What is the most likely cause for the poor pregnancy rate and the distribution for stage of pregnancy in the histogram?

Autor: Rosenkrans KS; Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia 65211, USA., Hardin DK, Watson D
Jazyk: angličtina
Zdroj: Journal of the American Veterinary Medical Association [J Am Vet Med Assoc] 2001 May 15; Vol. 218 (10), pp. 1565-6.
DOI: 10.2460/javma.2001.218.1565
Databáze: MEDLINE