Over the course of the past few months, the majority of my work-related conversations have been on developing artificial diets to mass rear mosquitoes. The result has been heaps of suggestions for what to use as an alternative to live blood meals. People have suggested an array of alternatives. Some alternatives have been strange, e.g. coconuts, raw eggs, cheese. Some less strange, e.g. milk, whey, salt solutions. But one thing that repeatedly comes up is the idea of using salvaged blood from the meat industry. Salvaged blood would presumably be less expensive than the cost of purchasing live animals or blood from a blood bank, and might pose less disease risk if it is considered food-grade. My argument for using insects over all of these other alternatives has been that insects are easy. Insects are less regulated, faster to rear, cheap, less prone to giving us disease and contain hemolymph presumably more similar to mammalian blood than, say, a coconut. But after what felt like the ten-billionth time I’d been asked the slaughterhouse question, I felt I needed to see for myself — how hard is it to collect slaughterhouse waste?
That question is what led me to find myself on Wednesday morning covered boots-to-neck in a yellow rubber apron, one hand holding onto a turkey head, and the other clinging to a ziplock bag. I was collecting blood from a turkey slaughter at the Poultry Education and Research Center (PERC). The center is not far from the insectary, found by a small store that sells eggs and packaged meat. The slaughter house is just beyond the store, behind a biohazard gate. If you’re looking for locally sourced meat, this is the place. I had emailed the manager of the PERC, Scott Kephart, a few weeks back asking whether Penn State salvages any of the slaughterhouse waste for research purposes. His short answer was no, but he was willing to let me try.
Slaughters happen at least once a week, sometimes turkeys, sometimes chickens and sometimes pigs and sheep in the other meat labs on campus. Wednesday happened to be turkey. So on Wednesday morning, I woke up early and headed to the campus slaughter house to meet Scott, an accompanying veterinarian, and a guy named Steve who would actually do the slaughtering. We walked through the education center, stepping through a foot wash on the way in and a foot wash on the way out, crossed a gravel parking lot and headed into a barn-like building, the abattoir. The turkeys came in. They walked around the enclosed room, while we suited up into blood-splatter-proof aprons. Turkey slaughtering goes something like this: (1) the turkey is grabbed by her feet, (2) in one sweeping motion, the turkey’s flipped upside down and her talons are slid into a ceiling foothold, (3) the turkey gets dizzy from being upside down and passes out, (4) a trained professional makes one deep slit in an external jugular vein, and (5) the turkey hangs until the blood drains out before butchering.
The slaughtering process is quick, clean and efficient when done by people who know what they are doing. The turkeys didn’t move and showed no signs of suffering, no lugubrious sounds, no attempts to resist. The room was quiet when the necks were slit. The only sound came from the sound of the blood coming out. Blood drains fast from the jugular. The force of the heart is surprising, more energetic than the word draining implies, the blood rushes out, gushing in one thick stream. My gallon bag was empty and then it was full, filled with enough blood to feed at least a thousand mosquitoes, one turkey’s worth.
I had brought with me an anticoagulant, CPDA, aliquoted into tubes. I then transferred blood from the collection bag into tubes and shook to mix the anticoagulant into the blood. So far so easy. I brought the tubes back to lab and did my first turkey feed on Wednesday afternoon. Some mosquitoes supposedly lay more eggs off of bird blood than mammalian blood, possibly because of extra nutrients found in nucleated red blood cells. Small boosts in fecundity could make a huge difference in the success of mass rearing efforts. For results on whether Anopheles stephensi mosquitoes also lay more eggs off of slaughterhouse-salvaged bird blood vs blood-bank-sourced human blood, stay tuned at the next lab meeting.