ABSTRACT
Experiment was conducted to evaluate the effect of different levels of egg yolk for coating and storing spermatozoa. Ejaculates were collected from four rams. In each session, second ejaculates [n=4] were collected in a tube containing 1 mL coating buffers which were prepared by 10, 15 or 20% egg yolk plus Tris-fructose. Samples were pooled, centrifuged and the supernatant removed in the laboratory. The pellets were diluted with Tris-fructose containing egg yolk which was equal to its concentration in coating. To perform four replicates for each sample, diluted sample was split into four parts then each part was split into two fractions. One of them [cold-shock] was suddenly put on ice water and the other was chilled at 0.25°C/min until 5°C. Aliquots were kept at 5°C for 36 h and sperm motility, viability and functional membrane integrity were determined at 0, 12, 24 and 36 h. The results showed that functional membrane integrity was highest in 20% yolk egg under gradual cooling at 0, 24 and 36 h [85.7, 75.9 and 71.7%, respectively; P<0.05]. In the presence of 20% egg yolk, sperm viability was highest under cold-shock [74.8%] and gradual cooling [78.5%] and sperm motility was lower in cold-shock than gradual cooling at all storage times [76.9, 60.7, 36.2 and 27.7% vs. 85.4, 73.1, 54.6 and 40.8%, respectively; P<0.05]. Therefore, 20% egg yolk can improve coated sperm longevity in normal gradual cooling; but it does not prevent the destructive effect of cold-shock from taking place
ABSTRACT
In this experiment, the effect of consecutive oral levamisole usage on cellular and humoral responses of broilers immune system was evaluated. The aim of this experiment was to determine the best level of levamisole for stimulating immune system of broilers. The experiment was conducted by 250 day old [male and female] broiler [Ross] chicks with an average live weight of 40.2g. Effect of zero [control L0], 3.5 [L3.5], 7 [L7], 14 [L14] and 28 [L28] mg/l of levamisole in drinking water from 5 to 25 days under randomized design using a factorial experiment with 5 replication were studied. Cellular immune responses were assayed by PHA-P injection in the skin fold of wings [day 15] and thickness of skin were measured after 24 and 48 hours. Sheep Red Blood Cell [SRBC] 25% were injected in the breast muscle in days 7 and 21 to investigate humoral immune responses, and IgG titer against SRBC was determined in days 7, 14, 28, 35, and 42 by agglutination test. Cellular immune responses to PHA-P in treatments containing 7 and 14 mg/l of levamisole [0.272 and 0.205, respectively] were significantly affected [p<0.05]. IgG titer against SRBC in treatment containing 14 mg/l of levamisole [6.16] was significantly higher than other groups [p<0.05]. Carcass trait of broiler chicks were not affected by different level of consecutive oral levamisole [p>0.05]. The low level [up to 14 mg/L] of consecutive oral levamisole promotes cellular and humoral immune system responses of broiler chicks