Poultry semen has high spermatozoa concentration and needs to be extended (diluted) for efficient artificial insemination; extenders containing egg yolk often have various limitations to their use. This study assessed chicken egg yolk plasma (EYP) as replacement for chicken whole egg yolk (EY) in semen extenders. The preservative potential under room and cold storage and its influence on fertility and hatchability in breeder chicken flock was also assessed. Ten broiler breeder cocks and one hundred hens were used for the study. Semen ejaculates from the cocks were pooled and divided into five portions. One portion each was extended with egg yolk plasma (EYP); phosphate buffer saline (PBS); egg yolk (EY) +PBS or EYP +PBS while the fifth unextended portion termed fresh undiluted semen (FUS) served as the control. The ratio of EYP and EY to PBS was 1:4. The semen samples were evaluated at 1, 2 and 3 hours after extension under room temperature and at 24, 48 and 72 hours after cold storage (4℃). The hens were inseminated with the freshly extended semen or with cold preserved semen, each for three weeks. Fertility and hatchability of the eggs were recorded on 18th and 21st day, respectively post setting. At room and cold storage temperatures, the quality parameters of the semen significantly reduced as the holding time increased. The EYP groups had the highest spermatozoa motility of 55.33% at 72 hours of cold storage. Freshly extended semen with EYP+ PBS had higher quality and fertilizing potentials which resulted in increased egg fertility (87.49%) and hatchability (84.95%). Cold preserved EYP + PBS semen resulted in significantly higher fertility (75.66%) and hatchability (90.90%). It was concluded that egg yolk plasma could conveniently replace whole egg yolk in chicken semen extender resulting in improved sperm viability and egg hatchability.

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The histological and histochemical variation in association with morphological variation in the repro-ductive system of Archachatina marginata ovum was the target of this investigation. Forty- five snails were dissected and categorized into 5 different reproductive stages (low mating, high mating, high egg, gravid and post reproductive). The reproductive tracts which include: hermaphroditic duct, albu-men gland, spermoviduct and spermatheca and the ovotestis were processed for histological and histochemical staining. There were some variations in the architecture of the reproductive organs be-tween the active (high mating, high egg and gravid) and non active stages (low mating and post repro-ductive) states. The active states were generally associated with colloidal or granular secretions. Gly-cogen and alkaline phosphatase activities were associated together throughout the epithelium of the reproductive system of A. marginata ovum and they were more strongly indicated in tissues that are intimately connected to the growth and development of gametes. It was concluded that morphological variation in the secreting glands of the reproductive system of A. marginata ovum is closely associated with changes in the functional secretory activities of the glands.