Fall Nutrition; Potential Forage Shortages on the Horizon?

Published on Mon, 08/12/2019 - 3:36pm

 Fall Nutrition; Potential Forage Shortages on the Horizon?

 By Michael Cox

 Localized feed shortages may be a strong possibility this Fall and winter, as the season challenging weather conditions limited normal forage production in many dairy regions across the country. Delayed planting, flooding and a wetter and cooler summer than average in many areas have had their impact both on the tonnage and quality of the forage harvest. If limited feed supplies are a possibility, industry advice recommends being as proactive as possible, both in assessing stocks on-hand and in formulating changed diets if forage availability is restricted.

Role of forage
Forage is a critical part of a ruminant’s diet, and cows must receive a minimum level of forage in the diet to maintain rumen function, production and health. A well-balanced milking string diet usually delivers half of crude protein and energy requirements from forage sources such as alfalfa, corn silage, haylage etc., along with over 80 percent of fiber requirements. While grain and other more concentrated feedstuffs may appear to be ‘better’ as they are more nutrient dense, the benefits from their inclusion in the diet are limited. A high-quality forage-based diet with 20 percent grain inclusion will almost always outperform a low forage, high grain diet. Two problems arise when nutritionists look to change forage levels dramatically in a diet; the effects of forage quality and the ‘starchiness’/ low NDF levels of a high grain diet.

If forage is in short supply, it’s often the case that what forage is on hand is not of stellar quality. Not all forages are created equal, and simply assuming that any quality standard of fiber source will cover the fiber requirements of the diet will lead to poor performance. Low grade forages will limit dry matter feed intake, as they are typically bulkier and slower digested than high quality forages, for example straw versus alfalfa. When NDF figures reach the mid to low 30 percent range, intakes will decrease.
Acidosis is one of the primary concerns when formulating a low forage diet. Low forage quantities will promote less rumination and saliva production, which can lead to acidosis symptoms of laminitis, low butterfat component tests and a drop in milk production.
North Dakota State University extension recommends maintain minimum NDF of 26 percent of total ration, ADF of 20 percent and overall forage inclusion at 40 percent or more of the diet. If 40 percent roughage is a challenge to meet, several byproduct feeds offer advantages of high fiber and high energy density, which can help meet the required NDF and ADF levels and maintain the energy output of the diet. Corn gluten, beet pulp, soyhulls, hominy, ear corn, cottonseed hulls and oat byproducts can all play a useful role in formulating low forage diets. Fat and protein levels will often become compromised in low quality forage diets and additional supplementation may be necessary. Including the same pounds of fat in the diet as butterfat produced per cwt is a useful rule of thumb to ensure production is not compromised. Fats are less ‘hot’ than starchy grains and can increase energy in the ration without increasing acidosis risk.

Supply and demand
Other options to reduce feed demand such as drying off cows earlier towards late lactation, feeding lesser quality feeds to dry cows and heifers, selling cows, culling cows earlier, raising less heifers etc. can have positive effects on reducing feed demand in the short term, but each carries longer term consequences that may hinder future profitability down the road. The introduction of the FEEDD Act by Congress offers some window of flexibility for prevented planted acres to grow cover crops as the November 1st deadline can now be waived. This option is unlikely to fulfill a major feed deficit but cover crops can go some ways to help bring more forage into the equation. The benefits of cover crops are fantastic for not only providing quality forage, but also protecting and building soil reserves and limiting erosion. Perhaps a successful cover crop season this year could encourage more farmers to incorporate this practice regularly in future years. For now, the advice from Congress down to the local nutritionist on the ground is for each farm to assess its forage situation and make a practical feed plan to ensure any feed deficits are identified early and solutions identified.