March 13, 2007

 

Bentoli workshop emphasises strategic use of fishmeal in aqua feeds
 

Press release
 

 

Some 50 representatives of aqua feed manufacturing companies worldwide flocked to the Bentoli Workshop on Fishmeal Use in Aqua Feeds held on Feb 26, 2007 in Texas, US.

 

The workshop purported a clear message: Fishmeal is a highly valuable aqua feed ingredient of finite availability and has to be managed strategically in aqua feed formulas to get the most out of it and manage costs associated with its use at the same time.

 

As one of eight experts who spoke on various topics, Dr Jonathan Shepherd, Director General of the International Fishmeal and Fish Oil Organization, kicked off the session.

 

Dr Shepherd remarked that average annual fishmeal production is fairly stable at 5 to 7 million tonnes, indicating that fishmeal resources are sustainable and well-managed, with short-term fluctuations in supply due to periodic El Nino warm currents off the Pacific coast of South America.

 

Growth of aquaculture, particularly in China, significantly bolstered fishmeal demand, doubling prices in 2006.

 

Dr Shepherd cited the case of feed manufacturers learning to manage fishmeal levels in poultry and swine feeds in the past, and noted that fishmeal usage in aquaculture would also be managed by increasing levels of complementary ingredients when fishmeal prices are high.

 

He said it is likely that prices will continue to remain firm as fishmeal and fish oil move from being commodities to strategic ingredients used at critical stages in the animal's life cycle for optimum health and performance. The challenge for the formulator will be to optimise diet costs with less fishmeal, but without compromising fish performance or losing the omega-3 related health benefits for the final consumer.

 

Speaking on the value of fishmeal in aqua feeds, Dr Ronald Hardy, Director of the Aquaculture Research Institute at the University of Idaho, mentioned that the aqua feed industry must now focus on the qualities of fishmeal that have the highest value in aqua feeds, and limit fishmeal use to situations where its value is realised.

 

He added that fishmeal is a high-value ingredient in starter feeds even for omnivorous fish species. As pond culture in Asian countries shifts from extensive rearing where no prepared feeds are used to semi-intensive rearing where formulated feeds are used, feed usage for the fry and fingerlings of omnivorous fish such as carp, catfish and tilapia is driving fishmeal demand.

 

Dr Hardy concluded that fishmeal is an important ingredient in fry and fingerling production, and will continue to be valued as such.

 

Dr Allen Davis, an associate professor at Auburn University's Department of Fisheries and Allied Aquacultures, Alabama, narrated his research experience on fishmeal replacement in practical shrimp feeds and asked feed manufacturers to consider data from trials that showed that no fishmeal is needed in the diets of Pacific white shrimp (vannamei) that are raised in ponds.

 

He said that cheaper, high-quality plant (such as combinations of solvent extracted soymeal, corn gluten meal, distillers grain solubles, pea meal) or terrestrial animal protein sources (such as poultry meal) can be used to successfully replace fish meal in shrimp feeds without compromising shrimp growth.

 

Such modifications to the feed, however, can only be done if the replacement strategy takes into account nutrient requirements of the species in terms of essential amino acids, fatty acids and minerals as well as potential palatability shifts in the diets.

 

He also asked that nutrient requirements of shrimp in pond systems be determined more precisely, especially in the case of limiting nutrients such as sulfur amino acids.

 

Dr Alberto Nunes, who directs the Labomar research programme on shrimp feeds at the Instituto de Ciencias do Mar, Brazil, spoke about feeding effectors in shrimp.

 

Using a system called Y-maze aquarium, his laboratory has evaluated several ingredients and commercial feeding effectors in shrimp feeds. He mentioned that some ingredients such as fish oil are not effective at all as feed attractants, despite being commonly perceived to be so.

 

Providing data on his research on Aqua Savor, a commercial attractant manufactured by Bentoli AgriNutrition, he said that the product was a highly effective feed attractant, incitant and feeding stimulant that worked at levels as low as 0.2 percent in feeds that contained no fishmeal. It also improved animal intake of feeds containing fishmeal, demonstrating its effectiveness as a fishmeal fortifier.

 

Dr David Stone, who is a research scientist with the Aquaculture Research Institute at the University of Idaho, spoke about his research experience in the use of plant proteins in aqua feeds.

 

He said that plant protein ingredients already used in practical feeds include soymeal and corn gluten meal, adding that there is potential for modified ingredients from oilseed or grain protein concentrates made to feed grade standards such as soy beans, barley, rapeseeds and lupins. Proteins recovered from ethanol or bio-fuel production also have tremendous potential.

 

Presenting the channel catfish industry's case in the Mississippi Delta region of southern US, Dr Stone said that strategic nutrition research investigating nutrient requirements, nutrient digestibility and availability and growth studies, has led to production of grow-out diets containing soymeal in combination with several other plant ingredients to completely replace fishmeal with no adverse effects on fish growth for this industry.

 

He remarked that fishmeal replacement for carnivorous species is proving to be more difficult. Rainbow trout may be grown successfully on all plant diets, assuming amino acid requirements have been met by supplementation, but growth appears to be approximately 5 to 10 percent less than trout fed fishmeal-containing feeds.

 

Reviewing past work on plant protein use in shrimp feeds, Dr Addison Lawrence, a professor and regents fellow in the Texas A&M University System, said that soymeal can be included up to 50 percent with no detrimental effects. Further increase in soymeal levels results in pelleting problems and requires the use of oil and binders.

 

Dr Lawrence added that methionine, lysine, and arginine, the three most limiting essential amino acids in shrimp feeds, are not as limiting as protein levels in least cost formulated feeds.

 

He said the potential for increasing plant meal levels in shrimp feeds is currently most limited by the availability of a cost effective food grade plant protein source containing at least 60 percent protein with a digestibility value of over 85 percent. There is a need for production of a feed grade plant protein source such as soybean concentrate, corn gluten and wheat gluten.

 

Also, there is a need to improve digestibility of by-products from corn processing and distilleries to make those products more valuable, remarked Dr Lawrence.

 

Dr Sergio Nates, President and Director of Technical Services of the Fats & Proteins Research Foundation, spoke on the use of rendered animal by-products in aqua feeds.

 

He noted that a wide variety of by-products are available and many present cost-effective opportunities for fishmeal replacement. Some products such as meat and bone meal and poultry by-product meal are highly digestible protein sources. Recent research has shown that they can be significant sources of cholesterol, an essential nutrient in shrimp feeds.

 

Providing a case study of formulating practical shrimp feeds, Dr Victor Suresh, Research Director of Bentoli AgriNutrition, said that practical alternatives to fishmeal were difficult to find in 40 percent protein shrimp feeds. This situation, however, has changed dramatically as crude protein levels in feeds fell to 35 percent and lower.

 

At the recent price of US$1070/tonne, fishmeal was included at a very low level (less than 2 percent) or not at all in different versions of shrimp feeds containing 35 percent or 30 percent crude protein. Fishmeal is justified in the lower protein formulas only at prices below US$500/tonne.

 

Among the different ingredients that replace fishmeal, rendered animal proteins are generally favoured over plant proteins in high-protein formulas while plant proteins are favoured in lower-protein formulas. Dr Suresh pointed out aspects such as attractability or palatability in ingredients deserve as much attention as the more quantifiable nutrients. Hence, it is important to develop methods to quantify such aspects and plug the values into the formulation system so that formulators can effectively manage ingredients and produce diets that are nutritionally adequate and meet performance goals of the farmer.