In 2050 the worldwide population is
expected to reach upwards of 9.6 billion people. A global food crisis could result from this drastic
jump in population. What would happen to
the population if there wasn’t enough food to feed everyone?
With already almost 400 million undernourished, the possibility of less food is frightening. Animal protein is becoming a major concern as the population
increases. Animals such as pigs, goats,
sheep, and cattle are key components of many people’s diets. With that said, currently between 30%-40% of
embryos within food animals die. With hopes of avoiding this crisis, the
reproductive success of food animals has become more important than ever.
Many food
animal embryos die before elongation can even occur. If appropriate development of the embryo,
along with the extra-embryonic membranes doesn’t occur then the pregnancy
cannot be successful. In order for
proper development the corpusluteum must secrete progesterone creating the best
environment for the embryo to implant within the uterus. These conditions allow for things such as water
and electrolyte transport, uterine blood flow, recognition of the pregnancy by
the mother, transportation of amino acids and nutrients between the uterine
lining and the embryo, and selective transport of components of the complex histotroph. All these processes are necessary to keeping
the embryo alive along with furthering embryonic developing.
A histotroph
is a combination of amino acids, enzymes, growth factors, cytokines, hormones,
transport proteins, and many other nutrients.
These are all important for the development of the trophectoderm (the
outer layer of the blastocyst). The amino
acids within the histotroph are necessary for protein synthesis along with the
activation of many cellular functions. These
processes aid in the survival of the animal pre-weaning, meat quality, tissue
composition with fat and protein, and even lifetime health. The main amino
acids responsible are arginine (Arg), leucine, and glutamine; they cause cellular
migration, hypertrophy, and hyperplasia.
In sheep,
by day 20 of pregnancy, the extra-embryonic membranes have to have extended
into the uterine horn. After which
elongation must begin to occur in order for implantation of the embryo. At this point the trophectoderm can come into
contact with the uterine lining resulting in the placenta beginning to form. Molecules, mainly proteins are then
transported to the lining where they can diffuse into the embryo in order for
further growth and development. As the development
of the placenta continues, placentomes must form as the site for
embryo-maternal exchange. The exchange
of gases and nutrients is obviously necessary for the survival of the
embryo.
Nutrients
diffused from the mother to the embryo then stimulate mTOR. mTOR stimulates cell migration, cell growth,
and proliferation. mTOR also aids in ribosome
synthesis, mRNA translation, and cytoskeletal rearrangement. mTOR is found in abundance within the
cytoplasm along with in the nuclei of the embryos trophectoderm cells and
within the extra-embryonic endoderm. It
is heavily involved in the elongation of the trophectoderm. During elongation, cytoskeletal rearrangement
facilities cell motility and stabilized adhesion among trophectoderm
cells. These processes result in expansion
and elongation of the embryo, and therefore getting the embryo beyond the stage
where embryos are more likely to die.
Dietary supplementation
throughout the animal’s life has shown to aid in many of the developmental
processes of the embryo discussed. This therefor
increases the chance of successful reproduction. Supplementation even increases birth weight
of many animal species, meaning more food for the population. Arginine was found to be the best dietary supplement
for most food animals.
Knowing
that by simply giving supplements to food animals we can increase our chances
of supporting our rapidly growing population.
With this in mind we should still be aware that there is already a large
underfed population. Knowing how to
increase the success of reproduction of food animals is important, but it is
only a stepping stone to how the population will be completely feed in the
future.
This figure shows how important Arginine is to embryonic development within food animals.
Citation:
Bazer, Fuller W., Johnson, Greg A., Wang, Xiaoqiu, Wu,
Guoyao. “Select Nutrients and Their Effects on Conceptus Development in Mammals.”
Animal Nutrition (2015): 1-11. 10.1016/j.aninu.2015.07.005. 9 July 2015.
Web. 9 October 2015.
I used to be a vegetarian because I felt bad for the animals who were suffering from poor treatment and unhealthy conditions. Is that one of the reasons why 30-40% of embryos cannot make it past the elongation phase in development? It would be interesting to compare the reproductive success of different animals in the food industry such as cows, pigs, and chickens. What are some of the supplements take are given to the animals and what effect will it have on humans because we are then consuming these animals? Will dietary supplements prevent the impending global food crisis or at least help alleviate it? I think this is a very interesting field of study and should be studied further because we can extrapolate what we learn from these animals' embryological development and apply it to humans.
ReplyDeleteAlthough the paper didn't discuss the living conditions of these animals, I would have to imagine that they play a role in the number of lost pregnancies. Many large farms put little effort into looking into why they have losses because like Daniel said, they can afford the loss. It is more efficient for them to pump out as much meat with as little effort as possible. This means that they don't have time or maybe don't care to look into the problems. If a fetus is carried to term and born into bad living conditions their chance of surviving to adulthood is narrowed. There are many animal rights groups that actually fight for better living conditions for these animals.
DeleteContinuing off of what Kathleen said...
ReplyDeleteI'd like to know more about the animals that are housed in CAFO style barns. Given that the study was done on sheep, I would assume that this would be more of a family farm type of set up. Going off of how stress effects human pregnancies, I would say that the same could be said in animals. So, even if the animals were given these components to promote the pregnancy, is it possible that they still would abort because of stress induced by the CAFO setting. Coming from a dairy farming background, we take great care to breed our animals in ways that promote healthy pregnancy. It is important for us to reduce the amount of miscarriages because we often spend a lot of money on semen that has been pre-sexed so we get female calfs. I definitely see the importance in the family farm setting.
I completely agree. Even with the supplements, many pregnancies would still fail due to living conditions in CAFO style barns. Small/family farms seem to put more time and effort into full term pregnancies.
DeleteI've lived on a dairy farm all my life, it has been in the family since 1866. Like Kelsi said, those of us who make a livelihood off of these animals do everything we can to keep the number of abortions down. We do our best to keep the cattle nutritionally balanced to promote a full term pregnancy, seeing as any abortion is a financial hit. However, like Kelsi brings up, the larger farms can afford many more abortions than a small one, and as a result they do not need to worry quite so much about nutrition. Sadly, these are the ones who will be bearing the brunt of feeding the growing human population. Also, I do not think that the current number of farms will be able to support a population of 9.6 billion even if they had 100% full term pregnancies. Once an animal is pregnant, there are several months that it is not able to be bred again. In other words, regardless of the efficacy, livestock can only produce so many offspring, and with the rate at which farms seem to be diminishing the percentage of full-term pregnancies are not going to be the only thing that we have a problem with in the future of farming.
ReplyDeleteOne thing that i wonder with this issue is that if we are having so many issues with embryos surviving is there anything we can change with their living conditions to allow for healthier pregnancies. Perhaps if more farms allowed their animals to roam freely or have more space to move around and live a normal life, that they would be more successful in carrying their embryo to term. I also wonder that if our population is going to grow that significantly if an increase in successful pregnancies would even make a dent in the amount of food we would need. I think that as a nation and world we need to switch back to having our diet consist of more vegetables and plant based items. Plants are easier to maintain and increase amount. They also can be better for our bodies if they are not sprayed with chemicals. If you could buy from a local farm or go to the farmers market you would be saving yourself money as well as getting the best nutrition. There aren't many things that can be done to fruits and vegetables. You can see what they are. Do you really know what is in your meat? I think that if food will become that scarce with meats that we need to rethink our meals.
ReplyDeleteI think you brought up very good points throughout your blog post and also took your topic into great depths. It is absolutely amazing to sit back and think about all of the processes and steps that need to successfully take place in order to actually have the outcome of a successful pregnancy. With so many different steps and processes there is a lot of room for things to go wrong. I think that looking into and exploring strategies to increase the birth success rate is a wonderful thing but I also agree with the others above that there may be bigger problems heading our way. Like Daniel said the number of farms are slowly diminishing and as you have pointed out the population continues to expand exponentially, so I wonder if it is possibly time to start looking into other main food source options.
ReplyDeleteI can see research in this area continue to expand due to our increasing population. We are already dealing with food shortages and I can't imagine what it will be like in the future if we do not come up with effective solutions. I never knew that 30-40% of embryos in food animals died. Increasing reproductive success by supplementation seems like a good start. Even though it certainly won't be enough to feed the growing population, every bit helps. Perhaps this, combined with other methods, will be able to make a difference. I wonder how expensive supplementing all food animals would be. I'm also curious as to why arginine worked the best.
ReplyDeleteThe web address below gives a little more information on research done with arginine supplements. These supplements range in price from $5-$35 on amazon, but I would think that farmers could order it in bulk through their feed providers and get better pricing.
ReplyDeletehttp://www.farmandranchguide.com/news/livestock/feeding-arginine-to-ewes-may-increase-percentage-of-live-births/article_c8f58d35-c530-5232-92cd-7bd582db992f.html
As Nicole mentioned above, I was also wondering why arginine worked the best. My first thought was that it must have something to do with the structure of the amino acid, since often times structure dictates function. However, you had also mentioned that leucine and glutamine were the other useful amino acids. This goes against my theory because arginine is a positively charged amino acid, but leucine is hydrophobic and glutamine is polar. Since arginine worked the best, maybe if further research was done they would find that lysine and histidine would also be useful because they are also positively charged amino acids. I like the idea of using amino acids as a way to increase fetal size and health because since amino acids are already naturally used by the body, it is a more natural way to achieve this outcome than using artificial growth hormones to unnaturally and inhumanely beef up animals for eating, which puts unnatural and harmful chemicals into our bodies as well.
ReplyDeleteThis is a very interesting article and it definitely raises a lot of questions. This article got me thinking what if we made it so that way the rate of successful births was 100% then we would need a lot more land to house these animals (especially if we wanted as humane conditions for farm animals as we can get) and they are going to require a lot more land to grow the grains that they are typically fed too. So with an increase in the human population and an increase in the livestock population it doesn't seem to me that the increase in reproductive success would be the answer to feeding the human race it seems to be we would need to have a diet based more on plants with small amounts of meat in order for the species to survive. Or find some way to live on another planet to save this one solely for food production.
ReplyDeleteThis topic is very interesting. I had no idea that the population is estimated to be that size and already have so many starving people. I think it is amazing that dietary supplementation can be a simple fix to having healthier embryos develop to later be a protein source. I also find it intriguing how big if a role the extra embryonic membrane plays in the developing embryos. I wonder what the development would be of a human embryo without extra embryonic membranes?
ReplyDelete