title: Preliminary results on the use of diagnostic ultrasonography as a management tool to quantify egg production potential in breeding ostrich (Struthio camelus australis) females.
abstract: An ostrich breeding flock, joined as individual breeding pairs (n = 136 pairs), was used to investigate the possibility of diagnostic ultrasonography as a method to predict the reproductive performance of ostrich females during a breeding season. Follicular activity was easily detected and quantified by using diagnostic ultrasonography. One to 8 follicles were recorded in 25% of females scanned at the beginning of the 9-month breeding season. At the end of the breeding season, 1-3 follicles were observed in 28.7% females. Females in which follicular activity was observed came into production earlier than those in which no follicles were observed, with the mean (+/- SE) number of days to the production of the 1st egg being 22.3 +/- 12.5 and 87.4 +/- 7.2 days, respectively. Females in which follicular activity was observed at the beginning of the breeding season, produced on average 181% more eggs during the 1st month of the breeding season (P < 0.01) than females in which no follicular activity was observed (6.67 +/- 0.70 vs 2.37 +/- 0.41 eggs). Egg production over the first 2 months of breeding and over the entire breeding season were similarly affected (P < 0.01), with the mean number of eggs produced over the first 2 months of the breeding season being 14.7 +/- 1.5 for females with observed follicular activity and 7.4 +/- 0.9 eggs for females with no observed follicular activity. Females in which follicular activity was observed at the end of the breeding season produced on average 108% more eggs (P < 0.01) during the last month of the breeding season than females in which no follicular activity was observed (2.77 +/- 0.43 vs. 1.33 +/- 0.27 eggs). There was a tendency (P = 0.06) for egg production over the last 2 months to be similarly affected (6.10 +/- 0.85 vs 4.19 +/- 0.54 eggs). No relationship with egg production over the entire breeding season was found for the end-of-the-breeding-season observations. Diagnostic ultrasonography can thus be used as a management tool to identify reproductively healthy ostrich females and also females with a higher egg production potential over a period of 2 months after or prior to assessment. Future studies should focus on the development of the technique to predict reproductive performance over entire breeding seasons for selection purposes.
authors.affiliation: Klein Karoo Agricultural Development Centre, Oudtshoorn, South Africa. heletl@wcape.agric.za
authors.forename: H
authors.initials: H
authors.lastname: Lambrechts
authors.forename: S W P
authors.initials: SW
authors.lastname: Cloete
authors.forename: D
authors.initials: D
authors.lastname: Swart
authors.forename: J P C
authors.initials: JP
authors.lastname: Greyling
mesh_terms: D000818:Animals; D001947:Breeding; D005260:Female; D008297:Male; D006080:Ovarian Follicle / Q000000981:diagnostic imaging*; D010053:Ovary / Q000502:physiology; D010058:Oviposition / Q000502:physiology*; D020310:Struthioniformes / Q000502:physiology*; D013997:Time Factors; D014463:Ultrasonography