Calculating Target Daily Gains of Meat Wethers and Replacement Doelings
How much weight must your goat kid gain in a day to reach your desired market weight or breeding weight? I did a little math. Just for fun. I can’t believe I am saying that - I loathed mathematics in school. This isn’t trying to make any serious points about management or growth rates, just a way for me to visualize, to better set goals. I thought this might be helpful for others, too, as the Kinder community often discusses gains!
For this, I had my Kinders in mind. I figure 5lb is an average birthweight. The proposed adult doe weights are based on animals I own and know of to make a small – average – large. It could easily be adjusted for different estimated adult weights, for various birthweights, and for different dates. I highly recommend using the online date calculators found at timeanddate.com!
𝙈𝙚𝙖𝙩 𝙒𝙚𝙩𝙝𝙚𝙧𝙨/𝘽𝙪𝙘𝙠𝙡𝙞𝙣𝙜𝙨 The first calculation is for selling kids directly off the dam at 12 weeks – that is my personal minimum weaning age. Here, the best weanling kid weight at auction is a minimum of 40lb.
Assume a birthweight of 5lb. To hit 40lb in 12 weeks, the kid must gain 35lb. (35 pounds / 84 days = .42 pounds a day) X 7 days = approximately 2.94 pounds in a week. OR .42 pounds a day X 30 days = 12.6 pounds a month.
I often try to hit the December market with spring-born kids. By doing this, I keep numbers and thus costs and hay consumption down. December prices are usually good, though January might be better. This market it is better to have kids that weigh a minimum of 50 pounds. The sale is the third Friday of the month, so the exact date varies. For ease of calculation, I will make the “end date” December 31st.
For example, if I have a freezer-bound meat kid born on March 1st at 5lb that I want to hit 50lb by December 31, he must gain 45lb in 305 days. (45 pounds / 305 days = .15 pounds a day) X 30 days = 4.5 pounds a month.
If I want those same kids to hit the bigger end of that market, which seems to be about 70lb, they would have to gain .21 pounds a day or 6.3 pounds a month.
𝙍𝙚𝙥𝙡𝙖𝙘𝙚𝙢𝙚𝙣𝙩 𝘿𝙤𝙚𝙡𝙞𝙣𝙜𝙨 For breeding purposes, many folks go by weight (at least in part) to determine when to breed doelings. I’ve seen breeding weight minimums anywhere from 60 to 80% of the estimated adult weight. For this, I am using 70%. I should note that I do not go by weight alone, here, though I think it should be a consideration when determining when to breed a doeling.
These are 90lb for ‘small’ – 120lb for ‘average’ – and 140lb for ‘large.’
To find the target breeding weight of these numbers, multiply .7 (this is 70%) by the estimated adult weight. 90lb adult weight X .7 = 63lb 120lb adult weight X .7 = 84lb 140lb adult weight X .7 = 98lb
These are the minimum weights for those doelings will have to hit before they are bred.
Let’s figure the proposed breeding weight and the needed daily gains for a yearling first freshener. Again, I am going to assume a 5lb birthweight and March 1 birthdate. So this hypothetical doeling would be bred at 7 months old to kid at 12 months old.
Using the numbers above, subtract the birthweight from the target weight to calculate in pounds how much the doeling will have to gain by 7 months old. 63lb breeding weight – 5lb birthing weight = 58lb to gain 84lb breeding weight – 5lb birthing weight = 79lb to gain 98lb breeding weight – 5lb birthing weight = 93lb to gain
To figure the daily gain, calculate how many days old the doeling will be at 7 months old – the proposed breeding age. From March 1 to October 1 is 214 days. Divide the number of pounds to gain by the number of days to gain it in. I rounded up to the nearest hundredth place. You can then multiply the pounds per day by 30 to get pounds per month. 58lb / 214 days = .27lb a day or 8.1lb a month 79lb / 214 days = .37lb a day or 11.1b a month 93lb / 214 days = .43 a day or 12.9lb a month
Breeding the doeling to kid at 13 months to kid at 18 months, still assuming a March 1 birthday and a birthweight of 5lb. 13 months = 397 days. 58lb / 397days = .15lb a day or 4.5lb a month 79lb / 397 days = .2lb a day or 6.3lb a month 93lb / 397 days = .23lb a day or 6.9lb a month
Breeding the doeling to kid at 19 months old to kid at 24 months old, still assuming a March 1 birthday and a birthweight of 5lb. 19 months = 579 days. 58lb / 579 days = .1lb daily gain or 3lb a month 79lb / 579 days = .14lb daily gain or 4.2lb a month 93lb / 579 days = .16lb daily gain or 4.8lb a month