Bovine Reproduction. Группа авторов

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Bovine Reproduction - Группа авторов


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experienced by the group. When a bull fails to meet the minimum morphology standards for a satisfactory classification due at least in part to a high proportion of DMRs it is appropriate to reevaluate the bull in as little as two weeks. Not only do DMRs appear fast following an insult, but also if all goes well the numbers of affected sperm will decline rapidly.

Photo depicts distal midpiece reflexes with and without droplet material and detached heads on an eosin-nigrosin stained smear. Photo depicts distal midpiece reflexes.

      Mitochondrial Sheath Defects

Photo depicts mitochondrial sheath defect.

      Accessory Tails

      Stump Tail

Photo depicts stump tail defect.

      Dag Defect

Photo depicts dag defect.

      Principal Piece Defects

      Coiled Principal Piece

      Bent Principal Piece

      Occasionally, sperm displaying a loop bend in the principal piece with cytoplasmic droplet material trapped in the loop are encountered. The loop begins just past the midpiece, so technically it is not a DMR. Most of the sperm with bent principal pieces are noted in spermiograms where DMRs are present and are believed to have the same origin.

      1 1 Koziol, J. and Armstrong, C. (2018). Society for Theriogenology Manual for Breeding Soundness Examination of Bulls, 2e. Pike Road, AB: Society for Theriogenology.

      2 2 Barth, A. (2013). Bull Breeding Soundness, 3e. Saskatoon, SK: Western Canadian Association of Bovine Practitioners.

      3 3 Mosure, W., Meyer, R., Gudmundson, J., and Barth, A. (1998). Evaluation of possible methods to reduce pain associated with electroejaculation in bulls. Can. Vet. J. 39: 504–506.

      4 4 Ohl, D. (1993). Electroejaculation. Urol. Clin. North Am. 20: 181–188.

      5 5 Stafford, K. (1995). Electroejaculation: a welfare issue? Surveillance 22: 15–17.

      6 6 Whitlock, B., Coffman, E., Coetzee, J., and Daniel, J. (2012). Electroejaculation increased vocalization and plasma concentrations of cortisol and progesterone, but not substance P, in beef bulls. Theriogenology 78: 737–746.

      7 7 Dziuk, P., Graham, E., Donker, J. et al. (1954). Some observations in collection


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