Visiting a poultry slaughter house (Day 523)

Today’s Diary Entry is sponsored by Supreme Pet Foods

It’s amazing how much supermarkets insulate us from the reality of where the food comes from – so much so that some school children even believe that chickens come from Tesco (but that’s another rant). In the matter of an hour or so today I saw thousands of chickens slaughtered, butchered and packaged ready to go out to supermarkets to be selected by people to go onto the dining room table. For some reason even though I knew where chicken came from, and had some theory about the way that slaughter happens, I never actually expected what I saw today.

I think one of the things that made me think the most about it was that we started the process backwards because of hygiene reasons. Basically any slaughter house is split into clean and dirty areas, and you cannot cross between them to avoid contamination. This meant that we started with the packing areas, and then went backwards along the line to the trucks offloading crates of birds.

So after going through hygiene control, we entered the clean area, the first thing noticeable is the noise, and the second the automatic rails (like in a dry cleaners) traversing the massive room with featherless headless chickens hanging from them. Generally I was not expecting so many workers to be here, however there were close to a hundred or so workers in this room.

Going back to the line, there was a lot of automation, the first stage selected whole chickens by their weight automatically to be packed and sold as such. Any that do not make the weight classes will move forward along the line which will then remove the wings for packing, the chest/breasts and then the legs. The breasts will have the skin removed by a machine, however the breast muscles cannot be automatically separated so have a separate line where this is done manually before these are also packed.

Now the most disturbing part of my day, leaving this spotlessly clean area we went through two sets of doors into what could be described as a older area of the plant. Broken tiles on the floor, and a single machine sat in the middle by itself with wheeled bins full of the waste bones that came off the original line. This was the mechanical recovery device, the one that produces the pink slime that the processed food and fast food (McDonalds) industry likes to pretend is chicken. The waste bones were emptied into the top of this bin, and a pipe coming out spewed waste bones from the end whilst the pink slime was squeezed from the side… Pretty much put me of any product with mechanically recovered chicken for life…

After this we worked our way further up the line to the stage before the packing. This was the evisceration (removal of the internal organs) and post mortem section of the line. The evisceration was done automatically, a drill like machine came down and cut the skin around the anus of the bird, and then on the next machine a hook basically slipped in and pulled the internal organs out. I found this interesting as I had always wondered how it was done! The bird carcass and the organs were kept together on separate hooks as the next stage was the post mortem station where a vet does a visual inspection. Personally I am not sure how effective it is when you have 30 or so birds going past every minute (and how the vet is not put into a trance) however it does allow the very obvious diseased meat to be discarded. These then pass along the line to where more manual workers separate the liver, gizzard and heart from the rest of the organs as these are the organs used for human consumption. The final step at this stage was the changing of the position of the chicken so that the feet could be removed automatically.

After we moved to the slaughter area, this has a loading ramp and several workers unload the trucks hanging the birds onto the conveyor system by their feet before then enter the killing room. The killing room was pretty automated, the birds went through a water bath to stun them, before having their necks cut by an automatic blade. A single worker ensures that this is done correctly and manually does this for any birds where the automatic blade is not effective.

The final stage we saw was the removal of the feathers, this is done using high temperature to scald the dead carcass and make the skin looser before the feathers are removed using brushes along the conveyor belt. The feathers are then dried and stored for other products.

After returning I then had pharmacology practical where we looked at sulfonamides (a type of antibiotic) and the plasma concentrations. After this I managed to make it in to watch a surgery for a prolapsed uterus and rectum in a guinea pig.

Animal Hygiene, or how to prevent environmental diseases in animals… (Day 158)

Draught wind speed and velocity measurement device

Today’s Diary Entry sponsored by Pet Hooligans

Nearly the end of the first week of my second semester here in vet school, today is the start of Animal Hygiene which is a module I have been looking forward to as it is actually taught by the vice-rector. We have just 4 weeks of classroom learning at the start of the semester and then each week will alternate between a farm visit and looking at the needs of specific animals. When posting on Twitter I’ve realised that many people do not understand just what animal hygiene is or covers (It’s not as simple as bathing animals!) so wanted to take a few minutes today to introduce the subject to you. Taking the definition of hygiene from the free dictionary it is simply

“The science that deals with the promotion and preservation of health.”

Ok, so its now become a science, and it promotes and preserves health. Relating this to animals basically animal hygiene becomes the science that promotes and preserves the animals health. This is where it gets interesting as instead of just purely treating diseases as vets we are responsible for preventing disease in the first place!

The first thing to consider when thinking about animal health is the conditions in which the animal lives – in fact with reptiles incorrect environmental conditions cause around 90% of medical problems! Sadly this module is primarily focused at production animals so things like sheep, goats, pigs, cattle, and chickens. When we talk about hygiene we are considering what the animal needs; the temperature, ventilation, light, space, materials, layout etc.

Today we covered the equipment used to measure these things – aka we spent an hour having thermometers explained to us – before moving onto cool things such as this…

Draught wind speed and velocity measurement deviceLooks pretty cool, basically its a fan that the wind or draught in the building blows around and it measures the velocity. Having proper ventilation is good as animals produce a lot of waste gases (not just methane but things like ammonia too) which are detrimental to their health. Ventilation also allows for the distribution of heated air and the limit for the speed of the movement of air is dependant on the animal species and season however above 3 meters a second is considered a draught.

Obviously temperature is also important as too cold the animals have depressed metabolism, however too hot and the animals have hyperthermia which is even worse. Then you have the lighting, animals are sensitive to light patterns (and even to the colour of the light) with it actually regulating the reproductive cycle in sheep.

I hope that I’ve explained just what animal hygiene is pretty well, as always feel free to leave comments and questions below!

Crop Feeding Chickens, Taking Blood, Digestion, and the Joints…. (Day 87)

Chicken dissection tools and materials

Well today I got a suprise when I walked into Physiology and was told we were going to feed a cock starch solution and then take blood from it before we euthanised it and inspected the digestive tract.

Now the starch solution was to look at the different areas of absorbtion within the avian digestive tract which is important in our knowledge of animal nutrition. As with any practical in vet school anywhere it is important that animals are treated with respect and do not suffer unnecesarily. This is something that is at the front of my mind at all times as I am here to learn how to relieve suffering and each animal that helps me on this path will be remembered forever.

Now avian species (birds) have a different digestive anatomy to mammals, it starts with something called a crop. A crop is like a storage pouch at the end of the esophageus before the stomach (called a gizzard in birds) allowing it to store food for later, and also soften food before feeding it to their young. Within veterinary medicine birds are often fed by crop feeding, which is where a tube is passed down the esophageus into the crop (it is painless to the animal!!!) for liquid food to be directly given to birds too weak to feed themselves. This is the method that was used today to allow the starch solution to be inserted into the digestive system.

Crop feeding chicken a food solutionThe solution was given 20 minutes to pass through the digestive tract, during this time we took blood samples from the chicken to analyse for white blood cells. I was the first person to do this, and with my previous disasters was a little nervous. I attempted to collect blood from the metatarsal vein which is located on the foot of the chicken and shows as a really thin darker line. With this I was determined to get it first time! Following aseptic techniques I cleaned the area with antiseptic, before then inserting the needle at 45 degrees and with the point towards the skin. I was amazed when I immediately got the needle into the vein and was collecting blood for my sample. This really has been one of my highlights as I finally managed to collect blood first time!!!

After the 20 minutes required for the solution to pass through the entire digestive tract were up the chicken was then humanely slaughtered for dissection. Something at the forefront of our minds is animal welfare and we requested to observe this for ourselves and were allowed to watch. Whilst happy it was humanely done, one of the observations was it really is a humbling when considering how few people can relate the pack of meat obtained in a supermarket to having been a living breathing animal.

Chicken dissection tools and materialsSomehow I ended up being the person that dissected the digestive tract from the chicken, one of the things I was most suprised about was how much of the body cavity was actually given to digestion in relation to the size of the bird. Previously I had watched the dissection of a quail on my previous degree and remember the tract being a lot smaller and less defined then it was in this chicken.

The afternoon then was our anatomy practical with a different lecturer than usual, todays test was different as instead of being questioned using a cadaver we were asked to describe a area from memory. I did pass however after getting out realised that being put on the spot I had forgotten some things from my description which I knew but totally got distracted from. I think I am going change my revision stragety and get someone to question me each week before the exam from memory as its valuable being able to picture the anatomical structures in the mind.

During the practical we looked at the different ligaments of all the joints of the body, something I found really interesting was being able to see and touch an intervertebral disc as its something I had heard so much about. Something else that got me was just how difficult it actually is to get the cruciate ligaments, this has given me a much greater respect for the vets out there that do CCL repairs!

As the course gets more interesting something I’d like to do is be able to make it so people that want to can see the more graphic photo’s whilst keeping the main posts friendly for everyone. Anyways, until next time 🙂