Video | Agriculture | Confidence | Economy | Energy | Employment | Finance | Media | Property | RBNZ | Science | SOEs | Tax | Technology | Telecoms | Tourism | Transport | Search

 


Stay on guard for heat stressed herds this summer

30 January 2014

Stay on guard for heat stressed herds this summer

Higher summer temperatures can evaporate record dairy returns unless farmers stay on guard for heat stress in their herds.

SealesWinslow Science Extension Manager, James Hague says if farmers are feeling the heat, their herds will be too and heat stress can hit production, milk quality, earnings and overall herd health.

“Cows are not terribly good at regulating their body temperatures as their ability to sweat is limited. The digestive system also creates heat and as a result core body temperature increases. When cows are heat stressed, dry matter intake reduces, and demand for water greatly increases.

“Losing just one kilo of dry matter intake is worth around two litres of milk (0.16 kgMS) which at an $8.30 milk price equates to $1.33 in lost income per cow per day. The financial loss quickly adds up and there are the animal welfare concerns including the risk of health and fertility issues cause by heat stress.”

Heat stressed cows tend to crowd around any available shade and as their water demand is high, they also crowd troughs. Stressed animals will also pant. Adequate shelter and ample water, as well as misting or spray systems can alleviate heat stress, but James Hague says attention to the herd’s diet is also crucial.

“Loss of dry matter intake accounts for around half the loss of milk yield. The other half is potentially due to inefficient digestion and damage to the animal, so it is important the diet is well balanced to maintain rumen conditions. Nutritionally there are a number of practical and very cost effective options.”

Levucell yeast, fed at a rate of 0.5 g per cow per day controls rumen pH and improves fibre digestion under heat stress conditions. This means more Feed Conversion Efficiency (FCE) at a cost of less than four cents a day. Rice bran feed, which does not have to undergo extensive fermentation to provide the cow with energy, keeps the heat of digestion low. It can be fed at rates of up to 2 kg a day. Salt, potassium, and sodium bicarbonate can also aid with heat stress as stressed animals lose electrolytes.

“Keeping the electrolyte balance with sodium and potassium is crucial as animals can lose around 13% of their daily potassium requirement through sweating. Damage can occur in the liver, which reduces the animals’ ability to process glucose, which impacts on milk production. Additives such as betaine and chromium assist with maintaining liver function and have been found to be valuable under heat stress conditions.”

Both high temperature and high humidity combined result in the worst effects on stock. A Temperature Humidity Index (THI), combining temperature and humidity, can be used as indicator of heat stress risks. SealesWinslow provides an online calculator which enables farmers to log temperature and humidity and calculate potential milk losses due to heat stress.

The higher the THI, the more severe the impact. As the accompanying graphic shows, when the THI gets above 68, signs of heat stress will set in. Above 80 causes moderate to severe stress and above 90 is severe. There is an almost linear drop off in the relative amount of milk produced as the THI rises.

The calculator and additional nutrition advice is available at www.sealeswinslow.co.nz

ENDS

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

Final Frontier: Rocket Lab And NASA Sign Commercial Space Launch Agreement

Rocket Lab has signed a Commercial Space Launch Act Agreement with the National Aeronautics and Space Administration (NASA). The agreement enables Rocket Lab to use NASA resources - including personnel, facilities and equipment - for launch and reentry efforts. More>>

ALSO:

Scoop Business: Wheeler Downplays Scope For ‘Large’ Rates Fall

Reserve Bank governor Graeme Wheeler says some market commentators are predicting further declines in interest rates that would only make sense for an economy in recession, although some easing is likely to be needed to maintain New Zealand’s economic growth. More>>

ALSO:

Ruataniwha Dam: Consent Conditions Could Mean Reduced Intensity

Legal advice sought by the Hawke’s Bay Regional Council on the Ruataniwha Dam consent conditions has confirmed that farmers who sign up to take water from the dam could be required to reduce the intensity of their farming operation to meet the catchment’s strict nitrogen limit. More>>

Health And Safety: Bill Now Sees Rules Relaxed For Small Businesses

Health and safety law reform sparked by the Pike River coalmine disaster has been reported back from the industrial relations select committee with weakened requirements on small businesses to appoint health and safety representatives and committees. More>>

ALSO:

Bearing Fruit: Annual Fruit Exports Hit $2 Billion For First Time

The value of fruit exported rose 20 percent (up $330 million) for the June 2015 year when compared with the year ended June 2014. Both higher prices and a greater quantity of exports (up 9.0 percent) contributed to the overall rise. More>>

ALSO:

Get More From Scoop

 
 
 
 
 
 
 
 
 
Business
Search Scoop  
 
 
Powered by Vodafone
NZ independent news