Figuring out how a lot forage cows will eat on a per day and per thirty days foundation at some point of winter all the time requires a bit of “cowboy math”. Chapter 16 of the eighth version of the OSU Beef Cattle Handbook is a superb reference for estimating consumption and the dietary necessities of dry and lactating beef cows.
This yr, with many “non-traditional” sources of hay resembling soybean, milo, cotton and corn fields that have been become hay out of dire necessity, requires a bit of further math to make an excellent estimate. Making the very best estimation of how a lot hay you have to over the following few months nonetheless requires a feed evaluation take a look at. The knowledge gained by way of an evaluation, like TDN (vitality content material) and Crude Protein function a information of two issues: 1) how a lot cows will devour, and a couple of) how a lot they are going to want of a particular hay (or feed complement) to fulfill their dietary necessities.
For instance, a 1300 pound, dry cow within the final trimester of being pregnant requires 13.3 kilos of TDN and 1.84 kilos of vitality per day. A hay testing with 54% TDN and seven.5% Crude protein consumed at 1.9% of her physique weight leads to a every day dry matter consumption of 24.5 kilos of dry matter. This consumption of this hay will meet her every day wants with out further supplementation.
If we contemplate how a lot precise hay we have to present every day a number of extra gadgets should be considered:
- Hay isn’t all dry matter. Assuming our hay is 90 – 93% dry matter (or 7-10% water). Taking this into consideration provides one other 2-3 kilos of hay per day “as fed”.
- Hay will probably be wasted. Relying on high quality of the hay, climate, kind of hay feeder used or feeding methodology, cows will waste 6 – 20% of every bale fed. In case you are feeding a non-traditional hay there could also be extra sorting by cows. Particularly, the underside finish of the corn or sorghum stalk may be very low in nutrient high quality, cows will kind out most of this portion and consumption will probably be very low. Prior to now few weeks, I’m listening to estimates from producers feeding cornstalk hay that as much as 30-40% of the bale is stalks which cows is not going to eat. This must be considered. Assuming 20% of every bale is wasted, it provides one other 7-8 kilos of hay per day “as fed”. After taking dry matter content material and waste into consideration we’re 34-35 kilos of hay per day wanted.
- What else must you contemplate? What does every bale weigh and the way a lot is spoiled? You probably have bought hay by tonnage, it’s straightforward to calculate the common weight of every bale. Rule of Thumb for estimating how a lot spoilage per bale: roughly 1/3 of the bale weight of a 5 ½ foot diameter spherical bale is within the outer 6 inches. Even 2-3 inches of spoilage on the underside facet of the bale can equal a considerable loss.
Hay is extremely invaluable and in brief provide. Use these tips to estimate at how a lot you want to be offering per cow per day and prolong it over the winter to determine how a lot hay stock is sufficient.
One closing level, feeding waste will be diminished! Open backside spherical bale feeders can have as much as 30% waste, sheeted backside feeders can scale back this to twenty%. Cone feeders can scale back the waste to lower than 10%.
References: Chapter 16, web page 131. Eight Version OSU Beef Cattle Handbook
