Pork (Continued from Pag* C 4) respiratory lesions. Feed efficien cy wasn’t measured in the Purdue studies. However, Dan McManus, a private veterinarian from lowa, does have feed data on some 34,000 hogs in his practice. While not under controlled con ditions, his data show a 0.3 pound of feed/pound of gain advantage for hogs raised under group sys tems compared to those in continu ous systems. McManus also sees a 5 percent drop in death loss in the all-in, all-out operations. Dr. Kirk Clark, D.V.M. from Purdue University, suggests that handling growing-finishing hogs in an all-in, all-out system will save about $4 per hog ($l2 per year per finishing pig space). Based on the data from Purdue and McManus’ practice, the savings could easily be twice that amount A Hypothetical Example for a Small Operation. Let’s pretend we have a one-room, 16-crate farrow ing house, a one-room 150-pig nursery, and a one-room 450-pig grower-finisher. Everything cur rently operates on a continuous flow basis, weaning pigs at about 4 weeks. We're going to consider break ing the facilities into rooms so that we can farrow sows by groups, and raise their offspring in groups as well. We’ll split the farrowing house in half, so that we can farrow g sows at a time. Each room will turn over once every five weeks, so we’ll be far rowing 8 sows once every 2'/j weeks. We’ll also split the nursery into two rooms, each of which can house the pigs from 8 sows (roughly 75 pigs). And we’ll Prose break the finisher into six sections, each of which will house the hogs from 8 sows (roughly 75 hogs). By making these changes, we’ll assume that the sows will raise 0.25 more pigs per litter. Since we’re farrowing eight sows at a time, that comes to 2 pigs per group. To be conservative, we’ll assume each extra pig is worth $2O, for a total of $4O per group. We'll also assume that the savings in disease control, death losses, and performance in the finished hog will amount to $4 per head. For 75 pigs that comes to $3OO per group. So our total estimated savings per group is $340 (about $4.50/head). The estimated costs of the facility changes are itemized below; Farrowing House: New ventilation New wall, alley Nursery: New ventilation New wall, alley Finishing: New walls Total (Note the gestation area will still operate in a continuous flow pattern.) Now to estimate what the cost is per farrowing group, we’ll first assume that this $15,500 invest ment will be depreciated over 5 years. $15,500/5 = $3,100 per year (not including interest). Since each room will be used about 20 times per year, the cost per group is only $155 ($3,100/20). So we have an added facility cost of roughly $155 per group farrowed. We’ll also plan for an extra 20 hours of labor per group for cleaning the facilities. At • Gestatlng Sows • Boars $7.00 per hour that's $l4O per group, for a total cost of $295. For our example, the $293 spent per group is slightly offset by the $340 saved. So the decision isn’t easy. But keep in mind that, while my figures may be realistic, they won’t necessarily apply to your situation. What About Your Conditions? Some rules of thumb; 1) If the average days from birth to market is more than 180, and you have more than 3 percent death loss from weaning to market, you can probably assume that you’ll save at least $4 per head by changing to all-in, all-out. 2) Multiply that $4 figure times your total production per year. That will be your annual savings. If your herd performance is already high and your slaughter checks show few respiratory lesions, the savings will be a lot lower. 3) Determine (with some help from your veterinarian or extension specialist) how to best remodel your facilities. (Use two weeks as the maximum age-spread within a room.) Estimate the cost of renovation, decide how many years you need to depreciate it, and calculate the annual cost. Compare this to the estimated annual sav ings. 4) Since the amount saved is only an estimate, proceed with remodeling only if annual savings is significantly higher than the annual cost $1,500 $2,500 $1,500 $2,500 $7,500 $15,500 Loula, Tim. at al. 1991. All-In, All- Out Management. "National Hog Farmer.’ Vol. 36 (No. 5), Spring 1991. Miller, Marlys. 1990. AII-ln/AII- Out Can Fit Your Farm. "Pork ’9o.’ May issue, pp 18-25. References Miller, Marlys. 1990. Time To "Pork *9l.* May issue, pp. 40-44. Get Out Your Hammer and Saw... Purdue Swine Day. 1988. “Pork ’90." November issue, pp. Vinson, Ralph. 1991. All In/AII 66-73. Out Can Cause and Solve Prob- Miller, Marlys. 1991. Get $l2 lems. “Hogs Today." March issue, More Per Pig Space Per Year. p. 44. Livestock Notes Oral Larvicide For Fly Control Oral larvicide (trade name Rabon) has become increasingly more popular in the last few years for controlling flies in and around livestock facilities. Let’s look at what oral larvicide can and can’t do, when it may be effective, and how to use it. Oral larvicide contains stiro phos which, when fed to animals, passes through the digestive tract and is concentrated in the manure where it prevents development of hom, face, house, and stable fly larvae. Oral larvicide has no effect on adult flies. Also, house and stable flies lay eggs in decaying organic matter other than manure, so oral larvicide may not totally eliminate these species. Other fly control measures may be neces sary when these species are a problem. Isolation from other livestock is essential if oral larvicide is to be effective, especially if neighbor ing livestock farms don’t use oral larvicide and/or store any amount of manure. Hies hatched in a neighbor’s manure pile can easily migrate to your facility and impair your fly control program. Sanita uon and overall farm cleanliness Lancaster Farming, Saturday, Juna 8, 1991-C5 are also very important if you plan to use oral larvicide. Non-manure breeding sites must be eliminated in order to control house and stable fly populations. Oral larvicide is most effective when used together with other fly control measures because it tends to break down quickly in decom posing manure. Also, insecticide resistance develops more rapidly when immature insects are treated. Oral larvidde is fed by mixing a small amount into the animal’s ration when the feed is ground or mixed. Inclusion rate per ton of complete feed depends on how much feed the animal consumes each day. Oral larvicide should be prc blended with ground shelled com or other feedstuff before dumping it in the mixer. Preblcndmg ensures proper distribution throughout the entire feed mix. Oral larvicide is not recommended for pelleted, predominantly pel leted, or liquid rations. Feeding of oral larvicide should begin in early spring before flics become a problem and continue until cold weather limits fly activity.