3 min read
Heifer growth, best measured by liveweight, is a vital aspect of dairy farming. Consistent weigh-ins, ideally every 4-8 weeks, help monitor growth and spot issues early on. Particularly in young heifers, monthly weigh-ins can be beneficial as they grow rapidly. Following a set process during weigh-ins, taking into account factors like time since feeding and changes in diet, ensures accuracy. The aim is for heifers to double their weight in their first 3 months and then again in the next 7 months. Regular observation and weight monitoring help identify poor performance symptoms. Weight data serves different purposes, including tracking individual and mob growth rates.
Heifer growth should be measured by liveweight, the only objective measure of dairy heifer performance. Weight performance is also useful to inform working relationships between stock owners and the heifer grazier.
Weighing systems and weigh scales are essential for heifer management. Good practice for weighing is every 4-8 weeks, a minimum of every 12 weeks.
Younger heifers can benefit from monthly weighings because the necessary growth rates are a higher percentage of body weight at a young age. If heifers fall behind weight early it can be difficult to get them back on track. To achieve target weights heifers should double their weight in the first 3 months of life and double it again over the next 7 months.
Grazing contracts should stipulate weighing expectations, reporting and actions for underweight animals.
Ideally every weighing event should be approached with a similar process. There is not a prescribed method for weighing but these key aspects should be consistent:
Weight variation can be influenced by “Gut Fill” which can account for up to 22% of a heifer’s liveweight.
Factors that influence gut fill:
Heifers grazed on forages have heavier rumen contents than animals with concentrates (e.g. grain or meal) in the diet. Gut fill can decline by 40% over 12 hours and 60% after 24 hours after being off feed.
There are two ways to identify animal performance: visually and through weight. Visual assessments should never replace weighing. Both methods have value, heifers can be weighed on a monthly to three monthly basis and should also be observed daily to multiple times a week. Visual observation may detect issues between weighings.
Separated from the mob
Lameness Physical Injury
Coughing /Laboured Breathing
Excessive nasal mucus
Scouring Cold / Drooping ears Poor condition score
Lethargic Abnormal behaviour
Uneasy / Restless
|Scouring Wheezing / Coughing|
* Please note there may be other symptoms not identified in the list.
There are four different uses for weight data:
Possible causes for many animals being behind target weights:
A 'tail end' in a mob of heifers is a situation where there is a greater than expected (10-30%) number of animals lighter than targeted weight range.
If a group of heifers has a tail end, then assess whether the group should be preferentially treated or if the corrective action will be applied to the whole mob.
Possible causes for a tail end:
When assessing individual heifer performance (less than 10% of the mob) it is important to judge the individuals by:
Birth date and weaning policy can increase the range of liveweights in a mob. Late born heifers may need heavier weaning weights or priority care to meet mob liveweight targets.
Poor performing individuals are easily identified with multiple weighing events, lesser liveweight or growth rate compared to the mob. Poor performing individuals may also show signs of illness or injury.