Most dairyfarmers now recognise that crossbred cows are healthier, breed back faster and are more profitable due to hybrid vigour. A recently completed study by Jo Coombe at Melbourne University into crossbreeding in Australia clearly shows the economic advantages of crossbreds over Holsteins.
What most dairy farmers may not realise is that hybrid vigour might also be helping the crossbreds be more efficient at converting feed into kilograms of protein and butterfat.
Understandably, there's some scepticism about this from farmers because crossbred dairy cows typically carry more body condition and look less "dairy" than purebred cattle.
In a three-year trial at the University of Minnesota, crossbreds were shown to be more feed efficient and more profitable than their Holstein herdmates.
Dr Brittany Shonka-Martin completed her Ph.D degree in dairy cattle genetics at the University of Minnesota. Her research project used cows from the university campus dairy herd, that has both crossbred and Holstein cows.
All of the crossbreds used were three-way crossbreds using the rotational mating system of Montbeliarde, Viking Red and Holstein. They were compared with the pure Holsteins for feed conversion efficiency, weight, production, body condition and economic difference between the two groups.
The Montbeliarde and Viking Red breeds have both selected for greater fertility than the Holstein and, unlike the Holstein breed, neither breed has selected against body condition. It is now known maintenance of baseline body condition is important for the fertility, health, mobility and survival of cows.
Feed intakes of individual cows are laborious and expensive to collect. For Dr Shonka-Martin's research, 123 first-lactation cows (63 crossbred and 60 Holstein) and 80 second-lactation and third-lactation cows (43 crossbred and 37 Holstein) were compared for dry matter intake, body weight, wither height, body condition score, milk volume, and fat plus protein production over a three-year period. All cows were fed the same total mixed ration twice daily in tie-stalls with partitions in the mangers. Feed samples were collected twice weekly to determine dry matter content. Feed intakes were recorded from days 4 to 150 of lactation. During the same lactational period, body weight, height, and body condition score were recorded for each cow.
Fat plus protein production (kg) wasn't different for the two genetic groups during first lactation or during second and later lactations. However, the crossbred cows had higher percentages of fat and protein in their milk than the Holstein cows . The milk volume, which is mostly water, was lower for the crossbred cows than the Holstein cows. However, despite equal fat plus protein production (kg), the crossbred cows had significantly lower dry matter intake than the Holsteins, and the difference was 141kg less dry matter intake (-4.8 per cent) during the 147-day study period in first lactation and 232kg less dry matter intake (-6.5 per cent) in the second and third lactations.
Feed efficiency is evaluated with alternative measures. Some of them are: Fat plus protein production divided by dry matter intake. Energy-corrected milk divided by dry matter intake. Dry matter intake divided by body weight. Residual feed intake (currently used for genetic evaluation of dairy cattle).
For all four of these measures, the crossbred cows were significantly more feed efficient than the Holstein cows.
Based on this new research, improved feed efficiency can be added to the list of advantages of crossbred cows over Holstein cows.D
*Steve Snowdon is a crossbreeding specialist and breeding adviser with Auzred Xb. Phone 0417 138 508 or email firstname.lastname@example.org.
Article supplied by Auzred XB, website www.auzredxb.com.au.