What is a four-event cow?
作者：Chrissy Meyer 亚达遗传公司
She lives on an 1500-cow dairy farm in Wisconsin, where she’s milked three times per day through a double-20 parallel parlor. She’s fed a well-balanced ration, and spends her time resting in sand-bedded freestalls. She is a second lactation cow, sired by 11HO11499 AltaMEGLO, and she’s what we call a 4-event cow.
A 4-event cow?
If you look at any cow card in DairyComp or your herd management program, a 4-event cow has only four major events listed throughout her lactation:
In the case of 8968, this means she had a live calf with no troubles. She had no milk fever, ketosis, or retained placenta. No other metabolic issues slowed her down after calving, and by avoiding those issues, she did not incur treatment costs.
After a 60-day voluntary wait period, 8698 was bred. Since BRED is only listed once on her cow card, we know it took only one unit of semen – just one insemination for her to conceive.
She was later confirmed pregnant, noted as PREG on her cow card. This is only possible because she did not have early embryonic death loss or an abortion, and no other reproductive troubles.
The fourth, and final event of 8968’s lactation shows as DRY on her cow card. This means there were no other lingering issues throughout her lactation. She went about her business as usual, until it was time to be dried off in preparation for her next lactation.
You might wonder what is missing from 8968’s cow card. Of course, maintenance events like pen moves, foot trims, vaccinations, and pregnancy rechecks also occur during a cow’s lactation.
But what’s really missing in a 4-event cow’s lactation are the setbacks – the costly, time-consuming issues that hinder overall herd profitability. A 4-event cow like 8968 does not get mastitis. She doesn’t become lame, and she does not abort her calf midway through the pregnancy. She avoids the sickness, infections and troubles that cause major headaches for every dairy producer.
Can genetics help create a herd of four-event cows?
One of the best ways to create more four-event cows is to select for Productive Life (PL) within your customized genetic plan. Genetic selection for PL doesn’t just mean more old cows. It predicts which cows are toughest, healthiest and easiest to manage.
Including Productive Life in your genetic plan will increase your odds of having a herd full of four-event cows. The actual measure of PL is not calculated until after a cow leaves the herd. However, we can use other ways to see if higher PL bulls actually create healthier and more trouble-free cows.
Table 1 breaks down the events within the herd where cow 8968 lives. It includes all animals with known Holstein sire ID’s. Based only on each animal’s parent average for Productive Life, this shows the real difference in the health events between high PL pedigreed cows and low PL pedigrees.
These are real numbers, recorded on this farm’s herd management software program. Keep in mind, management is consistent throughout the herd, and no preferential treatment is provided for any given cow.
The table clearly shows the high PL cows had fewer issues after calving and throughout their lactation. High PL cows had fewer aborts, were coded as ‘do not breeds’ (DNB) less often, and had fewer cases of DA’s, lameness, mastitis, and RPs. This led to fewer of the high PL cows leaving the herd involuntarily.
Compare those results to 8968. Her sire, AltaMEGLO is a 6.3 for sire PL, which is a big part in her status as a 4-event cow with no issues.
Make more 4-event cows like 8968 创造更多像8968的四事件母牛
Cow 8968 is not only a 4-event cow. She’s a profitable cow. Consider the time and money you save, and peace of mind you gain, with 4-event cows. A herd full of cows like 8968 don’t require costly treatments, and don’t drop in milk production due to those health concerns.
Keep these costs – or savings – in mind as you customize your genetic plan. If healthy, trouble-free cows are your goal, genetic selection for Productive Life will help you create more of those desirable 4-event cows – just like cow 8968.