The avian immune system is a complex system of defence mechanisms that protect bird hosts against threats from ubiquitous pathogens. According to the co-evolutionary models, variability in immune traits of hosts is the key component providing ability to adapt and enhance their defence mechanisms in presence of constant selective pathogen pressure. Domestic chicken (Gallus gallus f. domestica) is used as a model organism in avian biology and also is one of the most important food-producing animals, not only for their meat but also for the egg production. Unfortunately, in research usually only inbred chicken lines are used and modern poultry husbandry is tight with unilateral breeding towards highly productive breeds. Those approaches decrease intra-population polymorphism in chickens. However, especially in case of farm animals, searching and extending the pool of immune variability and enhancing pathogen resistance is crucial for sustaining healthy and biologically secure populations and their products. Morphologically highly distinct traditional chicken breeds, which have evolved for hundreds years under different selective pressures, may represent this desirable immunological variability. In my thesis I described variability in chosen immunological traits, haematological parameters and proteomic...

The avian immune system is a complex system of defence mechanisms that protect bird hosts against threats from ubiquitous pathogens. According to the co-evolutionary models, variability in immune traits of hosts is the key component providing ability to adapt and enhance their defence mechanisms in presence of constant selective pathogen pressure. Domestic chicken (Gallus gallus f. domestica) is used as a model organism in avian biology and also is one of the most important food-producing animals, not only for their meat but also for the egg production. Unfortunately, in research usually only inbred chicken lines are used and modern poultry husbandry is tight with unilateral breeding towards highly productive breeds. Those approaches decrease intra-population polymorphism in chickens. However, especially in case of farm animals, searching and extending the pool of immune variability and enhancing pathogen resistance is crucial for sustaining healthy and biologically secure populations and their products. Morphologically highly distinct traditional chicken breeds, which have evolved for hundreds years under different selective pressures, may represent this desirable immunological variability. In my thesis I described variability in chosen immunological traits, haematological parameters and proteomic...

The objective of this study was to determine sheep production practices, constraints, flock dynamics, body condition and weight variation in two ecologically different resource-poor communal farming systems of the Eastern Cape Province of South Africa. Mean sheep flock sizes per household were not significantly different between the two ecologically different areas (villages); Gaga (19.0±3.10) and Sompondo (18.3±3.10). Shortage of feed, disease and parasite were reported the most important constraints across the two villages. In both villages, sheep housing was poorly constructed using acacia brushwoods. Fewer farmers owned rams: the rams to ewes ratio for the two villages were 1:20, 1:19 for Gaga and Sompondo, respectively. The low ram: ewe ratios reported suggest that inbreeding might have been reducing productivity of their flocks. There was also uncontrolled breeding due to undefined and mating seasons. Gall sickness, heart water and footrot caused most of the sheep mortalities. Dohne Merinos were the common genotypes in the two villages. Total entrances for each flock were higher (p < 0.05) in hot-dry season and hot-wet season than in other seasons. Most of the entrances were lambs and were born in hot-dry season (September) and cool-dry season (June) for larger flocks (10.90 ± 3.02) and for small flocks (3.65 ± 3.02). High lamb mortalities were experienced in the post-rainy (April) and hot-wet (December) season. There was a significant interaction between season and flock size. Most of the sales occurred in the hot-wet season. Ecological area had significant effect on sheep production potential (p < 0.05) in both flock classes. The average sheep production efficiency (SPE) value for Gaga and Sompondo were 0.50 ± 0.116 and 0.50 ± 0.096 respectively. The SPE for large flock was higher (p < 0.05) by season and flock size. Large flocks had a higher (p < 0.05) SPE values and the SPE ranged from 1.11 ± 0.193 in April, a post-rainy season month to 1.55 ± 0.193 in December, a hot-wet season month. Lamb mortalities constituted the greater part of outflows. High lamb mortalities occurred in hot-wet (December), hot-dry (September) and post-rainy (April) seasons. There was a significant interaction between season and age of sheep on body weight of sheep. Highest (p < 0.05) body weights were recorded in the post-rainy and autumn season in both lambs and ewes. It is therefore very important to come up with affordable interventions which take into play ecological differences of the areas for improved nutritional status of sheep in communal areas which will lead to improved sheep productivity and the poor-resourced farmer human nutritional and livelihood.

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