UNDERSTANDING the efficiency of cattle in tropical environments is essential for optimising productiveness.
Analysis from the long-gone Beef Cooperative Analysis Centre (CRC) continues to offer useful insights into enhancing beef manufacturing, particularly within the difficult climates of northern Australia.
AA Co composite breeders on the Barkly Tableland
Among the many most impactful research is the work by Barwick et al (2009), titled “Genetics of Heifer Efficiency in ‘Moist’ and ‘Dry’ Seasons and Their Relationships with Steer Efficiency in Two Tropical Beef Genotypes.”
This research investigates the genetic elements affecting cattle efficiency in tropical situations, specializing in Brahman and Tropical composite (TCOMP) breeds, and gives important insights into the genetic traits that affect each heifer and steer efficiency throughout completely different seasons.
The first goal of the venture was to discover how heifer traits, corresponding to liveweight and fats deposition, correlate genetically with steer efficiency traits, together with common every day achieve, feed consumption, and residual feed consumption.
The research encompassed information from 2159 heifers (1027 Brahman and 1132 Tropical Composite), with 54 Brahman and 51 Tropical Composite sires. Heifer traits had been measured after each moist and dry seasons, and steer efficiency was evaluated by means of a feedlot take a look at that spanned roughly 70 days, adopted by a 120-day ending interval.
The research discovered important efficiency variations between Brahman and Tropical Composite heifers over moist and dry seasons. Brahman heifers demonstrated sooner progress in the course of the moist season however slowed within the dry season, whereas Tropical Composites maintained extra constant progress throughout each seasons.
Brahman heifers additionally exhibited higher physique fats and better insulin-like progress factor-I (IGF-I) ranges in comparison with their Tropical Composite counterparts, traits possible tied to Brahman’s longer adaptation to tropical climates, which favour resilience in warmth and restricted feed availability throughout dry intervals.
The research estimated heritabilities for key traits between 20pc and 60pc throughout each genotypes. Nonetheless, Brahman cattle typically exhibited decrease genetic variances and correlations.
This means that whereas Brahmans are well-adapted to tropical situations, their genetic variability for enchancment in sure traits could also be extra restricted in comparison with Tropical Composites. Nonetheless, there may be room for genetic enchancment by means of focused choice, notably in feed effectivity and progress.
Excessive genetic correlations between traits in each moist and dry seasons had been discovered, suggesting that animals performing nicely in a single season are likely to carry out equally within the different.
Nonetheless genetic correlations between heifer and steer efficiency traits had been typically decrease, notably in Brahman cattle. As an illustration, the correlation between ADG in heifers and steers was low, indicating that the genetic elements influencing progress and effectivity could differ between the sexes.
It was additionally notable that there was a moderate-to-high genetic correlation between steer RFI and muscle space in Brahman heifers. This means that choosing for feed effectivity in Brahman steers might additionally improve muscle progress in heifers.
For Tropical Composites, constructive correlations between fats and muscle traits point out that choosing for elevated muscle mass wouldn’t negatively influence fats deposition, a fascinating attribute for sustaining meat high quality. These findings spotlight the significance of balancing feed effectivity, progress, and meat high quality traits when designing breeding applications.
Further Insights
The research noticed that genetic correlations between traits declined as environmental situations grew to become extra divergent. This means that sure traits, corresponding to progress and physique situation, are extra delicate to environmental modifications, notably in tropical climates, the place the moist and dry seasons current vastly completely different challenges.
Fats and Muscle Correlations
In Tropical Composite cattle, the research discovered that fats and muscle measures had been positively correlated. Which means that choosing for elevated muscle wouldn’t negatively have an effect on fats deposition, an necessary issue for meat high quality. Nonetheless, the alternative was true for Brahman cattle, the place a destructive correlation between fats and muscle means that choosing for one trait might cut back the opposite. This discovering is important for breeders trying to stability meat yield and high quality, particularly in markets the place each attributes are valued.
Residual Feed Consumption (RFI) in Brahman Heifers
The moderate-to-high genetic correlation between RFI in steers and muscle space in Brahman heifers signifies that choosing for improved feed effectivity in Brahman cattle could concurrently improve muscle progress. This twin profit is especially interesting for producers aiming to enhance each feed effectivity and carcass high quality of their herds.
Sensible implications for beef producers
This research supplies useful insights for beef producers, notably these in tropical environments. The findings recommend a number of sensible issues for breeding applications:
- Brahman Cattle: Whereas well-adapted to tropical climates, Brahman cattle could profit from extra focused choice efforts to enhance progress charges and feed effectivity in the course of the dry season with out sacrificing adaptability to warmth and sparse forage situations.
- Tropical Composites: The constructive correlations between fats and muscle traits make Tropical Composites an interesting possibility for sustaining each meat high quality and yield.
- Intercourse-Particular Choice: The low genetic correlations between heifer and steer traits, particularly in Brahman cattle, recommend that breeding methods ought to contemplate the differing roles of heifers and steers. Optimising choice standards for every intercourse might enhance general herd efficiency.
- Seasonal Consistency: The excessive genetic correlations between corresponding traits in moist and dry seasons point out that animals performing nicely in a single season are prone to carry out equally within the different, simplifying choice processes for year-round efficiency.
General, the research continues to assist more moderen analysis in addition to offering helpful insights for breeders to enhance cattle efficiency in tropical environments by means of focused choice, enhancing each productiveness and adaptableness in difficult climates.
Alastair Rayner is the Common Supervisor of Extension & Operations with Cibo Labs and Principal of RaynerAg. Alastair has over 28 years’ expertise advising beef producers & grasiers throughout Australia. He may be contacted right here or by means of his web site www.raynerag.com.au
Trending Merchandise
