Production

Crossbreds show production advantage under NT conditions

Jon Condon, August 31, 2012

Researcher Tim Schatz addresses the Kidman Springs field day audience A study comparing tropically adapted Taurus crossbreds versus straightbred Brahman calves in the NT’s Victoria River District has produced significant weightgain and other production advantages in favour of crossbred calves, under recent seasonal conditions.

A project summary was presented by researcher Tim Schatz, principal pastoral production officer with the NT’s Department of Resources, as part of the Kidman Springs field day held earlier this month.

The much-anticipated field day provided an opportunity for cattlemen and women from across the north to catch up on latest research being conducted by the NT Government’s Pastoral Production team. Almost 80 people attended, participating in an array of activities including interactive learning forums, Q&As and ‘in-the-paddock’ discussions.

The biennial Kidman Springs field day provides an excellent opportunity for beef producers to obtain first-hand research insights that can be applied on-property, as well as to access and share local knowledge.

Readers can view a short video summarising the main topics covered at the field day here.  

In the past, attempts have been made to crossbreed Brahmans with British breed Bos taurus bulls like Angus, Hereford with Brahman cows in the tropical north, but the bulls have often struggled to survive and produce calves.

Tropically-adapted taurus breeds like Tuli, Belmont Red and Senepol are better suited to harsher environments and may have more application as herd bulls in crossbreeding programs in northern Australia.

The NT’s DoR has carried out crossbreeding research with a number of breeds over the years, including Charolais, Tuli, Belmont Red and composites, however it is currently focussing on a major crossbreeding project using Senepols.

The aim is to investigate whether crossbreeding Senepol bulls and typical NT Brahman cows will produce offspring that perform well under NT conditions and have better meat quality than straightbred Brahmans. If this is the case, then the strategy would increase the marketing options for NT cattle producers, delivering cattle that would be in demand in both the live export and Australian processing markets.

The option has heightened relevance under the current market environment where the region’s live exports to Indonesia are greatly restricted.  

The Senepol breed, under natural selection in its Caribbean region of origin, is a tropically adapted Bos Taurus with good meat quality characteristics, which is also naturally polled.

The NT Senepol crossbreeding project has been underway since 2008 when Senepol Bulls were mated to Brahman cows for the first time in herds at the Victoria River Research Station and Manbulloo, outside Katherine. The first year group of calves was weaned in 2010 and the last year group will be weaned in 2013 (the last 2011/12 wet season was the last time the Senepol bulls will be used).

The project is still quite a way from completion but results so far include:

 

Weaning weight

In each year the average weight of the F1 Senepol cross first round weaners was heavier than the Brahman weaners. At VRRS the F1 Senepol cross calves averaged 23kg heavier than Brahman calves over three years (See Table 1). At Manbulloo, the F1 Senepol cross calves averaged 19kg heavier than Brahmans over two years (Table 2).

 

Post weaning performance of heifers

Each year shortly after weaning, the heifers born at Manbulloo were transported to VRRS and run as a mob with the VRRS-born heifers. From that point onwards, each year group of heifers were managed together.

The raw data shows that on average the 2010-weaned F1 Senepol x Brahman heifers were heavier at weaning (184kg vs 166kg), grew more over the post-weaning dry season, run on native pasture  (14kg vs 6kg), and grew slightly more over the following wet season (104kg vs 100 kg). By the time that the pre-joining weight was recorded in September 2011, the F1 Senepol heifers averaged 31kg heavier than the Brahmans, and their resultant pregnancy rates were 10pc higher (94pc vs 84pc). 

Among the 2011-weaned heifers, the F1 Senepol crosses that were bred on VRRS were on average 22kg heavier at weaning, and on average grew 5kg more than their Brahman counterparts over the following 2011 dry season. More heifers were added later (some of which were from Manbulloo and some were weaned during the second-round muster in September), and so it was possible to calculate growth rates over the 2011/12 wet season for a greater number of animals.

During this period, on average the F1 Senepol cross heifers grew 15kg more than the Brahman heifers (117kg vs 102kg). As a result on average the F1 Senepol cross heifers are about 45kg heavier a year after weaning than the Brahmans.

 

Post weaning performance of males

Each year the first round male weaners from VRRS and Manbulloo were transported to the Douglas Daly Research Farm near Adelaide River shortly after weaning where they grazed improved buffel pasture for a year.

They run together in the same paddocks, being part of a cell grazing mob that was rotated around paddocks, and were weighed periodically. Their post weaning performance was recorded and is presented below. 

The average liveweight gain of steers weaned in 2010 and run on improved pasture at DDRF showed the F1 Senepol cross steers were heavier at the start (+25kg) and grew slightly more over the post weaning year (+7kg). As a result at the end of the post weaning year they were on average 32kg heavier (using un-fasted weights) than their Brahman steer cohorts. Fat depth at the P8 site was measured using ultrasound at the end of the trial period and the average fat depths were similar (3.3mm for the F1 Senepol crosses and 3.7mm for the Brahmans).

The 2011 weaned steers were managed in the same way as those weaned in 2010. The main difference was that the cattle were kept longer than usual due to the live export situation.

The F1 Senepol cross 2011 steers were heavier at the start (+17 kg) and grew more over the post weaning year (+15 kg) on improved pasture at DDRF. As a result at the end of the post-weaning year they averaged 31kg heavier (using un-fasted weights recorded in May this year) than the Brahman steers grazing alongside them. Fat depth at the end of the trial period showedP8 depths were lower for the F1 Senepol cross steers (2.9mm) than the Brahmans (4.3 mm).

 

Incidence of polledness in progeny

At the start of the project the current thinking was that all the F1 progeny should be polled. The trial has shown that not to be the case, however the majority of animals are polled or scurred. Only a very small percentage (less than 5pc) grew horns and the rest had scurs that grew no longer than 5cm.

 

Calf siring ability of bulls

The common experience of cattle producers in northern parts of the NT in the past has been that that Bos taurus bulls have struggled with the conditions and have not performed well in producing calves.

The experience under this project was that when the Senepol bulls were introduced to paddocks in which Brahman bulls were already established, they appeared to be out-competed by the Brahman bulls. Often about two-thirds of the calves were sired by Brahmans.

However when the Senepols were the only bulls in the paddock, they sired plenty of calves and weaning rates were normal.

 

Coat colour

Most of the crossbred progeny ranged from dark red to yellow but a few were black or creamy and about 11pc of the 2012 weaned males were brindle.

 

Preliminary observations/conclusions:

  • The F1 Senepol cross calves were heavier at weaning than the Brahmans. This is a typical result when crossbreds are compared to purebreds due to hybrid vigour.
  • The F1 Senepol cross heifers appeared to grow more than Brahman heifers following weaning and so this, combined with their heavier weaning weights, means they are heavier at joining. Pregnancy rates were 10pc higher in the F1 Senepol-cross heifers in the one year group that there is data for so far. However the number of heifers in that first year group is low (only 33), so while the data can give an indication of performance, it should not yet be relied on to draw solid conclusions.
  • The performance of both year groups of steers (2010 and 2011 weaned) grazing improved pasture at DDRF over the post-weaning year showed that the F1 Senepol crosses grew slightly better than Brahmans (+7 kg and +15 kg in 2010 and 2011 weaned steers respectively). This combined with their heavier weaning weights resulted in them being considerably heavier (about 30kg) at the end of the year after weaning.

The project’s preliminary results indicate that the F1 Senepol cross progeny are performing better than Brahmans in these conditions.

The main reason for breeding these crossbred animals was to produce animals that have superior meat quality attributes than pure Bos indicus animals, and hence increase the marketing options for producers.

As the calves are 50pc Bos taurus they should grade better when chiller assessed or MSA assessed in Australian meatworks, making them more marketable in Australian domestic and export markets.

The fact that F1 Senepol crossbred offspring appear to perform at least as well as Brahmans in northern environments is important for northern producers considering crossbreeding, the summary concluded.

 

 

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