Different forage types require different harvest practices for optimal feed quality, says Courtney Vriens, ruminant nutritionist with Vriens Nutrition Consulting.
Each of the four main types of forage used by sheep producers, alfalfa, grass, small grain silages and corn silage, provide excellent feed quality if harvested and managed properly.
Why it matters: Accomplishing on-farm goals such as reproduction, milk production, lamb productivity and quality lies within a good feeding program and optimal feed quality begins with harvesting crops at the ideal stage.
Grass and alfalfa
Grass and alfalfa are the most common forages used by ruminant producers because they have the highest protein content.
The highest quality alfalfa is harvested within the bud to early bloom stage.
A forage sample showed that alfalfa cut at early bud stage has 57.3 per cent NDF (neutral detergent fiber) digestibility compared to that of alfalfa cut at full flower showing 39.6 per cent NDF digestibility.
“This demonstrates the difference in stage of maturity at cutting. What you are really losing out on here is availability of that feed,” says Vriens during the 2021 Grey Bruce Farmers’ Week Virtual Conference and Trade Show Sheep Day.
As well, undigestible fibre residue is higher within alfalfa cut at full flower, compared to that of early bud stage.
Plants that have reached full flower may have a place on farm for dry ewes, says Vriens, but if the hay is going to be baled there is going to be a lot of waste associated with that plant.
“You may get a little extra yield but there is potential that that yield will just be wasted because it is stalky and unpalatable.”
As well, when producers are after optimal quality, cutting intervals are important. Harvesting every 32 to 35 days in a four cutting system is typical.
With grass it is best to harvest within the boot stage, especially for first cut.
“Grass has really great quality in the spring but it loses its quality fairly quickly, so you need to be aggressive with getting it off at the right stage.”
Both alfalfa and grass are great options for sheep producers.
“It really comes down to what works on your farm in terms of your crop rotation and your management,” says Vriens.
Small grain silages
Small grain silages include oats, wheat, barley, sorghum and triticale. It is common for producers to intercrop them with peas for added protein and yield.
“These are becoming more and more popular. They also allow (producers) to increase their forage yield per acre, which can be very important for some farms with low acreage,” says Vriens.
These crops present excellent opportunities if harvested at the right stage and properly managed.
Quality is optimized at the boot stage and quality decreases fairly quickly.
“There is a really small window to get these crops off at the right maturity. Sometimes the weather doesn’t co-operate, which can make it challenging.”
As these crops mature, they tend to become more straw-like. If this is the case, it is best to harvest as a haylage at 60 to 65 per cent moisture because it provides better palatability if chopped.
Oats and peas harvested in the boot stage compared to oats and peas harvested in head showed a 12 per cent increase in protein.
Forage samples presented by Vriens showed sorghum sudan grass with a crude protein level at 17.4 per cent and winter triticale at 18.1 per cent when harvested properly.
“For commercial sheep they have a very good place in the business and I am seeing them utilized more and more and more.”
The quality of corn silage put away in storage is based on dry matter content at harvest.
Although using kernel milk line is a common practice for indicating moisture, it provides limitations.
There is a significant range in actual total plant moisture based on the milk line. This can range from 52 to 72 per cent moisture, says Vriens.
Select a whole plant that represents a field and chop through a harvester or wood chipper and then test the matter level of the total plant so figure out harvest timing, says Vriens.
Testing of the corn silage moisture should be done shortly after kernel denting. Corn will dry down around half a per cent per day following this stage and producers can decide from there when it is time to harvest.
“Feeding sheep looks different on every farm. There are many ways to feed sheep successfully. There are many options for different forages and different feed ingredients. It’s important you are working with a strategy that benefits your production goals.”