinophils increased significantly and decreased after delivery (P˂0.05). The number of monocytes and lymphocytes increased in late pregnancy and decreased during lactation (P˂0.05). The amount of total protein in the plasma decreased significantly from 150-100 days of gestation (P˂0.05). Thus, it is concluded that monitoring of changes in blood parameters of Lori ewes, dietary adjustment and preventive measures are necessary to prevent blood disorders such as anemia and thrombocytopenia.