REPLACEMENTS SHOULD BE HELD TO HIGH STANDARDS


by: Jacob R. Segers, Ph.D.
Department of Animal and Dairy Science, University of Georgia


As autumn makes its debut across the Empire State of the South, many spring-calving operations have been, or are in the process of, weaning; and in a few months, producers will be sorting through females and deciding which ladies get a job offer and which get shown the door. We have all read articles and heard presentations about the selection criteria for good replacement females. Heifers need to be sound, big-bodied, and adequate in their maturity pattern; but when making crucial decisions about the future of your program, there are some things that you should ask yourself before making the final call on who stays and who goes. Let's discuss a few of these questions in greater detail.
Is she a valid replacement?
At weaning time, certain traits need to be considered non-starters. Heifers that are too small, are poor doers, or have skeletal problems should not be considered as viable replacements. Additionally, heifers with disposition problems, rough hair coats, or a history of health problems should also be discriminated against. A final consideration for producers, who employ a creep feeding program for young calves, is to make sure that these females are not depositing excessive amounts of fat into their developing mammary gland. Premature fat development in the udder can lead to decreased milk production and overall shorter reproductive life of the animal.
Is she crazy?
Not only is this sound dating advice, but it should also be a consideration when deciding on replacement females. The average rancher in the U. S. is 58 years old; and by this point in life, most people have a very low tolerance for being chased up fences. Pay attention to the attitude of females when you are working in the pasture, and especially when working calves through the chute. It is not necessary to assign chute scores or record exit speeds, but use your common sense. Every time you work calves and you have one that really acts up, send her to town. Be critical of disposition and maintain a low tolerance for dangerous cattle. Cattle that are too nervous will not only pose a danger to you and your family, but also distract other cattle and make them anxious as well. In short, the best thing you can do for mean cattle is a car ride to the sale barn.
How efficient is this female?
If producers in Georgia have learned anything from years such as 2011 and 2016, it is that cow efficiency is a valuable trait. With drought and army-worm-ravaged forages and cattle prices on the downswing, cattle that make the most of inputs are more valuable than ever. Keeping records, so that you have knowledge of which animals are converting feed to gain with the greatest efficiency, is recommended. Also, develop heifers on an "average" plane of nutrition. Developing heifers alongside steers that are being fed for maximal gain gives you little information about the animal's pasture efficiency and may promote the development of fat as opposed to lean tissue. When selecting a rate of gain for developing heifers, slow and steady wins the race. Most of us have heard the horror about breeding undernourished heifers; but research has also shown that pushing females too hard in terms of post-weaning nutrition can have negative effects on reproduction as well. British-type heifers need to gain about 1 pound per day from weaning to breeding, while more growth-oriented cattle may reach average daily gains of approximately 1.5 pounds. If your operation focuses on registered cattle, don't forget to examine those EPDs. Most breed associations have developed some metric to give producers an idea of an animal's genetic potential for efficiency.
Is she reproductively sound?
Require all heifers to pass a reproductive evaluation as yearlings. While the final test will not be until a heifer actually has her first calf and breeds back, there are some things that should be evaluated beforehand to avoid feeding a non-breeder until preg check day. Cull any females that are not cycling at one year of age. Additionally, have a qualified veterinarian check for abnormal reproductive tracts and small pelvic areas, so that any "calving risks" can be culled and sold as feeders before any additional resources are expended on them as breeding heifers. Any heifer that has a reproductive tract maturity score less than 2 or a pelvic area less than 40 cm2 should be considered a calving risk.
Will she calve with my other cows?
Many of the management problems faced by producers can be solved by switching to a controlled calving season. Most nutritional mismanagement that I encounter in Georgia stems from producers having cows at various stages of production, and they want to manage the herd as a single group. It is simply not possible to appropriately manage early lactation cows, dry cows, and calves with the same nutritional program. Thus, any replacement heifers that are predicted to calve outside of your acceptable calving window should be sold as bred heifers.


Fuente: http://cattletoday.com/archive/2016/November/CT3401.php

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