Monday, 29 January 2018 11:55

Production worth is more than just kgMS

Written by  Rachel Bloxham, Animal Evaluation Manager, LIC
A cow's production worth is more than just the milksolids it produces. A cow's production worth is more than just the milksolids it produces.

There's more to production worth (PW) than milk solids, explains Rachel Bloxham, Animal Evaluation Manager, LIC.

I spend a lot of time out onfarm in my job, talking to farmers about their cows, breeding plans and how the economic indices assist in decisionmaking.

I often get asked about production worth, in particular: how can a cow producing 500kgMS have a low PW? The simple answer is there is more to PW than milk solids.  

LIC in 1996 added PW to breeding worth (BW) and lactation worth (LW) -- our three pillars of animal evaluation. 

The PW economic index provides an estimate of the lifetime producing ability of a cow and the efficiency at which she can convert feed into profit. 

A number of factors can influence how much a cow will produce -- how well she has been reared, her age, what she is being fed, and environmental conditions, to name a few.

PW is designed to provide an accurate, objective calculation, to aid farmers’ decisions relating to the culling and purchasing of dairy cows. It includes components associated with genetic merit and permanent environmental factors which will affect a cow’s performance throughout her life, e.g. hybrid vigour (heterosis).

It considers the age of a cow and how she ranks against her peers of the same age. It also weighs up the balance between milk volume, protein and fat data from herd tests. Liveweight, from an efficiency point of view, is also incorporated.

Herdmate comparisons

PW takes an animal’s recorded herd test results for milkfat, protein and volume and compares these to how the rest of her herdmates of the same age and season performed. 

This practice of comparing ‘like’ animals within a herd means that only your animals on your farm are compared against each other, within their identified contemporary groups.  

This is what makes PW about the production of your cows on your farm.

The differences between records for animals in the same contemporary group provide a better indication of an animal’s relative genetic merit than the actual records themselves, and thus removes the effects associated with temporary environmental factors and management.

Milk volume vs protein vs milkfat

Just because an animal appears to be producing well doesn’t necessarily mean she is doing so efficiently or profitably. 

PW does more than review production data; it also considers how much volume is produced and the ratio of milkfat to protein. The animal evaluation system balances the income and costs associated with these three factors.

Two cows could be producing the same amount of milksolids, but under the current economic weightings the animal that is producing more protein will be the more profitable animal and have a higher PW (everything else being equal).

If one of those cows was to produce less volume but the same milk solids she would also have a higher PW as she is more efficient. The cow that produced more volume but the same milk solids will incur more costs to the farmer -- in feed to generate the extra volume and cost at the factory to remove the liquid component.

Currently, the industry’s economic value for protein breeding value is $6.63 and milk fat breeding value is $1.90. 

Emphasis on first three lactations

Finally, in calculating the potential performance of an individual animal, more emphasis is placed on the animal’s first three lactations, which is how age comes into the equation. 

This is because we are trying to predict the lifetime performance of an animal as early on in her life as possible, so that farmers can make decisions on whether they should retain that animal in their herd or not.

Once an animal reaches eight years of age, herd test information stops feeding into the PW calculation. 

Realistically, if she’s still in the herd at this stage then generally she must still be producing well and have proven her right to be in the herd.

More like this

Next generation of DNA testing

Herd improvement co-operative LIC is combining its DNA parentage testing and genomic evaluation services into one convenient service to help farmers identify their highest genetic merit animals.

All in the family

Taking over the chairmanship of LIC feels like a generational responsibility for Tākaka farmer Corrigan Sowman.

Featured

Sheep drench resistance costly

Analysis by Dunedin-based Techion New Zealand shows the cost of undetected drench resistance in sheep has exploded to an estimated $98 million a year.

Dairy sheep and goat turmoil

Dairy sheep and goat farmers are being told to reduce milk supply as processors face a slump in global demand for their products.

Hurry up and slow down!

OPINION: We have good friends from way back who had lived in one of our major cities for many years.

National

Govt urged to reduce ETS units

The Climate Change Commission wants the new Government to reduce NZ Emissions Trading Scheme (ETS) auction volumes as son as…

Dairy sheep, goat woes mount

Dairy sheep and goat farmers are being told to reduce milk supply as processors face a slump in global demand…

Machinery & Products

All-terrain fert spreading mode

Effluent specialists the Samson Group have developed a new double unloading system to help optimise uphill and downhill organic fertiliser…

Can-Am showcases range

Based on industry data collected by the Motor Industry Association, Can-Am is the number one side-by-side manufacturer in New Zealand.

» Latest Print Issues Online

Milking It

Papal visit

OPINION: European farmers are going to extreme lengths to have their message heard.

Thai egg tarts

OPINION: The hustle and bustle of one of Bangkok's most popular fast food outlets may feel a world away from…

» Connect with Dairy News

» eNewsletter

Subscribe to our weekly newsletter