Use of fat in pig feed
Fat in pig diets is used as an energy source, besides, it serves as a vehicle for fat-soluble proteins and adds flavor to the meat. In fact, lipids present in muscle tissue in a proportion no greater than 3-5% provide juiciness, tenderness, and good taste, as well as palatability and texture, essential properties of some meat products.
Fat supplementation in pig feed improves palatability and productive performance (FEDNA 2013) and modifies the carcass. The use of oils may increase the risk of rancidity of the feed (FEDNA 2013). Therefore, it is important to include it under the appropriate levels to optimize production without compromising the quality of the final product.
Effects of fat and maximum recommended levels
Fat inclusion levels in the diet should vary depending on the age, breed, and the desired carcass qualities. Fat supplementation helps to reduce the costs and improve performance results (Vos, Dewey, and DeGrau 2000). For this reason, the cost per calories of fat should be considered when comparing corn to use the least expensive source of calories.
Fat has approximately 2.25 more metabolizable energy than corn. Thus, it is considered that 1 to 5% fat supplementation in grow-finishing diets helps to improve feed conversion and daily gain without any adverse effect on carcass quality (NCSU n.d.). On the contrary, the inclusion of more than 5% of fat in the diet can have a negative impact on feed quality (NCSU n.d.) and carcass characteristics if the amino acid to energy ratio gets decreased, although it will lead to an improvement in the productive performance.
To calculate whether it is profitable to include ingredients that are rich in fat, such as tallow, corn oil, or soybean oil, the percentual improvement in the feed conversion rate necessary to offset the increase in the price of the diet needs to be calculated. That is, if the cost increases by 5%, feed efficiency needs to improve by at least 5% (NCSU n.d.).
Fat can also be used to increase energy concentration of the diet during the warm seasons or in any stage where feed intake is compromised in order to make sure that animals receive enough calories.
Effects of at in the different production stages
In sows, fat improves milk production and fat content, which has a positive impact on piglets’ weight at weaning and can also improve birth weight and the survival rate of weaned piglets (FEDNA 2013).
In weaned piglets, fat increases weight gain and fed efficiency, while in the growing stage it improves the meat deposition rate. Besides, in finishing pigs, each 1% of supplemented fat is considered to increase weight and feed conversion by 1% and 2%, respectively.
Energy and fat requirements in pigs
Energy requirements are tightly related to fat supplementation in diets for pigs, as it is an energy-rich ingredient with a high concentration of calories. Requirements vary broadly depending on the production stage and the age of the pigs.
Fat is a source of linoleic acid, too, an essential fatty acid that needs to be provided through the diet. According to the NRC (2012) (Council 2012), linoleic acid requirements are insignificant in this species, so that the recommended values are above 0.10% and 1.50% in the majority of the production stages and need to be increased in case of skin problems (Blas et al. 2019). However, the fat supplementation will help to improve performance results. Anyway, breeds with greater gain rates (Large White, Landrace Duroc) have greater protein requirements than other breeds such as Berkshire or Hampshire. That is why in highly productive breeds it is highly important to keep an eye on protein to fat ratio, particularly when fat inclusion in the diet goes up.
Table 1. Energy, fat, and linoleic acid requirements in sows and boars (FEDNA)
| Gestation | Lactation | Boars | ||
| Adults | Growing | |||
| Net energy | 2130 | 2250 | 2150 | 2190 |
| Metabolizable energy | 2875 | 2980 | 2930 | 2935 |
| Fat, min. | 3.1 | 5.4 | 3.0 | 4.5 |
| Linoleic acid, min. | >0.10 | >0.10 | >0.10 | 0.70 |
Table 2. Energy, fat, and linoleic acid requirements in fattening pigs (FEDNA)
| 5-7 kg | 7-12 kg | 12-22 kg | 20-60 | 60-100 | >100 | |
| Net energy | >1480 | >2470 | >2460 | 2400 | 2400 | 2400 |
| Metabolizable energy | >3290 | 3285 | 3280 | 3180 | 3175 | 3150 |
| Fat | 5-9 | 5-8,5 | 5-8 | 4-8 | 4-8 | 4-8 |
| Linoleic acid, min. | >010 | >0.10 | >0.10 | >0.10 | >1.50 | >1.50 |
Fat sources
The most frequently used fat sources are soybean and sunflower oils, as well as animal fat (Service 2000). Oils are liquid at an outside temperature range, while animal fat remains solid. Generally, oils are the preferred choice, particularly for diets formulated for piglets below 7 kg (Service 2000) due to they are much more digestible.
Supplemented fat in the diets should always be accompanied with antioxidants to prevent rancidity, which would have a negative impact on meat acceptance, animal health and the quality of the final product. Several antioxidants are available in the market, some of which, such as BHA and BHT, can accumulate in animals’ fat and reach the products intended for human consumption. In contrast, natural antioxidants do not have such drawbacks.
How can Delta Labs help you?
In Delta Labs, we offer the feed formulation and analysis service to optimize feed composition and adjust it to the requirements of the species, commercial breed, ages, and productive stages. We also recommend you the best antioxidants.
To use these services, please contact us through our webpage www.globalvetslab.com or email at info@globalvetslab.com
References
- Blas, C. de, P. Carcía-Rebollar, M. Gorrachategui, and G.G. Mateos. 2019. Tablas FEDNA de composición y valor nutritivo de alimentos para la fabricación de piensos compuestos FEDNA (Fundación Española Para El Desarrollo de La Nutrición Animal). 4th ed. Madrid. http://www.fundacionfedna.org/ingredientes-para-piensos.
- Council, National Research. 2012. Nutrient Requirements of Swine. 11th editi. ed. NRC. Washington, DC. https://www.nap.edu/catalog/13298/nutrient-requirements-of-swine-eleventh-revised-edition.
- FEDNA. 2013. Necesidades Nutricionales Para Ganado Porcino: Normal FEDNA. https://www.fundacionfedna.org/sites/default/files/Normas PORCINO_2013rev2_0.pdf.
- NCSU. “ENERGY – NCSU Extension Swine Husbandry (MARK).” projects ncsu swine nutrition. https://projects.ncsu.edu/project/swine_extension/nutrition/nutritionguide/energy/energy.htm (October 25, 2021).
- Service, Coopoerative Extension. 2000. Swine Nutrition Guide. University of Nebraska and South Dakota State University.
- Vos, L, C Dewey, and A DeGrau. 2000. “Value of Pigs by Growth Rates.” American Association of Swine Practitioners (Proceedings Indianapolis): 39–43.