Research Progress on Nutritional Requirements of Carp

Carp is a temperate freshwater fish native to Asia,distributed in all regions of the world except Australia and South America.With the improvement of comprehensive and healthy breeding technology of carp,the unit yield has been greatly increased mainly due to the exten-sive use of compound feed.In this study,the nutritional requirements of carp were summarized from the aspects of protein,amino acids,fat,carbohydrate,calcium and phosphorus,vitamins and taurine.This study provides a certain theoretical reference for scientific formula of carp feed.

Nutritional requirements of meat-type and egg-type ducks: what do we know?

The demand for duck meat, duck eggs, and associated products is increasing each year. Classic and modern selection programs have been applied to enhance the economic traits of ducks to satisfy the requirements of consumers and enhance the incomes of producers. The nutritional requirements of unselected ducks may not be adequate, however, to fulfill the potential productivity performance of modern birds, including both meat-type and egg-type ducks. In particular, an imbalanced diet is associated with low productive performance and signs of nutritional deficiency（if insufficient nutrients are supplied）, as well as with high feed costs and manure problems that reflect flock health and welfare（if excessive nutrients are supplied）. Thus, the main aim of this review is to summarize the results of previous studies that estimated the nutrient requirements of meat-type and egg-type ducks in order to evaluate current knowledge and to identify further issues that need to be addressed. In addition,the results obtained in previous studies are compared in order to understand how to lower commercial feed costs,fulfill the genetic potential of selected ducks, protect the environment from pollution, and satisfy the welfare and health needs of ducks.

Isoenergetic-practical and semi-purified diets for protein requirement determination in Hermetia illucens larvae:consequences on life history traits

Background:Black soldier fly(BSF)is one of the most promising species for the intensive breeding of insects given its adaptability and its efficiency in the conversion of waste.To maximize the production and use waste as substrates,it is essential to determine the larvae nutritional requirements.The study aims to evaluate the effects of5 practical,semi-purified and isoenergetic diets(PSPID)with increasing protein levels(10%,CP10;14%,CP14;16%,CP16;19%,CP19)on BSF life history traits.A total of 2000 six-day-old larvae were weighed and divided into groups of 100(4 replicates/treatment[PSPID and Gainesville diet(GA)used as environmental control]).In larva-prepupa stage,sampling was carried out on 30 individuals/replicate,while in prepupa-adult stage on 35.Results:In the whole larval stage,the CP16 treatment performed better when compared to the other groups.At18 days old,the CP14 treatment showed a higher weight than the CP19(P<0.01),while the CP10 and CP16weights were intermediate.On the contrary,the CP10 prepupae weight was higher than the CP19(P<0.01).The CP10 and CP14 pupae performed better in terms of weight when compared to the others(P<0.01).The dietary treatments did not affect the adult parameters.The sex significantly influenced both the exuvia weight,which was the greatest in females(P<0.001),and the fly lifespan,longest in males(P<0.05).Fly lifespan was also influenced by the interaction between treatment and sex,with the CP19 females showing a longer life than the others(P<0.05).Conclusions:In conclusion,the optimal protein level considering the whole larval stage is 16%on dry matter(DM).At 18 days old,looking at the size intended for the meal production,it can be considered 14%on DM.The result obtained on adult emergence in PSPID may not be attributable to the protein content.Further researches on macronutrients requirements determination have to be conducted to evaluate the substrates composition effects on BSF life history traits.

Sociodemographic Factors Associated with Dietary Intake of Thiamine, Riboflavin, and Niacin among Chinese Adults in 2015

Objective To estimate the association between three B-vitamin intakes and sociodemographic factors among adults in China.Methods We derived our data from the China Health and Nutrition Survey(CHNS) among 12,241 individuals aged 18–64 years. Log binomial regression was used to estimate adjusted prevalence ratios for factors associated with the inadequate intake of B-vitamins.Results Females with low incomes and living in the north had a higher prevalence of inadequate riboflavin intake than those with high incomes and living in the south. Both males and females living in a village had a higher prevalence of inadequate riboflavin intake than adults living in a city. Adults with low income, low education, and living in the north or in a village had a higher prevalence of inadequate niacin intake than adults with a high income, high education, and living in the south or in a city.Conclusion We found that income, region, and area of residence were associated with riboflavin intake. Education, income, region, and area of residence were associated with niacin intake. Welltailored strategies and policies are needed to improve nutritional status in China.

True grit: ingestion of small stone particles by hummingbirds in West Mexico

Background: Grit is used by birds mainly for grinding hard food items but can also serve a nutritional role as a source of minerals. Ingestion of grit by birds has been documented primarily in species that feed on seeds and invertebrates.Although feeding mainly on nectar and small arthropods, hummingbirds also ingest grit, but why they do so is unclear. We quantified the number of grit particles in the stomachs of six species of hummingbirds during an annual cycle in a seasonal ecosystem of West Mexico.Methods: We compared the number of grit particles in the stomachs of different hummingbird species(Mexican Violetear Colibri thalassinus, Amethyst-throated Mountaingem Lampornis amethystinus, White-eared Hummingbird Basilinna leucotis, Rivoli's Hummingbird Eugenes fulgens, Broad-tailed Hummingbird Selasphorus platycercus, and Rufous Hummingbird S. rufus), and between sex and age categories during the different seasons of a year. To deter-mine if grit was used to grind ingested arthropods, we examined the relationships between the number of grit parti-cles, the biomass of arthropods ingested, and their chitin content.Results: Although species did not differ in the number of grit particles in their stomachs, we found that grit was mostly ingested by female individuals, with only one male of one species(Mexican Violetear) presenting grit in its stomach. We also found that female hummingbirds had grit in their stomachs during the rainy and the cold-dry season(June-February) but not during the warm-dry season(March-May). Our analyses revealed no relationship between the number of grit particles and the amount of ingested arthropods and arthropod chitin content. However,high grit consumption was related to wasp ingestion on Mexican Violetears.Conclusions: Our results indicate that grit is used mainly by female hummingbirds. The seasonal variation in the ingestion of grit by female individuals suggests that it can be used to meet mineral requirements related to breed-ing;however, this topic needs further exploration. Additionally, the use of grit was proportionally higher in juvenile individuals, suggesting it is used for grinding arthropods during a period of fast development.

Optimization of Mycelial Culture Conditions and Fructification of Lentinus Species Using Rice Straw and Sawdust Based Substrates

Lentinus(Basidiomycota,Polyporaceae)species are naturally-occurring mushrooms with nutritional and pharmacological importance.Unlike shiitake Lentinula edodes,a widely cultivated mushroom,Lentinus species are often ignored because they are underutilized and unpopular.However,like shiitake,Lentinus spp.could also be valuable resources of functional food and bioactive compounds.It is therefore of high interest to understand their cultural requirements leading to their efficient biomass production.Thus,this study established the optimal culture conditions for the maximum mycelial growth of seven wild strains under four Lentinus species.Their cultivation potentials were also determined using rice straw and sawdust(7:3 v/v)substrate formulation.Mycelia of all Lentinus strains evaluated favorably grew on coconut water gulaman(local crude agar)and other culture media for specific strain with suitable pH ranging from 5.0 to 8.0.Aeration was not a major physical factor for all Lentinus strains except L.squarrosulus strain 1,which favored sealed condition.Both lighted and dark conditions were found suitable for both strains of L.sajor-caju,L.strigosus strain 2 and L.swartzii whereas both strains of L.squarrosulus and L.strigosus strain 1 favorably grew in lighted condition.However,all Lentinus strains evaluated recorded the highest mycelial growth rates and thick mycelia at 30℃.In terms of fruiting body production,all Lentinus strains demonstrated cultivation potential.The seven Lentinus strains completely colonized the substrate for 18.0-25.6 days and initiated primordia for 21.6-33.5 days.The highest yield(52.5 g bag^(-1))and biological efficiency(10.5%)was recorded in L.strigosus strain 1,whereas the lowest was noted in L.strigosus strain 2 with 21.1 g bag^(-1) yield and 4.2%biological efficiency.L.sajor-caju strain 2 and L.squarrosulus strain 1 showed the widest cap diameter and longest stipe,respectively.The mycelial growth and fruiting body performance of Lentinus may vary depending on species and strains.Altogether,the seven new wild strains of Lentinus can be artificially cultivated by providing the nutritional and physical requirements.