Optimizing performance in finishing pigs through proper feeder adjustment

Monday, December 3, 2012

Research indicates that narrowing the feeder gap as finishing pigs approach market weight helps reduce wastage and yield significant savings of 12-15 kilograms in feed

by JANICE MURPHY

Advances in genetics and nutrition have had a tremendous impact on finishing pig performance of late. However, inefficiencies in feed delivery can translate into feed wastage of up to 30 per cent. Producers can spend all the time and money they want developing complex rations to meet their finishing pig's needs but, if the feeder is not properly adjusted, the benefits are lost.

If the feeder space provided is too small or too narrow, feeder adjustment can limit feed intake and result in lost performance. Researchers have observed that pigs that have difficulty getting to the feeder tend to spend more time there, therefore restricting the number of pigs who are able to get to the feeder and eat their fill. On the other end of the spectrum, offering feeder space that is too large or too wide can result in higher levels of feed wastage and poor feed efficiency. This is a key production area that requires tight management and attention to detail in order to achieve success.

Researchers at Kansas State University recently performed two experiments to evaluate the effects of feeder adjustment and feeder space on growth performance and carcass traits of finishing pigs.

In the first experiment, 234 pigs (initial bodyweight 41.5 kilograms) received one of three treatments over an 89-day trial – narrow, medium, or wide feeder adjustment (minimum gap opening of 1.27, 1.91, or 2.54 centimetres respectively). The feeder adjustment settings were achieved by tightening the feeder plates onto a wooden block cut to the appropriate size. However, the pigs could still move the agitation plate upward to a maximum gap opening of 1.91, 2.54, or 3.18 centimetres, respectively.

Feeder settings were maintained for the duration of the trial. Feeder adjustments of 1.27, 1.91, and 2.54 centimetres resulted in 28, 58, and 75 per cent pan coverage, respectively, as assessed by digital photos of feeder pans scored by trained panellists.

In the second experiment, 288 pigs (initial bodyweight 41.3 kilograms) were evaluated over a 91-day period to assess the effects of feeder trough space (4.45 versus 8.9 centimetres per pig) and minimum feeder gap opening of 1.27 centimetres (narrow) versus 2.54 centimetres (wide). Feeder trough space was adjusted by having pens of either eight to 16 pigs per pen with all pigs provided 0.74 square metres floor space per pig. In this experiment, feeder adjustments of 1.27 and 2.54 centimetres resulted in 45 and 83 per cent pan coverage, respectively.

All pigs were fed a common corn-soybean meal-based diet in meal form  containing 20 per cent dried distillers grains with solubles over four phases (Table 1.) The diet was formulated to meet or exceed NRC (1998) requirements for 20-to-120-kilogram pigs.

In experiment 1 (Table 2), from day 0 to 58, increasing the feeder gap significantly improved average daily gain (ADG) and average daily feed intake (ADFI), but decreased feed efficiency (G:F). Although the response was linear for ADG, there was no increase beyond the 1.91 centimetre feeder gap setting. For the remainder of the experiment, increasing the feeder gap setting tended to worsen G:F. Overall, pigs fed with increasing feeder gap had significantly lower G:F due to increased intake.

In experiment 2 (Table 3), from day 0 to 56, pigs with the wide feeder gap setting had significantly lower G:F compared with those with the narrow feeder gap setting. Similarly, in the second half of the experiment, from day 56 to 91, pigs with the wider feeder gap setting had increased ADFI, but consequently had decreased G:F. However, ADG tended to increase as feeder trough space increased from 4.45 to 8.9 centimetres per pig. Overall, pigs fed with the wide feeder gap setting had significantly increased feed disappearance and decreased G:F compared with pigs with the narrow feeder gap setting.

None of the carcass criteria evaluated showed any significant differences between pigs fed any of the different feeder gap settings evaluated.

Maintaining proper feeder adjustments has been proven time and time again to be effective for decreasing feed wastage and optimizing feed efficiency. The results of both experiments agree with previous research indicating that intake increased as feeder gap increased. Overall, there was a four to five per cent improvement in G:F with the narrow feeder adjustment compared with the wide adjustment observed in these two experiments. This represents a significant savings of 12-15 kilograms of feed, assuming a typical pig gains 100 kilograms at a 0.333 G:F.

These studies also showed that, as finishing pigs approach market weight, feeder gap should be decreased to reduce feed wastage. While small pigs need a larger feeder gap to help accommodate their slower consumption rates and ensure that all pigs are able to access adequate amounts of feed for optimum performance, feeders should be adjusted accordingly as pigs grow from weaners (25 kilograms) into market weight hogs.

Evaluating a subjective measure like the percentage of the feeder pan covered is a common management practice to minimize feed wastage in commercial production. In this study, the researchers attempted to evaluate this subjective measure quantitatively by photographing each feeder at different time points and having multiple evaluators come up with a score of pan coverage. They found that when pigs are 37 to 70 kilograms, the ideal feeder pan coverage is about 60 per cent, and as the pigs grow from 70 to 130 kilograms, the ideal feeder pan coverage decreases to about 30 per cent.

The researchers were quick to point out that these studies were conducted with one specific type of feeder. In reality, the pan coverage recommendations might vary depending on feeder type, not to mention diet form (meal versus pellet), formulation and the flow characteristics of the diet.

It should also be noted that the feeder adjustment of 1.27 and 2.45 centimetres in the first experiment resulted in approximately 27 and 75 per cent pan coverage, respectively, whereas the same settings in the second experiment resulted in 45 and 83 per cent pan coverage. So, it is a challenge to establish a specific feeder gap adjustment setting in order to achieve a specific degree of pan coverage. Common sense must prevail.

Previous studies have evaluated the ideal number of pigs per feeder space, but research is limited on the actual feeder space dimensions required by the pig. Although it was not significant, there was a tendency in the second experiment for increased ADG as feeder trough space went from 4.45 to 8.9 centimetres per pig.  Both Australia and the European Union (EU) have specific guidelines regarding recommended trough space per pig – about 6.25 centimetres per pig trough space in Australia and 5.9 centimetres in the EU. Considering the overall study (days 0 to 91), pigs with 8.9 centimetres of trough space had a tendency for increased ADG. This could be explained by the fact that the pigs averaged 130 kilograms at the time of marketing and, due to their size, feeder space could have become a limiting factor.

Based on the results, the researchers determined that pigs from 37 to 70 kilograms need a larger feeder gap, or about 60 per cent feeder pan coverage to maximize ADG but, from 70 to 130 kilograms, feeder gap needs to be decreased to about 30 per cent feeder pan coverage to reduce feed wastage while optimizing growth.

Establishing feeder pan coverage targets as an indicator for proper feeder adjustment may be a practical method that can be standardized across a wide range of commercially available feeder types. BP

Janice Murphy is a former Ontario agriculture ministry swine nutritionist who now lives and works in Prince Edward Island.

Source :
A.J. Myers, R. D. Goodband, M. D. Tokach, S. S. Dritz, J. M. DeRouchey and J. L. Nelssen. 2012. The effects of feeder adjustment and trough space on growth performance of finishing pigs. J ANIM SCI published online July 24, 2012 http://jas.fass.org/content/early/2012/07/23/jas.2012-5389