We will always have to face drought. It’s inevitable. This past year is no exception. The biggest question you need to ask yourself as a cow-calf operator is, “DO I HAVE ENOUGH FEED TO GET THROUGH THE WINTER?” You need to take an inventory of your stored feed and then calculate backwards to see how long the feed will last. Basically a 1,400-pound cow will consume between 35 and 40 pounds or 2.5 per cent of body weight of hay a day and this includes waste. “It’s essential to take samples of your feed supply,” says Barry Yaremcio, beef and forage specialist with Alberta Agriculture and Forestry. “One needs to sample 10 per cent of the feed supply or a minimum of 20 bale core samples for a complete feed analysis. It is important to get a representative sample so take a core sample from different locations in your bale yard. Combine your samples into three or four packages and have them analyzed separately so you can see the variation in your nutritional analysis. This will give you a very good summation of the quality of feed you have in store. You need to focus on the available energy in the feed and realize the importance of supplemental protein and minerals. Good-quality hay has 12 per cent or more protein.”
Most provincial Agriculture Departments have information on their websites about different ways of feeding beef cows during the winter and making your feed last through the winter. Dr. Hushton Block, a beef cow-calf nutritionist formerly at Brandon and now at Lacombe, says cows in good body condition will have fat reserves that can offset some quantity and feed-quality shortages without much risk of negative impact providing cows are on a rising plane of nutrition after calving.
Feed lots of straw this winter, especially before calving. Save your best feed for after calving when the nursing cow needs to be on a rising plane of nutrition so she will quickly conceive during the first part of the breeding season.
At the Melfort Research Station in Saskatchewan in the 1980s we had a big research program on the use of straw in the cow wintering diet. At the same time Dr. Gary Mathison at the University of Alberta was also working on feeding high straw-based rations.
At Melfort, we fed straw all winter, free choice in round bale feeders and limited the supplementation of hay, barley silage or grain. This way cows didn’t waste valuable feed.
In another series of trials at Melfort in co-operation with the Western College of Veterinary Medicine we fed different pens of fatter or thinner cows at 75-80 per cent of the NRC requirements and compared the results to similar pens of fatter and thinner cows fed at NRC requirements from weaning to calving time. After calving, all cows were on a rising plane of nutrition as indicated by NRC up to and through the breeding season. All cows had free access to barley straw and were supplemented with silage and grain according to the designated ration strategy. The supplement was increased to NRC standards after calving.
Our cows calved in pens in February and March and over three years we saw no difference in conception rates and calving dates between groups. The basic thing that we observed was in times of feed shortages cows can be on a lower plane of nutrition prior to calving but THEY MUST BE ON A RISING PLANE OF NUTRITION (at NRC levels) AFTER CALVING! This only works in times of short feed supply and is not recommended over the long term.
Dr. Block suggests, “One needs to look at least-cost feed formulation to determine which supplement feeds have the best value relative to cost. Grain is usually twice the price of hay due to the higher energy content but this might not be true during periods of short forage supplies.”
We also did the Pepsi Taste Challenge or should I say the straw taste challenge on our cow herd at Melfort and later at Lacombe. We fed all sorts of different types and varieties of straw in round bale feeders out in a field. Every other day we changed the type of straw in the different round bale feeders so that the cows had to find the straw they preferred. We measured consumption and the number of head at the different feeders at different times of the day. Cows consumed all types of straw but they preferred the thinner straw types. It was interesting to note that they preferred ground flax straw called schives that I got from a mobile flax fibre plant the best. Since the flax schives were ground by the flax plant, cows were able to increase their intake of this byproduct. The increased processing of the flax straw resulted in increased intake and passage rate causing reduced digestibility and possibly no net change in available nutrient intakes.
A lot of work was done in the early 1980s at Melfort on fine grinding of low-quality hay to increase intake. In today’s economics it doesn’t pay the farmer to finely grind forages.
We found no clear-cut preference between two-row and six-row straw stored inside or outside for one year compared to fresh straw. However, there was a trend towards two-row straw being preferred. The year of harvest had the greatest impact on straw quality and preference.
We found that pea straw provided an excellent feed. The key issue was keeping the pea straw dry and baling it right after combining. We ran into problems with mouldy pea straw that had sat in the field prior to baling and dirt being picked up when we baled. If you bale right behind the combine, the pea straw will stay up on the stubble and out of the moisture and dirt.
At Lacombe Research Centre we fed our pregnant cows up to 66 per cent of the ration in straw. All cows were supplemented with silage and grain to meet NRC requirements. Cows fed a high-straw diet free choice, need a high-protein supplement for adequate digestion by the microbes in the rumen. We successfully fed the supplement on alternate days as a means of cutting down labour. Cows received two days’ amount of protein and energy supplement every other day. Alternate-day feeding of the protein supplement had no effect on straw intake, ruminal degradability and diet digestibility. There was no incidence of lactic acidosis.
Block adds, “Several studies have found no issue with providing protein supplements on alternate days. However, it is still important to ensure the type of protein supplement is appropriate for the diet. Non-protein nitrogen sources are only of benefit if there is enough fermentable carbohydrate for the rumen microbes to synthesize microbial protein. Sources with high bypass protein can meet cattle requirements once the rumen microbes are fed, but tend to be more costly.”
Barry Yaremcio recommends using an ionophore to improve digestibility of straw-based diets. “The ionophore will increase feed efficiency by six to seven per cent. It’s advisable that you have a mineral mix of Ca : P in the ratio of 26:4 and that the ionophore and the vitamins be added to this mixture. There is a need to supplement to prevent winter tetany, downer cows and milk fevers.”
I spent my research career looking at low-cost wintering rations for beef cows and how they relate to cow body condition. The big thing that I learned over the years was cows going into the winter with good body condition had no problems in time of short feed supplies or harsh winters. At Melfort and also at Lacombe we developed pasture programs that provided excellent fall and early-winter grazing that put back fat on our cows. We used Italian ryegrass, spring-seeded fall rye, winter wheat or winter triticale to provide lush fall pastures. These crops were intercropped with our oat or barley silage crops and the regrowth became available after silage harvest. With rotational grazing and fertilizer we also had excellent late-fall brome alfalfa regrowth pastures for the weaned cows.
Early weaning is another key method in regulating your feed resource in time of short feed supplies. In periods of drought or limited fall grazing, early weaning should be used to extend the grazing season. At Lacombe we evaluated the effects of early weaning and found that early-weaned calves should be moved onto a finishing diet sooner than normally weaned calves in order to obtain growth rates superior to gain on pasture.
Dr. Christoph Weder formerly with Alberta Agriculture did a study at the University of Alberta and found that calves could be weaned at 140 to 150 days of age with no long-term problems. He was also able to successfully wean calves at 90 days of age but the calves needed to be trained to drink water and consume high-energy rations prior to weaning. Thus in years of drought, wean your calves early and get them onto good feed. Save the balance of the grazing period for your cows so that they can go into the winter in good condition.
Dr. Block says, “The reduction of cow nutrient requirements will allow poor-quality feeds to still meet the cow’s daily requirements. Windbreaks, bedding with straw, lowering stocking density in pens or confined pastures will help to keep the cows dry and clean. This will reduce their energy requirements to get through the winter.”
In drought years there will be opportunities to graze or harvest drought-affected crops. Dr. Vern Baron, plant physiologist and grazing researcher at Lacombe, found in drought years or when early frost hit after seeding, farmers who reseeded often had problems with immaturity. “What we learned from the drought in 2002 is that farmers can just as well swath graze the immature crop rather than spend extra money on baling, hauling etc. etc. The cows consumed it all. Farmers usually make money on crop insurance and then feed. Feed it in the field. It will rain some time and farmers will get caught not being able to dry and store the immature crop cheaply. Rain came on the long weekend in August in 2002 and then several crops emerged or second growth came on. Opportunities emerged from neighbours who didn’t have cows, but became custom swath grazers. It’s important to recognize that conditions that reduce conventional feed supplies also tend to create increased supplies of alternate feeds from other crops.
“Maybe some nitrate problems and issues from grazing immature canola or brassicas, but there were really very few real issues if balanced diets were constructed. Many people swath grazed canola and peas with no problems observed with the cows,” says Baron.
“Cattle have some ability to adapt to elevated nitrate levels but the dilution of the feed with supplemental feed is a sound option,” says Block.
“Immature canola or frost-damaged canola can be successfully grazed or baled. One needs to cut it at bloom or early-pod stage for best nutritional quality,” says Yaremcio. The protein content will be between 14 and 16 per cent and the energy or TDN around 60 per cent. It is basically no different than high-quality first-cut brome alfalfa hay.
“In the areas where forage seed is grown, the aftermath from seed harvest can be an alternative feed source and it has the same nutritional quality as good-quality straw.
“When feeding frost-damaged crops do it slowly and let the cattle get used to the feed. Have alternative feed available when getting the cattle onto the frost-damaged feed.”
Duane McCartney is a retired forage beef systems research scientist at Lacombe, Alta.