Empty feeders reduce feed intake. As simple as they seem quite often as many as 10 per cent of the feeders may not be providing proper access to pigs for a variety of reasons including too tight feeder adjustment, bridging problems, in addition to other mechanical issues. While feed intake can be one of the more elusive challenges to monitor, its importance cannot be over-stated since feed intake is key to developing diet specifications, achieving targeted growth rates, and efficiency of production.

Past surveys have indicated feed intake can varies by least 25 per cent between farms, and with feed costs ranging from 50 to 70 per cent of the cost of production, getting a handle on feed intake is exceedingly important.

Checklist to Maximize Feed Intake

1. Temperature
   1. Too high reduces feed intake. Feed intake will be reduced by 1 to 2 per cent for every 10°C above the pig's thermoneutral (comfort) zone.
   2. Too low reduces feed efficiency
   3. Older pigs are impacted much more profoundly than younger pigs
   4. Reduced nocturnal temperatures: lowering set-point temperatures by 6°C in the finishing barn in the summer.
2. Feed and water access
   1. Feeder design and type of feed (mash or pellet) will impact carrying capacity of the feeder. Feeder space capacity can vary from 11 to 20 pigs.
   2. Performance was maximized when the feeder gap allowed for 40 per cent of the trough to be covered with feed, as well as reducing eating time in increasing feeder capacity.
   3. Mash diets and wet/dry feeders can increase feed intake up to 5 per cent.
   4. Ensure pigs have free access to water. Water intake in growing pigs with free access to feed is about 2.2 to 3.0 times the intake of feed.
   5. One functioning nipple drinker is required per pen of 12 pigs.
3. Space allocation
   1. Floor space allowance that maximizes growth rate and feed intake is = 0.035m² x BW^0.667
   2. Growth is depressed by 0.5 per cent for every 1.0 per cent reduction in space allowance below a critical point
   3. Growth rate can be reduced up to 10 per cent in the last part of the finisher under a crowded scenario
   4. Negative impacts of reduced space on average daily gain are not corrected by feeding pigs diets with high nutrient density.
4. Social interaction
   1. Rooms containing variable weight pens empty 4 to 6 days sooner than rooms with uniform weight pens
   2. Studies have shown (Stookey & Gonyou, 1994) mixing pigs two weeks before marketing reduced growth rate by 11 per cent, and subsequent market weights. Mixing may make economic sense when it significantly improves building utilisation. (Mixing partially marketed pens of pigs to make room for the next group of pigs being transferred into the room.)
5. Barn entry weight
   • Bigger pigs eat more feed. Therefore anything that can increase the size of pigs entering the grow-out will increase feed intake.
6. Health status
   1. Moderate health issues can reduce feed intake by 5 per cent or more.
   2. Severe health problems can reduce feed intake by 15 per cent or more.
7. Diet composition
   1. Excess minerals, especially calcium, may reduce feed intake.
   2. Ensuring a proper amino acid balance and energy to amino acid balance is met. Otherwise, feed intake may be adversely impacted.
   3. The use of various feed additives may increase feed intake. However, the cost-effectiveness of using these additives will vary between farms.
   4. Increasing levels of energy in diets will increase feed efficiency but not growth rate. As a simple rule of thumb, if the percentage increase in digestible energy concentration is greater than the percentage increase in diet cost, the increase will pay for itself in terms of feed efficiency.
8. Anti-nutritional factors
   1. Complete diets containing up to 0.10 per cent ergot can be fed to a weanling pig. Do not feed to the breeding herd.
   2. Complete diets containing 1 per cent ergot will reduce pig performance by more than 30 per cent.
   3. Choose ingredients with low tannin levels. Tannins are compounds that have the ability to bind to proteins, including dietary protein, thus impairing the ability of the pig to use dietary protein. Tannins also reduce palatability due to a sour taste.
   4. The impact of aflatoxin is age- and dose-dependent. At low levels (20 to 200 ppb), effects range from depressed performance to immune suppression.
   5. Guidelines for feeding vomitoxin (DON)-infected grain are: nursery, 0.5 ppm; finisher, 1.0 ppm and breeding herd, 1.0 ppm.

Checklist to Optimize Water Intake

1. Mounting water nipples correctly reduces wasted water. For nipples pointed straight out, pigs should drink from shoulder height. For nipples mounted downward at 45 degrees, the nipple should be 5 cm (2 inches) above the back of the pig. Mounting lower will increase water wastage. Nipples should be set for the height of the smallest pig in the pen.
2. Check flow rates. Flow rates determine time spent at the nipple, water intake and water wastage. Too little is just as costly as too much when it comes to flow rates. Flow rates of 1,500 ml for lactating sows, 700 ml in grow-finish are recommended. Research on wastage found 23 per cent at 2080 ml per minute versus 8.6 per cent at 650 ml per minute.
3. Use wet/dry feeders in grow-finish. Wet/dry feeders reduce water used by 34 per cent, and slurry volume by 20 to 40 per cent compared with dry feeders and a bowl. Wet/dry feeders also increase consumption of mash diets compared to dry feeders and a separate water nipple, resulting in a five per cent improvement in average daily gain.
4. Feeding diets containing excessive protein and/or excessive mineral levels results in increased water usage.
5. Temperature impacts water requirements. For every 1°C above 20°C results in a sow drinking 0.2 litres more water each day.
6. Some of the factors that contribute to increased water intake are: heat stress, hunger, boredom, elevated dietary protein, elevate dietary minerals and moderately elevated minerals in the water.
7. Factors that depress water intake include cold stress, warm water temperatures and a high level of salinity in the water.
8. Water:feed ratios decrease as pigs grow. Studies have shown water:feed ratios with nipple drinkers were 3.35:1 for nursery pigs and 2.5:1 for growing pigs.
9. Generally, for groups larger than ten pigs in the nursery and 15 to 20 in the finisher facility, a minimum of two water delivery devices is required (Brumm, 2006).

February 2009