By Jerry Shurson and Pedro Urriola, University of Minnesota
In Mesoamerican history, chocolate was considered as “food of the gods” by the Aztec people. In fact, cacao beans were considered to be such a luxury item by upper class Mayan and Aztec elites that they were considered to have the same value as gold, and were used to pay taxes to Aztec rulers. When the Spanish conquered the Aztecs and brought cacao beans back to Europe in the early 1500s, chocolate quickly became a luxurious and indulgent food that was given as a gift representing appreciation toward others. This tradition of giving and receiving chocolate as a gift of appreciation on Valentine’s Day has continued for centuries, and is enjoyed by billions of people around the world.
In the United States, we consume about 2.8 billion pounds of chocolate per year (more than 11 pounds per person). However, not all chocolate that is produced is consumed, which leads to significant amounts of byproducts and waste chocolate that are deemed unacceptable for human consumption because of appearance or packaging. As a result, these chocolate byproducts become available in the feed industry for use in animal feeds. Historically, pigs have been extensive consumers of recycled food products. Recycling nutrients from food byproducts provide many benefits including opportunities to reduce feed cost, reduce negative environmental impacts and add value to these otherwise wasted nutrients by producing highly nutritious pork products for human consumption.
While we don’t usually think of waste chocolate or chocolate byproducts being a potential feed ingredient in swine diets, there have been several studies showing that it can be a valuable source of energy, especially lactose for weaned pigs. Although chocolate contains theobromine, which is a similar alkaloid compound to caffeine, the concentrations are relatively low and considered to be safe consumption by humans as well as pigs.
Researchers at the University of Minnesota (Yang et al., 1997) conducted the first studies to evaluate feeding a dried milk chocolate byproduct (MCP), consisting of about 33% whole milk, 33% cocoa and 33% sucrose, to nursery pigs as a partial replacement for dried whey. Results from four experiments showed that pigs preferred diets containing MCP compared with those containing dried whey, and that milk chocolate byproduct could replace 5% of dried whey without affecting growth performance. However, adding 10% or more of MCP to the diet reduced growth performance. These researchers speculated that reasons for reduced growth performance at higher diet inclusion rates of MCP may have been due to inadequate dietary lactose and high-sucrose content, excess theobromine content or inaccurate estimates of digestible threonine in MCP.
However, researchers at Louisiana State University further evaluated MCP in nursery pig diets and showed even more positive results. Naranjo et al. (2010) conducted three experiments to evaluate partial or total replacement of dried whey with MCP on feed intake during the first week post-weaning, and subsequent growth performance of nursery pigs. The MCP fed in these experiments contained 20% lactose and 60% sugars. Results from this study showed that adding MCP up to 20% in Phase 1, up to 10% MCP in Phase 2, and up to 5% in Phase 3 nursery diets can be an effective partial or total replacement for dried whey without affecting feed intake during the first week after weaning or subsequent growth performance of nursery pigs.
More recently, researchers at North Carolina State University and Murphy Brown LLC (Guo et al., 2015) evaluated feeding a chocolate candy byproduct as an alternative carbohydrate source of lactose on growth performance and health status of weaned pigs on a commercial farm. The chocolate byproduct was used to replace zero, 15, 30 or 45% of dietary lactose. There were no differences in pig fecal scores and mortality among dietary treatments.
However, it was interesting that pig morbidity tended to decrease linearly as dietary inclusion of the chocolate byproduct increased. There were no differences in growth performance among dietary treatments suggesting that this chocolate byproduct could be used as an economical alternative to partially replace lactose in weaned pig diets. These data would also suggest that requirements for lactose in weaned pig diets are less than previously thought.
Waste chocolate also appears to be a useful ingredient for finishing pigs. Researchers at the University of Guelph (McNaughton et al., 1997) evaluated feeding diets containing zero, 10, 20 or 30% of a waste chocolate confectionary byproduct to finishing pigs on growth performance, carcass composition and meat quality. Results showed that regardless of diet inclusion rate of the chocolate byproduct, there were no differences in growth performance, carcass fat and lean composition, or meat quality. Therefore, there appears to be no adverse effects of feeding this chocolate byproduct to finishing pigs, and there may be an economical opportunity to reduce feed cost if a supply of chocolate byproduct is available for use.
Cocoa husks are another chocolate byproduct that are high in dietary fiber (49.3% neutral detergent fiber) and contain multiple polyphenolic compounds. Feeding cocoa husks to nursery pigs may alter the gut microbiome and promote beneficial bacteria (Magistrelli et al., 2016). Phenolic extracts from cocoa husks may contain potential antioxidant properties that may be beneficial for reducing oxidative stress, but no studies have been conducted to evaluate these potential benefits.
While waste chocolate may not necessarily be “food of the gods” for pigs, it is one of many byproducts produced by the food industry that has significant nutritional and economic value in nursery pig diets because of its relatively high lactose content. Waste chocolate can also be added up to 30% of finishing pig diets to support optimal growth performance without affect carcass composition or pork quality.
Happy Valentine’s Day!