In Taiwan, millions of livestock are raised for animal protein supply, however most of the feed ingredients are imported. For food safety and sustainable environment, exploring the available locally produced feed resources is more and more urgent. There are lots of by-products produced from agriculture and food processing. The previous and ongoing utilization research work are introduced in this paper. The high moisture content (> 90%) of pineapple pulp (PP) restricts its utilization. It was suggested that PP could be mixed with the drier source like rice straw (RS), wheat bran (WB) or Flammulina velutipes (FC) spent substrate. Diet containing 12 kg a day of fresh PP+RS silage supported normal milk yield and milk fat percentage for Holstein cows. Unfortunately, PP sugars were almost used up by lactic acid bacteria when ensiling. No response to our high milk protein and gravity expectation, but PP+WB still performed as a good alternative feed source that 8% in lactating goats diet was suggested. The proper adding ratio in diet for PP+FC silage for milking goats was 8%, and for Holstein cows 8% to 12% was suitable. Some by-products possess negative effect as feed to livestock and need awareness. About 15% of sweet potato harvested was discarded as sub-quality sweet potato (SSP). It still holds strong trypsin inhibitor (TI) activity. By ensiling, 28.7% of the TI activity was diminished. When SSP+WB silage directly added into diets to occupy 13.5% diet dry matter, it caused a significant 10% decrease in milk fat percentage that rumen acidosis was recognized. Another case was the feeding of tomato pomace+corn meal silage. Lactating goats accepted when added into diets from 6% to 10% dry matter, however, cows responded poorly. How high the by-products could be suitably adopted in diets for milking ruminants was evaluated. Formulated by commonly used by-products, the 333 diet is recommended so that mid to high-lactating cows could keep their performance including by-products from 10% to 32%. Besides offering as an alternative feed resource, adoption of by-products in diets also showed the benefits in decreasing greenhouse gas emission and health improvement. Rumen methane emission numerically decreased by 9% and 22% and carbon dioxide by 10% and 13% when diets having 10%, 20% or 32% by-products (Rusitec) are implemented. The off-bottom of mushroom during shaping process was fed to goat kids around weaning. Off-bottom from Pleurotus eryngii and Flammulina velutipes added at 1.5% each in diet stimulated the best daily gain and had significant lower diarrhea occurrence. Agriculture and food processing by-products are valuable feed resources. More studies are needed to confirm the proper preserving, wrapping technique, efficient transportation, nutrition balance knowledge, and its price. It is planned to set up the whole industry link that could really establish the business.
Keywords: By-products from agriculture and food-processing, feed, Holstein dairy cow, Sannan and Alpine dairy goat