Hot, windy, dry conditions across many areas of Alberta have slowed forage growth in pastures and hay fields and, if it stays that way, could mean problems for producers.
“If it stays dry the amount of growth will be limited and it’s possible that pastures will run out much earlier than normal,” says Barry Yaremcio, beef/forage specialist, Alberta Agriculture and Forestry. “In general, 70 per cent of total forage growth occurs before the 15th of July. We are in early August so the potential for most grass species for regrowth is small even if significant amounts of rain do come soon. Total growth could be compromised.”
Yaremcio suggests one strategy to stretch limited forage supplies is to creep feed calves throughout the summer. “Calves that are 45 to 60 days old can digest grains and use the nutrients to improve growth rates. On poor pastures, for every five pounds of creep feed consumed, calf growth rates improve by one pound. A second advantage of creep feeding calves is that the amount of grass consumed by the calf is reduced which stretches the amount of grass available for the cow.
“Calves weighing less than 700 pounds eat grain slowly and chew the material sufficiently that processing isn’t required. Average daily gain and feed conversion efficiency is equal to that of processed grain.”
Yaremcio says that using whole oats or barley as the sole ingredient in a creep ration for small calves doesn’t work. A creep ration requires 14 to 16 per cent protein to ‘frame out’ the skeleton properly and to develop muscle. Intakes generally are in the two to three pounds a day range for 350 pound calves and can get as high as eight pounds a day when the calves are 600 to 700 pounds. A recipe for a home grown creep feed is to include split or cracked peas at 35 per cent of the mix with oats or barley (or a combination of the two grains). If wheat is to be part of the creep feed, inclusion rate should not exceed 20 to 25 per cent of the mix to minimize the chance of acidosis. If no additional protein is added to the creep feed, it’s possible to have short fat calves that could be discounted at the auction market come fall.
Another option is a commercially prepared creep ration. “These products should contain a minimum of 75 per cent TDN (total digestible nutrients) and, again, the 14 per cent to 16 per cent protein content is required. Screening pellets generally have lower energy content than grain and don’t deliver the necessary energy needed to get the additional gains on the calves.
“Creep feeding the calves for the majority of the grazing season can result in 25 to 100 pounds of additional gain compared to animals that aren’t supplemented. If 700 to 800 pound calf prices stay at the current price of $2 a pound for steers, this could increase the value of the calf by $50 to $200 per calf. It’s a good return on investment.”
Nitrates and hail damage
There are many things to consider when salvaging a damaged cereal, oilseed or hay crop after a hail event.
“It’s not unusual to have hail storms travel across the province this time of year,” says Barry Yaremcio, beef/forage specialist, Alberta Ag-Info Centre. “Depending on the severity of the storm, damage to annual and perennial crops can range from minimal to complete destruction.”
Nitrate accumulation occurs in a plant when it is injured and unable to convert nitrate to protein efficiently after a hailstorm. In non-legume crops, water and nutrients are pushed into the plant from the root system as quickly after the storm as was provided prior to the hail event. Nitrate accumulates in the top leaves and concentrations peak roughly four days after the injury. If the plants recover, and new growth is observed, nitrate levels can return to normal 12 to 14 days after the injury.
“Soil fertility, in particular the nitrogen content in the soil and stage of crop development, are critical factors as to whether or not there will be a nitrate problem in the plants,” says Yaremcio. “Crops such as canola and wheat have high amounts of nitrogen fertilizer applied. If the crop is thin and not overly productive, there could be significant amounts of soil nitrogen remaining in the soil into July. A crop that is thick with high yield potential would use up the available nitrogen much earlier in the growing season. With less nitrogen left in the soil, there is less available to be transported into the plant and thus less risk for nitrate accumulation.”
Hay crops tend to have lower fertility than annual crops. “The risk of a hay stand having high nitrate concerns is much lower. Alfalfa and legume crops have nodules in the root system that regulates nitrate transport into the plants. The nodules only allow as much nitrogen into the plant as is needed; therefore, it’s extremely rare to have nitrate accumulation in legume forages.”
Feed test labs can test for nitrates. “If the sample is taken the fourth day after the storm, the results will indicate the ‘worst case’ situation,” says Yaremcio. “Talk to the lab and request a ‘rush’ analysis. The results could be available one to two days after the sample is received.”
Ensiling the crop will not reduce nitrate levels if the product is put up properly, “Adequate amounts of packing, sealing with plastic as soon as possible and allowing the silage to ferment for three to four weeks produces a stable product,” says Yaremcio. “Silage that is poorly made can reduce nitrate levels, but the quality of the silage is greatly diminished. To get a representative sample when the silage is being made, take one handful of silage out of each load as the trucks unload. Put each handful into a plastic pail and keep the lid closed as much as possible. At the end of the day, mix up the sample and collect a half bread bag full, squeeze out the air and freeze the sample. Send the sample in for analysis on a Monday or Tuesday so it gets to the lab without being in transport over the weekend.”
Bottom line, says Yaremcio, is that nitrate in a forage or silage can be managed so that there are no problems or difficulties encountered during the feeding program. “Talk to your feed sales person or company nutritionist, nutritional consultant or contact the Ag Info Centre and talk to a livestock specialist.”
For more information, see the Nitrate Poisoning and Feeding Nitrate Feeds to Livestock factsheet on Alberta Agriculture and Forestry’s website (http://www.agric.gov.ab.ca/app21/rtw/index.jsp).