Availability Of Feed Resources Research Articles

Seasonal autoregressive integrated moving average (SARIMA) time-series model for milk production forecasting in pasture-based dairy cows in the Andean highlands.

Milk production in the Andean highlands is variable over space and time. This variability is related to fluctuating environmental factors such as rainfall season which directly influence the availability of livestock feeding resources. The main aim of this study was to develop a time-series model to forecast milk production in a mountainous geographical area by analysing the dynamics of milk records thorough the year. The study was carried out in the Andean highlands, using time-series models of monthly milk records collected routinely from dairy cows maintained in a controlled experimental farm over a 9-year period (2008-2016). Several statistical forecasting models were compared. The Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Mean Absolute Percent Error (MAPE) were used as selection criteria to compare models. A relation between monthly milk records and the season of the year was modelled using seasonal autoregressive integrated moving average (SARIMA) methods to explore temporal redundancy (trends and periodicity). According to white noise residual test (Q = 13.951 and p = 0.052), Akaike Information Criterion and MAE, MAPE, and RMSE values, the SARIMA (1, 0, 0) x (2, 0, 0)12 time-series model resulted slightly better forecasting model compared to others. In conclusion, time-series models were promising, simple and useful tools for producing reasonably reliable forecasts of milk production thorough the year in the Andean highlands. The forecasting potential of the different models were similar and they could be used indistinctly to forecast the milk production seasonal fluctuations. However, the SARIMA model performed the best good predictive capacity minimizing the prediction interval error. Thus, a useful effective strategy has been developed by using time-series models to monitor milk production and alleviate production drops due to seasonal factors in the Andean highlands.

Biochemical composition of Hediste diversicolor (OF Müller, 1776) (Annelida: Nereidae) reared on different types of aquaculture sludge

IntroductionSustainable growth of the salmon aquaculture industry is highly dependent on the availability of new feed resources as well as improved management and utilization of waste streams from production. Polychaetes are capable of recapturing and recycling valuable biomolecules contained in aquaculture sludge and at the same time constitute a possible resource for aquafeeds.Material and methodsIn this study, the potential of Hediste diversicolor (OF Müller, 1776) to recover nutrients and energy contained aquaculture sludge was evaluated. Hereby, the effect of two different diets, smolt and post-smolt sludge, and different feed levels on polychaete growth, and biochemical and elemental composition was assessed.Results and discussionSurvival ranged from 80-90%, independent of treatment. Specific growth rates at the highest feed levels were significantly higher than at the lowest feed levels and growth was not affected by the type of diet. Similarly, total lipid and total fatty acid content of polychaetes were positively correlated with feed level while the type of diet had a limited effect. Fatty acid composition of polychaetes reflected feed levels: in both diet groups, polychaetes at lower feed levels showed a higher percentage of saturated fatty acids; monounsaturated fatty acids increased with increased feed supply for smolt sludge-fed group and polychaetes fed post-smolt sludge showed increased polyunsaturated fatty acid content with increasing feed levels. Neither diet nor feed levels affected protein content and amino acid composition of polychaetes. In conclusion, H. diversicolor could be successfully cultivated on both smolt and post-smolt sludge and was rich in proteins and lipids as well as essential amino and fatty acids. The species can be considered a promising candidate for recycling valuable nutrients from different types of side streams salmon aquaculture.

Weather conditions, distribution of resources feed and dynamics of the spatial structure of the Great Cormorant in the water area of Lake Baikal

On the basis of long-term observations (2018-2023), the features of the distribution of the Great Cormorant in the water area of Lake Baikal during the mass rise of young birds “on the wing” are considered, depending on the distribution of feed resources and the state of weather conditions. At this time, young birds do not yet have experience of independent food production and parents feed them for 10-15 days. In this regard, the availability and abundance of feed resources is very important for birds. Our observations revealed large, but temporary concentrations of birds in areas of high abundance of feed. Large concentrations of birds are also formed in places convenient for recreation during long periods of adverse weather conditions (from 3-4 to 6-7 days) – strong winds. Such clusters can reach several thousand and even several tens of thousands of birds. They form quickly and also disappear quickly as more favorable conditions are restored on other parts of this lake. This feature of the behavior of birds must be taken into account when carrying out accounting work on large areas, which include snd the water area of Lake Baikal. Accounting of birds from a launch along the coastline, with a detailed survey of colonies in places of their concentration, is the only acceptable method of monitoring the state of the population of the Great Cormorant on Lake Baikal.

Availability, nutritional balance, and needs for dairy cattle feed resources in Derashe Special District, Southern Ethiopia

The goal of this study, which was conducted in the Derashe District of Southern Ethiopia, was to balance the district's needs for dairy cattle with the availability of feed resources. Data were gathered by field observations, key informant interviews, and a standardized questionnaire. With 149 responses, the district was divided into three agro-ecologies. Using a technique called probability proportional to size-sampling, the number of responders was calculated. Lowland,mid-altitude, and highland regions all had average land sizes of 1.67, 0.27, and 1.38 ha, respectively. The research district's entire livestock population was calculated to be 134,948.84 TLU. Cattle made up 83.23% of this, followed by goats 6.19%, donkeys 5.09%, sheep 3.51%, chickens 1.19%, mules 0.53%, horses 0.18 percent, and camels 0.002% of the district's total TLU of the animal population. There were 9.5 heads of local and crossbred cows in each household'saverage herd. Dairy cattle in the study locations primarily ate natural pasture, crop residues, crop aftershock grazing, standing hay, maize that had been thinned, and unconventional feeds (Cheka atella and Areke atella). Grazing land produced 97.75 tons of dry matter per year, crop leftovers 827.21 tons, conventional feeds 264.78 tons, fodder trees and shrubs 1.29 tons, crop aftermath grazing 110 tons, concentrates 0.5 tons, and forest land 30.54 tons. A total TLU value of 1693.5 was obtained by analyzing the overall feed balance in terms of DM yield annually. The present TLU units with a negative balance of 2513.16 tons demand about 3861.85 tons of DM annually. There was a deficit of 140 tons in the total CP produced and needed for the TLU, which came to 477.18 and 617.72 CP tons, respectively. Overall metabolizable energy (ME) produced and needed for the TLU were 25,739.3 and 73683.72 tons MJ, respectively, with a negative balance of 47,944.42 tons MJ of ME. Free grazing, stall feeding, and tethering were the three main feeding methods used in the research locations. Lack of feed, a lack of grazing pasture, subpar extension services, and a lack ofwater were the main obstacles and issues for the development of dairy cattle. Possibilities for increasing dairy feed output include favorable meteorological conditions, cereal crop productivity, and road access. The growth of forage, the collecting and storage of crop leftovers under sheds, the conservation of forage, particularly hay and silage, and the facilitation of feed selling mechanisms in local market areas could all help ease feed scarcity issues.

Evaluation of Livestock Feed Resources and Feed Balance in Selected Districts of Gamo Zone, Southern Ethiopia

The study was conducted in Bonke, Mirab Abaya and Dita districts of Gamo Zone, Southern Ethiopia with the objectives to assess available, opportunity, constraints and copying strategy of livestock feed production and estimate of feed balance. Primary and secondary data sources and field observations, key informants interview, focus group discussions and individual interview was employed to generate data. The survey data was stratified into districts, coded and analyzed usingthe Statistical Package for Social Sciences (SPSS version 20) windows 10 and general linear model procedure were used to analyze data . Statistical variation of categorical data (perception data) was tested by means of cross tabulation. In study districts, the palatable and perennial fodder trees were Erythrina brucei, Arundinaria alpine, Ficus sur, Dombya torrida and Hagenia abyssinica were supported major feeds for livestock. The major opportunity related to livestock feed productionin study districts was presence of different feed resource types, distinctive agro-ecologies and accessible of crop residues, but the major constraints related to livestock feed production were land scarcity, shortage of dry season forages and land degradation due to erosion. Minimize livestock number, conserving optional feeds and purchasing optional feeds were major copying strategies of feed resources in study districts. The overall mean of feed supply in terms of DM yield per year to TLU was found to be 5.782tons of DM /Hh/ annual with negative feed balance of 5.47tons. Based on the findings of the present study, low productivity of livestock in Bonke, Dita and Mirab Abaya districts is clearly associated with the meager availability of feed resources. Hence, in order to alleviate these problems, alternative feed production technologies should be undertaken, such as, farmers should practice forage development on their own crop land and collect crop residues during crop harvesting times and conserve it under shed, the nutritive value of different types of fodder trees and shrubs should be further determined in the future, feed storage methods, particularly hay and silage during an excess of feed resources available should be practiced.

Is scat marking a reliable tool for otter census and surveys at the landscape scale?

Biological significance of scat marking by otters has been a controversial subject among scientists. Using multiyear (2014–2017) data of otter spraint counts in South Korea, this study aimed to test whether the observed pattern of spraint presence/absence is driven by detection error and if/how scat counts can be a proxy for otter abundance at the landscape scale. To test the first hypothesis, spraint presence/absence was analyzed through occupancy models, which relied on environmental variables related to otter detectability and presence. Spraint count models were used to test the second hypothesis against resource-related covariates in combination with landscape, anthropogenic, and climate variables through machine learning algorithms (MLAs). The detection probability has specifically decreased in areas characterized by high rainfall and human population densities, whereas the probability has increased near food-rich sites, characterized by high marking frequencies. The temporal trends of spraint count predictions were in line with changes in the diversity of fish communities in 2014–2017 instead of fish biomass, suggesting that the availability of feeding resources is higher where fish communities are more diverse. Because diverse fish communities can attract otters, fish diversity conservation is critical for preserving this mammal's populations. This fine scale four-year monitoring has contributed to the disentanglement of the role of spraint presence/absence and spraint counts in detectability and population trends. This will assist in identifying key resource areas and planning strategies to promote otter conservation and dispersal dynamics.

Milk Yield of Dairy Buffaloes Supplemented with Yeast Solution and Yeast-fermented Cassava Pulp

Feed resource availability and quality are two of the major factors limiting dairy production in the Philippines. Utilization of microbial-based feed additives and agricultural by-products such as cassava pulp aided by fermentation technology can help provide the needed resource. This study aimed to determine the effect of activated yeast (Saccharomyces cerevisiae) solution (AYS) and yeast-fermented cassava pulp (YFCP) on milk production and feed cost-efficiency in dairy buffaloes. The study followed RCBD design using 63 dairy buffaloes at the Philippine Carabao Center in Ubay Stock Farm, Bohol. The average daily milk yield (ADMY) of buffaloes supplemented with 0.5L AYS and 1L AYS twice daily were greater than that of control buffaloes by 0.67L and 0.69L, respectively (P = 0.0039).On the other hand, the ADMY of buffaloes fed with YFCP and YFCP+AYS were greater than that of control buffaloes by 0.64 and 0.68L, respectively (P = 0.0320). Supplementation of AYS and feeding YFCP yielded the lowest cost per liter of milk produced at PhP 20.25 and PhP 16.24, respectively. It is recommended to supplement milking dairy buffaloes with AYS or feeding YFCP in areas with cassava pulp to increase feed resource, increase milk production and improve feed cost-efficiency thereby increasing significantly the farmer’s income.

Trophic position of dolphins tracks recent changes in the pelagic ecosystem of the Macaronesian region (NE Atlantic)

Dolphins play a key role in marine food webs as predators of mid-trophic-level consumers. Because of their mobility and relatively long life span, they can be used as indicators of large-scale changes in the ecosystem. In this study, we calculated the trophic position (TP) of 5 dolphin species from the Canary, Madeira and Azores Islands using bulk and compound-specific stable isotope ratios from muscle tissue to assess trophic adaptations to recent changes in the availability of feeding resources. Dolphin TP values were then compared with those of 7 other species of cetaceans from this region. Analysis of stable nitrogen isotopes in amino acids of the common dolphin indicated non-significant effects of changes in the basal resources of the food web and thus supported the use of bulk samples for TP estimations. Dolphins occupied an intermediate TP (mean: 3.91 to 4.20) between fin (3.25) and sperm whales (4.95). Species-specific TP were equivalent among islands. However, TP increased for the common dolphin and decreased for the bottlenose dolphin (the latter also becoming more oceanic) between 2000 and 2018 in the Canary Islands. These results suggest different impacts of recent changes in the oceanography and in the pelagic food web of the Macaronesian region on the trophic ecology of dolphin species.

ОБЕСПЕЧЕННОСТЬ КОРМОВЫМИ РЕСУРСАМИ И ВИДОВОЙ СОСТАВ ПОТРЕБЛЯЕМЫХ ВИДОВ РАСТЕНИЙ ГРЕБЕНЧУКОВОЙ ПЕСЧАНКОЙ (MERIONES TAMARISCINUS PALLAS, 1773) В СЕВЕРНОЙ ЧАСТИ ЗАПАДНОГО ПРИКАСПИЯ

In 2015-2017, the study of the ration of tamarisk gerbil in the arid zone of the North-Western Precaspian, which use almost the entire available range of growing plant species in nutrition, was carried out. However, in each season, only a small number of plant species formed the basis of nutrition. The availability of feed resources of tamarisk gerbils in all seasons of the year is achieved both due to the natural change of vegetating plant species and due to the change of the type of feed resource (green parts of plants, bulbs, seeds, fruits and insects).

Livestock feed resources in the West African Sahel.

Limited supply of quality feed is the most important factor limiting livestock productivity in many sub‐Saharan African (SSA) countries. Having a systematic inventory of available feed resources, identifying main challenges and potentials for improvement is the first step towards designing development strategies to improve feed quality and quantity. The objective of this study was to review the available feed resources and their quality in West African Sahel across different agro‐ecological zones and to identify the research gaps and strategies to improve feed resource availability. The West African Sahelian zone is home to 135 million people who herd 173 million head of ruminant livestock. The main feed resources for grazing ruminants are pastures and crop residues; commercially formulated feeds are increasingly being used in poultry and pig production, particularly in peri‐urban areas. Feed resources for livestock are diverse and vary markedly across agro‐ecological zones in the West African Sahel and across seasons in terms of type, quantity, and quality. Given that crop residues are among the most important feed resources, there is need to invest in promoting adoption of proven methods for improving their quality and preserving it. Given poorly developed feed markets in the Sahelian rural areas and cities, strengthening the feed value chain is critical for improving the feed resource base in West Africa. Additional critically important needs are to increase awareness about the importance of feed quality, to create quality‐based feed marketing systems, and to appreciate and enhance women's roles in feed production.

Preface

The 1st of International Conference on Livestock in Tropical Environment (ICLiTE-1) 1-2 September 2021, Surakarta, Indonesia https://iclite.id/Proudly present by:Master Program of Animal Science Universitas Sebelas MaretIn collaboration withIndonesian Society of Animal SciencePrefaceFirst, it is our time to thank all the participants at the 1st International Conference on Livestock in Tropical Environment (ICLiTE-1) on September 1-2, 2021. This conference is proudly organized by the Master Program of Animal Science, Faculty of Agriculture, Universitas Sebelas Maret, in collaboration with the Indonesian Society of Animal Science, commonly known as PB-ISPI.At this conference, we invite talks from academicians, professionals, and industries. We consider the current conditions where we are still in a COVID-19 pandemic to hold this conference virtually. Though it is in a pandemic situation, science must go forward, especially in animal science, which is believed to have good prospects during and later after the pandemic. This conference is held to identify ideas, practices, and policies that constitute our concept of livestock production in the tropical environment. For that, we insist on holding the conference online to be a platform between scientists and industry to have a recent view of research during the pandemic situation.The livestock industry in tropical areas is continuously facing complicated challenges due to harsh environmental conditions. These challenges exposed the livestock to both direct and indirect effects. The direct impacts of the tropical environment are related to health, physiology, production, and reproduction. In contrast, indirect effects involved the quality and availability of feed and water resources and the impact on housing design and rearing systems. On the other hand, the livestock industry also contributes to environmental issues related to land space, waste, and greenhouse effects. In addition, tropical areas are the location for most of the developing countries. This part of the world has less investment in the industry and research in livestock as the contributor for animal-based food, while the issues related to food resilience and safety still prevail. The 1st International Conference on Livestock in Tropical Environment is conducted to address the two-way issues regarding the environmental challenges faced by the livestock industry and the impact of the livestock industry on the environment in tropical areas. We also invite some influential distinguished speakers to share their valuable information and knowledge for the plenary session at this conference.List of Conference photographs gallery, Sponsor or funding acknowledgements, List of committees are available in this pdf.

Constraints and Way Forward for Boosting Income from Dairy Farming in India: A Review

For a sustainable livelihood model of farming under Indian conditions, dairying becomes an inevitable part along with crop production. Dairy farming has been a continuous source of income to the farmers which help them in their socioeconomic development. Increased quantity and quality of milk always fetches good returns to the farmers. Hence, it becomes the priority of almost all the farmers to extract more and more milk from the animals which may sometimes pushes them into faulty husbandry practices which ultimately lead to loss of income and loss of health of animals. Nonetheless, dairy production in India has boosted many folds as shown by increased livestock population and production scenario in the country. However, under Indian conditions, for enhancing the income from dairy farming certain constraints have to be layout and correspondingly firm solutions have to be made. Constraints such as poor availability of high producing Germplasm, rapidly decreasing availability of feed and fodder resources, poor husbandry practices, reproductive and other health problems among several other problems hinder the income obtained from dairy farming to the farmers. In addition to the much needed solutions of such constraints, there needs for the reforming government policies for overall development of dairying in India. This article discusses on such probable constraints and their solutions in concise yet informative way so that wholesome development of income through dairy industry may be achieved.

Production performance and egg quality evaluation of indigenous chickens across different agro-ecologies of Southern Ethiopia

Indigenous chickens were evaluated for their egg production, growth performances, and external and internal egg quality parameters across three agro-ecologies. For experiment 540 (180 male and 432 female) chickens were distributed to the three agro-ecologies (lowland, midland, and highland) at their 20 weeks age. Body weight was recorded from each chicken during distribution, 4th week, and 8th week after distribution into pre-selected households. Egg production potential was identified from the indigenous chickens across different agro-ecologies. Moreover, egg quality traits were evaluated from randomly selected 270 (90 from each agroecology) eggs. Egg production of indigenous chickens in the highland was 47.7 which was highly significantly (P = 0.0001) lower number than of midland (54.2) and lowland (51.4). Except for Shell weight, all the external egg quality parameters evaluated were exhibited significant differences across different agro-ecologies. Among the internal egg quality parameters only albumen weight had a significantly (P = 0.007) higher in midland than highland. Most of the variation in egg weight was due to the positive correlation with egg length (69%), and egg width (67%). There was a variation for performance and egg quality traits of indigenous chickens in different agro-ecologies, especially better in midland, which might be resulted from the variation in environment, feed resources availability, and better management followed by households.

Development strategy to improve beef cattle business in Pati Regency

Most of beef cattle farmers in Pati Regency are dominated by smallholder farming system. The research was conducted to determine the alternative strategies for the development of beef cattle business in Pati Regency. Focus Group Discussion (FGDs) was used in this research for data collection. Based on the results, FGDs had benefit to formulate strategies in order to increase beef cattle sector in Pati Regency based on stakeholder’ perspective. Beef cattle sector in Pati Regency had opportunity to develop to improve productivity and able to compete with import product from other country. It had availability of feed resources by mix farming system practices between crop and livestock production. In order to support smallholder farmers, government need to plan long term strategies such as open access to capital, build partnership to improve marketing system as well as regulate production system and processing of beef product.

Finishing season and feeding resources influence the quality of products from extensive-system Gascon pigs. Part 1: Carcass traits and quality of fresh loin

Consumers perceive pork products from local breeds reared in extensive systems positively because of their specific quality properties and regional identity. The sensory, nutritional and technological qualities of these products depend, among other things, on pig production, especially its climatic conditions and the availability of feed resources, which can influence traits of muscle and fat tissue. The present study (part 1) was part of a larger project that assessed the influence of the finishing season and feeding resources on carcass and tissue traits and the quality of meat and dry-cured ham from Gascon pigs in an extensive system. Following the specifications of the Protected Designation of Origin “Noir de Bigorre”, castrated Gascon males were reared on rangelands (grassland and forest areas) and received a supplementary diet from 5 to 6 months of age until slaughter at a minimum of 12 months of age and ca. 170 kg live weight. Three finishing seasons were considered as follows: Winter (n = 18), Spring (n = 22) and Autumn (n = 23). To estimate specific effects of season on productive and quality traits and avoid bias due to effects of genes known to influence these traits, polymorphisms in the RYR1, PRKAG3, MC4R and LEPR genes were included in the analysis models. The finishing season did not influence growth rate. Compared to Winter pigs, Spring and Autumn pigs had slightly lower carcass fatness (P < 0.05), higher ultimate pH and redder and darker color of the Longissimus muscle (LM) (P < 0.01). Loin drip loss was low overall, but was higher for Spring pigs, whereas cooking loss and shear force were similar among seasons. Spring pigs tended to have the lowest LM lipid content, whereas LM myoglobin content remained unaffected. Autumn pigs had lower potential of lipid oxidation in LM than Winter and Spring pigs (P < 0.01), but muscle metabolic traits assessed via glycolytic and oxidative enzyme activities did not differ among seasons. The finishing season modified the backfat fatty acid (FA) profile, with a lower polyunsaturated FA percentage in Autumn pigs than Winter or Spring pigs (P < 0.001), even though the saturated and monounsaturated FA percentages did not differ. In particular, Spring pigs had the lowest n-6:n-3 and C18:2:C18:3 ratios (P < 0.001), as a result of grazing. Overall, Spring and Autumn finishing seasons seem more favorable to technological and sensory pork attributes, with an additional positive effect of Spring finishing on pork nutritional value.

Critical Aspects of Aquafeed Value Chain in the Kenyan Aquaculture Sector- A Review

This article reviews critical aspects of the aquafeed value chain in the Kenyan aquaculture sector. Aquaculture production in Kenya has grown steadily in recent years, to more than 18,000 tons in 2019. Due to the growing demand for fish and fish products, there has been a gradual shift from extensive to semi-intensive to moderately intensive aquaculture systems, leading to an increased demand for high quality commercial fish feeds. The current annual demand for fish feed in Kenya is estimated at 34,000 tons. It is the lack of sufficient and high-quality local fish feed production that has created a market for fish feed importers, which is currently estimated at 7,000 tons annually. However, the imported fish feed is expensive for most fish farmers, leading to low production. Local fish feed production through home-based formulation should be driven by fish farmers to contain the rising cost of feeds. Most cottage feed manufacturers produce mash, crumbles or sinking pellets because they lack extruder for making floating pellets, hence the need for quality control in the aqua-feed sector. Fish feed producers are weakly covered by financial services providers, hence the inability to compete effectively with other value chains. The paper outlines five key actors in the aqua-feed value chain from production to marketing. These include; raw material (ingredients) suppliers, feed manufacturers (feed formulators), distributors/wholesalers, retailers, and customers who are fish farmers. We recommend intensification of local aqua-feed production using locally available materials to reduce the importation. This will ensure the long term economic and ecological sustainability of the aquaculture sector. There is a need for favourable policies to lower importation rates for raw materials as a way of boosting the availability of additional feed resources and inputs.

Livestock Feed Resources and Feeding Practices in Bonke and Geresse Districts, Gamo Zone, Southern Ethiopia

The study was conducted at Bonke-Geresse District of Gamo Zone, Southern Ethiopia with the objectives of assessing the availability of feed resources in terms of quantity and quality and feeding practices of livestock. The district was stratified into three distinct agro-ecologies. A total of 138 farmers were randomly selected based on the probability of proportional sampling by means of a structured questionnaire. Direct field observation was also used in the collection of data. The major feed types used by farmers were identified and categorized into five classes: natural pasture grazing, green feeds, hay, concentrate (commercial mix and agro-industrial by-products) and non-conventional feed resources. The total Data were analyzed using statistical Package for Social Sciences version 20. Chemical analysis on crop residues indicated that they have low crude protein (2.66 to 6.7) and are composed of high lignin content ranging from 8.42 to 16.83. The major constraints related to livestock feed were shortage of feed, shortage of grazing land, poor market access, lack of sample awareness on forage cultivation and poor feeding system. Overall feed balance in terms of DM yield per year to a total TLU value of 7,068.8 was found to be 12,947.51 tons of DM per annum with negative feed balance of 5,878.71tons. Based on the findings of the present study, low productive and reproductive performances of livestock at Bonke are clearly associated with meager availability of feed resources. Therefore, introduction and adaptation of alternative feed production technologies such as development of improved forages, feed processing and conservation technologies, skill improving training and efficient feed utilization strategies would be taken as important steps to overcome the prevailing feed supply problem.

Thought of Alternate Aquafeed: Conundrum in Aquaculture Sustainability?

The exponential growth of human population and their ever-increasing demands have challenged the aquaculture sector with respect to its growth, sustainability and environmental well-being. Due to the rapid intensification, aquaculture’s share of global fishmeal and fish oil consumption has more than doubled over the past decade with limited availability and high prices. Hence, the key concern of aquaculture in recent times is to reduce the environmental footprint while feeding the farmed fish with nutritionally balanced, economic and environmentally sustainable feed. But the changes in feed systems are dependent on several potential drivers, including environmental, political, economic, cultural, technological and demographic ones. The use of compound feeds formulated with a great variety of ingredients was a major step in the development of the worldwide aquaculture industry in the last century. However, the main challenges are the availability and cost of alternate feed resources, their competitiveness with other sectors, demand-supply consort with the environmental quality, social acceptability and economic growth. This review is an attempt to assess the present scenario of conventional aquafeed with an understanding of the gaining importance of alternate aquafeed along with their trade-offs addressing the principal issues of sustainability for future policy making.

Variación espacio-temporal en la dieta del coyote en la costa norte de Jalisco, México

El presente trabajo analiza los cambios a nivel local, en espacio y tiempo, que manifiesta el coyote en su dieta. Se desarrolló en una zona de Bosque Tropical Subcaducifolio de la costa norte de Jalisco, en donde se efectuaron recolectas de excrementos, de marzo del 1999 a abril del 2001, en cuatro sitios con condiciones diferentes. Las muestras fueron analizadas anualmente, estacionalmente (seca y húmeda), para toda el área y por sitios. Resultando que en general el material vegetal (44.20%) y mamíferos (36.05%) alcanzaron el 80% de la frecuencia relativa de ocurrencia (FRO) de los elementos contenidos en su dieta, observandose cambios significativos entre las estaciones seca y húmeda en ambos grupos. Los elementos con mayor FRO fueron Vitex hemsleyi, Sigmodon mascotensis y Liomys pictus. El material vegetal consumido fue diferente entre sitios, registrándose la más altafrecuencia de consumo en el sitio 1 (47.35%) y la menor en el sitio 3 (22.22%), en cambio el consumo de mamíferos fue mayor en el sitio 4 (44.83%) y la menor en el sitio 2 (30.77%). Estacionalmente el material vegetal mostró diferencias en los sitios 2 y 4, mamíferos en los sitios 2 y 4, aves en el sitio 4 e insectos en el sitio 1. Se analizó la diversidad de categorías alimenticias consumidas, mediante el índice de Shannon (H'), resultando H'= 2.33 para toda el área de estudio; entre sitios y estaciones se presentaron diferencias en los valores de H'. Se concluye que el carácter oportunista del coyote prevalece aún a nivel local, lo que pone de manifiesto su capacidad de adaptación a la disponibilidad y abundancia de recursos para su dieta.

Food preferences of nilem carp (Osteochilus hasselti) at paddy-fish culture pond in Kuningan, Garut and Tasikmalaya, West Java Province

The research aims are to determine the availability of natural feed resources and to study the food habits of nilem carp (Osteochilus hasselti) in the paddy-fish culture system in Kuningan (300 m from sea level), Garut (700 m from sea level) and Tasikmalaya (500 m from sea level) districts. The research used a survey method with descriptive analysis. The treatment was without commercial feeding so that it utilizes natural feed, and consists of two replications in each location. The research was conducted in August 2018 - May 2019. The fish used was java carp with a length of 5-7 cm and a stocking density of 2000 fish/paddy field 200 m2. The results showed that there were two types of feed composition, namely phytoplankton and zooplankton. The preponderance index of nilem carp in each location generally utilizes phytoplankton from the phylum Bacillariophyta as its main feed. The index of electivity shows that the preference level of Java carp for phytoplankton has similarities in each region. Its mostly preferred phytoplankton, such as Cyclotella, Gomphonema, Gyrosigma, Navícula, Nitzschia, and Synedra from Bacillariophyta and Closterium, Coelastrum and Cosmarium from Chlorophyta.