Management strategies of stocking density and length off culture period for the Catarina scallop Argopecten circularis (Sowerby): a bioeconomic approach

1997 ◽  
Vol 28 (3) ◽  
pp. 223-229 ◽  
Author(s):  
A Hernández-Liamas
Keyword(s):  
Management Strategies ◽  
Stocking Density ◽  
Culture Period

scholarly journals 76 Evaluating Nitrogen Management Strategies to Improve Southern Bermudagrass Grazing Systems

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 26-26
Author(s):  
Justin C Burt ◽  
Jennifer J Tucker ◽  
Lisa Baxter
Keyword(s):  
Nutritive Value ◽  
Cynodon Dactylon ◽  
Management Strategies ◽  
Stocking Density ◽  
Warm Season ◽  
The South ◽  
Forage Crops ◽  
University Of Georgia ◽  
Annual Grasses ◽  
The University

Abstract Bermudagrass (Cynodon dactylon) is one of the most common perennial warm-season forage crops grown in the South. While prominent in the region bermudagrass management requires large amounts of fertility and forage quality is moderate at best. Incorporating a legume into bermudagrass pastures could serve as an alternative to the necessary applications of synthetic N, while also improving the nutritive value of the forage base. A two-year grazing evaluation was conducted from May-Sept. 2018 (Y1) and May-Aug. 2019 (Y2) at the University of Georgia Tifton Campus in Tifton, Georgia, to compare concurring production of alfalfa/bermudagrass mixed pastures (BGA) with bermudagrass monoculture pastures with (BGN) or without (BGZ) the application of synthetic nitrogen. The experimental design was a randomized complete block with three treatments and two replications. All paddocks were evaluated pre and post grazing event for herbage availability, botanical composition, forage species competitiveness, and nutritive value. Paddocks (0.8-ha) were rotationally grazed using put and take management with stocker steers (Y1 BW=195.9±22.9 kg; Y2 BW=228.5±30.0 kg), two testers per treatment. Steers were weighed at initiation, conclusion, and on a 28–30 day interval for calculation of ADG and gain/ha. Statistical analysis was conducted using the PROC MIXED procedure of SAS. Despite significant drought in Y2, year did not affect total gain/ha, however treatment did (P = 0.04), such that BGA was highest (383.6±35.1 kg/ha), and BGN and BGZ were not different (261.2±35.1 kg/ha and 239.0±35.1 kg/ha, respectively). This is likely due to the lower stocking density and inclusion of high-quality volunteer annual grasses in BGZ treatments which allowed for selective grazing. These data suggest that rotationally grazing alfalfa/bermudagrass mixtures can result in a higher gain/ha, than bermudagrass pastures that are supplemented with or without synthetic N in the South.

scholarly journals Growth Performances and Proximate Composition of Mystus Cavasius (Hamilton, 1822) Cultured in Recirculating Aquaculture System Under Different Stocking Densities

2020 ◽  
Vol 29 (2) ◽  
pp. 137-145
Author(s):  
Md Mizanur Rahman ◽  
Gouri Mondal ◽  
MD Marufujjaman Mithu ◽  
Md Golam Rabbane ◽  
Md Ghulam Mustafa
Keyword(s):  
Survival Rate ◽  
Proximate Composition ◽  
Stocking Density ◽  
Culture Period ◽  
Recirculating Aquaculture System ◽  
High Density Culture ◽  
Crude Lipid ◽  
Recirculating Aquaculture ◽  
Aquaculture System ◽  
Growth Performances

Experiment was conducted to evaluate the high density culture of Mystus cavasius and its effects on growth performances, survival rate and proximate composition of the fish in recirculating aquaculture system. Fishes were cultured at 571, 714, 857 and 1000 fries/m3 as the initial stocking density. No significant differences (p > 0.05) were found in specific growth rate, average daily gain, food conversation ratio, protein efficiency ratio, condition factor (k) and survival rate (%) of fish under the culture period of 120 days among the different stocking densities. The average survival rate was ≥ 99% among the treatments at the end of the culture period. The moisture contents were between 77.10 and 77.75%, ash content was 2.58 and 2.61%, crude protein was 15.86 and 16.07%, crude lipid was 5.45 and 5.68% with no significant differences (p > 0.05) among the treatments. There were no significant variations in DO, TAN, NO3-N, NO2-N and pH among the treatments during culture. This study showed that stocking density of at least 1000 fries/m3 was the best option as the total gain was highest compared to other lower densities under similar facilities. Dhaka Univ. J. Biol. Sci. 29(2): 137-145, 2020 (July)

scholarly journals Intensification of “mola” (Amblypharyngodon mola) culture in homestead ponds

2020 ◽  
Vol 9 (2) ◽  
pp. 23-29
Author(s):  
SN Mona ◽  
S Sultana ◽  
KK Ahmed ◽  
N Khan ◽  
KA Huq ◽  
...  
Keyword(s):  
Water Quality ◽  
Fish Species ◽  
Stocking Density ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Culture Period ◽  
Total Biomass ◽  
Supplementary Feed ◽  
By Products ◽  
Indigenous Fish Species

The research was carried out with small indigenous fish species (SIS) named mola (Amblypharyngadan mola) in monoculture system to intensify production in farmers’ homestead ponds with 50% household women involvement during June to December, 2016. Brood mola was stocked at the rate of 2, 4 and 6 m-2 with three replications in each treatment. Supplementary feed (27.1% protein) consisted of commonly available agricultural by-products was provided daily at the rate of 2% of the total biomass along with natural feed as mola is planktivorous species. Seven different water quality parameters were measured fortnightly and found within cultivable range. Gross production of mola were obtained 520.59±23.4, 599.06±258.87, 1063.94±42.87 kg ha-1 from T1, T2 and T3, respectively after 4 months’ culture period. The yield of T3 was significantly greater (P < 0.05) than T1 and T2. The highest gross production was obtained in T3 where stocking density was 6 brood mola m-2. Int. J. Agril. Res. Innov. Tech. 9(2): 23-29, December 2019

scholarly journals 77 Evaluating Nitrogen Management Strategies to Improve Southern Bermudagrass Grazing Systems

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 18-18
Author(s):  
Justin C Burt ◽  
Jennifer J Tucker ◽  
Lisa Baxter
Keyword(s):  
Nutritive Value ◽  
Cynodon Dactylon ◽  
Management Strategies ◽  
Stocking Density ◽  
Warm Season ◽  
The South ◽  
Forage Crops ◽  
University Of Georgia ◽  
Annual Grasses ◽  
The University

Abstract Bermudagrass (Cynodon dactylon) is one of the most common perennial warm-season forage crops grown in the South. While prominent in the region bermudagrass management requires large amounts of fertility and forage quality is moderate at best. Incorporating a legume into bermudagrass pastures could serve as an alternative to the necessary applications of synthetic N, while also improving the nutritive value of the forage base. A two-year grazing evaluation was conducted from May-Sept. 2018 (Y1) and May-Aug. 2019 (Y2) at the University of Georgia Tifton Campus in Tifton, Georgia, to compare concurring production of alfalfa/bermudagrass mixed pastures (BGA) with bermudagrass monoculture pastures with (BGN) or without (BGZ) the application of synthetic nitrogen. The experimental design was a randomized complete block with three treatments and two replications. All paddocks were evaluated pre and post grazing event for herbage availability, botanical composition, forage species competitiveness, and nutritive value. Paddocks (0.8-ha) were rotationally grazed using put and take management with stocker steers (Y1 BW=195.9±22.9 kg; Y2 BW=228.5±30.0 kg), two testers per treatment. Steers were weighed at initiation, conclusion, and on a 28–30 day interval for calculation of ADG and gain/ha. Statistical analysis was conducted using the PROC MIXED procedure of SAS. Despite significant drought in Y2, year did not affect total gain/ha; however, treatment did (P = 0.04), such that BGA was highest (383.6±35.1 kg/ha), and BGN and BGZ were not different (261.2±35.1 kg/ha and 239.0±35.1 kg/ha, respectively). This is likely due to the lower stocking density and inclusion of high-quality volunteer annual grasses in BGZ treatments which allowed for selective grazing. These data suggest that rotationally grazing alfalfa/bermudagrass mixtures can result in a higher gain/ha, than bermudagrass pastures that are supplemented with or without synthetic N in the South.

scholarly journals Influence of density on growth and survival of freshwater prawn Macrobrachium americanum (Bate, 1868) (Caridea: Palaemonidae) cultured in a cage-pond system

2019 ◽  
Vol 16 (4) ◽  
pp. e0508
Author(s):  
Jesus Ponce-Palafox ◽  
Fermin López-Uriostegui ◽  
Fabiola Lango-Reynoso ◽  
María Castañeda-Chávez ◽  
Itzel Galaviz-Villa ◽  
...  
Keyword(s):  
Growth Rate ◽  
Open Systems ◽  
Management Strategies ◽  
Stocking Density ◽  
Freshwater Prawn ◽  
Feed Conversion ◽  
Caridean Shrimp ◽  
Maximum Increase ◽  
Shrimp Culture ◽  
Growth And Survival

The domestication and culture of freshwater shrimp native of tropical and subtropical American Pacific zone requires the study and development of technologies in open systems where their response to types of farming, feeding and management strategies generate practical information for the production of this species. The aim of this study was to evaluate the effect of stocking density on growth and survival in M. americanum juvenile-adult, cage-cultured and to determine the optimal density for grow-out production. The caridean shrimp Macrobrachium americanum was cultured for 152 days in a 16 cage-culture (3 m3 each) at densities of 1, 3, 6 and 9 org / m3, respectively, with stocking sizes from 12.1 ± 1.7 to 13.5 ± 2.3 g. The prawns were fed twice daily with Camaronina 35%. Water quality parameters were within standard range for caridean shrimp culture. There was a significant effect of density on final weight, growth rate, specific growth rate, K condition and survival, and an inversely proportional relationship with the feed conversion ratio. The growth was affected by density, resulting to a maximum increase of 6 org / m3 in the asymmetry of the prawn and also increasing the number of small organisms by 9 org / m3. However, it is necessary to study such aspects as the rate and frequency of feeding, the initial size-grade and the implementation of shelter, among others.

scholarly journals EVALUASI PERTUMBUHAN BENIH PATIN (Pangasius hypophthalmus) YANG DIBERI PAKAN TAMBAHAN CACING SUTRA (Tubifex sp.)

2019 ◽  
Vol 6 (2) ◽  
pp. 77
Author(s):  
Dini Islama ◽  
Nurul Najmi
Keyword(s):  
Growth Rate ◽  
Survival Rate ◽  
Stocking Density ◽  
Fish Farming ◽  
Conversion Ratio ◽  
Feed Conversion Ratio ◽  
Culture Period ◽  
Feed Conversion ◽  
Randomized Design ◽  
Completely Randomized Design

This study aimed to evaluate of patin seed (Pangasius hypothalamus) that is given Tubifex sp. as additional feed. The experiment design was used  completely randomized design with four treatments and four replications. The treatments studied were 100 % pellet without the addition of Tubifex sp. (A), 95 % pellet with the addition of  Tubifex sp. 5 % (B), 90 % pellet with the addition of  Tubifex sp. 10 % (C) and 85 % pellet with the addition of  Tubifex sp. 15 % (D). Patin seed stocking density was 1 individu/l with the length of  3-4 cm and weight of  0,15-0,28 g. The culture period for one cycle of fish farming was 40 days. The ANOVA test showed commercial feeding with the addition of Tubifex sp. as additional feed gave the significant effect on the specific of growth rate, length and feed conversion ratio, but did not give the significant effect on survival rate of patin seed. The best dose to increase the growth of catfish seeds is 85% commercial feeding with the addition of Tubifex sp. 15%.

Incorporating Alfalfa into Warm-season Grass Systems in the Southeast

2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 35-36
Author(s):  
Jennifer J Tucker
Keyword(s):  
Management Strategies ◽  
Forage Quality ◽  
Stocking Density ◽  
Warm Season ◽  
Growing Season ◽  
Great Success ◽  
Supplemental Feed ◽  
University Of Georgia ◽  
Warm Season Grass ◽  
Management Recommendations

Abstract Bermudagrass is the primary warm season perennial forage crop grown in the Southeast (~20 million acres) for livestock and forage operations. While prominent in the region, bermudagrass requires large amounts of fertility and forage quality is moderate relative to other options. There has been great success and a growing interest in interseeding alfalfa into existing bermudagrass stands in the region. This combination eliminates the need for nitrogen fertilization, increases relative forage quality (RFQ) better meeting the nutritional needs of livestock, and decreases the need for supplemental feed. In recent years, research evaluations have been conducted across the Southeast to evaluate the use of alfalfa when incorporated into warm-season grass forage systems under various management strategies. Three projects conducted from 2016–2020 at the University of Georgia Tifton campus evaluated ‘Bulldog 805’ alfalfa interseeded into Tifton-85 bermudagrass (1) when harvested as baleage, (2) under grazing management and(3) in a clipping study to better define defoliation management recommendations. Overall findings from this work observed that alfalfa-bermudagrass mixtures provide greater seasonal herbage accumulation, extend the growing season by three to four months annually, and increase forage DM digestibility and CP compared to bermudagrass alone. Steers on ABG managed under rotational stocking had greater total gain/ha (~%33 increase) due to a higher stocking density throughout the growing season than a bermudagrass monoculture. Results indicate that interseeding alfalfa into bermudagrass is a viable option for southeastern forage systems and can be an effective way to improve forage quality, extend the grazing season, and reduce the need for additional supplementation when fed to livestock.

Beef cattle welfare in the USA: identification of priorities for future research

2015 ◽  
Vol 16 (2) ◽  
pp. 107-124 ◽  
Author(s):  
Cassandra B. Tucker ◽  
Johann F. Coetzee ◽  
Joseph M. Stookey ◽  
Daniel U. Thomson ◽  
Temple Grandin ◽  
...  
Keyword(s):  
Risk Factors ◽  
Beef Cattle ◽  
Animal Health ◽  
Management Strategies ◽  
Stocking Density ◽  
Climatic Conditions ◽  
Additional Research ◽  
Future Research ◽  
Feed Water ◽  
The Usa

AbstractThis review identifies priorities for beef cattle welfare research in the USA. Based on our professional expertise and synthesis of existing literature, we identify two themes in intensive aspects of beef production: areas where policy-based actions are needed and those where additional research is required. For some topics, considerable research informs best practice, yet gaps remain between scientific knowledge and implementation. For example, many of the risk factors and management strategies to prevent respiratory disease are understood, but only used by a relatively small portion of the industry. This is an animal health issue that will require leadership and discussion to gain widespread adoption of practices that benefit cattle welfare. There is evidence of success when such actions are taken, as illustrated by the recent improvements in handling at US slaughter facilities. Our highest priorities for additional empirical evidence are: the effect of technologies used to either promote growth or manage cattle in feedlots, identification of management risk factors for disease in feedlots, and management decisions about transport (rest stops, feed/water deprivation, climatic conditions, stocking density). Additional research is needed to inform science-based recommendations about environmental features such as dry lying areas (mounds), shade, water and feed, as well as trailer design.

scholarly journals EVALUASI PERFORMA BIBIT RUMPUT LAUT Gracilaria verrucosa HASIL KULTUR JARINGAN DI KABUPATEN LUWU, SULAWESI SELATAN

2018 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Makmur Makmur ◽  
Sri Redjeki Hesti Mulyaningrum
Keyword(s):  
Stocking Density ◽  
Gracilaria Verrucosa ◽  
Culture Period ◽  
Alternative Source ◽  
Daily Growth ◽  
The Third ◽  
Agar Yield ◽  
Seed Sources ◽  
Graphical Visualization ◽  
Production Cycles

Penelitian ini bertujuan untuk mengevaluasi performa bibit rumput laut Gracilaria verrucosa. hasil kultur jaringan yang dibudidayakan di salah satu daerah sentra produksi rumput laut di Sulawesi Selatan. Penelitian dilaksanakan di Desa Murante Kecamatan Suli Kabupten Luwu, Sulawesi Selatan pada 2014 selama tiga siklus pemeliharaan dengan lama pemeliharaan 40 hari/siklus. Luasan tambak yang digunakan pada siklus pertama adalah 1,2 ha; siklus kedua 2 ha; dan siklus ketiga 4 ha. Sebagai perlakuan adalah bibit rumput laut hasil kultur jaringan dibandingkan dengan rumput laut lokal sebagai kontrol. Padat penebaran bibit rumput laut adalah 1.000 kg/ha yang dipelihara dengan metode tebar dasar. Penimbangan rumput laut dilakukan pada awal dan akhir penelitian untuk mengetahui laju pertumbuhan harian (LPH) dan produksi, sedangkan kandungan agar dianalisis setelah panen. Analisis data dilakukan secara deskriptif dan disajikan dalam bentuk grafik dan tabel. Dari tiga siklus budidaya menunjukkan bahwa bibit rumput laut hasil kultur jaringan memiliki performa pertumbuhan, produksi, dan kandungan agar yang lebih tinggi dibandingkan bibit rumput laut lokal dengan perbedaan masing-masing 12,1%; 17,8%; dan 6,7%. Pertumbuhan tertinggi terjadi pada siklus kedua, sedangkan kandungan agar tertinggi terjadi pada siklus ketiga baik pada bibit hasil kultur jaringan maupun bibit lokal. Bibit rumput laut Gracilaria sp. hasil kultur jaringan dapat dijadikan alternatif sumber bibit yang berkualitas.This study was aimed to evaluate the performance of G. verrucosa seaweed seed produced from tissue culture and cultivated at the seaweed production center in Murante Village Suli District Luwu Regency South Sulawesi in 2014. The seeds were cultivated for three production cycles, with each cycle lasted for 40 days. The first culture period was conducted in 1.2 ha, the second in 2 ha, and the third in 4 ha of pond areas. The treatments consisted of two different seaweed seed sources, i.e: tissue cultured seaweed seed and local seaweed as a control. The seaweed stocking density used was 1.000 kg/ha cultivated using broadcast method. The daily growth rate (DGR) and biomass as production indicators were measured at the initial and the end of the culture period. The agar yield was measured after harvest. The data were analyzed descriptively and presented in graphical visualization and data tabulation. The present study showed that tissue cultured seaweed had a higher performance in terms of growth, biomass production, and agar yield with the values of 12.1%, 17.8%, and 6.7%, respectively, than that of the local seedling. The highest DGR was produced at the second cycle, and the highest agar yield was measured at the third cycle for both of seaweed seedlings. Given this result, tissue cultured seaweed can be an alternative source of quality seeds.

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