Protein hydrolysates in animal nutrition：Industrial production, bioactive peptides,and functional significance

Recent years have witnessed growing interest in the role of peptides in animal nutrition. Chemical, enzymatic, or microbial hydrolysis of proteins in animal by-products or plant-source feedstuffs before feeding is an attractive means of generating high-quality small or large peptides that have both nutritional and physiological or regulatory functions in livestock, poultry and fish. These peptides may also be formed from ingested proteins in the gastrointestinal tract, but the types of resultant peptides can vary greatly with the physiological conditions of the animals and the composition of the diets. In the small intestine, large peptides are hydrolyzed to small peptides,which are absorbed into enterocytes faster than free amino acids（AAs） to provide a more balanced pattern of AAs in the blood circulation. Some peptides of plant or animal sources also have antimicrobial, antioxidant,antihypertensive, and immunomodulatory activities. Those peptides which confer biological functions beyond their nutritional value are called bioactive peptides. They are usually 2–20 AA residues in length but may consist of 〉20AA residues. Inclusion of some（e.g. 2–8%） animal-protein hydrolysates（e.g., porcine intestine, porcine mucosa,salmon viscera, or poultry tissue hydrolysates） or soybean protein hydrolysates in practical corn-and soybean mealbased diets can ensure desirable rates of growth performance and feed efficiency in weanling pigs, young calves,post-hatching poultry, and fish. Thus, protein hydrolysates hold promise in optimizing the nutrition of domestic and companion animals, as well as their health（particularly gut health） and well-being.

Replacing fishmeal with soybean meal affects survival, antioxidant capacity, intestinal microbiota, and mRNA expression of TOR and S6K1 in Macrobrachium rosenbergii

Using alternative plant-derived dietary protein to replace fishmeal,combined with practical evaluation indexes,is a recent focus for aquaculture practices.An 8-week feeding experiment with giant freshwater prawn Macrobrachium rosenbergii post-larvae was conducted to determine the eff ects of replacing fi shmeal(FM)with soybean meal in the feed,in terms of growth performance,antioxidant capacity,intestinal microbiota,and mRNA expression of target of rapamycin(TOR)and ribosomal protein S6 kinase B1(S6K1).Four isonitrogenous diets with isocaloric value were prepared to contain 100%,75%,50%,or 25%FM as the protein source(dietary treatments FM100,FM75,FM50,and FM25,respectively).Each diet was fed to post-larval prawns(mean weight 0.045±0.002 g)twice a day in four replicates.No signifi cant diff erence in weight gain was observed among all groups,but the survival rate of prawns fed the FM50 and FM25 diets was signifi cantly lower than that of prawns fed the FM diet.The mRNA expression of both TOR and S6K1 were the lowest in hepatopancreas of prawns fed the FM25 diet.Superoxide dismutase activity of prawns fed the FM25 diet was significantly lower than that of prawns fed FM50.In contrast,the malondialdehyde content was signifi cantly higher in prawns fed FM25 as compared with those fed FM75.The proportion of fishmeal in the diet did not affect the composition of core(phylum-level)intestinal microbiota,but greater fishmeal replacement with soybean meal had a potential risk to increase the relative abundance of opportunistic pathogens in the gut when considered at the genus level.These results suggest that fishmeal replacement with soybean meal should not exceed 50%in a diet for post-larval M.rosenbergii.

Insulin resistance is associated with subclinical vascular disease in humans

Insulin resistance is associated with subclinical vascular disease that is not justified by conventional cardiovascular risk factors,such as smoking or hypercholesterolemia.Vascular injury associated to insulin resistance involves functional and structural damage to the arterial wall that includes impaired vasodilation in response to chemical mediators,reduced distensibility of the arterial wall(arterial stiffness),vascular calcification,and increased thickness of the arterial wall.Vascular dysfunction associated to insulin resistance is present in asymptomatic subjects and predisposes to cardiovascular diseases,such as heart failure,ischemic heart disease,stroke,and peripheral vascular disease.Structural and functional vascular disease associated to insulin resistance is highly predictive of cardiovascular morbidity and mortality.Its pathogenic mechanisms remain undefined.Prospective studies have demonstrated that animal protein consumption increases the risk of developing cardiovascular disease and predisposes to type 2 diabetes(T2D)whereas vegetable protein intake has the opposite effect.Vascular disease linked to insulin resistance begins to occur early in life.Children and adolescents with insulin resistance show an injured arterial system compared with youth free of insulin resistance,suggesting that insulin resistance plays a crucial role in the development of initial vascular damage.Prevention of the vascular dysfunction related to insulin resistance should begin early in life.Before the clinical onset of T2D,asymptomatic subjects endure a long period of time characterized by insulin resistance.Latent vascular dysfunction begins to develop during this phase,so that patients with T2D are at increased cardiovascular risk long before the diagnosis of the disease.

Visualization of amino acid composition differences between processed protein from different animal species by self-organizing feature maps

Amino acids are the dominant organic components of processed animal proteins,however there has been limited investigation of differences in their composition between various protein sources.Information on these differences will not only be helpful for their further utilization but also provide fundamental information for developing species-specific identification methods.In this study,self-organizing feature maps(SOFM) were used to visualize amino acid composition of fish meal,and meat and bone meal(MBM) produced from poultry,ruminants and swine.SOFM display the similarities and differences in amino acid composition between protein sources and effectively improve data transparency.Amino acid composition was shown to be useful for distinguishing fish meal from MBM due to their large concentration differences between glycine,lysine and proline.However,the amino acid composition of the three MBMs was quite similar.The SOFM results were consistent with those obtained by analysis of variance and principal component analysis but more straightforward.SOFM was shown to have a robust sample linkage capacity and to be able to act as a powerful means to link different sample for further data mining.

The Dutch, The World Tallest Are Shrinking in the Latest Decade or So: The Lessons from the Case of South Korea and Japan in North-East Asia

The Dutch have been the world tallest since the 1980s but plateaued in height for the past few decades. A century and a half ago, young men at 20 in the Netherlands were 165 cm in mean height, as tall as men in France and Portugal. They grew to 178 cm, as tall as Norwegian in 1960, and 183 cm in mean height in the 1990s and levelled off. It is most likely that the Dutch may have nearly attained genetic potential as a human being. The statue is a net measure that captures the supply of inputs to health. Based on the changes in per capita supply of protein from animal products, FAOSTAT, the Dutch seem to have reached the highest level in per capita supply of animal protein. Increases in the supply of protein, however, do not result in increasing human height, if consumption of other “essential nutrients” is insufficient (Blum, 2013;Mori, 2018)[1][2]. With the close case studies of Japan and South Korea in respect of food consumption specifically by children in growing ages, the author suspects that children in the Netherlands may have been insufficient in the supply of vegetables, “essential nutrients” on the top of animal products.

Review on Using of Housefly Maggots(Musca domestica)in Fish Diets

The main animal protein ingredient in fish diets is most often fishmeal because of its nutritional quality.However,the limited availability and increasingly cost of fishmeal has lead to investigations of either lowering or replacing the fishmeal content with more economic protein sources of animal and/or plant origin.The research for appropriate and cheap cost alternative sources of protein to use in commercial fish diets will be the most important factor in intensive fish culture development.Insect meals are healthy and nutritious alternatives to fish meal due to their rich nutritional values,particularly protein,fat and minerals.Housefly maggots(Musca domestica)meal is also rich in B complex vitamins,trace elements and phosphorus.From the results of previous studies,Housefly maggots meal can be used successfully to replace the fish meal portion partially or completely in the fish diets.Also,the results observed that not physiological stressful was introduced in the fish by feeding Housefly maggots meal diets.This indicates that Housefly maggots meal were well utilized by the fish thus resulting in good growth of fish.In other study,observed a best growth performance with fish feeding on diets containing maggot’s meal compared with fish feeding on fishmeal diet.This indicates the high nutritional quality and fish acceptance of maggot’s meal.

Imbalanced dietary methionine-to-sulfur amino acid ratio can affect amino acid profiles, antioxidant capacity, and intestinal morphology of piglets

Animal protein sources such as fishmeal and plasma powder are excellent and indispensable sources of energy,amino acid s,and minerals in animal production.Amino acid imbalance,especially methionine-to-sulfur amino acid(Met:SAA)ratio,caused by an imbalance of animal protein meal leads to growth restriction.This study was conducted to evaluate the effects of imbalanced Met:SAA ratio supplementation of different animal protein source diets on growth performance,plasma amino acid profiles,antioxidant capacity and intestinal morphology in a piglet model.Twenty-four weaned piglets(castrated males;BW=10.46±0.34 kg),assigned randomly into 3 groups(8 piglets/group),were fed for 28 d.Three experimental diets of equal energy and crude protein levels were as follows:1)a corn-soybean basal diet with a Met:SAA ratio at 0.51(BD);2)a plasma powder diet with a low Met:SAA ratio at 0.41(L-MR);3)a fishmeal diet with a high Met:SAA ratio at0.61(H-MR).Results revealed that compared to BD,L-MR significantly decreased(P<0.05)the activities of plasma total antioxidant capacity and glutathione peroxidase,plasma amino acid profiles,and significantly reduced(P<0.05)villus height and crypt depth in the duodenum and jejunum.Additionally,L-MR significantly reduced(P<0.05)the mRNA expression level of solute carrier family 7 member 9(SIC7 A9)in the ileum,and significantly increased(P<0.05)mRNA expression levels of zonula occludens-1(ZO-1)in the duodenum,and Claudin-1,ZO-1,sodium-coupled neutral amino acid transporters 2(SNAT2)and SIC7 A7 in the j ejunum.HMR significantly increased(P<0.05)plasma SAA levels,and significantly reduced(P<0.05)average daily feed intake,villus height,and villus height-to-crypt depth(VH:CD)ratio in the ileum compared to BD.In conclusion,L-MR may result in oxidative stress and villous atrophy but proves beneficial in improving intestinal barrier function and the activity of amino acid transporters for compensatory growth.H-MR may impair intestinal growth and development for weaned piglets.The research provides a guidance on the adequate Met:SAA ratio(0.51)supplementation in diet structure for weaned piglets.