Three-day diet keeps sows satisfied
The modern gestating sow has a problem we can all identify with - she really likes to eat but, at the same time, has to watch her weight.Restricting feed intake in gestating sows is necessary to limit excessive weight gain and fat deposition, stimulate lactation feed intake and increase overall sow productivity. Limit feeding does not, however, allow the sow the chance to feel full or satisfied after eating and can lead to frustration and, ultimately, stereotypic behaviour. Given the opportunity, a sow would voluntarily eat almost twice the amount of feed that she receives.
Normally a hormone, cholecystokinin or CCK, signals the end to feeding behaviour. When meal size is small, this hormone may not reach high enough levels to trigger. Without this trigger, the sow has the motivation to continue eating after the feed is gone. In response, she will often engage in stereotypic feeding activities such as rubbing the feeder, biting bars, chewing, playing with the water nipple, or drinking in an attempt to get that satisfaction.
Skip-a-day feeding is a common practice in modern swine production that may help. Recent research in Iowa has taken this idea one step further and looked at feeding once every third day. Researchers compared sows being fed a 12-per cent corn-soymeal ration either 2 kg daily or 6 kg once every third day. The weight gain of sows on the two regimens did not differ.
Overall, behaviour observations suggested the large meal fed to interval-fed sows decreased feeding motivation and arousal substantially. (See Feeling full.)
The interval-fed sows did not compensate for the lack of feed on non-feed days with excessive water consumption or waterer manipulation. In contrast, daily-fed sows spent more time exhibiting a wide range of behaviour, such as sham chewing, drinking or playing with the drinker.
The researchers suggest that these behaviours can result in increased energy expenditure by a magnitude of 40 per cent, which likely increases the nutrient requirements needed to maintain body weight and condition.
Based on this research, it is obvious that interval feeding is one management practice that can be used to increase the sow's level of satisfaction after feeding. Another option is the inclusion of low-energy nutrients or roughage to increase satiety without the risk of increasing weight gain during gestation.
Researchers in France have shown that feeding fibrous diets can reduce feeding motivation and the resulting behaviour. Sows were fed wheat-barley-soymeal diets containing increasing levels of sunflower meal, wheat bran, sugar beet pulp, soybean hulls and corn gluten feed to achieve crude fibre levels of 3.3, 10.6 and 18.14 per cent. Sows fed high levels of fibre ate more slowly, taking three times longer to eat their meals, and were quieter.
Regardless of the diet the sows received, overall the sows were engaged in oral activity (feeding and non-feeding) for the same length of time. Sows fed the low-fibre diet spent more time exhibiting stereotypic feeding behaviour, such as licking and bar biting. The researchers did note that substrates in the sow's environment, such as straw bedding, can provide a supplementary source of fibre and potentially alter the nature of the behaviour exhibited.
Reducing feeding motivation is generally assumed to be associated with improved animal welfare but that remains to be confirmed. The consequences of interval-feeding and fibrous feeding regimens need to be evaluated, namely their impact on subsequent litters, reproductive parameters as well as the environmental consequences.
Janice Murphy is OMAFRA swine nutritionist based in Wellington Place
© copyright 1999 Agricultural Publishing Company Limited.
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Drug-free feeding
Danish organic additive has better scours control but poorer growth promotionBY NORMAN DUNN
A Danish organic feed additive for pigs, designed to take the place of prophylactic growth-promoting antibiotics in rations, has proved in on-farm trials to give better diarrhea control in young pigs than one of the most widely used feed antibiotics.Piglets from four weeks to 10 weeks of age receiving Bio pro - a new blend of lactic, formic, citric and propionic acids in liquid form added to their conventional feed at two kg/tonne - had a diarrhea treatment frequency of 3.2 per cent. (See Organic vs. antibiotic.) Control pigs, which had the antibiotic avilamycin added to all feed, recorded a diarrhea frequency of 5.3 per cent in the trials.
Another three non-antibiotic feed additives were compared in the trials, run by the Danish National Committee for Pig Breeding, Health and Production. Diarrhea frequency among the piglets testing these products ran from six per cent to 25.9 per cent. A control group of piglets with no antibiotic and no other feed additive had a diarrhea frequency of 44 per cent in the same trials.
Another surprise for the researchers was that the manufacturer of the successful diarrhea medication, Den Lokal Handel (dlh), is not a specialist feed additive or nutrition company but a Danish group consisting of 40 agricultural co-operatives.
The group decided that not enough was being done by the big European milling companies to produce non-antibiotic additives for feed. It decided to go it alone and develop its own products. Since then, dlh has invested about C$210 million in the last decade in one of the world's most modern feed production complexes.
On top of the medicinal effect, growth promotion effect of the organic acid product was 15 per cent better than the non-additive control and only three per cent less than that for the piglets with avilamycin added to their feed.
Except for the non-antibiotic control group, all groups of pigs in the trial reached a liveweight of 30 kg in 73 or 74 days. Bio pro is added to weaner feed in liquid form at two kg/tonne. Cost: C$6 per tonne of treated feed.
© copyright 1999 Agricultural Publishing Company Limited.
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No place like home
Familiarity breeds better pigs, according to preliminary Danish researchMoving and mixing feeding pigs only once in their lifetime can save two weeks from birth to slaughter by improving health and reducing stress. The findings come from Danish research in which pigs were moved into pens at weaning and kept in the same pens and groups until slaughter.
Although full results have not yet been computed by the Danes, researcher Bjarne Petersson says that with the weaning to slaughter penning (WTS) days to slaughter at 100 kg liveweight were cut by between 10 and 14 days.
Housing costs with the one-pen system are estimated at about the same as conventional systems. Pen dimensions in first trials were 4.8 x 2.4 m for 20 pigs, giving 0.55 m2 per pig. One-third of each pen floor was slatted with gaps of maximum 15 mm. Underfloor heating was used, with a special feeder allowing access for very young pigs with a trough lip only 10 cm above floor level.
Petersson points out that on commercial farms, the weaners up to 30 kg would probably be double-stocked in pens, then split for the remainder of the feeding period. "There's more research needed here," he admits. "Does this splitting of pen groups at around 30 kg lead to renewed hierarchy fighting - and what kind of effect does this have on commercial production figures?
"Our experience so far, however, indicates that the production penalties involved will be more than balanced by the financial and space savings of having full pens at the beginning of the sequence."
The Danes are also studying farrowing to slaughter (FTS) penning for even greater reductions in stress and infection risk. Here, the sow is moved out of the pen and the pigs remain. Pen cleaning is then required only twice per year - at the end of each feeding cycle.
First tests have returned improvements in both production and health. Reduction in labour costs is in the 10 per cent range. - Norman Dunn
© copyright 1999 Agricultural Publishing Company Limited.
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Hands-free hog handling
Pig sorting is one of the few low-tech jobs left in the pig business, and it's especially onerous in open-style outdoor shelters.Help's on the way from an Alberta company that has introduced the Super Sorter, an electronic hog sorter tailored to hoop-type operations.
In open pens, it's almost impossible to sort pigs, says Liesel MacPhee of K&L Technical Services in Airdrie. With the Super Sorter, the producer could go to bed and wake up in the morning with up to 800 pigs weighed and sorted.
The system involves a lightweight, portable electronic scale that weighs, sorts and even paints pigs. In the fully automated system, which sells for $5,500, pigs are motivated to enter the sorter by feed and water in the sorted area. Pigs that don't meet the weight target leave the scales to the underweight area.
In the system for conventional small-pen barns, the producer guides the pigs to the sorter and operates the back gate by remote control. Depending on the pig weight, the front gate opens, directing hogs to the left or right. The system, which costs $6,500 due to the remote control, allows a single operator to sort 200 pigs an hour.
The company will exhibit at the Ontario Pork Congress.K&L Technical Services Ltd., 24 Spring Haven Cr., Airdrie, AB. T4A 1A7. (403) 948-0341. leonking@telusplanet.net
© copyright 1999 Agricultural Publishing Company Limited.
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Give your herd some summer fan support
There are a number of reasons to include summer cooling systems in your facilities, just as there are a number of reasons to include heaters.In hot weather, pigs will decrease feed intake, just as we lose our appetite. Supplemental cooling greatly benefits grower-finisher hogs. The effective use of high air speeds (> 50 ft/min) and sprinklers together can provide as much as 25F reduction in pigs' effective environmental temperature (EET). Sprinklers reduce EET 8 to 10F and high air speeds reduce EET 15 to 18F. Grow-finish pigs reduce feed intake by 0.92 per cent for every 1F rise in EET above 70F.
For breeding stock, temperatures over 90F in the barn will affect the immature semen in boars, resulting in poorer performance down the road. And finally, from an animal husbandry point of view, it is humane to provide the best comfort level we can.
The best way to cool once hot weather hits is to use a water-based cooling system effectively in combination with fans. Overuse will result in more costs to pump and spread the water from your manure storage. There are several techniques of water cooling.
1) Evaporative cooling pads. These are pads that are large enough to allow all summer ventilation air to pass through. The pads are constructed of a material that soaks up water from a dipper pipe along the top, while allowing air to pass through. The air picks up the moisture (yes, raising the relative humidity) and as a result, drops in temperature by at least 10F. The big advantage is the cooling effect occurs without any water touching barn surfaces, preventing slippery floors and potential for accelerated corrosion on metal components.
The pads are extremely efficient at converting water to cooling air. They cause, however, large static pressure drops across fans, sometimes requiring additional fan capacity. The pads develop algae growth and require regular maintenance. The system is also fairly complex and relatively costly.
2) Drippers. A dripper system is best used where animals are closely confined, such as in farrowing crates and stalls. With water dripping at a slow rate on to the sow's head, a reasonable cooling effect is created for her. With the right positioning, the sow can escape the drip if she wants.
Drippers use low volumes of water, but can result in unwanted water build-up on any solid flooring. They are plastic, and easy to install, maintain and operate.
3) Sprinklers. Sprinkler systems are exactly as the name implies: Water droplets are sprinkled liberally in a pattern defined by the water nozzle and pressure. Circular patterns are most prevalent; square and triangular are also available. The goal with this sprinkler is to wet the pigs' skin (not soak them) and allow the air to evaporate the water slowly, causing a chilling effect. Even hard water causes little problem for these low-pressure (40 psi) cooling sprinklers. They are easy to install and made of plastic parts. Maintenance consists of soaking components in vinegar and scrubbing when required.
Due to the large sprinkler areas and relatively limited control on whether pigs are in the zone when they run, water wastage occurs. Although producers have used garden sprinklers, they usually have excessively large and widely varying droplet sizes, resulting in even greater wastage.
A sprinkler system can be used to assist with dunging patterns in swine finisher barns as well as cooling. A controller that allows a timed event (on/off) and can be overridden due to temperature rise (increased on, decreased off) will allow a smoother conversion to cooling as required.
4) Misters. Misting systems are higher in pressure (200-1,200 psi) and use brass and other metal nozzles. As nozzle holes tend to be tiny, combined with the higher pressures, water droplets tend to atomize into moisture in the air, functioning like the pads in this regard. Air temperature drops and relative humidity rises.
Water quality must be higher, with filtration needed. The higher the pressure and harder the water, the greater the filtration required. Pumps get larger as well, increasing operating costs.
Supplemental cooling
On a day with an average inside temperature of 90F, without supplemental cooling, pigs will reduce feed intake by 18 per cent. Using high air speed and sprinklers will provide as much as 25F of cooling and eliminate any reduction in intake. Stirring fans are optional. If necessary, they can be added at a later date.Drying (evaporative cooling) is the key to effective use of a sprinkler system, so give the pigs ample time to dry off. Air movement from the use of stirring fans and air inlets will quicken this process.
Ron MacDonald consults with Guelph-based Agviro Inc.
© copyright 1999 Agricultural Publishing Company Limited.
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Dollars and scents
Manure pit aerator and separator help quell the smell - at a costBY DON STONEMAN
Aerators stirred manure pits back in the 1980s. But they didn't stir pig farmers.Aerators force oxygen into liquid manure storages, turning the manure into an aerobic mix and reducing the eye-watering odour. Producers found that aerators sucked more electricity than they were deemed to be worth, and opted to put up with odour complaints.
Today, barns are bigger and environmental complaints are louder, reviving the market for technology that will deal with pig effluent. Aerators are better, too, says John Brown, who describes himself as "an owner" of Dunham, Quebec-based Brome Agri Sales Ltd.
"Aerators have such a bad name," says Brown. "We like to call it a liquid composter." He says that the Kemomatic he sells introduces oxygen to the manure tank, gets rid of odour and breaks down solids.
Brown says the Kemomatic was developed in Denmark 20 years ago, but its use stalled because of high electricity costs, about 20 times as expensive as in North America. The product was shelved for 15 years: "It came down to what price being a good neighbour was worth."
Today, priorities have changed. "I think North America is ready for it," says Brown, who first saw the Kemomatic at Pork Expo in Iowa last year. He brought four units into North America, and demonstrated them over the fall and winter in Quebec, at the University of Guelph, and in Illinois.
"We can aerate anything," Brown says. He demonstrated the largest unit last month at Joe and Miriam Terpstra's Acre T Farms' No. 10 nursery barn, east of Brussels. The manure pit there is 150 feet in diameter and about 14 feet deep, capable of holding about 1.5 million gallons of manure. "This is the biggest we have done to date with a single unit," Brown says. The amount of aeration power is calculated according to the number of animals putting manure into the pit. Aerators are sized according to the amount of oxygen that is needed to aerate the manure.
"You can only push oxygen so far," Brown says. Larger pits will require more than one unit, or a single unit can be relocated periodically around the tank to achieve the same results.
Farmers concerned about odour all summer will run the machine for 24 hours a day for 14 to 16 days to create an aerobic state in the manure, then switch it to work for between one and three hours a day to maintain that state. Farmers concerned about the odour only at spreading time will run it continually for 10 days to reduce the smell.
Brown is also promoting the T-R Separator, made by Blossom Agritec Ltd, in Abbottsford B.C., to deal with concerns about manure that is too rich in phosphates.
The separator will remove as much as 40 per cent of the phosphates before liquid manure goes into the tank, reducing the land base needed to spread a pig barn's effluent.
Brown says the Quebec government is considering subsidising farmers' purchase of both machines.
While admitting that "these are two old technologies," Brown says "the right separator and the right aerator have never been put together as far as I am concerned."
The solids are a rich, sticky, smelly guck. For every 1,000 gallons of liquid manure, the separator removes one cubic metre of solids. In drying, that volume of solids shrinks by half. When it is mixed with leaves or grass and composted it ends up as a usable, marketable product.
On its way from the barn, manure is pumped into a 14x14x10-foot deep holding tank. The solids are lifted out by the separator and, like a bale elevator, lifted on flights over 16 feet of screens, which allows the liquids to run back into the lagoon before aeration. For the purposes of the demonstration at the Terpstra farm the solids were caught in a solid manure spreader.
"Some people just want to get rid of the smell," Brown says. "The guy who is thinking 'system' will do both."
A farmer considering buying a system should have a nutrient management plan designed first, Brown says. The system costs between $60,000 and $75,000, including installation.
Running continuously for 20 days, and three hours a day for the rest of the year, the aerator will operate 1,176 hours annually. At five cents a watt, the electrical bill will total 86 cents/hr., for an annual energy cost of about $1,000.
The big motor needed to turn the aerator (30hp on the largest Kemomatic used in the Acre-T pit) is one drawback, Brown admits: "You need access to three-phase power." The separator - requiring a 5hp motor - could also do with three-phase power.
"You see a direct impact on your bottom line" with the separator, says Byron Ballagh, of Hi-Tech Feeding Equipment, a division of Acre-T Farms and local sales agent for both machines. Less agitation of the manure tank is necessary before spreading, and the compost can be sold off the farm.
With the solids that can burn young corn removed, the liquid can be spread directly on crops as tall as 16 inches, opening up the manure spreading season to as late as July 1.
© copyright 1999 Agricultural Publishing Company Limited.
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