Yellow Milk?

Sybil has been at our homestead for about a week and she's gradually getting more adventurous in her eating. I've both seen her eating grass in the pasture and noticed it in her milk. 

The fresh milk we get has stayed the same color, but the freeze dried milk has more of a yellow tint. My theory was that the higher nutrients in the pasture were causing the color change. 

I asked Google to make sure:

Why Goat Milk Stays White

• Beta-Carotene Conversion: Fresh pasture grass contains beta-carotene, a yellow-orange pigment. When cows eat grass, this pigment passes into their milk, giving it a golden-yellow hue. [1, 2]
• Vitamin A Metabolism: Goats (like sheep) metabolize beta-carotene much more efficiently. Their bodies convert the pigment into colorless Vitamin A instead of passing the yellow color into the milk. [1, 2, 3]
• Consistent Appearance: Because of this efficient conversion, goat milk remains stark white whether the animals eat stored hay or graze on fresh, green spring pasture. [1]

Hmm, interesting, but doesn't explain the color change. Maybe because ours is freeze dried? 

"While a goat's body normally prevents fresh milk from turning yellow, the process of freeze-drying changes the rules entirely. When you alter your goat's feed, you alter the concentration of certain nutrients and fats that freeze-drying exposes to plain view.

Diet Shifts Overwhelm the "Vitamin A Switch"- A rapid shift to a much richer feed (such as lush green grass, clover, or fresh alfalfa high in carotenoids) can temporarily disrupt the goat's high-efficiency conversion of beta-carotene into colorless Vitamin A. When this happens, trace amounts of yellow carotenoids slip past the liver and bind to the milk fat globules. While you won't see this in the liquid milk, the dehydration process concentrates these fats, making the yellow hue visible in powder form." 

It also said the color could be from higher riboflavin levels, changes in fat globule size, or a higher lactose (milk sugar) level (causing a faint Maillard reaction -caramelization between milk sugars and proteins). 

Fascinating!

Her milk production has dramatically dropped. Friday morning she produced half what she started at when we got her. Apparently this shift happens for the first 1-2 weeks in a new place. We just gotta hang in there and ride it out. 

If she does end up drying out, I don't think either G or I will be terribly sad about it. Dealing with all the milk has been challenging. Even so, I would probably feel a bit of failure that we couldn't acclimate her well enough to keep milk going. The environment change she's adjusting to is pretty massive, so it wouldn't surprise me. 

We do want the lamancha genetics in our herd, so we plan to keep her around long enough to breed/kid, even if we don't keep her specifically long-term.