Individual precision feeding
Optimizing nutrient efficiency in swine production
By Berta Llorens, Aline Remus and Candido Pomar
Over the years, pork production has continuously evolved, but nutrient efficiency remains a key challenge to the industry. One of the main goals in swine production is to maximize nutrient efficiency while minimizing costs and environmental impacts. A significant portion of the environmental impact in pig farming comes from nutrient excretion, particularly nitrogen and phosphorus. Reducing nutrients loses not only lowers the environmental impact but also improves the overall production sustainability.
The primary objective in growing-finishing pig operations is to efficiently convert dietary nutrients into edible protein-rich meat. Dietary protein efficiency is particularly critical given that this nutrient is one of the most expensive in pig diets. However, the conversion efficiency of dietary protein into body protein is relatively low in growing pigs, typically ranging between 15% and 33% (1, 2). Protein inefficiency increases nitrogen losses while increasing feeding and production costs.
Factors affecting nutrient efficiencySeveral factors influence nutrient efficiency, including animal-specific characteristics (e.g. physiological stage, or genetics), feeding strategies (e.g. dietary nutrient balance, feeding phases), and environmental conditions (e.g. housing system, environment temperature, cleanliness). At the animal level, nutrient losses occur due to digestive inefficiencies, endogenous secretions, metabolic processes cost associated with protein degradation and synthesis and excess nutrient supply. In cereal-based diets for growing-finishing pigs, losses associated with digestion, maintenance and body protein deposition can account for up to 33% of total ingested nitrogen (1). Nonetheless, excess nutrients significantly contribute to nutrient inefficiency, but because these losses are related to feed composition and feeding methods there is great potential for improvement.
Traditionally, nutrient requirements have been estimated using factorial methods, such as those outlined by the National Research Council (NRC) (3). In large-group feeding systems, pigs receive the same feed for extended periods, typically in three- or four-phase feeding systems. Since appetite increases faster than nutrient requirements in growing pigs, dietary nutrient concentration decreases over time. However, within a population, individual pigs have varying nutrient requirements that change according to their unique growth trajectories (Figure 1). To account for this variability, phase-feeding programs typically formulate diets to meet the requirements of the most demanding pigs in the group, often targeting the average requirement plus an additional safety margin of 15% to 20%. While this approach ensures that the most demanding pigs receive adequate nutrition, it also results in overfeeding many animals, leading to nutrient losses and inefficiencies.
Describing individual precision feeding In contrast to conventional group feeding, Individual Precision Feeding (IPF) seeks to provide daily to each pig the required amount of nutrients. This approach relies on a mathematical model to estimate in real time the individual nutrient requirements. By integrating feed intake and body weight data, the model predicts future weight gain and feed consumption. Using these projections, it is possible to determine the optimal lysine concentration required by each pig for the starting day, ensuring a daily-tailored feeding strategy that minimizes excess nutrient intake (4). Automated precision feeders play a crucial role in implementing IPF (Image 1). These feeders use radio-frequency identification (RFID) technology, where each pig is identified through an ear tag containing a passive transponder. Two feeds, one with high-nutrient-density and another with low-nutrient-density are required to implement IPF systems. Precision feeders simultaneously blend and dispense the appropriate amount of the two feeds based on each pig’s daily nutrient requirements.
Benefits of individual precision feedingStudies comparing IPF to conventional phase-feeding systems have demonstrated significant improvements in nutrient efficiency. While growth performance (average daily gain and protein deposition) remained similar between feeding systems, IPF led to a 26% reduction in standardized ileal digestible (SID) lysine intake and a 16% reduction in crude protein intake. These reductions translated into a 10% decrease in production costs and a 30% reduction in nitrogen excretion (5, 6). Furthermore, precision feeding improved nitrogen efficiency by 17% during the most demanding growth phases and by 14% overall. By reducing nitrogen and phosphorus excretions, the system also contributed to lower environmental impacts. Compared to conventional group-phase feeding in Quebec conditions where all the feed ingredients are produced at a close distance, IPF reduced CO₂-equivalent emissions by 8% and lowered acidification and eutrophication potential by 16% (7).
Future perspectivesTo further develop precision feeding systems, a deeper understanding of individual animal variation is needed. For example, pigs can respond differently to immune challenges, environmental stressors (e.g., heat stress) or to the same dietary amino acid intake. Incorporating these individual responses into precision feeding models will help optimize nutrient utilization and improve performance under varying conditions.
Additionally, sustainability efforts should extend beyond feeding strategies to consider alternative feed ingredients. Currently, more than half of the CO₂ eq. emissions associated with pig production stem from feed ingredient sourcing and feed production (7). Identifying and incorporating alternative feed sources with lower environmental impacts could further reduce emissions and enhance the overall sustainability of growing-finishing pig production. Our lab is currently working on a project that introduces timothy hay meal into the pelleted low-nutrient-density feed given the fact that in the Quebec production system, where all the crops are locally grown, cereals are the feed ingredient with higher CO2 eq. emissions related to its production (7).
ConclusionsIndividual Precision Feeding represents a transformative approach to swine nutrition, offering a more sustainable and cost-effective alternative to conventional feeding strategies. By providing pigs with the exact nutrients they need daily, IPF minimizes nutrient losses, enhances nutrient efficiency and reduces feeding cost and environmental impact, all while maintaining animal performance. As the industry continues to focus on improving sustainability and production efficiency, precision feeding is poised to become a key tool in modern swine production systems.
Literature cited:1.) Dourmad JY et al., 1999. doi: 10.1016/S0301-6226(99)00015-92.) Flachowsky G et al., 2012. doi: 10.3390/ani20201083.) NRC. 2012. doi: https://doi.org/10.17226/13298.4.) Hauschild L et al., 2012. doi: 10.2527/jas.2011-42525.) Andretta I et al,. 2014. doi: 10.2527/jas.2014-76436.) Andretta I et al,. 2016. doi: 10.1017/s17517311150030677.) Llorens B et al,. 2024. doi: 10.1093/jas/skae225
Llorens, Remus and Pomar are researchers with Agriculture and Agri-Food Canada.
