Whey, which is a co-product from dairy processing plants that extract fat and protein from milk to make cheese, has been used in diets fed to weanling pigs as a source of lactose. Whey powder does not contain much protein because the majority of the milk protein ends up in the cheese during processing. However, cheese co-products, which contain 40 to 50% crude protein may be used in the feeding of pigs, but there is limited information about the nutritional value of cheese co-products fed to pigs. Therefore, the objective of this research was to test the hypothesis that a cheese co-product may replace traditional protein sources in diets for weanling pigs without affecting growth performance.

Pharmacological levels of Zn (i.e., 2,000 to 3,000 mg/kg) is often included in diets for weanling pigs to prevent post-weaning diarrhea. However, pharmacological levels of Zn may reduce microbial phytase efficacy by chelating the phytate molecule, which subsequently prevents access for phytase.  However, it is possible that this effect can be reduced by adding more phytase to diets. Therefore, an experiment was conducted to test the hypothesis that inclusion of increasing levels of phytase increases pig growth performance and mineral digestibility in diets with 3,000 mg/kg of Zn.

Blavi, Laia, David Solà, Alessandra Monteiro, J. Francisco Pérez, and Hans H. Stein. 2021. Inclusion of dicopper oxide instead of copper sulfate in diets for growing–finishing pigs results in greater final body weight and bone mineralization, but reduced accumulation of copper in the liver. Journal of Animal Science, 2021, Vol. 99, No. 6, 1–8. doi:10.1093/jas/skab127.

Rundle, C. M., Y. Dersjant-Li, B. Hillen, M. S. F. Oliveira, and H. H. Stein. 2021. Buttiauxella Phytase Improves Growth Performance of Weanling Pigs Fed Corn, Soybean Meal, and Canola Meal Based Diets. J. Anim. Sci. 99(Suppl. 1): 49–50. doi.org/10.1093/jas/skab054.084. (Abstr.) Link to Absctract.

Lagos, L. Vanessa, Su A Lee, Mike R. Bedford, and Hans H. Stein. 2021. Formulating diets based on digestible calcium instead of total calcium does not affect growth performance or carcass characteristics, but microbial phytase ameliorates bone resorption caused by low calcium in diets fed to pigs from 11 to 130 kg. Journal of Animal Science, 2021, Vol. 99, No. 3, 1–11. doi:10.1093/jas/skab057.

Ren, Ping, Laia Blavi, Caroline González-Vega, Yanhong Liu, Deana Hancock, Mercedes Vazquez-Añón, Ferdinando N. Almeida, and Hans H. Stein. 2020. Effects of a novel E. coli phytase expressed in Pseudomonas fluorescens on growth, bone mineralization, and nutrient digestibility in pigs fed corn–soybean meal diets. Transl. Anim. Sci.

Espinosa, C. D., J. P. Acosta, and H. H. Stein. 2020. Growth performance not sacrificed with corn protein. National Hog Farmer, On-line edition, October, 2020. Link to full text.

Lancheros, J. P., C. D. Espinosa, H. H. Stein. 2020. Effects of particle size reduction, pelleting, and extrusion on the nutritional value of ingredients and diets fed to pigs: A review. Animal Feed Science and Technology 268 (2020) 114603. https://doi.org/10.1016/j.anifeedsci.2020.114603.

Calcium requirements by pigs are expressed as total Ca because of a lack of data for the digestibility of Ca in feed ingredients, but it is believed that a ratio between standardized total tract digestible (STTD) Ca and STTD P is a more appropriate way to express requirements for Ca by pigs. Values for Ca digestibility in different Ca-containing feed ingredients were recently generated using diets without or with microbial phytase, which allowed for the formulation of diets based on STTD Ca values. A number of experiments were also conducted to determine STTD Ca to STTD P requirements to optimize growth performance and bone mineralization of pigs from 11 to 25 kg, 25 to 50 kg, 50 to 85 kg, and 100 to 130 kg. However, these experiments were performed independently and in experiments lasting only 3 to 5 weeks. Therefore, a follow-up experiment was conducted to test the hypothesis that the requirement for Ca expressed as a ratio between STTD Ca and STTD P obtained in short-term experiments may be applied to pigs fed diets without or with microbial phytase from 11 to 130 kg.