About Careers MedBlog Contact us
Medindia LOGIN REGISTER
Advertisement

Summer Heat Hard To Beat – Bovines’ Rates Of Conception Dip

by Medindia Content Team on September 8, 2007 at 7:53 PM
Font : A-A+

Summer Heat Hard To Beat – Bovines’  Rates Of Conception Dip

A research group from the UAB Faculty of Veterinary Medicine gives that summer heat stress is a main factor related to low conception rates in high producing dairy herds. The group studied the impact of several climate variables on conception rates in high producing dairy cows in northeastern Spain , by examining 10,964 inseminations.

The environmental temperature, radiant energy, relative humidity, and wind speed all contribute to the degree of heat stress. Heat stress may be defined as any combination of environmental variables that give rise to conditions that are higher than those of the temperature range of the animal's thermal neutral zone. The temperature-humidity index (THI) incorporates the effects of both ambient temperature and relative humidity (RH) in an index. This index is widely used in hot areas worldwide to assess the impact of heat stress on humans and dairy cows.

Advertisement

We analyzed data derived from 10,964 inseminations in 4 herds during 3 years. Climate data such as daily mean and maximum temperature mean and minimum relative humidity, and rainfall were obtained from a meteorological station located less than 6 km away within the herds. Mean and maximum THI were calculated during 7 days before insemination to 3 days postinsemination. Fans are activated when temperature arise at 23-27ºC.

Results indicated that high THI during 3 days before insemination, specially the Day 3 before, reduced fertility, probably due to ovulation failure. Ovulation failure was 3.9 times higher in cows inseminated during the warm period (May-September) compared to the cool period (October-April). THI on the day of insemination is also important for fertility, probably because heat stress could affect oocytes, spermatozoa and embryos.
Advertisement

A high maximum temperature on day 1 after insemination was found to reduce conception rate. Although it has been described that hyperthermia in lactating dairy cows can occur at air temperatures as low as 27°C, only maximum daily temperatures <20ºC led to a significant increase in fertility. It should be stressed that in our geographical area, the maximum temperature was only <20ºC for 170 days per year.

As an overall conclusion, climate factors seem to be highly relevant for conception rate. The use of maximum temperatures gives more information that the one provided by THI variables. Thus, the use of the THI or temperature to control a farm environment would depend on the individual farm and on each environmental situation, but it is important to check temperature and humidity to know when to adopt cooling measures.

Further studies should try to establish the effect of global warming at the farm level. This problem is reflected with warm summers and even with peaks of temperatures in winter.

Source: Eurekalert
LIN /J
Advertisement

Advertisement
Advertisement

Recommended Reading

Latest Environmental Health

 Plants Filter Airborne Pollutants That Cause Cancer
The Ambius small green wall, which contains a variety of indoor plants, was shown to be quite successful at removing hazardous, cancer-causing pollutants.
Uncovering the Link Between Dirty Air and Premature Death
Public health measures to prevent air pollution could lead to positive effects on patients with heart failure.
Solving the Nitrate Puzzle: Contradictory Hazards and Benefits of Nitrate
Nitrate has brought in two contradictory results, where one study states that it could be heart-healthy while the other points to it as a cancer risk.
Are We Ready for the Future Health Impacts of Climate Mitigation?
Worsened air quality due to climate mitigation efforts could lead to respiratory and cardiovascular problems.
Are We Ready to Reduce Plastic Pollution by 80% by 2040?
Reduction in plastic pollution results in an increase of 700,000 jobs by 2040, significantly improving the livelihoods of millions of workers in informal settings.
View All
This site uses cookies to deliver our services.By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use  Ok, Got it. Close
×

Summer Heat Hard To Beat – Bovines’ Rates Of Conception Dip Personalised Printable Document (PDF)

Please complete this form and we'll send you a personalised information that is requested

You may use this for your own reference or forward it to your friends.

Please use the information prudently. If you are not a medical doctor please remember to consult your healthcare provider as this information is not a substitute for professional advice.

Name *

Email Address *

Country *

Areas of Interests