Feeding for milk and fertility
27 March 2009

Feeding for Milk and Fertility
Last summer’s difficult grass silage-making season has resulted in many silages having lower energy values compared with the previous year, in many cases over 0.5MJ/kg DM lower. Assuming an intake of 10kg of silage dry matter, this is an energy deficit of 5MJ per cow per day, broadly equivalent to 1 litre of milk. Energy deficiency is one of the major causes of poor fertility.
One way to lift dairy cows’ energy intake is by including Megalac protected fat in the ration. Supplementing with half a kilo of Megalac per cow per day typically increases total ration energy density by 0.5MJ/kg DM, enough to lift milk yields by around 2 litres per cow per day. However, this is not achieved at the expense of the cow’s health, as it delivers extra energy without increasing the acid load in the rumen.
A recent trial at the University of Edinburgh has shown improvements in fertility from feeding Megalac whilst also lifting milk yield. The energy supplied by Megalac is very highly digestible and will help to get cows back into positive energy balance more quickly.
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Herd Performance
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Diet
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|
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Control
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Control + Megalac
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100 day in-calf rate (%)
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21.4
|
45
|
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200 day not-in-calf rate (%)
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45.2
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15
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Calving to conception (days)
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118
|
99
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ends
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