This week Tim and Steph discuss colostrum, its importance to neonatal (baby) animals, and its role in extending the communication between mother and offspring outside of the uterus.
What is Colostrum?
It is the first milk an animal produces after giving birth and contains the nutrients and other things such as immune factors they need to start a healthy life. The processes that culminate in production of colostrum actually start weeks before parturition (birth) but colostrum cannot be obtained from an animal until after parturition.
Why do animals make colostrum?
Many animals have a very thick placenta so antibodies and other important factors in the blood stream aren’t able to pass through to the fetus. Because of this in order for the offspring to have a good immune system they have to get colostrum soon after birth for that transfer of maternal antibodies to occur and protect the calf or pig or whatever it might be. This inability for antibodies to cross the placenta isn’t universal but in some species colostrum is the sole way immunity is transferred from mother to offspring.
Why do calves and other animals need to get colostrum soon after birth?
Absorption of antibodies through the gut of an adult animal isn’t generally thought to be possible because they are fairly large particles. For a brief period after birth, around 12 hours, an animal’s intestinal epithelium is “leaky” allowing those antibodies to cross through to the blood stream. Within 24 hours the intestines have tightened up to keep pathogens out of the blood stream.
Colostrum testing and storage
Some cows give better colostrum than others and some just give straight up poor quality stuff. There are a few different ways to test the quality of cow colostrum. Colostrumeters and refractometers are two methods used to test the quality of colostrum. There are many different ways store colostrum but the big thing to keep in mind is proper labeling of colostrum when refrigerating or freezing to ensure it gets used in the proper amount of time depending on temperature it’s stored at. Spoilage of refrigerated colostrum can have a very large effect on the quality when it comes time to feed it to a calf.
What is lactocrine signaling?
The idea that the mother communicates with the developing fetus in the uterus seems common sense to most people but the idea that mothers continue to shape development of their offspring postpartum isn’t so obvious. Researcher Carol Bagnell from Rutgers University coined the term lactocrine to describe the many factors in milk that affect development of their offspring. The route through which milk transferred factors affect development is epigenetic programming or the turning on and off of genes. Young animals have many critical periods where things such as cells in their reproductive tract are still differentiating, developing the organs. Lactocrine signals can affect the development of those tissues.
Effect of feeding milk replacer instead of colostrum to pigs
In the paper by Bartol et. al. titled: “LACTATION BIOLOGY SYMPOSIUM: Lactocrine signaling and developmental programming” they test the hypothesis that factors contained in colostrum affect the reproductive tract tissue development of piglets. To test the hypothesis you fed piglets either colostrum or a milk replacer solution. They considered the milk replacer solution to be lactocrine null as it didn’t have the hormones and proteins that the colostrum had. They then looked at expression patterns of molecular markers and mediators of uterine and cervical development inluding the estrogen receptor, vascular endothelial growth factor and a special enzyme called matrix metalloproteinase 2 and 9. The results from this showed that the piglets who were fed normally from their mothers had higher levels of estrogen receptor in both the uterus and cervical tissues. Additionally, they had higher levels of vascular endothelial growth factor and matrix metalloproteinase2. However, matrix metalloproteinase 9 was not different between treatments suggesting not all neo- natal uterine and cervical protein expression is lactocrine sensitive.
A study measuring the antibody immunocrit levels in piglets blood which reflects colostrum intake in neonatal pigs. By analyzing approximately 380 animals, they found that lower immunocrit levels (equivalent to minimal colostrum consumption) were associated with reduced litter size. These data provide compelling support for the idea that lactocrine signaling affects uterine capacity and reproductive performance in adults.
That’s all folks!
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P.S. If you’re interested in the bone related discovery Tim mentioned you can read about it here.