Corn is harvested at a high moisture level, and thus must be dried to less than 15% moisture to ensure safe storage. Improvements to reduce the energy consumption of the dryers have been implemented, especially by increasing the inlet air temperature. However, overheating may have a negative impact on the stability of nutrients, especially amino acids (AA), because Maillard reactions may occur if heat and moisture are applied to feed ingredients. Consequently, Maillard reactions result in a decrease in the concentration and digestibility of AA, and it is possible that energy digestibility is also reduced. Therefore, the objective of these experiments was to test the hypothesis that both the temperature used in drying and the time that heat is applied will affect the standardized ileal digestibility (SID) of AA, and concentration of digestible energy (DE) and metabolizable energy (ME) in corn fed to growing pigs.

The majority of P in most plant feed ingredients is bound to phytate. Pigs, however, do not synthesize adequate endogenous phytate to release the P bound to phytate, which results in low digestibility of P in field peas. Values for ATTD and STTD of P in field peas without and with phytase have been reported, but there are no comparative values for the ATTD and STTD of P in field peas adding different levels of phytase. The objective of this experiment is to determine the effect of increasing levels of phytase on the apparent total tract digestibility (ATTD) and standardized total tract digestibility (STTD) of P in field peas fed to growing pigs.

Oliveira, M. S., and H. H. Stein. 2022. Direct fed microbials increase energy and nutrient digestibility. National Hog Farmer, On-line edition, Sep. 24, 2022. Link to full text.

Casas, Gloria A., Maryane S.F. Oliveira, Charmaine D. Espinosa, and H.H. Stein. 2022. Comparative digestibility of energy, dry matter, and nutrients by gestating and lactating sows fed corn–soybean meal diets without or with full-fat or defatted rice bran. Can. J. Anim. Sci. 102: 401–405 (2022) dx.doi.org/10.1139/cjas-2021-0086.

Addition of probiotics to swine diets may improve gut health by modifying the microflora, which may help control pathogens, enhance immune response, and increase nutrient digestibility. Once consumed by the pig, probiotics enter the stomach where they are subjected to a low pH and pepsin. The Bacillus strain are metabolically inactive spores that are thermostable and survive at a low pH and, therefore, are thought to survive feed processing and digestion in the stomach. Addition of a Bacillus strain may enhance fermentation of dietary fiber in swine diets and, subsequently, increase the available energy from the diet in the form of volatile fatty acids. Bacillus strain also may degrade non-starch polysaccharides to reducing sugars that may serve as an energy source for the pig. A novel probiotic Bacillus toyonensis M15750 has been developed, but there are limited data to demonstrate the efficacy of this probiotic to increase nutrient digestibility. Therefore, an experiment was conducted to test the hypothesis that probiotic Bacillus toyonensis M15750 improve the apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of energy and nutrients when included in diets fed by weanling pigs.

Espinosa, Charmaine D., Maryane S. F. Oliveira, Joseph R. Limbach, Natalia S. Fanelli, Markus K. Wiltafsky-Martin, and Hans H. Stein. 2021. Long-term steam conditioning is needed to maximize the nutritional value of expander-processed soybean expellers. Can. J. Anim. Sci. 101: 704–714 (2021) dx.doi.org/10.1139/cjas-2021-0029. Link to full text.

Zinc (Zn) is an essential trace element that is needed for growth, bone development, and immune competence. Inorganic Zn sources such as Zn oxide and Zn sulfate (ZnSO₄) are most commonly used in swine diets. However, because of low bioavailability of Zn the inorganic Zn sources chelated Zn sources may be used instead because these sources have greater bioavailability of Zn. Chelated zinc may also reduce reactiveness with other components of the diet. A new chelated Zn source, zinc bis-glycinate, in which Zn is bound to two glycine molecules, was recently developed, but there is limited information about effects of this new chelated Zn source on digestibility and Zn retention in pigs. Therefore, an experiment was conducted to test the hypothesis that the relative bioavailability by weanling pigs of Zn in Zn bis-glycinate is greater than in Zn mono-glycinate and in ZnSO₄.

Oliveira, M. S. F., J. K. Htoo, J. C. González-Vega, and H. H. Stein. 2021. Optimal tryptophan:lysine Ratio for 25–40 Kg Growing Pigs Fed Diets Containing 35 % Distillers Dried Grains with Solubles. J.  Anim. Sci. 99(Suppl. 1): 57–58. doi.org/10.1093/jas/skab054.097. (Abstr.). Link to Abstract.

Dried whey is often used as a source of lactose in diets for weanling pigs. Whey is a co-product from dairy processing plants that is generated after fat and protein in milk has been used to produce cheese. Whey powder is therefore, low in protein because the majority of the milk protein ends up in the cheese during processing. However, some of the cheese that is produced may not be suitable for human consumption, but can instead be used as a feed ingredient for pigs after being blended with other ingredients to improve flowability and handling.  One of the cheese co-products that is currently being marketed contains 40 to 50% crude protein and has a high digestibility of amino acids. There is, however, limited information about the energy value of cheese co-products fed to pigs although it is expected that because of the high concentration of fat in cheese, the energy value will also be high. Therefore, it was the objective of this experiment to test the hypothesis that digestibility of energy and concentrations of digestible energy (DE) and metabolizable energy (ME) in a cheese co-product is greater than that in fish meal and enzyme treated soybean meal when fed to weanling pigs.