Goat Eye Color Genetics

A unique trait of the Nigerian Dwarf is the ability to

have both blue or brown eyes.

I have to say it is one of the things

that intrigued and originally drew me to

the breed when I first started

looking at adding goats to our

little homestead.

Our focus is now on producing great milking animals but I do have a good mixture of eye colors in my herd now, even though that is not part of our focus when breeding our animals. But many people do want to know about blue eyes in the breed and how to get more of them in their herds. So I put this post together to try and teach you about the genetics behind eye color in the Nigerian Dwarf goat.

Unlike in people, in goats blue eyes are dominant. So brown eyes are recessive. This makes it easy for us to determine what color eyes we should get from different crossings, usually. You may remember Mendel and his pea plants from back in grade school? If not, we will do a short course and get you brushed back up on your 5th grade science. ;-)

First lets start with a few terms and their definitions.

Phenotype - literally means "the form that is shown"; it is the outward, physical appearance of a particular trait. Whether the goat has blue or brown eyes.

Genotype - the specific allelic combination for a certain gene or set of genes.

Allele - one alternative form of a given allelic pair; blue and brown are the alleles for the eye color of the goat; more than two alleles can exist for any specific gene, but only two of them will be found within any individual.   

Allelic pair - the combination of two alleles which comprise the gene pair

Homozygote - an individual which contains only one allele at the allelic pair; for example BB is homozygous dominant and bb is homozygous recessive; pure lines are homozygous for the gene of interest    

Heterozygote - an individual which contains one of each member of the gene pair; for example the Bb heterozygote.

Dominant - the allele that expresses itself at the expense of an alternate allele; the phenotype that is expressed in the F₁ generation from the cross of two pure lines

Recessive - an allele whose expression is suppressed in the presence of a dominant allele; the phenotype that disappears in the F₁ generation from the cross of two pure lines and reappears in the F₂ generation

Mendel's First Law - the law of segregation; during gamete formation each member of the allelic pair separates from the other member to form the genetic constitution of the gamete.


 

There are 2 Phenotypes for goat eye color, blue or brown. There are 4 Genotypes for goat eye color as shown above. Because blue is dominant it is represented with the B, while brown is represented with the b, because it is the recessive gene. Any time there is a dominant gene present that is what you will see as the phenotype.

So the following Genotypes will give you these Phenotypes (eye colors):

Genotype             Phenotype

BB            =         Blue Eyes

Bb            =          Blue Eyes

bB            =          Blue Eyes

bb             =          Brown Eyes

So I am going to do some examples and we will see what the kids will be as a result. The top line above the box is one parent's genotype while the letters to the left outside the rectangle are the other parent's genotype. Inside the rectangle are the available different genotypes that will result from this breeding. You can also calculate the chances of getting a certain genotype/phenotype with each breeding using this method as well.

The first example is a homozygous brown eyed goat (bb) bred to a homozygous blue eyed goat (BB)



So all of the kids of this breeding will have blue eyes and they will be heterozygous for blue eyes (Bb). So you have a 100% chance of getting blue eyes from this breeding.

The next breeding we will do will be between another blue eyed goat and brown eyed goat, but this time the blue eyed goat will be heterozygous for blue eyes (Bb) instead of homozygous for blue eyes (BB).



So with this breeding you will end up with blue and brown eyed goats,  there is a 50% chance of getting a heterozygous blue eyed goat (Bb) and a 50% chance of getting a homozygous brown eyed goat (bb).

The next breeding will be between a heterozygous blue eyed goat (Bb) and a homozygous blue eyed goat (BB).

All of the kids from this pairing will be blue eyed. Some will be homozygous (BB) while others are heterozygous (Bb). There is a 50% chance of them being either homozygous or heterozygous, but either way 100% will have blue eyes.

The next breeding we will do will be between two blue eyed goats, but they are bother heterozygous for blue (Bb). This is the breeding that confuses the most people when they first start breeding goats and are trying to predict the eye color of the future kids. But once you understand the genetics behind it you will no longer find it confusing.

So with this breeding most people expect they will end up with all blue eyed kids since they have been told that blue eyes is dominant in goats, and if they are breeding two blue eyed goats then they assume the only color eyes the kids of this breeding could have is blue. What you have to remember though is that when you look at a goat's eyes, you are only seeing their phenotype for that eye color, not the underlying genotype. So with this breeding you have a 75% chance of getting blue eyed kids (BB or Bb) and a 25% chance of getting brown eyed kids (bb).

The other thing to remember is these odds are for each kid born, not for the whole litter, so you could breed 2 heterozygous blue eyed goats and end up with a litter of 3-4 brown eyed kids. The reason is for each kid born there is a 25% chance of getting a brown eyed kid, not a 25% chance of a brown eyed kid in the whole litter. Just like there is a 50/50 chance of getting either a male or female kid with each breeding but we have all had either buck or doe heavy years, so you can see how the statistics don't always add up exactly like we think they should.

If you want to try and determine if you have a homozygous blue eyed goat (BB), a goat that will give you blue eyed kids every single time, no matter what you breed him or her to, you can try to determine that by doing some test breedings.  The first thing to remember is the goat must have come from blue eyed parents, you could never have a homozygous blue eyed goat out of a brown eyed parent. The next step in determining if you have a homozygous blue is to do several breedings to both blue and brown eyed goats. If 100% of the resulting kids (from every breeding you ever test) are blue eyed, then there is a good chance you have a homozygous blue eyed goat.  

This is all very interesting to me, I love studying genetics and trying to predict what will result with different breedings. But I do want to remind you that the eye color of the goat doesn't put milk in the pail and it should not be the focus of your breeding program if you are striving to improve the breed. 

I hope this post has been helpful and hopefully not too confusing. Please let me know what you think and if you have any questions.





So tell me, what color eyes does this girl have?

What do you think her phenotype and genotype are?

Goat Biosecurity Testing

Biosecurity testing is something we take very seriously on our farm. In this post I will share with you the supplies you need to test your herd, how to draw the blood and the diseases I test for and would recommend anyone with goats also test for.

To get started you will need to decide whether you will do the blood draws and send off the samples yourself or if you will have your veterinarian do them.  Some labs will allow you to send in your own samples, others will require they be sent in by a veterinarian. There are pros and cons to both. Pulling the blood and sending the labs off yourself will potentially save you a little money. On the down side, you will be limited to the labs you can use, you will need to learn to draw blood and you will need to acquire your supplies.

I have included a short video in this post of me drawing blood from several of our goats for testing. Please excuse the video movement and such, my 5yr old was the only videographer I could afford, I pay him in chocolate chip cookies 😅.

Supplies:

The following is a list of supplies you will need if you want to draw the blood yourself for testing:

• Clean needle & syringe for each goat.
• 3ml syringe with a 22g needle
• Red rubber or Tiger top blood tubes
• AKA: Serum Separator Tubes
• Alcohol
• Either in a spray bottle or cotton balls soaked in alcohol
• Laboratory Paperwork
• Goat Registration Papers
• Shipping container
• Check with your lab to be sure there are no special instructions
• Bubble wrap the tubes so they don't get broken in transit
• Place tubes in sealable bag in case they do get busted your lab work won't be ruined

Drawing the Blood:

The first step is to have someone properly secure your goat. Have them hold them steady and raise their head up, you don't want them to stretch them too high though or it becomes difficult to feel the vessels. You will spray or wipe the area over the jugular with alcohol. I like to use a spray bottle over an alcohol soaked cotton ball; less things for the other goats to try to pick up and eat or carry off.  Then you will need to place pressure on the vessels to hold them off, like a tourniquet does when you give blood. You will do this at the thoracic inlet, on each side of the trachea. I included a photo in the very beginning of the video to show you how and where to apply your pressure. As soon as you apply pressure, if your doing it correctly and the head is not stretched too high you should see both of the jugular vessels pop on each side of the trachea. Depending on if you are right or left handed one side will be easier than the other. I prefer the right side as I am right handed. You will then use a new needle and syringe, for each goat, to draw the blood. Once you have drawn the blood you need to place it in a red top or serum separator tube labeled for that respective goat.

Testing:

I usually send off for the following tests:

Caprine Arthritis Encephalitis (CAE) Virus

Caseous Lymphadenitis

Johne's disease

Brucellosis

However at the time of this posting the Johne's test is not available, the test itself is on some kind of back order. Also, if you want to test for Brucellosis you will have to have your veterinarian pull and send off your tests.

I will write a follow up post to go over the different diseases I test for and why.

If you have any questions please don't hesitate to send me an email or find me on Facebook and send me a message. If you enjoy my blog posts please let me know. If there is anything you would like me to make a post on please let me know

Top 10 Essential Oils for Dogs

Whether you're just getting started in using Essential Oils or have been a long time user, this list is for you!

These are the top 10 oils to have on hand if you have dogs and want to incorporate the use of essential oils in their lives. 

Top 10 Essential Oils for Dogs

#10 Lemon

Lemon is a great oil to help detoxify. You can add it to your dog's drinking water to help detoxify the internal organs (liver, kidneys & colon). Don't add lemon to the water if you have cats in your home that will be drinking from the same dish.  Lemon can also be applied topically but should be diluted well and you must remember that lemon is a photosensitive oil so you don't want to apply this oil and then let your pet be outdoors in the sun. Lemon is also great to diffuse, again no kitties, because it is wonderful for improving mood and energy and will help detoxify the air.  Lemon is also great for the skin, especially greasy/seborrheic coats.

#9 Massage Blend

This is a great blend to have on hand if you have senior pets! But its not just for seniors, it is great for dogs of all ages.  It is great for promoting healthy circulation and promotes relaxation. This oil blend provides instant relief for the occasional discomfort of tired, sore and worn down muscles and joints.

#8 Roman Chamomile

This is a great oil to use on the skin, it is soothing and calming. I use it for itchy skin, rashes, dry skin, etc. It is a very calming oil, both mind and body. It is a vey gentle oil, it is safe to use on your dogs and cats.  This oil is interchangeable with lavender or can be used in conjunction with it.

#7 Myrhh

Myrrh is a very cleansing oil. It is great to use over incision sites to speed up healing.  It is also a great oil for any oral concerns.  This is also a great oil for rescued dogs, dogs of neglect, for balancing emotions. You should take care when using this oil in your diffusers as it is a very sticky/thick oil (as it is made from  the resin) and it can clog your diffusers if you don't rinse them well after use. This oil is great to use in any blends you make for the skin because it is very soothing and because of its bitter taste; it will deter most dogs from licking the oils off.

#6 Grounding Blend

This is a great blend to improve focus, during training for example. Use this oil as your first oil when layering oils. Use this oil along the spine, at the base of the head and over the sacrum to help bring your dog back to homeostasis. Use this oil on the reflexology points of the paws. It is great for relaxation, calming and focus. You can use it in conjunction with or in place of lavender for relaxation/calming qualities.

#5 Protective Blend

This is one of my absolute favorite blends! It has antioxidants and is wonderful for immune support. Use this oil any time your dog may face threats to their immune system. When you know your dog will be facing environmental threats apply this oil prior, during and after when possible. An example would be going to the dog park or the grooming/boarding facility.

#4 Digestive Blend

This blend is great for all things digestive! If your pet is having any kind of digestive upset this is your go to oil! Apply to the abdomen every 2 hours during a car trip if your pet has trouble with car sickness. It is great for gas/bloating, abdominal discomfort, nausea, diarrhea, etc.

#3 Helichrysum

This oil is amazing for bleeding conditions. If your pet gets a minor cut apply this oil immediately. It is great to have in your emergency first aid kit. It is great even after a trauma has occurred, apply it to incisions after surgery or to bruises after minor traumas. It helps maintain cellular vitality. It is a wonderful oil to use on the skin and it great for the metabolism.

#2 Lavender

Probably the most well known essential oil and for good reasons, this oil is probably one of the most versatile oils you can have in your toolbox. It is wonderful for calming the mood. Diffuse during storms or for dogs that don't like to be alone. Apply to the spine, paws or diffuse prior to any event that could cause anxious feelings. This is a great oil to use when introducing a new pet to the home, or for going to the vet, there are so many scenarios that lavender can help both you and your pet!

#1 Frankincense

Known as the King of Oils and for good reason. This oil is a must have. It promotes Cellular function and DNA integrity, is great for the skin and healing. It induces feelings of peace, relaxation, satisfaction and overall wellness. It helps balance the mood. Use it after surgery to help speed up healing

If you want to learn more about essential oils please don't hesitate to reach out to me!

You can find more information or contact me through my Facebook page.

 

 Remember to always consult your veterinarian and dilute your oils prior to use.

Always Seek veterinary advice if

symptoms persist or get worse at any time.