In general, dairy cows need forages in order for the rumen to function properly. Rumen microbial fermentation must occur in the presence of complex carbohydrates such as cellulose. Complex carbohydrates are usually found in forages such as grasses and legumes. However, as these foraes mature, their cell walls thicken, making it difficult for rumen microbes to penetrate through them and ferment the sugar and protein inside the cells which is the main drawback when using in large amounts.
Feeding hay crops for high milk production:
The key to produce high amounts of milk on high-forage diets is focusing on hay crops forages that have low fiber as they have thin cell walls.
Immature plants with thin cell walls and minimum lignification are more easily ruminated and digested.
If you are growing your own forages, it is crucial to figure out the optimal yield per acre.
It is tempting to grow your own feed due to rising cost of feed but forages are completely unforgiving when it comes to quality.
If not managed properly, homegrown forages can quickly become horse and the milk quality would suffer.
Cows have a limit as to how much NDF they can consume coming from forages.
Studies have shown that the maximum recommended limit is around 1.2% of the bodyweight of the cow.
Take a Holstein cow weighing around 700kg for example, it is recommended to feed a maximum of around 8.4 kg of NDF coming from forage.
Forages with NDF levels near 60% will start to limit the amount of forages a cow can consume.
They will also be less digestible which will decrease milk production.
As dry matter from forage declines, other feedstuffs must increased in order to make sure the cow is sufficiently fed.
With that being said, this would increase the cost of diet.
Diets that maximise forage NDF must be managed properly.
These diets can be formulated to keep grains and supplements under 25% while supporting a milk production of around 36kg.
As for cows that are producing more than 45kg of milk per day, they have to be fed more expensive grains and supplement in order to maintain milk production.
Maximising forage consumption in dairy cow diets would make full use of the cow's natural capability to produce milk.
The more forage you can feed your cow, the less grain you have to buy, increasing the farm's profitability.