Factors affecting nutrient requirements
Nutrient requirements are influenced by a combination of performance potential and feed intake. The nutrient concentration in the diet is adjusted according to feed intake to meet the requirements during each stage of production. Providing diets with nutrient levels below the requirements results in suboptimal performance, whereas feeding nutrients above the requirements increases feed cost and nutrient excretion. Thus, in order to ensure optimal production at an economical cost, it is important to understand the factors involved in nutrient requirement estimates and adjust the diet formulation accordingly.
Several factors affect the estimation of nutrient requirements in pigs. In fact, any factor that influences performance and feed intake is likely to affect nutrient requirements estimates. Generally, improvements in growth performance or productivity and decreases in feed intake are associated with increased demand for nutrient fortification in the diet to meet the requirements. Some of the most important factors are:
- Genetics and gender
- Dietary energy concentration
- Environmental temperature
- Health status
- Stocking density
- Feeding strategy and degree of competition for feed
- Variability of nutrient content and availability in ingredients
- Presence of molds, toxins, or anti-nutritional factors in the diet
- Inclusion of growth promoters or feed additives in the diet