Weighing can be used to make selection/ culling decisions on unrecorded herds.The regular weighing of live animals is vital to increased productivity and farm profitability. Well informed management decisions come from animal weight data that is easily obtained and accurate.
Prepare a pre-numbered check list which has a space beside each animal’s number on which the weight can be recorded. Such check lists can either be produced by the computer used for the recording system, or you can buy a standard, ready printed list, or you can make your own.
Check lists help to prevent duplications. They instantly reveal if a weight has already been entered against an animal which has just had its tag read. You can then double check the number of the animal being held and if it is correct, then the previous one must be wrong. A computer generated list which is an accurate record of the mob being weighed will provide a means of sorting out duplications at the end of the session.
Electronic scales offer two main benefits to recording:
1. Pre-programming of the scales; which automatically carries out checks and calculations otherwise done manually.
2. Entering the animal’s weight directly into a computer or the scale memory; which eliminates the need to separately record the weight. This both speeds up weighing and recording, and eliminates potential errors in both reading and writing down weights. Where direct entry to a computer is used then the scale indicator on the computer carries out all the programmed calculations and checks.
However, we believe it is better not to have a computer in the yards, and instead to use electronic scales with a separate scale indicator which has reasonable data storage capacity and its own keyboard for entering tag numbers. When a weighing session is complete you can then upload the information into a computer at your leisure — away from the yards.
When these scale indicators are disconnected from the load cells they can be used independently as data loggers for recording information in the paddock and as electronic calculators.
A file containing tag numbers of animals expected to be weighed can be entered into the memory of the scales. Some models will have the facility for this information to be directly entered from a computer.
When the weigher keys in the tag number the program will validate the identity of animal. It will immediately show double ups, and animals not on the list. At the end of session it will list missing animals. Once identification is confirmed the weigher enters the weight by pressing the Weight key when he/she is satisfied the weight displayed is correct and stabilised.
We strongly recommend you connect a small printer to the scale indicator to provide a separate log of tag numbers and weights. When the data is successfully transferred to a computer this log can be thrown away. But if there are any problems during transfer the log means you have a permanent record from which the data can be re-constructed thus avoiding the hassle of re-weighing.
Electronic identification systems can now be linked to the scale indicator to provide automatic entry of both identification numbers and weights without the need for separate keying in of tag numbers.
Key selection weights
This is primarily a measure of cow performance. The ability to rear a calf to a good weight at weaning is a direct reflection of the cow’s mothering and milking ability. After fertility — the ability to get in calf once a year and give birth to a sound calf — weight of calf weaned is the most important trait on which you should base breeding cow selection. Weaning weights and all subsequent weights.
Yearling and rising two-year-old weight
Weight-for-age is the most important character of the slaughter animal. Once the dam’s influence has been removed at weaning, it is the weaner’s own genetic ability to grow you wish to identify. Adjusted yearling (12 — 15 month) weights and/ or adjusted rising two-year-old (18 — 20 month) weights provide post weaning weight growth data for selection decisions. In New Zealand these adjusted weights have proved better indicators of genetic merit of growth potential than post-weaning average daily weight gains.
Growth rate monitoring is used as a. guide to feed allocation and budgeting decisions and to check on the general progress of the herd. There is no need to weigh every animal in a mob, a random sample of around 10% of the mob will do.
Culling on weight straight off the scales can be done by weighing a random sample of animals and calculating target weights for the mob. The scales are then used to indicate ‘keep’ or ‘cull’ for each animal weighed.
Cow weights are a guide to management and feeding decisions at various times of the year. The important ones are during mid-pregnancy, and pre-calving.
Weighing animals for sale ensures you meet target weights for grades and do not lose money by failing to get animals to the best paying weights.
Weighing cull animals before sale gives a more accurate indication of likely returns than estimating liveweight.
Electronic scales make it feasible to calculate drenching rates on liveweight. This saves on quantities of chemicals used and ensures the animal receives the correct dosage. Weighing also enables you to pick up worm problems before it is obvious to the eye — such as when stock are losing weight at a time you were not expecting them to.