Enhancing growth and feed conversion

Choosing the right holistic feed solution can boost growth and survival performance of juvenile shrimp.

Aquaculture production in Asia-Pacific is expected to continue its growth momentum in the coming years.The region’s aquaculture market is projected to grow at a compound annual growth rate of 5.3% from 2025 to 2030, according to data from Grand View Research (2024). However,environmental and health stressors in the hatchery and nursey stages are anticipated to pose significant barriers to expanding production and achieving aquaculture success for shrimp producers in the region.

The challenge: Moving from controlled to open environments

In Southeast Asia, where high density culture in open environments are common systems for shrimp farms, there is a constant and increasing threat to shrimp post larvae from all pathogens despite efforts to in crease biosecurity. In the early stages of their development,the lack of adaptive immune system in shrimp makes them particularly vulnerable to external conditions, especially when they are exposed to diverse water quality, various infectious environments, during transportation, transfer and counting. Without proper immune support and precise nutrition solutions, the transfer of juvenile shrimp from hatchery to new environments to semi-open ones, may result in reduced survival rate and/or performance loss, and potentially affect the whole production process.

In the absence of a long-lasting immunity memory in shrimp after exposure to bacterial and viruses, immunity regulation is pivotal for crop success. Early-stage nutrition for shrimp plays a significant role in enabling shrimp to grow faster and remain healthy and robust for a successful harvest. To mitigate the growing challenge of antimicrobia resistance, aquaculture producers must adopt more efficient management practices, ensuring sustainable operations and profitability across production cycles.

An effective approach is to incorporate functional feeds to help shrimp cope with environmental, physiological and health-related stress. Shrimp producers in the region are turning to a new generation of functional feeds designed to support immune function and enhance post larvae resistance to pathogens. Choosing the right holistic feed solution to boost growth and survival performance of juvenile shrimp requires careful consideration of 3 key attributes.

High digestibility for protein

Small feed produced by cold micro-extrusion technology will have a high level of prtotein digestibility that directly supports the growth performance of juvenile shrimp.The low temperature of 70 ℃ to 80 ℃ during feed processing results in reduced protein denaturation and a lower loss of the vitamin content of the feed. In fact, an vin vitro test by ADM’s Product Development and Application team in 2021, found that feed produced using cold extrusion technology registered 92.5% protein digestibility as compared to convetional extruded feed with 87.7% to 91% protein digestibility.

Furthermore, when combined with spheronization (or marumerization), which ensures the homogeneity of size and shape of the feed, the feed intake by shrimp post larvae and juvelines is maximised.

High water stability 

Another advantage of cold extrusion and spheronization is that it helps to maintain water stability with reduced leaching of nutrients in water. This contributres to improved water quality in hatcheries and nurseries. This is especially vital during the critical early life stages of shrimp where frequent changes in water. Quality and environments can be harful to their future growth and performance.

Supporting stress mitigation and immune responses

Utilising special feed additives can be effective in countering stress factors such as during grading and counting, transport and during acclimatisation of youn shrimp to new environmental conditions in the hatchery and nursery. Addition of functional additives to nursery feed help shrimp mitigate stres, support immunity, and avoid the reduction in performance as a result of pathogens. It is important to note that while functional feed can be efficient in enhancing productivity to maximise benefits, shrimp farmers should complement their use with strict farming and biosecurity protocols.

Trial with a novel yeast

Pichia guilliermondii, a novel yeast, with its unique morphology, structure, and bioactive cell wall components, can assist in managing high periods of high heat through a modulating effect on gut microbiota and immune function. A study conducted by ADM in Thailand showed that the inclusion of P. guilliermondii in shrimp diets gave significant impacts on critical immune paramaters, offering immune support for enhanced productivity and performance in juvenine shrimp.

Pathogen-free vannamei shrimp with an initial live weight of 6.5g were housed in 2.5m3 tanks and fed either a control or treatment diet containing 0.18% P. guilliermondii. Feeding was five times a day over 28 days. At the end of the feeding period, a sample of 15 shrimp per group were infected by a Vibrio harveyi suspension and the concentration of total and granulaar haemocytes in haemolymph samples were measured three hours following the injection.

The granular haemocyte count significantly increased in the heamolymph of shrimp fed P. guilliermondii (P<0.05); Fig 1 and the number of Vibrio harveyi cells remaining in haemolymph three hours following a challenge was significantly lower as compared to the shrimp fed the control diet (P<0.05); Fig 2).

An elevated proportion of granular haemocytes amongst total heamocytes, as showcased in shrimp fed feeds with P. guilliermondii, demonstrated primed immune capabilities and a more effective response to pathogen challenges.

The inactivated yeast hence positively influences the innate and addaptive immune system of the shrimp with the proliferation of beneficial gut microflora and a faster and stronger inflammatory response to infection.  Other trials in Vietnam (ADM 2019) have also indiciated that the addition of P. guilliermondii to the shrimp basal diet resulted in signigicant improvements in average shrimp body weight gain, with the inactivated yeast supporting growth performance in the absence of pathogen infection.

Functional nursery feed for tilapia larvae

WeaN Prime is a top-quality nurser feed specifically formulated by ADM to improve the overall health of shrimp and fish juveniles. It combines three functional additives, including P. guilliermondii. Other ingredients include fish meal, krill meal, pea protein, wheat meal,  soy meal, soy lecithin and fish oil. This advanced blend has been proven to improve growth performance and feed conversion ratio (FCR), even under pathogen exposure or stress conditions.

A study by ADM on the effects of this nursery feed on young aquatic animals in Vietnam revealed significant growth improvements, increase in feed intake and imprved FCR in young tilapia, fed WeaN Prime as compared to other mash/micro extruded pellet feeds. During the research, 24 tanks of 200L were divided into three experimental groups (WeaN Prime; Competion 1; Competion 2) with 100 tilapia larvae per tank in water temperatures ranging from 28.5 C – 30 C. The tilapia fry (from one day aftẻ yolk sac absorption) were fed the nursery feeds four times a day for 40 days.

The results showed that the larvae fed WeaN Prime had a final weight of 6.8g after 40 days. This was 60% and 31% higher as compared to the other experimental groups (Fig 3), a 19% and 8% increase in feed intake (Fig 4) and FCR improved to 1.01 (Fig 5).

To solve the nutritonal challenges of today and future generations, WeaN Prime optimises nutrtion and maximises production for shrimp producers in the Asia-Pacific region while mitigating environmental impact and optimising the use of natural resources. Produced using cold-extrusion technology, the feed with lower leaching rates, can be easily adapted to farming systems with low water exchange.

Combined with improvements in growth performances and FCRs, active agents such as activated clay, organic acid blend and P. guilliermondii (Aquatrax) have been shown to reduce stress and boost the immunity of shrimp larvae during the early critical stages of their functional feeds in helping producers achieve aquaculture success.

Source: https://vietfishmagazine.com/