Since feed cost represents up to 70% of the total cost in modern pork production, feed efficiency has an enormous effect on profitability of producers.
Feed efficiency in swine is measured via feed consumed per unit of gain. Typically calculated as a feed conversion ratio (FCR) which is measured as the feed intake over a period divided by the average daily gain (ADG).
How to improve feed efficiency in pigs
Typically, one 70 kg pig fed on an ad libitum basis, approximately 34 % of daily energy intake is directed to maintenance (Patience, 2012). As a result, minimizing maintenance costs to improve nutrient availability directed towards weight gain can improve feed efficiency. Many factors can affect feed efficiency, such as:
- Nutrient density
- Feed form and quality
- Health status
- Feed additives
Pigs utilize dietary nutrients for maintenance, and protein and lipid accretion. The supply of energy, limiting amino acids, as well as minerals should meet the requirement for each phase of production to ensure efficient growth.
Feed form and quality
Particle size is strongly correlated with feed efficiency. It has been shown that reduction in particle size of feed ingredient increases the its surface area and improves digestibility. However, too fine of a grind can cause gastric ulcers (Cappai et al., 2013) and increase feed cost.
Research has shown that feed efficiency improves by 1% to 1.2% for every 100 micron reduction in particle size (Healy et al., 1994)
|Item||Particle size, microns|
|Average daily gain, lb||0.84||0.80||0.85||0.78|
|Average daily feed intake, lba||1.29||1.21||1.23||1.19|
|Production rate, tons/hour||4.06||2.84||1.63||0.85|
Table 1. Effect of diet particle size on growth performance of nursery pigs.
Adapted from Healy et al., 1994
aLinear effect (P < 0.08); bQuadratic (P < 0.01).
Pigs exposed to pathogens respond with depressed feed intake and hence result in poor growth. Short- and long-term inflammation causes gastrointestinal tract irritation and reduces protein deposition, further limiting nutrients absorption for growth (McCracken et al., 1999). Controlling the inflammation by limiting antinutritional factors such as mycotoxins and over expression of pro-inflammatory cytokines may alleviate subsequent intestinal disorders.
To minimize the negative effects of potential environmental change on growth, maintaining optimum temperatures, humidity, and air flow is critical. Poor sanitation can increase disease transmission and can impact feed efficiency. Furthermore, minimizing social stress can reduce unnecessary energy cost.
The addition of functional feed additives is essential for optimum animal growth. Swine supplements commonly added to diets to achieve better feed efficiency include:
- Organic acids
- Probiotics, prebiotics and synbiotics
- Phytogenic feed additives consisting of essential oils and other plant-based substances
Cappai M. G, M. Picciau, and W. Pinna. 2013. Ulcerogenic risk assessment of diets for pigs in relation to gastric lesion prevalence. BMC Vet Res. 9:36.
Healy, B. J., J. D. Hancock, G. A. Kennedy, P. J. Bramel-Cox, K. C. Behnke, and R. H. Hines. 1994. Optimum particle size of corn and hard and soft sorghum for nursery pigs. J. Anim. Sci. 72:2227.
McCracken, B. A., M. E. Spurlock, M. A. Roos, F. A. Zuckermann, and H. R. Gaskins. 1999. Biochemical and Molecular Action of Nutrients Weaning Anorexia May Contribute to Local Inflammation in the Piglet Small Intestine. J. Nutr. 129:613–619.
Patience, J. F. 2012. The Influence of Dietary Energy on Feed Efficiency in Grow-Finish Swine. In: Patience JF, editor. Feed Efficiency in Swine. Wageningen: Wageningen Academic Press. pp. 101–129.