Growing Great Heifers update

Growing Great Heifers - a real time update

Research tells us that better-grown dairy heifer replacements (of breed and bodyweight equivalence) that reach and maintain critical targets will:

• be healthier
• reach puberty sooner
• conceive faster as yearlings and calve more quickly as 2yo's
• produce more milk in their 1^st lactations & over their lifetimes
• get back in calf as 2yo's
• have high survivability to 3yo's and beyond

With the index mob of 90 2008-spring-born heifers enrolled in Totally Vets' Growing GreatHeifers program now approaching the end of their 1^st lactation, how do some of the important numbers stack up?

1.  Liveweight (LWT) for age and rates of average daily gain (ADG) over SIX weigh sessions

• almost 200kg difference in LWT @ 22mo with any effect of breed likely to be minimal in this instance
• overall average daily gain was 0.70kg/day from Apr '09 to May '10
• average LWT were consistently below target for age by about 5%

2.    Milk production and reproduction analysis

Three groups were created based on LWT at 22mo of age (May 2010): top 25%, 50% around median and bottom 25%.

• 3 groups of similar average age, although the bottom group did include the youngest animals
• Average BW & PW significantly lower for the bottom group Top group calved quickest (90% @ 3wks) contributing most DIM (ave 241), submitted quickest for AI (95% @ 21d) and conceived to give best 8.5 wk in-calf rate (71%)
• Highest MT rate occurred in top group (14%)
• Amongst 2yo's, top group has contributed most milk season to date

3.    So what conclusions can we draw?

Heavier heifers showed a 1^st lactation production advantage over their lighter herd mates, equivalent to about 0.5kgMS per kgLWT.

Expect that some of this advantage will carry through to 2^nd and subsequent lactations.

Reproduction advantages of heavier heifer LWT were mixed; faster calving, faster submission and faster in-calf performance were offset by higher MT rate in this instance.

There was a gross financial benefit to heifers being heavier through extra MS and DIM.

The net benefit will almost always be strongly positive ($$$) when full account is taken of production, reproduction and survivability advantages/disadvantages as well as extra feed costs for extra LWT and MS.       

2009 and 2010-born heifers are being weighed and monitored as part of the ongoing programme. Both groups are tracking ahead of the 2008-born group so their respective performances will be anticipated with interest.

Whether for financial motives or purely a sense of pride in knowing that your heifers have the opportunity to express their genetic potential, successful heifer-rearing is part of the process of continuous improvement in farm productivity.

Totally Vets has developed a total heifer-rearing action, advice and support package that includes:

• Estimation of mature LWT of your heifers - either from LW breeding values (BV) or by weighing
  6-8 yo cows
• Weighing service - both heifers and cows
• Management, feeding and husbandry advice
• Specific disease control advice
• Tailored mating strategies
• Reporting

Totally Vets is keen to be involved at any or all of the ‘measure, plan, do, review' stages of Growing Great Heifers. Talk to us today!