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April 8, 2015
Performance Standards for Shrimp Farms
The March/April 2015 issue of The Global Aquaculture Advocate (“The Global Magazine for Farmed Seafood”) contains an important article on performance standards for shrimp farms by Tom Zeigler, Craig Browdy and Peter Van Wyk, all associated with Zeigler feeds in Gardners, Pennsylvania. They write:
To be successful, a business must have standards of performance to annually set realistic objectives, measure results, track success over time and benchmark itself in relation to others in the same business. These performance standards must focus on the most important elements for success. They must be realistic, achievable and provide for special conditions. Finally, they should be dynamic, adaptable, flexible—and motivate the company to achieve higher levels of performance.
From their experiences and the experience of others, the authors have established a set of reasonable performance standards for various segments and types of shrimp facilities that produce Pacific white shrimp, Penaeus vannamei.
Shrimp production facilities vary in size, shape, construction, water quality, soil conditions and temperature, making setting performance standards exceptionally challenging. Nonetheless, farmers need to know how they measure up to industry averages and how much their performance metrics are improving year after year.
The performance standards presented here are intended to represent levels that should be achievable in well-managed systems. These systems are assumed to be reasonably free of chronic endemic diseases, have access to good quality water and use appropriate genetic stocks of animals.
For maturation systems, the goal is normally to maximize the number of nauplii produced. This is achieved by maximizing the spawning frequency, as well as the number and hatchability of the eggs produced by the females. However, the performance standards will vary, depending on the feeds used and the genetics of the broodstock.
While nauplii output is maximized by using live polychaetes and fresh bivalves and squid, these foods carry considerable risk of introducing pathogenic Vibrios and possibly early mortality syndrome to the hatchery. Nauplii production is typically lower when live and fresh feeds are replaced with frozen feeds, but the risk of introducing disease is greatly reduced.
For larval-rearing systems, the goal is normally to maximize the rate and efficiency of the production of large, healthy postlarvae (PLs) that survive and subsequently grow well in ponds or raceways. The parameters that are typically used to evaluate hatchery performance include stocking density, survival rate and the number of days to reach the PL-1 stage. However, producing PLs at very high densities may not be an optimal strategy if the quality and condition factors of the PLs decrease.
While maximizing PL output may maximize short-term profits for the hatchery, there may be a heavy price paid at the farm associated with stocking smaller and weaker postlarvae.
High-Intensity Nursery Raceways
For high-intensity nursery raceways, the goal is normally to produce reasonable numbers of large, healthy animals that exhibit fast growth and excellent survivability after being placed in the growout ponds. But in other cases, the goal may be to produce very large numbers of smaller animals, so that more animals are available for stocking into ponds when conditions are proper. This requires different performance standards.
For shrimp growout systems, the goal is normally to rear large quantities of shrimp as rapidly as possible, but because a wide variety of production methods and facilities are used, it can be difficult to identify appropriate performance standards. However, growth rate and survival are production parameters that should be maximized, regardless of the production system.
Shrimp growth rate is closely correlated with profitability. Feed rates are typically set based on assumed growth rates and assumed feed-conversion ratios. Therefore, it is important that these parameters are set properly to take advantage of the genetic growth potential of the shrimp. For example, targeting a fixed growth rate of 1.75 grams a week can be limiting if the animals are genetically capable of growing at a faster rate.
Another way of setting a performance standard for growth rate is to take a fixed percentage of the maximum growth rate expressed by the genetics of the animal. For example, many strains of shrimp used in the industry today are capable of growing 3 grams a week during the linear growth phase. Seventy percent of 3.0 grams is 2.1 grams. Thus, 2.1 grams a week growth should be a realistic standard for most growout systems using animals with the genetic potential to consistently grow 3 grams a week under ideal conditions.
Water temperature is a huge modifier of shrimp performance. During the linear growth phase of shrimp, the growth rate changes approximately 8% for each degree Centigrade of temperature change. Careful consideration of the water temperature in the rearing system is crucial for setting an effective performance standard.
Achieving and maintaining continuous improvement requires setting reasonable goals and keeping meticulous records that are analyzed, evaluated and compared with internal and external standards on a regular basis. By re-evaluating our goals over time, we can raise the bar and continually improve the productivity and profitability of sustainable shrimp farming.
The performance standards offered in this article are realistic for the conditions shown and can be used for initial comparisons, but the real benefits occur when performance standards are established and used internally for the specific culture system and then constantly changed to improve and track future performance.
Information: Thomas R. Zeigler, Ph.D., Senior Technical Advisor/Past President and Chairman, Zeigler Bros., Inc., 400 Gardners Station Road, Gardners, Pennsylvania 17324, USA (phone 1-800-841-6800, fax 1-717-677-6826, email firstname.lastname@example.org, webpage http://www.zeiglerfeed.com/html).
Sources: 1. The Global Aquaculture Advocate (The Global Magazine for Farmed Seafood). Editor, Darryl Jory (email@example.com). Major League Performance Requires System-Specific Performance Standards. Thomas R. Zeigler, Ph.D. (firstname.lastname@example.org), Craig L. Browdy, Ph.D. (email@example.com) and Peter Van Wyk, M.Aq. (firstname.lastname@example.org). Volume 18, Issue 2, Page 28, March/April 2015. 2. Bob Rosenberry, Shrimp News International, April 8, 2016.
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