By Frans Jordaan and Dr Ben Greyling (ARC-Animal Production, Irene)
For commercial producers, the goal is to create the ideal weaner for the feedlot and to satisfy market demand by producing more with fewer resources, thereby improving the efficiency of beef production.
Cow productivity is usually associated with the frame size of a cow. Bigger cows tend to produce larger calves at birth, as well as heavier calves at weaning, which is related to a higher or better price per kilogram paid by feedlots. However, is bigger always the more profitable option in a wean calf production system? Certainly, other factors that can play an important role should also be considered.
The input costs versus output should form the basis when considering a calf production system aimed at the feedlot market. Heavier animals are typically associated with a larger frame, as mentioned, which results in increased maintenance requirements due to higher milk production, greater visceral organ weight, and a higher need for feed supply to sustain high production.
These animals are typically higher in body lean weight and lower in body fat compared to smaller-framed animals, which are associated with lower maintenance requirements and lower milk production. Small-framed animals have lower visceral organ weight, lower body lean mass, and higher body fat mass. These animals require a lower feed supply than their bigger frame counterparts.
Smaller-framed animals will typically reach maturity at an earlier stage in life than larger-framed breeds. This is typical of the two extreme frame sizes, which are usually breed-specific; however, animals within the same breed can also differ significantly in frame size, indicating a need for balance and identifying an adapted, optimum animal based on a specific production environment and market requirements.
Breeding objectives to improve the efficiency of beef production
It is essential to maintain or increase production per unit (calf growth and/or milk production of the cow) to enable commercial beef producers to ensure the sustainability of their enterprises or achieve increased profitability. Due to the significant role of the cow-calf phase in beef production, it is logical to focus on this phase to enhance production efficiency. Sixty to seventy percent of the cost of producing beef is due to feeding costs, and the solution should be to look more closely at the bull and cow for feed efficiency.
Feed efficiency
According to the literature, the genetic variation for maintenance, linked to energy requirements, is moderate to high, highlighting the value of genetic selection in improving feed efficiency. All stakeholders in South Africa currently apply relevant research. Young bulls are tested in centralized bull testing centres of the Agricultural Research Council to identify the most effective young bulls at converting feed into meat.
Feed conversion ratio
Feed conversion ratio has long been regarded as an indicator of feed efficiency, representing the amount of feed required by an animal to gain one kilogram of live weight. This ratio, unfortunately, does not serve as an ideal trait for selection purposes due to the combination of two traits, such as feed intake and growth. If used as a selection criterion, the outcome will always be selection for growth as well as an increase in body weight and/or frame size.
Residual feed intake
When testing animals for residual feed intake, these two traits can be scientifically separated, allowing for the identification of the most efficient animals in relation to feed intake independently of growth. It makes sense to select for superior bulls due to the big genetic influence of the bull in a cow herd.
Also, keep in mind that if the female progeny of these bulls are kept as replacement heifers, genetic improvement can then be established within the herd by improving the feed efficiency of the cowherd, and therefore the efficiency of beef production for a specific environment.
Cow weight
Cow weight, as an indicator of cow size and the pace of calf growth, is a crucial factor for commercial breeders to consider, ensuring the efficiency of their production system. Hence, the importance of also weighing your cows at weaning.
Cow efficiency
Numerous methods have been investigated in the past to evaluate cow efficiency. A kilogram of calf weaned per cow exposed is a combination of the production and fertility of the cow to produce. Another option is a kilogram of calf weaned per cow exposed per kilogram of cow weight, which is the well-known cow-calf ratio used by farmers to evaluate their cows. The benchmark is usually a cow that can wean at least 50% of her weight, but this will only benefit the smaller cows. Keep in mind that 50% of a 300-kilogram cow will produce a 150-kilogram calf, which may not be in demand by feedlots. Generally, feedlot agents view calf wean weight as an indicator of potential growth in the feedlot.
The option of kilogram of calf weaned per cow exposed per unit of feed requirements (large stock unit) provides for feed efficiency, as well as the production ability and fertility of the cow. In South Africa, a large stock unit (LSU) is defined as equivalent to an ox with a weight of 450 kg and a daily weight gain of 500 g on grass pasture with a mean Digestible Energy (DE) concentration of 55%.
Fertility
Improvement in fertility, as indicated by the calving percentage, needs to be increased from the current 62% in the commercial sector. The general objective should be an increased wean calf production without an increase in mature cow weight. This can be accomplished by either using crossbreeding or increasing the milk production of the dam. The ideal is to produce more from fewer resources to improve the efficiency of beef production.
What is an ideal weaning weight for the feedlot?
According to a prominent and successful Bonsmara breeder, the goal of producing calves at birth weighing between 35 and 37 kilograms, with an average daily growth of 1 kilogram, will ensure a 240-kilogram weaner calf, which is in high demand by feedlots. This can serve as a benchmark for beef farmers using medium-frame animals. He also calculates profitability as the number of calves weaned divided by the number of cows mated during the mating season.
For the commercial producer, the goal is to produce the desired weaner for the feedlot and to meet market demand by succeeding in this endeavour. An average wean calf of 235 kilograms would allow the feedlot to add 200 kilograms of meat over a three or four-month period to ensure a profitable calf for the feedlot production system. This implies that the most profitable calf is not always the heaviest calf at weaning, but rather an optimal wean calf weight that meets commercial market requirements.
Management
Management is an environmental factor that has a big influence on the efficiency of cow-calf production. The need is for replacement heifers of high-quality genetics to maintain the cowherd’s production and also to improve herd production. Older cows become less efficient, experiencing a decline in milk production, and must be replaced with high-quality heifers. The teeth of older cows start to deteriorate, resulting in reduced feed intake, which has a detrimental impact on their body condition and milk production. Consequently, they wean below-average calves.
The production environment is also a determining factor, which guides breeders in selecting the best-adapted frame type. The production environment determines the optimum cow size, not the other way around. Manage the condition of cows before mating and before calving to ensure a higher pregnancy rate and a stronger calf at birth. Overfeeding will also increase the birth weights of calves, and this should be prevented.
If the breeder attempts to create an environment for the optimum cow through supplement feeding, it is not a sustainable environment for the cowherd and can impact the sustainability of their production system.
Always keep in mind that the easier the cow gives birth, the quicker and shorter her recovery period will be after birth, and as a result, it will be easier to get her pregnant again in the following mating season.
Genetic selection
The logical way to ensure genetic improvement is to consistently improve on the current herd sire by using BLUP breeding values and purchasing registered bulls. Never buy bulls without performance data and BLUP breeding values. The use of a terminal bull (with extreme breeding values) for specific traits, such as growth tempo, is another option to increase cow efficiency in the herd. However, all progeny of these bulls should be slaughtered, and the females should not be retained as breeding material or replacement heifers.
Cow efficiency selection index on auction catalogues
A combination of these traits should form part of a selection index:
- Fertility is the most important trait to ensure a cow produces at least one calf per year
- Growth ability of the calf to ensure a calf which is accepted by the feedlots
- Maternal or milk production of the cow to assist the calf to reach the potential weaning weight
- Cow weight, which is an indication of frame type and should be limited
- Birth weight of the calf to limit calving problems
Service providers calculate selection indices, which is a combination of all the above-mentioned traits into one value, known as a cow value index. BLUP breeding values are valuable tools for genetic selection. Breeding values represent the genetic merit of an animal and should be considered when selecting the most suitable bull to mate with cows, ensuring genetic improvement.
Conclusion
Dr Gordon Dickerson used to say, “On a farm, an efficient cow herd exhibits early sexual maturity, a high rate of reproduction, low rates of dystocia, longevity, minimum maintenance requirement, and the ability to convert available energy into the greatest possible kilograms of weaned calves”. Take home message Get hold of the auction catalogue as early as possible before the auction date and do a “genetic selection” of bulls that fit into the breeding objectives specified for the herd and maximum profitability is usually achieved before maximum productivity.
