Out-of-Season Breeding: Using Artificial Lighting
Unlike cow dairy farmers, who can have their cows serviced year-round, commercial goat milk producers face the traditional winter slump in milk output due to the seasonality of the doe's reproductive cycle. Even spreading the spring kiddings out as much as possible and holding heavy producers over, perhaps breeding them every other year, does not yield an acceptably even output and results in late-born kids that can't be bred that year, as well as a longer period of all the extra work of raising kids. By using the simple techniques below for inducing some of the does to cycle in the spring, the farmer can even out both the milk supply and the work load.
The goat's breeding hormone production is triggered by a decrease in day length, with cool nights playing a secondary role. Even though the temperatures generally soar in July and August (northern hemisphere, of course!), after the summer solstice in June the days are becoming shorter. On the average it takes about two months before the doe's hormonal apparatus kicks into gear and she comes into heat. Bucks are similarly affected, but tend to show this less -- most of them can be enticed to mount a doe in heat no matter what time of year; more on that later. Artificial lighting, or rather, the lack thereof, simulates the summer solstice and following shortened days. Once this principle is understood, it takes only a little planning to achieve fall freshenings.
To set up a fall kidding schedule it helps to work backwards. Let's say we are aiming for September/October; counting back five months brings us to April/ May for the breeding dates; counting back another two months gives us a "solstice" date of February. That is when the lights need to be shut off. Two months of extra light is generally considered sufficient, so we need to turn them on in December.
The lighting does not have to be an elaborate affair. I use clamp lights (the kind with the wire cage around it), clamp them to a beam (you can put a couple of nails into the clamp part and bend them over for added security), and plug them into a heavy-duty extension cord (outdoor type), which in turn is plugged into a timer that goes into the outlet. The timer should handle 24 hours and be able to be set for two separate periods (morning and night). Be sure none of the cords are accessible to inquisitive goat teeth!
The amount of light and the number of extra lamps depend on the size of the goats' pen and how high above the floor the lights will be. Rule of thumb for horses (their reproductive system works the opposite way, and lights are used with race horses to have foals born earlier in the year) is one 200W bulb (or energy-efficient equivalent) per 10x10 stall, 8-10 ft. high. My 9x18 pen has two 100W lights for day-to-day chores, and I add another 150W flood light and then put all three on the timer. The lights are a little less than 7 feet above the floor. Similarly, one of the doeling pens (approximately 5x8) can be set up with one 150W flood on a timer, and this arrangement has worked well, especially when there were late-born kids (they ended up being bred at 10-12 months, with nice size but not yet "fat yearlings").
Setting the timer is also quite simple. You need a total of 17 to 18 hours of light a day for two months. Obviously, there is no need to waste electricity during normal daylight, though I found an overlap of an hour beneficial. Starting between December 1 and 15, I set the timer to turn the lights on at 4 a.m. and to go off at 8:30 a.m., then on again at 4 p.m. and off at 10 p.m. (mind you, I'm in the Northeast US, so your times may vary). There is no need for a gradual lengthening. After two months, I go back to normal chore-time-only lights and sit back and wait for the heats (while delivering spring kids!).
Some time in April the does will start to cycle. Occasionally, esp. among Nubians, a doe will do so without lights as well.
However, careful observation is needed, because the heats tend to be shorter and less obvious. Most will only go through two or three noticeable cycles, and some might not show signs at all. Occasionally, a doe that kidded early will also cycle, so running the buck with the herd is not a good idea, unless separate facilities are available. Personally, I prefer to know when the does were bred more than I want to save what little extra time it takes to watch. I'll save that much more time and worrying at kidding!
One caveat: there is less chance of late December or January heats, so spring kidders should have been bred by the time you turn on the lights.
What little there has been written about the artificial lighting process, also indicates that bucks need the same treatment. Out of necessity -- my buck pen has no electricity -- the "boys" knew nothing about all this until I presented them with a doe in April. After a few quizzical looks, the "lucky one" went about his duty, albeit a bit more slowly -- with the first one. After that it was business as usual. Whether the results (below) were influenced by the "lightless" bucks, I don't know. (It's been suggested that the sperm carrying the X-chromosome, for the female offspring, is less motile but more viable, hence the "breed-early-in-the-heat-and-get-more-does-theory.")
The results are well-worth the effort. The watchful herdsperson should achieve the same rate of conception as during fall breeding. In my experience, the does had a slightly lower average number of kids per kidding, but tended to have more does. Without the summer heat stress, the milkers remained near peak longer and decreased production a bit more slowly, and the kids grew very well, perhaps better than in the spring.
As for myself, with the overall work load spread out throughout the year, I didn't become murderous by June because of too many sleepless nights waiting for goats to kid!
This article was originally published in HomeSteader's Connection, November/December 1993, and reprinted in The Best of HC 1994. It may not be reproduced in any format, electronic, print or otherwise, without the express written permission of the author. Copyright © 1993/1994/1998/2006 Brigitte M. Botnick. All rights reserved.