Grazing Corn Plants as an Alternative Summer Annual Forage for Growing Lambs to Reduce Chemical Dependency and Parasite Resistance to Chemicals

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2012: $7,500.00
Projected End Date: 12/31/2013
Region: North Central
State: Ohio
Project Coordinator:
Curt Cline
Cline Family Farms


  • Agronomic: corn
  • Animals: sheep


  • Animal Production: parasite control
  • Education and Training: demonstration, farmer to farmer, on-farm/ranch research
  • Farm Business Management: whole farm planning, budgets/cost and returns, feasibility study

    Proposal summary:

    Parasitism in lambs is one of the top limiting factors in a sheep grazing operation. Parasites, especially the Haemonchus contortus (HC), play havoc on lamb gains and can result in lamb mortality when not addressed properly. Over the past several years chemical dependency has led the sheep industry down a path to where a high number of grazing sheep operations have experienced chemical failure, or are on the verge of having chemical failure. Chemical failure can happen a few ways, one of which is under dosing lambs by either under guessing weight, or poorly calibrated dosing equipment. It can also happen when the parasites get frequent exposure to a chemical de-wormer combined with rotation to a “clean” pasture. This results in the resistant parasites that the chemical did not kill populating the pasture and reproducing, leading to more resistance to the chemical.

    Permanent pastures can provide highly nutritious forage for growing lambs but are limited to a single harvest with grazing lambs due to the existence of parasites shed the previous grazing pass. Annuals can provide a great forage for two reasons: First,the tillage necessary to establish the annual will kill any parasite eggs that had been previously shed on the paddock so that secondly the non-exisitence of parasites for the first grazing pass makes it a safe pasture capable of producing good lamb weight gains. However, a second grazing pass with lambs is difficult, because they can pick up eggs shed in the first pass, so the forage is now similar to the situation with permanent pasture. Sudan grass seems to be the natural fit to hit the summer growth slump for most grazing systems and can be high quality forage, as high as 21% protein, which is more than enough for growing lambs. The difficulty of sudan grass is the inability to control growth to keep it in a high enough quality for growing lambs (at 16%). Past work has shown that within a two week period quality can drop from 16% to 10%. Once the quality drops to that level it cannot be used for lambs, and cannot be harvested at a later date.

    What I am proposing is planting 1 acre of corn (90 day maturity) starting in early May every two weeks until late June–early July, 4-5 plantings (weather depending). I plan to strip graze lambs starting in early July (maybe June depending on planting dates due to weather) when the corn reaches high enough tonnage but before it develops an ear. I will strip graze the corn so the lambs will have access to the same area in the field for no more than 3 days (length of time necessary for HC(Haemonchus contortus), to develop into the L3 larva stage). Staggered planting should give a steady supply of forage without an ear of corn throughout the summer. It is necessary to graze the plant before it develops an ear. Studies have shown the protein drops dramatically when the plant is in the blister stage and beyond. Articles written by Dr. Anibal Podomingo in the Stockman Grass Farmer show cattle grazing the corn plant at this stage had higher gains than cattle grazing alfalfa and rye grass mixed (2.8 as opposed to 2.0 lbs./hd/day.) The advantage of planting corn is it will work as a single pass forage as well as the whole plant can be captured unlike other annuals. Excess corn unused can be either harvested for grain or in my case left unharvested for winter grazing by ewes in mid gestation. Areas grazed by lambs can be seeded with Oats in August for winter grazing as well giving the land a double crop situation. It will also provide a parasite free pasture for grazing lambs.

    I plan to use 25 lambs as my test animals, born in April, strip grazed on grass legume pastures to start then switched to alfalfa in early June. I will use a back fence to keep sheep from having exposure to new deposited parasites. Lambs will be weaned and dewormed in late June then moved to the corn. Strip grazing will be continued throughout the summer. Parasites will be monitored with fecal egg counts (FEC) starting in early June. A composite sampling technique will be used to monitor the group of lambs before corn grazing begins to establish a time line as well as monitoring the welfare of the flock. Weights will be taken of the 25 lambs before, during and after the project ends. Forage quality and quantity samples will be taken on the corn starting in Mid-June and continue on a 2 week schedule to establish a quality/quantity timeline. Lambs will be grazed with other non-test lambs in a larger group to control forage growth.

    FEC will be done by the Ohio State University Extension Veterinarian Lab in Columbus and over seen by Dr. Shulaw. Forage test will be done by Dairy One Lab in New York.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.