Dairy science and health in the tropics: challenges and opportunities for the next decades

EditorialIn the next two decades, the world population will increase significantly; the majority in the developing countries located in the tropics of Africa, Asia, Latin America, and the Caribbean. To feed such a population, it is necessary to increase the availability of food, particularly high-value animal protein foods produced locally, namely meat and dairy products. Dairy production in tropical regions has a lot of growth potential, but also poses a series of problems, particularly as dairy production systems were developed in temperate countries and in most cases are difficult to implement in the tropics. Drawbacks include hot weather and heat stress, the lack of availability of adequate feeds, poor infrastructure, and cold chain and the competition with cheap imports from temperate countries. This position paper reviews the major drawbacks in dairy production for the five major dairy species: cattle, water buffalo, sheep, goat, and camel, as well as the future trends in research and development. It also concerns the major trends in reproduction and production systems and health issues as well as environmental concerns, particularly those related to greenhouse gas emissions. Tropical Animal Health and Production now launches a topical collection on Tropical Dairy Science. We aim to publish interesting and significant papers in tropical dairy science. On behalf of the editorial board of the Tropical Animal Health and Production, we would like to invite all authors working in this field to submit their works on this topic to this topical collection in our journalinfo:eu-repo/semantics/publishedVersio

Dissecting the Genetic Components of Adaptation of Escherichia coli to the Mouse Gut

While pleiotropic adaptive mutations are thought to be central for evolution, little is known on the downstream molecular effects allowing adaptation to complex ecologically relevant environments. Here we show that Escherichia coli MG1655 adapts rapidly to the intestine of germ-free mice by single point mutations in EnvZ/OmpR two-component signal transduction system, which controls more than 100 genes. The selective advantage conferred by the mutations that modulate EnvZ/OmpR activities was the result of their independent and additive effects on flagellin expression and permeability. These results obtained in vivo thus suggest that global regulators may have evolved to coordinate activities that need to be fine-tuned simultaneously during adaptation to complex environments and that mutations in such regulators permit adjustment of the boundaries of physiological adaptation when switching between two very distinct environments

The functional maturation of M cells is dramatically reduced in the Peyer's patches of aged mice

The transcytosis of antigens across the follicle-associated epithelium (FAE) of Peyer's patches by microfold cells (M cells) is important for the induction of efficient immune responses to mucosal antigens. The mucosal immune response is compromised by ageing, but effects on M cells were unknown. We show that M-cell density in the FAE of aged mice was dramatically reduced. As a consequence, aged Peyer's patches were significantly deficient in their ability to transcytose particulate lumenal antigen across the FAE. Ageing specifically impaired the expression of Spi-B and the downstream functional maturation of M cells. Ageing also dramatically impaired C-C motif chemokine ligand 20 expression by the FAE. As a consequence, fewer B cells were attracted towards the FAE, potentially reducing their ability to promote M-cell maturation. Our study demonstrates that ageing dramatically impedes the functional maturation of M cells, revealing an important ageing-related defect in the mucosal immune system's ability to sample lumenal antigens

Luminal-Applied Flagellin Is Internalized by Polarized Intestinal Epithelial Cells and Elicits Immune Responses via the TLR5 Dependent Mechanism

Bacteria release flagellin that elicits innate responses via Toll-like receptor 5 (TLR5). Here, we investigated the fate of apically administrated full length flagellin from virulent and avirulent bacteria, along with truncated recombinant flagellin proteins in intestinal epithelial cells and cellular responses. Flagellin was internalized by intestinal epithelial cell (IEC) monolayers of IEC-18. Additionally, apically applied flagellin was internalized by polarized human Caco-2BBe and T-84 cells in a TLR5 dependent mechanism. More, flagellin exposure did not affect the integrity of intestinal monolayers. With immunofluorescent staining, internalized flagellin was detected in both early endosomes as well as lysosomes. We found that apical exposure of polarized Caco-2BBe and T-84 to flagellin from purified Salmonella, Escherichia coli O83:H1 (isolate from Crohn’s lesion) or avirulent E. coli K12 induced comparable levels of basolateral IL-8 secretion. A recombinant protein representing the conserved amino (N) and carboxyl (C) domains (D) of the flagellin protein (ND1/2ECHCD2/1) induced IL-8 secretion from IEC similar to levels elicited by full-length flagellins. However, a recombinant flagellin protein containing only the D3 hypervariable region elicited no IL-8 secretion in both cell lines compared to un-stimulated controls. Silencing or blocking TLR5 in Caco-2BBe cells resulted in a lack of flagellin internalization and decreased IL-8 secretion. Furthermore, apical exposure to flagellin stimulated transepithelial migration of neutrophils and dendritic cells. The novel findings in this study show that luminal-applied flagellin is internalized by normal IEC via TLR5 and co-localizes to endosomal and lysosomal compartments where it is likely degraded as flagellin was not detected on the basolateral side of IEC cultures

Breeding for resistance to gastrointestinal nematodes - the potential in low-input/output small ruminant production systems

AbstractThe control of gastrointestinal nematodes (GIN) is mainly based on the use of drugs, grazing management, use of copper oxide wire particles and bioactive forages. Resistance to anthelmintic drugs in small ruminants is documented worldwide. Host genetic resistance to parasites, has been increasingly used as a complementary control strategy, along with the conventional intervention methods mentioned above. Genetic diversity in resistance to GIN has been well studied in experimental and commercial flocks in temperate climates and more developed economies. However, there are very few report outputs from the more extensive low-input/output smallholder systems in developing and emerging countries. Furthermore, results on quantitative trait loci (QTL) associated with nematode resistance from various studies have not always been consistent, mainly due to the different nematodes studied, different host breeds, ages, climates, natural infections versus artificial challenges, infection level at sampling periods, among others. The increasing use of genetic markers (Single Nucleotide Polymorphisms, SNPs) in GWAS or the use of whole genome sequence data and a plethora of analytic methods offer the potential to identify loci or regions associated nematode resistance. Genomic selection as a genome-wide level method overcomes the need to identify candidate genes. Benefits in genomic selection are now being realised in dairy cattle and sheep under commercial settings in the more advanced countries. However, despite the commercial benefits of using these tools, there are practical problems associated with incorporating the use of marker-assisted selection or genomic selection in low-input/output smallholder farming systems breeding schemes. Unlike anthelmintic resistance, there is no empirical evidence suggesting that nematodes will evolve rapidly in response to resistant hosts. The strategy of nematode control has evolved to a more practical manipulation of host-parasite equilibrium in grazing systems by implementation of various strategies, in which improvement of genetic resistance of small ruminant should be included. Therefore, selection for resistant hosts can be considered as one of the sustainable control strategy, although it will be most effective when used to complement other control strategies such as grazing management and improving efficiency of anthelmintics currently

Toll-like receptors in inflammatory bowel diseases: A decade later

Differential alteration of Toll-like receptor (TLR) expression in inflammatory bowel disease (IBD) was first described 10 years ago. Since then, studies from many groups have led to the current concept that TLRs represent key mediators of innate host defense in the intestine, involved in maintaining mucosal as well as commensal homeostasis. Recent findings in diverse murine models of colitis have helped to reveal the mechanistic importance of TLR dysfunction in IBD pathogenesis. It has become evident that environment, genetics, and host immunity form a multidimensional and highly interactive regulatory triad that controls TLR function in the intestinal mucosa. Imbalanced relationships within this triad may promote aberrant TLR signaling, critically contributing to acute and chronic intestinal inflammatory processes in IBD colitis and associated cancer. (Inflamm Bowel Dis 2010

Creation of a model of market-timing from two industrial models : Simulation of the management of a portfolio of commodity contracts

Dans l’industrie, des méthodes de Maîtrise Statistique des Procédés (MSP) sont utilisées pour savoir si des pièces usinées lors d’un processus de fabrication sont non conformes aux spécifications. Les deux méthodes utilisées sont la méthode de Shewhart et la méthode EWMA (moyenne mobile à pondération exponentielle). Une adaptation de ces deux méthodes à la bourse est faite pour créer un modèle qui anticipe les cours sur les marchés à termes de matières premières. Ces deux méthodes sont utilisées simultanément, ce qui est une première. Le modèle présenté différencie plusieurs types de mouvements et plusieurs types d’investisseurs sur les marchés. C’est un modèle prudent. L’obtention de fortes performances est importante mais la diminution du risque et la limitation des pertes le sont également. Une simulation de la gestion d’un portefeuille pouvant être investi dans douze marchés à terme est faite. Ces marchés sont les suivants : le gaz naturel, le pétrole, le blé, le maïs, le soja, le bois, le jus d’orange concentré surgelé, le café, le cacao, le sucre, le coton et le cuivre. Cette simulation dans laquelle le portefeuille n’est pas « en levier » donne des résultats impressionnants. La simulation est faite du 3 janvier 2000 au 31 décembre 2013. Le capital initial est de 10 000 000 dollars et à la fin de la simulation il est de 189 868 766 dollars. Le taux de rendement actuariel est de 23%. La seule rentabilité annuelle négative est celle de 2013 (-0.5%) et la meilleure est celle de 2010 (67%) La volatilité annualisée est de 17%. Le ratio d’information est exceptionnel : 0.85 ! La capacité au market-timing est de 47%. Ce pourcentage est ordinaire mais il recouvre le fait que la performance moyenne d’une position gagnante est de 17% tandis que celle d’une position perdante est de -6%. La performance d’une position gagnante compense, en moyenne, celle de trois positions perdantes.Methods of Statistical Process Control (SPC) are used in the industrial sector to know if work pieces are conforms to specifications. Two methods are used: the Shewhart method and the Exponentially-weighted moving average method (EWMA). An adaptation of these methods to the financial markets is done to create a model which anticipates prices on commodities markets. Both methods are used simultaneously which is the first time. The developed model distinguishes several types of market movements and various types of investors. It is a safe model. Obtaining strong performances is important but reducing risk and limiting losses are too. A simulation of the management of a portfolio which may be invested of twelve commodities is done. The markets are: natural gas, oil, wheat, corn, soybeans, lumber, frozen concentrated orange juice, coffee, cocoa, sugar, cotton and copper. We decide to simulate a portfolio without “leverage” and results are impressive. The simulation is done from January 3rd 2000 to December 31th 2013. The initial capital of the portfolio is 10,000,000 dollars and at the end of the simulation is 189,868,766 dollars. The rate of annual return is 23%. The only negative annual return is that of 2013 (-0.5%) and the best is that of 2010 (67%). The annualized volatility is 17%. The information ratio is exceptional: 0.85! The ability to market timing is 47%. This percentage is ordinary, but the average performance of winning positions is 17% while that of a losing position is -6%. The performance of a winning position, on average, corrects that of three losing positions

Genomic variants from RNA-seq for goats resistant or susceptible to gastrointestinal nematode infection

Gastrointestinal nematodes (GIN) are an important constraint in small ruminant production. Genetic selection for resistant animals is a potential sustainable control strategy. Advances in molecular genetics have led to the identification of several molecular genetic markers associated with genes affecting economic relevant traits. In this study, the variants in the genome of Creole goats resistant or susceptible to GIN were discovered from RNA-sequencing. We identified SNPs, insertions and deletions that distinguish the two genotypes, resistant and susceptible and we characterized these variants through functional analysis. The T cell receptor signalling pathway was one of the top significant pathways that distinguish the resistant from the susceptible genotype with 78% of the genes involved in this pathway showing genomic variants. These genomic variants are expected to provide useful resources especially for molecular breeding for GIN resistance in goats