By Frank Wardynski, Michigan State University Extension
Severe drought and conversion of hay acres to corn production has contributed to a shortage of forage for feeding dairy cows. Estimates indicate that there will not be enough forage supply to feed the current dairy cow population in drought stricken areas. Dairy producers are looking for forage alternatives that will extend their current feed supply, without sacrificing milk production. Corn stalks appear to be a cost effective purchase to supplement forage inventories.
Corn stalks are high in fiber content and can slow passage rate. Over-feeding corn stalks, particularly to lactating cows, will result in feeding a ration too high in fiber content that will slow passage and reduce dry matter intake. General recommendations are to feed no more than 20% of the forage ration to lactating cows. If the ration is cheapened too much, decreasing milk production will result and profitability will be sacrificed. While dairy farmers are constantly challenged to reduce feed costs, it should not be done by sacrificing milk production.
Dairy farmers should calculate feed inventory and feed requirements. Feed inventory should account for forage quality. Certainly, if feed inventory is less than feed needs, actions must be taken to secure the needed feed resources.
Corn stalks have similar nutrient contents to straw. Dairy producers who have already inventoried straw for dairy rations may not want to add cornstalks into their rations. The nutrient content range can be large depending on the percentage of stalk, leaf, husk, cob and grain content. Sampling and testing is critical for proper ration formulation.
Given current prices of forages and grain concentrates, corn stalks appear to be favorably priced using the extension tool, Feedval 2012 to compare feedstuffs. Feedval 2012 is a feed pricing spreadsheet that can be found online, through the Dairy Cattle Nutrition, University of Wisconsin Extension website.
Body Condition Scoring (BCS) is an important management tool used on dairy farms to ensure that cows possess proper fat reserves. Opinions vary as to the proper BCS dairy cows should possess at the beginning of lactation. Most agree that cows should have a BCS within 0.5 dry off. Condition scoring can be used in evaluating ration quality. Feeding high fiber feedstuffs, such as cornstalks, can assist producers to extending forage supplies and reducing ration cost; however precautions must be taken to ensure that inclusion rate is not too high resulting in less than optimal fat reserves. Observation of BCS should be used in the evaluation of corn stalk inclusion rates. If cows are not gaining condition and body weight through late mid and late lactation, rations should be re-evaluated and reducing corn stalk inclusion rate considered.
Harvesting and feeding of corn stalks has been conducted in an assortment of methods. Each mechanical harvest and feeding system will change the proportion of stalk to leaf to husk ratio. This ratio will have a great effect on the nutritive value of the feedstuff. Consequently feed testing is important.
Corn stalks can be cost effectively included in lactation cow rations. Producers need to be use caution and not add corn stalks at excessive inclusion rates. If dry matter intake is depressed causing milk production to drop and body condition to be adversely affected, inclusion rate must be reduced. For more information about feeding of corn stalks to lactating dairy cows contact Frank Wardynski, Ruminant Educator withMichigan State University Extension.