Genetics and Breeding

The opportunity exists to utilise our knowledge of major genes that influence the economically important traits in wool sheep. Genes with Mendelian inheritance have been identified for many important traits in wool sheep. Of particular importance are genes influencing pigmentation, wool quality and the keratin proteins, the latter of which are important for the morphology of the wool fibre. Gene mapping studies have identified some chromosomal regions associated with variation in wool quality and production traits. The challenge now is to build on this knowledge base in a cost-effective way to deliver molecular tools that facilitate enhanced genetic improvement programs for wool sheep. more »

Aim: To evaluate two extenders and two cryoprotectant agents (CPA) for alpaca semen cryopreservation. Methods: Semen samples were obtained from four adult alpacas (Lamapacos) and frozen using extender I (TRIS, citrate, egg yolk and glucose) or extender II (skim milk, egg yolk and fructose), each containing either glycerol (G) or ethylene glycol (EG) as CPA. Consequently, four groups were formed: 1) extender I‐G; 2) extender I‐EG; 3) extender II‐G; and 4) extender II‐EG. Semen was diluted in a two‐step process: for cooling to 5 °C (extenders without CPA), and for freezing (extenders with CPA). Viability and acrosome integrity were assessed using trypan blue and Giemsa stains. Results: When compared, the motility after thawing was higher (P < 0.05) in groups II‐EG (20.0 %± 6.7 %) and II‐G (15.3 %± 4.1 %) than that in groups I‐G (4.0 %± 1.1 %) and I‐EG (1.0 %± 1.4 %). Viable spermatozoa with intact acrosomes in groups II‐EG (18.7 %± 2.9 %) and II‐G (12.7 %± 5.9 %) were higher than that in groups I‐G (5.7 %± 1.5 %) and I‐EG (4.0 %±1.0 %). Conclusion: The skim milk‐ and egg yolk‐based extenders containing ethylene glycol or glycerol to freeze alpaca semen seems to promote the survival of more sperm cells with intact acrosomes than the other extenders. more »

I. Background and current research interests. II. Recent cooperative studies with alpacas. III. Animal fiber metrology. IV. Genetic tools that are being used to improve alpaca fiber quality and production. more »

The quality and quantity of alpaca fibre is affected by not only the body condition and nutrition of the animal but also by season and sex hormones. These factors can interact with the genetic potential of each animal to such an extent that they can mask the true genetic value of an animal. This RIRDC report provides scientific data that can be used by producers, consultants to the industry, and feed manufacturers to design more appropriate diets and feeding strategies that will allow the industry to make genetic progress because these management procedures will decrease the impact of nutritional and environmental factors on the expression of the animal’s genetic potential for fibre production. more »