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John Maltman, Swine Specialist, Dugald
Improving growth rate in pigs is one way for producers to improve profit margins. As growth rate improves, the rate of stock turnover increases, lowering the cost per pig raised and increasing the total kilograms of pork produced.
Today’s marketplace puts a high value on lean meat. To meet the needs of the market, pig operations need to be concerned with developing the most economical rate of gain and the best lean pork yield.
This involves feeding rations that match pig requirements for developing the maximum lean tissue without over-feeding protein or energy. Nutritional requirements have changed substantially over the past 10 years with the development of herds selected for increased lean meat production.
Some of the performance of the feeder pig is built-in during the pre-weaning and nursery barn phase. Health status plays a major role. A pig’s body can divert dietary nutrients in two directions—maintenance and growth. A proper vaccination program with rigorous bio-security will ensure the highest health status, minimizing use of energy in fighting diseases and leaving more for growth.
In the past, genetic potential was divided into low, medium and high-growth potential. In Manitoba, all common pig genetic varieties are capable of delivering excellent growth rates with high carcass lean yields.
What differs, is the shape of the growth curve. The most important differences are at the point where growth plateaus. The range changes with different varieties but is usually between 75 and 90 kilograms. Following this period, energy and amino acid requirements drop. Excess energy, fed after the growth plateau, will be deposited as fat. Excess amino acids can reduce overall intake but will also be broken down by the body and excreted, raising the level of nitrogen in the manure. In the long run, any excesses will increase the overall cost of raising the pig.
Improved monitoring of soil and manure levels has focussed attention on nutrient levels in feed and manure. Nitrogen in excess of growth needs is excreted and becomes a manure management issue. By accurately formulating rations, nitrogen excretion will be minimized. This can also result in savings on the cost of feed.
Low energy finisher rations such as all barley are not as common as they used to be. Many modern pig hybrids stall out when the energy levels fall too low in the finisher ration.
The National Research Council (NRC) published updated nutrient requirements for pigs in 1998. These guidelines have been extremely useful in estimating amino acid and energy levels for age-specific ration balancing.
According to the NRC guide, a 20 kilogram pig at maximum lean tissue accumulation will need 17.5 grams of lysine intake per day from 1.85 kilograms of feed. Pigs routinely eat more than this amount daily and will consume more protein than they require for maximum growth unless their ration is reformulated to contain less protein. In this way the pigs consume all they need to maximize growth while reducing the costs of feed and of dealing with excess nitrogen in manure.
Monitoring feed intake can be accomplished in several different ways. Check with your feed company reps or check your on-farm milling destination sheets. Any assistance in discussing feed rations can be obtained from Manitoba Agriculture and Food or your animal nutrition specialist.