Effect of dietary duckweed (Lemna spp.) with or without enzyme supplementation on nutrient digestibility and economics of broiler chicken production

Introduction

Domestic economic expansion coupled with evolving consumer demand has facilitated the transformation of India's poultry and especially the broiler chicken sector into a vibrant and commercially significant business. The development of the poultry industry is contingent upon several factors, notably the consistent provision of cost-effective, quality feed ingredients (Kumar et al., 2025) [16] . Feed is the single largest component in poultry production which accounts for about 70-75% of total cost of production (Adaszyńska-Skwirzyńska et al., 2025) [1] . The use of new edible plants that can meet the energy and protein requirements in poultry nutrition is always an important and strategic option in new studies and food security (Seidavi, et al., 2023; Biyatmoko et al., 2025) [21,6] . In Jammu and Kashmir, due to non-availability of quality feed ingredients, most of the poultry feeds are imported from neighbouring states. The cost of feed is higher in Kashmir valley compared to other parts of country because of additional transportation cost incurred during importation. The adoption of locally produced unconventional feed ingredients can decrease feed expenditure and consequently raise the profitability of poultry ventures (Bhosale et al., 2025) [5] . Non-conventional green forages, which are locally accessible, can function as cheap feeds offering both protein and vitamins. Incorporating locally available nonconventional feeds, particularly aquatic macrophytes, can reduce poultry feed costs and improve profitability (Kumar et al., 2022) [17] . The duckweed plant family represents an alternative protein crop.

The term duckweed describes a group of plants of the family Lemnaceae with five genera and 36 species (Bog et al., 2019) [7] . Duckweed (Lemna spp.), which is abundant in the Kashmir Valley, is a high protein aquatic macrophyte well suited for formulating low cost diets for poultry, fish, and other domestic animals as well. This diminutive floating macrophyte proliferates in still waters and is commonly found throughout tropical countries in ponds, lakes, and waterlogged paddy fields. The biomass of duckweed can contain up to 45% crude protein (CP), with a favorable amino acid composition (Xu et al., 2021) [25] . The digestibility of most amino acids in L. minor ranged from 70% to 96%, with lysine and methionine at 87% and 86%, respectively (Niermeyer et al., 2026) [19] . While its high moisture content can limit direct use in poultry diets, duckweed remains a valuable feed ingredient; it contains 28% crude protein, 3.7% crude fat, 33.8% ash, 11.5% fibre and 42.6% carbohydrates. Comparable bodyweight was recorded in broiler chicken while Duckweed was used at 5% level with enzyme supplementation (Zaffer et al., 2021) [26] . Although numerous studies have examined duckweed as poultry feed ingredient (Ahammad et al., 2003; Khandaker et al., 2007) [2,15] , there appears to be very minimum systematic investigation of its effects in the Kashmir Valley, despite its abundant presence in local water bodies. Therefore, the present experiment was aimed to incorporate Duckweed in the diet of broiler chicken to study the cost of production and nutrient utilization.

Materials and Methods

Location of the study: The work was conducted at the Poultry Farm of Division of Livestock Production and Management (LPM), Faculty of Veterinary Sciences and Animal Husbandry (F.V.Sc. and A.H.), Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir (SKUAST-K), Shuhama, Jammu and Kashmir, India.

Collection of duckweed:

It was collected from natural water bodies in and around Srinagar and Ganderbal districts. The harvested material was subsequently dried under appropriate conditions and stored properly for subsequent use in the experiment.

Experimental diet formulation:

A total of ten (10) experimental diets (five starters and five finisher) were formulated to be iso-nitrogenous and iso-caloric following BIS (1992) [8] recommendations. Duckweed was incorporated into the basal diet at two inclusion levels with or without enzyme supplementation. The treatments were: T 1 (control)-basal diet without duckweed; T 2 -basal diet with 5% duckweed without enzyme; T 3 -basal diet with 5% duckweed with enzyme; T 4 -basal diet with 10% duckweed without enzyme; and T 5 -basal diet with 10% duckweed with enzyme.

Proximate analysis of diets and duckweed:

The dry matter (DM), crude protein (CP), ether extract (EE), crude fibre (CF) and total ash (TA) contents of the experimental diets and dried duckweed samples were determined following the standard procedures of AOAC (2005a) [4] .

Management and rearing of experimental chicks:

A total of one hundred fifty (150) day-old broiler chicks were procured from a reputed hatchery and brooded in cages during the first week. On the eighth day, the chicks were randomly allotted to five treatment groups (as mentioned above), each further divided into three replicates containing ten chicks per replicate. The birds were subsequently reared for a period of five weeks under deep litter management system with feed and water provided ad libitum.

Digestibility trial: At the end of the experiment, a three-day balance trial was conducted to determine the apparent digestibility of DM, CP, CF, EE. Two birds from each replicate were randomly selected and housed individually in battery cages. The trial included one day of adaptation followed by three days of excreta collection. Daily feed intake and total excreta output were recorded. The 24-hour excreta were weighed and homogenised. For DM estimation, about 1/20 of the total excreta was oven-dried at 80 °C to constant weight. For nitrogen estimation, about 1/10 of the excreta was preserved in a stoppered bottle and analysed promptly. Representative feed samples were also collected. All samples were analysed following the methods of AOAC (2005a) [4] . The metabolizable energy (ME) was calculated as per Pauzenga (1985) [20] .

Economics of feeding:

The economics of feeding were evaluated based on the market prices of feed ingredients at the time of purchase; miscellaneous expenses (electricity, vaccination, medication, tonics, and sawdust), feed consumption, and body weight of the birds were taken into consideration.

Statistical analysis:

The obtained data were analysed following the procedures of Snedecor and Cochran (1994) [23] . Significance was assessed at p≤0.05.

Results

Proximate analysis of duckweed:

The proximate composition of duckweed showed the percentages of dry matter (DM), crude protein (CP), ether extract (EE), crude fibre (CF), total ash (TA), acid insoluble ash (AIA), nitrogen free extract (NFE), phosphorus (P), calcium (Ca) as 89.85±1. 25

Proximate analysis of experimental diets:

The proximate compositions of all the experimental diets were also estimated and have been presented in Tables 1 and2 for starter phase and finisher phase, respectively. [20] ME = 37×%CP + 81×%EE +35.5×%NFE

Digestibility of nutrients:

The digestibility of nutrients of broiler chicken fed different levels of duckweed with or without enzyme supplementation is depicted in Table 3. Dry matter (%) digestibility differed significantly (p≤0.05) among the treatments, with T 1 showing higher digestibility than T 4 and T 5 . Crude protein (%) digestibility also varied significantly (p≤0.05), with T 1 recording higher values than T 2 , T 3 , T 4 , and T 5 , which did not differ significantly (p>0.05) among themselves. Total fibre (%) digestibility showed significant differences (p≤0.05) too, with T 1 , T 3 , and T 5 exhibiting higher values compared to T 2 and T 4 . However, ether extract (%) digestibility did not differ significantly (p>0.05) among the treatments.

Cost of production of broiler starter diet:

The cost of broiler starter diets under different treatments is presented in Table 4. Inclusion of duckweed reduced the feed cost compared to T 1 . The cost per 100 kg feed decreased with increasing levels of duckweed, with the lowest cost observed in T 4 and T 5 . Thus, partial replacement of conventional ingredients with duckweed lowered the overall cost of starter diets.

Cost of production of broiler finisher diet:

The cost of broiler finisher diets under different treatments is presented in Table 5. Incorporation of duckweed reduced the feed cost compared to T 1 . The cost per 100 kg feed declined with increasing levels of duckweed, with the lowest cost observed in T 4 followed by T 5 . Consequently, the feed cost per kg was lower in duckweed-based diets, indicating that partial replacement of conventional ingredients with duckweed reduced the cost of finisher diets.

Economics of feeding:

The economic evaluation of broilers. fed diets containing duckweed with or without enzyme supplementation is presented in Table 6. Inclusion of duckweed in the diets reduced the feed cost per kg compared to T 1 , with lower feed costs observed in T 4 and T 5 . Final body weight gain and feed Conversion ratio varied among the treatments, which subsequently influenced the overall production cost and economic returns. The feed cost per kg live weight gain was lowest in T 5 , followed by T 3 , indicating relatively better feed efficiency in these groups. Sale proceeds per bird and per group were highest in T 3 , followed by T 1 and T 5 , whereas T 4 recorded the lowest returns. A similar trend was observed for profit, where T 3 yielded the highest profit per group as well as per bird, while T 4 showed the lowest profitability.

Discussion

The values of proximate analysis of duckweed fall within the ranges reported for duckweed in earlier studies, although considerable variation occurs depending on species and nutrient availability. Demann et al. (2022) [11] reported that duckweed species such as Lemna minor, Lemna minuta and Lemna obscura contain appreciable protein and mineral fractions, with nutrient composition varying widely with cultivation conditions. The crude protein content of duckweed was comparable with the findings of Kalita et al.

(2008) [14] who also reported a similar crude protein level of 20.8% in duckweed. The crude fibre content of duckweed recorded in the present study was consistent with the values reported by Ansal and Dhawan (2007) [3] . The ash content of duckweed observed in the present study was consistent with the findings of Iram et al. (2015) [13] , who also reported comparable ash levels in duckweed; however, the calcium and phosphorus contents recorded in the present study were lower than those reported by the same authors. The metabolizable energy estimated in the present study was lower than the value reported for duckweed by Syamsuhaidi et al. (2025) [24] . The reduced digestibility of dry matter and crude protein in the duckweed supplemented group may be attributed to the high fibre content of duckweed, which can increase digesta viscosity and consequently reduce the digestibility of nutrients (Demann et al., 2022) [11] . Furthermore, the digestibility of crude fibre in the duckweed supplemented group was significantly (p≤0.05) lower than that of the control and the duckweed + enzyme supplemented groups. This may be attributed to the ability of exogenous enzymes to degrade non-starch polysaccharides and phytates, thereby improving nutrient availability and enhancing crude fibre digestibility in birds (Morgan et al., 2022) [18] . The ether extract values recorded in the present study indicate that inclusion of duckweed in the diet did not adversely affect fat digestibility; this could be attributed to the generally high digestibility of dietary lipids in poultry and the relatively low ether extract content of duckweed, which may have limited its influence on overall fat utilisation. However, in the present study, crude fibre digestibility was significantly (p≤0.05) higher in the enzyme-supplemented groups than in those without enzyme supplementation. This finding is consistent with previous studies reporting that exogenous enzymes improve nutrient digestibility in poultry by reducing digesta viscosity and enhancing the breakdown of non-starch polysaccharides, thereby increasing nutrient availability (Hu et al., 2020; Cai et al., 2026) [12,9] . The digestibility of crude protein and ether extract in the present study was higher than those reported by Sheikh and Sapcota (2010) [22] in broilers while diet supplemented with Silk worm pupae meal.

Regarding the economical findings of the study, it can be said that incorporating duckweed into broiler diets led to a decrease in feed costs compared to the control group. However, the profit per bird in the duckweed-fed group was lower than that of the control, which was enhanced when enzymes were added to the diet. This improvement is attributed to increased nutrient digestibility in the enzyme supplemented groups, allowing more nutrients to be utilized for growth and resulting in higher body weight gains. These results are consistent with the observations of Khandaker et al. (2007) [15] and Iram et al. (2015) [13] , who also reported reductions in feed costs when duckweed was included in broiler diets.

Conclusion

The present study found that the use of duckweed as a partial substitute for conventional broiler feedstuffs is viable to reduce the cost of broiler production without impairing the overall cost of production. The use of higher levels of duckweed without enzyme supplementation, however, showed relatively lower nutrient digestibility and economic returns. This may be attributed to the relatively higher fibre content of the duckweed. The supplementation of exogenous enzymes was found to improve the nutrient utilisation efficiency. This consequently showed better economic returns of the broilers fed with duckweed supplemented with enzymes compared to the group fed with the duckweed material without enzyme supplementation. The present study indicated the potential of the use of duckweed material as an alternative cost effective and locally available broiler feed.

Conflicts of interest: None

References

1. Adaszyńska-Skwirzyńska M, Konieczka P, Bucław M, Majewska D, Pietruszka A, Zych S, et al. Analysis of the production and economic indicators of broiler chicken rearing in 2020-2023: a case study of a Polish farm. Agriculture. 2025;15(2):139-139.
2. Ahammad MU, Swapon MSR, Yeasmin T, Rahman MS, Ali MS. Replacement of sesame oil cake by duckweed (Lemna minor) in broiler diet. Pak J Biol Sci. 2003;6(16):1450-1453.
3. Ansal MD, Dhawan A. Spirodela for low cost carp feed formulation. In: Proceedings of the 8th Asian Fisheries Forum; 2007 Nov 20-23; Kochi, India. p. 164-164.
4. AOAC. Animal feed. In: Official methods of analysis of the Association of Official Analytical Chemists International. 18th ed. Gaithersburg (MD): AOAC; 2005.
5. Bhosale TR, Dhage SA, Gaikwad US, Adangale SB, Birari DR. Nutritional perspectives and innovations in alternative feed resources for sustainable poultry production: a review. Int J Vet Sci Anim Husb. 2025;10(9):168-173.
6. Biyatmoko D, Sulaiman A, Amilia P. Duckweed (Lemna minor) in feed to increase the carcass and giblet proportion of male Alabio ducks. J Penelit Pendidik IPA. 2025;11:99-105.
7. Bog M, Appenroth KJ, Sree KS. Duckweed (Lemnaceae): its molecular taxonomy. Front Sustain Food Syst. 2019;3:117-117.
8. Bureau of Indian Standards. Nutrient requirements for poultry (IS 13574:1992). New Delhi: Bureau of Indian Standards; 1992.
9. Cai Y, Zhang M, Hamada O, Song Z. Multi-enzyme supplementation enhances performance, intestinal and skeletal development in broilers fed low-nutrient diets. Poult Sci. 2026;105(2):106234-106234.
10. Chaji M, Pormhammad A. Nutritional evaluation and fermentation characteristics of duckweed (Lemna gibba) in ruminant diets. Discov Anim. 2025;2:35-35.
11. Demann J, Petersen F, Dusel G, Bog M, Devlamynck R, Ulbrich A, et al. Nutritional value of duckweed as protein feed for broiler chickens: digestibility of crude protein, amino acids and phosphorus. Animals. 2022;13:130-130.
12. Hu J, Ingale S, Rathi P, Zhang JY, Kim IH. Influence of exogenous acid protease in broiler chickens fed cornsoybean meal-based diets. J Anim Physiol Anim Nutr. 2020;104(1):204-211.
13. Iram S, Abrar S, Ahmad I, Khanam T, Azim A, Nadeem MA. Use of duckweed growing on sewage water as poultry feed. Int J Sci Res Publ. 2015;5:1-8.
14. Kalita P, Mukhopadhyay PK, Mukherjee AK. Supplementation of four non-conventional aquatic weeds to the basal diet of Catla catla and Cirrhinus mrigala fingerlings: effect on growth, protein utilization and body composition of fish. Acta Ichthyol Piscat. 2008;38(1):21-27.
15. Khandaker T, Khan MJ, Shahjalal M, Rahman MM. Use of duckweed (Lemna perpusilla) as a protein source feed item in the diet of semi-scavenging Jinding layer ducks. J Poult Sci. 2007;44:314-321.
16. Kumar D, Rathod KD, Kale SM, Maurya R, Bhosale TR. Alternative feed ingredients in poultry diets: a review of nutritional potential, processing technologies, and challenges. Int J Vet Sci Anim Husb. 2025;10(9):16-19.
17. Kumar G, Sharma J, Goswami RK, Shrivastav AK, Tocher DR, Kumar N, et al. Freshwater macrophytes: a potential source of minerals and fatty acids for fish, poultry, and livestock. Front Nutr. 2022;9:869425869425.
18. Morgan N, Bhuiyan MM, Hopcroft R. Non-starch polysaccharide degradation in the gastrointestinal tract of broiler chickens fed commercial-type diets supplemented with xylanase or enzyme cocktails. Poult Sci. 2022;101(6):101846-101846.
19. Niermeyer JF, Demann J, Petersen F, Dusel G, Devlamynck R, Ulbrich A, et al. Digestibility, energy value, and performance of Lemna minor as a novel protein source in broiler chicken diets. Poultry. 2026. doi:10.3390/poultry5020024.
20. Pauzenga U. Feeding parent stock. Zootecnica Int. 1985;17:22-24.
21. Seidavi A, Hosseintabar-Ghasemabad B, Gorlov IF, Slozhenkina MI, Mosolov AA, Oteri M, et al. Feed additives and future perspectives. In: Sustainable use of feed additives in livestock: novel ways for animal production. Cham: Springer; 2023. p. 929-961.
22. Sheikh IU, Sapcota D. Effect of feeding silkworm pupae meal on nutrient and mineral retention in broilers. Indian Vet J. 2010;87(10):1049-1050.
23. Snedecor GW, Cochran WG. Statistical methods. 8th ed. Ames (IA): Iowa State University Press; 1994.
24. Syamsuhaidi, Purnamasari DK, Putra RA, Abdullah U. Adding duckweed (Lemna minor) to local duck diet: effects on performance and heavy metal concentration in meat. Am J Anim Vet Sci. 2025;20(1):86-96.
25. Xu J, Shen Y, Zheng Y, Smith G, Sun XS, Wang D, et al. Duckweed (Lemnaceae) for potentially nutritious human food: a review. Food Rev Int. 2021;39:36203634.
26. Zaffer B, Sheikh IU, Banday MT, Adil S, Ahmed HA, Khan AS, et al. Effect of inclusion of different levels of duckweed (Lemna minor) on the performance of broiler chicken. Indian J Anim Res. 2021;55(10):1200-1205. doi:10.18805/IJAR.B-4201.