The substitution of chicken litter for feed in the commercial production of peneid shrimp in Honduras

D.R. Teichert-Coddington and B.W. Green, Department of Fisheries and Allied Aquacultures, Auburn University, AL 36849-5419, USA

N. Matamoros, Granjas Marinas San Bernardo S.A., Apdo. Postal 184, Choluteca, Honduras

R. Rodriguez, Secretaria de Recursos Naturales, Direccion Agricola Regional del Sur, Choluteca, Honduras

3 May 1990, CRSP Research Report 90-26

Abstract The objective of this research was to determine the effects of substituting chicken manure for the common feed stuffs used in the first four to eight weeks of the growing period of shrimp. Economical evaluations of shrimp production was also considered. Twelve man made pond (2.2-3.0 ha) located at Granjas Marinas, San Bernardo, S.A., San Bernardo, Choluteca, Honduras were assigned to four treatments at random and seeded with young shrimp (average weight 0.8 g) at a rate of 5m^-2 on September 7, 1988. The treatments tested were: 1) (STANDARD) the normal treatment used at Granjas Marinas San Bernardo which consisted in the application of chicken manure during the first eight weeks plus added feed, 2) (FEED) feed only, 3) (4WEEKS) chicken manure only during the first four weeks followed by feeding, 4) (8WEEKS) chicken manure only during the first eight weeks followed by feeding. After ninety nine days of shrimp cultivation, there was no increase in production using low rates of chicken manure (60 kg total solids/ha/week) during the first eight weeks of feeding. It was also found not to be economical to substitute feeding for low rates of fertilization with chicken manure, especially after the first two or three weeks of cultivation. The average weight of shrimp for treatments FEED 14.4, and STANDARD 14.1, was significantly greater than that observed for 4 WEEKS 12.2, and 8 WEEKS 12.1. The average shrimp production was 7-41% greater in STANDARD and FEED treatments (%) and 518 kg/ha respectively) compared to 4 WEEKS (476 kg/ha) and 8 WEEKS (368 kg/ha). However, there were no significant differences between treatments due to the high amount of variability caused by survival rate (P < 0.01). The total costs for FEED and STANDARD were significantly greater compared to 4 and 8 WEEKS. This was due to a greater feed utilization in the previous treatments. Estimated gains in FEED (L.3085/ha) and STANDARD (L.3026/ha) were 27-58% greater than 4 and 8 WEEKS (L.2389/ha, and 1947/ha respectively). This was due to the increased reproduction obtained with greater prices recieved for the larger shrimp obtained in FEED and STANDARD treatments. There was potential to significantly increase the estimated gains by substituting feed for fertilization with chicken manure at a higher rate of application (250 kg/ha/week) during the first four to eight weeks of cultivation.

This Abstract was reprinted from the original, which was published in Agronomia Mesoamericana, 1:73-78 (1990)

Implementing the large-scale production of young males of Tilapia nilotica using hormonal sex inversion in Honduras

B.W. Green, Department of Fisheries and Allied Aquacultures, Auburn University, AL 36849-5419, USA

L.A. Lopez, Estacion Experimental Acuicola El Carao, Recursos Naturales Renovables, Comayagua, Honduras

3 May 1990, CRSP Research Report 90-27

Abstract The demand for young male fish of Tilapia nilotica for seeding in reproduction ponds has significantly increased in the last five years. New production technologies are necessary in order to have adequate supply for existent and future demands of the young fish. One of those is the hormonal sexual inversion of the young fish of Tilapia nilotica via the oral ingestion of a synthetic male hormone (17 a-methyl-testosterone) during a period of 28 days which starts shortly after hatching and before differentiation of genital tissue. The objective of this work which was conducted during the months of January through November, 1988 was to determine the feasibility of implementing the massive production of young males of Tilapia nilotica using the hormonal sexual inversion process at the experimental station "Acuicola El Carao" in Comayagua, Honduras. The process requires obtaining young fish less than 13 mm long from reproduction ponds (0.05-0.1 ha) that have been seeded with Tilapia nilotica (2 females: 1 male). The ponds are then drained within 18 to 20 days after having been seeded, the reproducers are transferred to concrete separating tanks and the young fish are harvested by hand using a net 1.6mm long. The complete cycle for young fish production lasts approximately 23 days. The average number of harvested fish varies between 66,500 to 99,500. The fish are seeded at a population of 4,400/m² in "japas" (wire nets of 1.6 mm, with dimensions 2 m x 2.5 m x 1 m x 1 m x 2 m x 1 m, with an average water depth of 60 cm) after having been passed through a 3.2mm separator net. The hormone is incorporated into the ground feed (23% protein) at a rate of 60 mg kg¹. The ground feed is applied four times per day, seven days a week. The duration of the treatment described is 28 days. The average life span of the hormonal treatment was 87.6%. Treated fish were seeded in prefattening ponds (0.2 ha) for additional growth (102,500 ha^-1). A total of 1.935,000 fish were harvested from the reproduction ponds of which 350,000 were discarded due to excess size. Of the 1.585,000 fish, 1.313,500 were treated with the hormone. Of that 1.189,600 fish were found to complete the treatment cycle. Of the seeded pre-fattening ponds with a total of 661,700 fish an average survival rate of 81.6% was obtained. Up till November, 1988, 399,000 18 g fish were produced, 97% being males. The cost of production of treating the fish (0.15 g each) was L 9.12/1000. This technology has resulted in being feasible not only for the experiment station in Comyagua but should also be feasible for qualified fisheries.

This Abstract was reprinted from the original, which was published in Agronomia Mesoamericana, 1:21-25(1990)

Pond culture of tilapia in Rwanda, a high altitude equatorial African country

B.J. Hanson, Rwanda Pond Dynamics/Aquaculture CRSP (Collaborative Research Support Program), Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon 97331 USA

J.F. Moehl, Jr., K.L. Veverica, Rwanda Fish Culture Project, International Center for Aquaculture, Auburn University, Alabama 36849 USA

F. Rwangano, M. Van Speybroek, Faculté d'Agronomie, Universitié Nationale du Rwanda, BP 117, Butare, Rwanda

16 October 1990, CRSP Research Report 90-28

Abstract Tilapia culture in Rwanda is practiced in ponds at altitudes from 1,300 m to 2,500 m. Air and water temperature are lower than those in other tropical countries where tilapia culture is typically practiced. These conditions require careful pond water management practices for tilapia culture to be successful. Results from experiments and rural harvest indicate that Oreochromis niloticus is superior to Tilapia rendalli and O. macrochir in Rwandan conditions.

Reproductive tendencies of O. niloticus are different from those seen elsewhere: age at first reproduction is higher, time before resumption of reproduction after restocking is longer, and number of fingerlings produced per surface are is less. Natural productivity measured in local ponds ranged from 40 to 210 kg/ha/year and net productivity in poorly managed ponds receiving inputs was generally less than 500 kg/ha/year. However, in well managed ponds, O. niloticus can show average growth of over 1.0 g/day and net productivity of 3,000 kg/ha/year.

This paper originally appeared in The Second International Symposium on Tilapia in Aquaculture, pp. 553-559. R.S.V.Pullin, T. bhukaswan, K. Tonguthai, and J.L. MacLean (eds) 1988. ICLARM Conference Proceedings 15, Department of Fisheries, Bangkok, Thailand, and International Center for Living Awuatic Resources Management, Manila, Philippines.

Hatchery techniques for egg and fry production of Clarias batrachus (Linnaeus)

Christopher F. Knud-Hansen, Ted R. Batterson, Clarence D. McNabb, Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI 48824, USA

Yani Hadiroseyani, Darnas Dana and H. Muhammed Eidman, Insitut Pertanian Bogor, Facultas Perikanen, Jalan Raya Pajajaran, Bogor (Indonesia)

10 November 1990, CRSP Research Report 90-29

Abstract Egg hatching, and fry growth and survival of the walking catfish, Clarias batrachus (Linnaeus), were investigated under hatchery conditions in West Java, Indonesia. Spawning was environmentally induced in a specialized breeding pond. Gravid females utilized nests containing kakaban, a fibrous matting from local palm trees (Arenga sp.), which facilitated egg collection. Newly hatched fry fed with Artemia nauplii through day 8 (after hatching), and Artemia and cladoceran mix from days 9 to 16, and cladocerans only from days 17 to 23 resulted in over 90% survival of young from hatched eggs. Other diets examined (rotifers, cladocerans, ground fish meal, and ground Nile tilapia flesh) proved inadequate for fry through day 16. Fry reared in hatchery aquaria for 16 days versus 23 days before introduction into nursery ponds showed no significant differences in mean length, mean weight, or percent survival when harvested at day 58. Suggested guidelines are given for hatchery production of C. batrachus fry and fingerlings.

This paper was published in Aquaculture, 89 (1990) 9-19.

Response of tilapia yield and economics to varying rates of organic fertilization and season in two Central American countries

Bartholomew W. Green, David R. Teichert-Coddington, and Ronald P. Phelps, Department of Fisheries and Allies Aquacultures, and Alabama Agricultural Experiment Station, Auburn University, Auburn, AL 36849-5419, USA

24 January 1991, CRSP Research Report 91-30

Abstract The response of Nile tilapia (Oreochromis niloticus) yield to weekly applications of chicken litter at 125, 250, 500 or 1000 kg total solids (T.S.)/ha was determined in Honduras and Panama using a completely randomized design. Tilapia were stocked at 10,000/ha into 0.1-ha (Honduras) and 0.087-ha (Panama) earthen ponds. Each experiment, which lasted approximately 150 days, was performed during the rainy and dry season. Enterprise budgets were developed for each fertilization rate in each country.

Gross yield of tilapia (y) increased significantly with chicken litter applications (x) in both countries, and was described by the model y=797.3 +2.945x -0.001 x² (r²=0.775; n= 48). Gross yields ranged from 827-2729 kg/ha in 147 days during the rainy season, and from 1145-2984 kg/ha in 150 days during the dry season. Maximum tilapia gross yields were achieved at 1000 kg T.S./ha week^-1 chicken litter in both countries. In Honduras, rainy (1761 kg/ha in 152 days) and dry (1705 kg/ha in 150 days) season mean tilapia gross yields were similar (P=0.05). Dry season (2071 kg/ha in 149 days) mean tilapia gross yield in Panama was significantly greater (P<0.05) than rainy season mean gross yield (1683 kg/ha in 141 days). Rainy season climatic conditions in Panama probably contributed to the lower fish yields. Mean fish gross yield at the cooler, drier Honduras site (1733 kg/ha in 151 days), an upland valley located 580 m above sea level, and at the Panama site (1855 kg/ha in 145 days), a coastal plateau 100 m above sea level, was similar (p=0.05). Mean gross yields were similar in both countries for all but the highest fertilization rate, where the Panama mean yield was significantly greater. This difference was caused by site-specific factors other than nutrient input.

The use of chicken litter as an organic fertilizer was profitable in both Honduras and Panama. Net returns to land, labor and management during the 5.5-month production cycle ranged from $ 642 to $ 1724/ha (Honduras) or from -$ 237 to $ 313/ha (Panama) for the low to high fertilization rates, respectively. Application of 1000 kg T.S./ha week^-1 chicken litter yielded the greatest estimated profit in both countries.

This abstract was reprinted from the original, which was published in Aquaculture, 90 (1990) 279-290.