Front Page VSPN Message Boards Chat Library Continual Education Search MyVSPN - Coming Soon Help Frequently Asked Questions Send us Feedback! Go to VIN Industry Partners Go to VetQuest Go to Veterinary Partner Go to Y2Spay
 
Menu bar   Go to the VIN.com Portal
 

ABSTRACT OF THE WEEK

Theriogenology
Volume 153 | Issue 0 (September 2020)

Heat stress and bull fertility.

Theriogenology. September 2020;153(0):62-67.
Jane M Morrell1
1 Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden. Electronic address: jane.morrell@slu.se.
Copyright © 2020 Elsevier Inc. All rights reserved.

Abstract

Since bull fertility may be adversely affected by hot humid conditions, the current increase in global temperature is of concern for future livestock production. Heat stress occurs when the body's normal physiological mechanisms to regulate body temperature cannot cope with external conditions. The testes and scrotum have their own complex regulatory mechanisms to protect developing sperm during their most vulnerable stages, but even these may be overwhelmed by unfavourable external conditions. The effects of mild, moderate and severe heat stress are somewhat different, with cattle exposed to mild and moderate heat stress apparently showing an adverse effect on fertility, whereas cattle in very hot, humid climates almost continuously may not exhibit any difference in sperm quality throughout the year. This apparent paradox may be due to differences in the cattle populations being studied, since they could differ in breed, age, purpose (beef versus dairy), or even in the methods used to assess sperm quality. The adverse effects on fertility may occur through the effects of reactive oxygen species on sperm DNA, or through perturbation of the production of antioxidants that usually protect sperm from oxidative attack. These effects can be mitigated to some extent by choosing breed and age of bulls with care, and adopting breeding strategies that avoid semen collection or ejaculation at the most adverse times of year. Husbandry measures such as controlled ventilation, misting, provision of shade or cool surfaces for lying down, could aid temperature regulation. Avoiding heat stress during late pregnancy aids calf growth in early life; careful feeding regimens for young bull calves create good conditions for sperm quality after puberty. Bull fertility is too important to be left to chance. Breeds should be chosen according to climate conditions and the purpose of livestock production.

Keywords
Scrotum; Sperm morphology; Sperm quality; Spermatogenesis; Testicular heat regulation; Thermal humidity index;

Article Tools:
   Medline
   Email to me

Archives Highlights:
Comparative evaluation of canine cadaver embalming methods for veterinary anatomy education.
Cadavers embalmed with saturated salt solution (SS) or Thiel's solution (TS) were superior in facilitating joint and muscle movement. Compared to formalin solution (FS), the color and texture of muscles and internal organs were similar to those of living animals and there was no irritating and offensive smell in SS and TS cadavers.
Disappearance of signs of heat and induction of ovulation in oestrous queens with gonadorelin: a clinical study.
This is the first study to document the efficacy of a 50 µg/cat gonadorelin dose to induce ovulation in oestrous queens when administered IM on days 2-4 following the onset of oestrus.
Randomized, controlled clinical trial to assess the effect of antimicrobial-impregnated suture on the incidence of surgical site infections in dogs and cats.
Overall, 50 of 862 (5.8%) animals developed surgical site infections (SSIs). Incidence of SSI was 6% (24/428) in the non-triclosan-coated (non-TC) suture group and 6% (26/434) in the triclosan-coated (TC) suture group. No significant difference was found in the incidence of SSI between groups. No significant difference was detected in the incidence of incisional problems (eg, redness, dehiscence, and seroma formation) between animals in which TC suture was used and those in which non-TC suture was used.
Equine Dental Floating (Crown Osontoplasty).
Odontoplasty (floating and occlusal equilibration) is the most commonly performed procedure in equine dentistry. From an anatomic perspective, an irregular occlusal surface, prominent cingula, transverse ridges, and enamel points all contribute to the function, form, and longevity of the equine cheek tooth. With limited reserve crown available and an average functional life range between 18 and 25 years, removal of tooth structure should be conservative.
Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents.
The analysis of 22 studies reveals that human coronaviruses such as Severe Acute Respiratory Syndrome (SARS) coronavirus, Middle East Respiratory Syndrome (MERS) coronavirus, or endemic human coronaviruses (HCoV) can persist on inanimate surfaces like metal, glass, or plastic for up to 9 days, but can be efficiently inactivated by surface disinfection procedures with 62-71% ethanol, 0.5% hydrogen peroxide, or 0.1% sodium hypochlorite within 1 minute. Other biocidal agents such as 0.05-0.2% benzalkonium chloride or 0.02% chlorhexidine digluconate are less effective.

Back Print Save Bookmark in my Browser Email this article to me. Top of Page. VSPN AOW : Heat stress and bull fert...
Contact Us