Mammary stem cells： expansion and animal productivity

Identification and characterization of mammary stem cells and progenitor cells from dairy animals is important in the understanding of mammogenesis, tissue turnover, lactation persistency and regenerative therapy. It has been realized by many investigators that altered lactation, long dry periods （non-milking period between two consecutive lactation cycles）, abrupt cessation of lactation （common in water buffaloes） and disease conditions like mastitis, greatly reduce milk yield thus render huge financial losses within the dairy sector. Cellular manipulation of specialized cell types within the mammary gland, called mammary stem cells （MaSCs）/progenitor cells, might provide potential solutions to these problems and may improve milk production. In addition, MaSCs/progenitor cells could be used in regenerative therapy against tissue damage caused by mastitis. This review discusses methods of MaSC/progenitor cell manipulation and their mechanisms in bovine and caprine animals. Author believes that intervention of MaSCs/progenitor cells could lessen the huge financial losses to the dairy industry globally.     

Punch-excised explants of bovine mammary gland to model early immune response to infection

Background Mammary gland(MG) infections(mastitis) are frequent diseases of dairy cows that affect milk quality, animal welfare and farming profitability. These infections are commonly associated with the bacteria Escherichia coli and Staphylococcus aureus. Different in vitro models have been used to investigate the early response of the MG to bacteria, but the role of the teat in mastitis pathogenesis has received less attention. In this study, we used punchexcised teat tissue as an ex vivo mode...     

Fecal microbiota dynamics and its relationship to diarrhea and health in dairy calvesOA

Background: Diarrhea is a major cause of morbidity and mortality in young calves, resulting in considerable economic loss for dairy farms. To determine if some gut microbes might have resistance to dysbiotic process with calf diarrhea by dictating the microbial co-occurrence patterns from birth to post-weaning, we examined the dynamic development of the gut microbiota and diarrhea status using two animal trials, with the first trial having 14 Holstein dairy calves whose fecal samples were collec...     

Sulforaphane prevents LPS-induced inflamm tion by regulating the Nrf2-mediated autophagy pathway in goat mammary epithelial cells and a mouse model of mastitisOA

Background Mastitis not only deteriorates the composition or quality of milk, but also damages the health and productivity of dairy goats. Sulforaphane(SFN) is a phytochemical isothiocyanate compound with various pharmacological effects such as anti-oxidant and anti-inflammatory. However, the effect of SFN on mastitis has yet to be elucidated.This study aimed to explore the anti-oxidant and anti-inflammatory effects and potential molecular mechanisms of SFN in lipopolysaccharide(LPS)-induced pri...     

Lactobacillus rhamnosus GR-1 attenuates foodborne Bacillus cereus-induced NLRP3 inflammasome activity in bovine mammary epithelial cells by protecting intercellular tight junctionsOA

Background: Bacillus cereus is an important pathogen that causes human food poisoning, specifically diarrhea and vomiting. B. cereus can also induce mastitis in dairy cows and has a strong survival ability in milk, as it cannot be inactivated by high-temperature short-time pasteurization. Therefore, B. cereus can enter the market through pasteurized milk and other dairy products, imposing enormous hidden dangers on food safety and human health.Results: In this study, B. cereus 2101(BC) was isola...     

Potential roles of the rectum keystone microbiota in modulating the microbial community and growth performance in goat modelOA

Background Ruminal microbiota in early life plays critical roles in the life-time health and productivity of ruminant animals. However, understanding of the relationship between gut microbiota and ruminant phenotypes is very limited. Here, the relationship between the rectum microbiota, their primary metabolites, and growth rate of a total of 76 young dairy goats(6-month-old) were analyzed, and then 10 goats with the highest or lowest growth rates respectively were further compared for the diffe...     

Fibroblast growth factor 21 in dairy cows:current knowledge and potential relevance

Fibroblast growth factor 21(FGF21)has been identified as an important regulator of carbohydrate and lipid metabolism,which plays an important role for metabolic regulation,particularly under conditions of energy deprivation or stress conditions.Dairy cows are subjected to a negative energy balance and various kinds of stress particularly during the periparturient phase and during early lactation.It has been shown that the plasma concentration of FGF21 in dairy cows is dramatically increased at parturition and remains high during the first weeks of lactation.This finding suggests that FGF21 might exert similar functions in dairy cows than in other species,such as mice or humans.However,the role of FGF21 in dairy cows has been less investigated so far.Following a brief summary of the previous findings about the function of FGF21 in humans and mice,the present review aims to present the current state of knowledge about the role of FGF21 in dairy cows.The first part of the review deals with the tissue localization of FGF21 and with conditions leading to an upregulation of FGF21 expression in the liver of dairy cows.In the second part,the influence of nutrition on FGF21 expression and the role of FGF21 for metabolic diseases in dairy cows is addressed.In the third part,findings of exogenous FGF21 application on metabolism in dairy cows are reported.Finally,the potential relevance of FGF21 in dairy cows is discussed.It is concluded that FGF21 might be of great importance for metabolic adaptation to negative energy balance and stress conditions in dairy cows.However,further studies are needed for a better understanding of the functions of FGF21 in dairy cows.     

Cecal microbiota transplantation: unique influen e of cecal microbiota from divergently selected inbred donor lines on cecal microbial profil,serotonergic activity,and aggressive behavior of recipient chickensOA

Background Accumulating evidence from human trials and rodent studies has indicated that modulation of gut microbiota affects host physiological homeostasis and behavioral characteristics.Similarly,alterations in gut microbiota could be a feasible strategy for reducing aggressive behavior and improving health in chickens.The study was conducted to determine the effects of early-life cecal microbiota transplantation(CMT) on cecal microbial composition,brain serotonergic activity,and aggressive be...     

Heat stress in pigs and broilers:role of gut dysbiosis in the impairment of the gut-liver axis and restoration of these effects by probiotics,prebiotics and synbioticsOA

Heat stress is one of the most challenging stressors for animal production due to high economic losses resulting from impaired animal’s productivity,health and welfare.Despite the fact that all farm animal species are susceptible to heat stress,birds and pigs are particularly sensitive to heat stress due to either lacking or non-functional sweat glands.Convincing evidence in the literature exists that gut dysbiosis,a term used to describe a perturbation of commensal gut microbiota,develops in br...     

Functional characterization of oligopeptide transporter 1 of dairy cows

Background: It is wel known that peptides play a vital role in the nutrition and health of dairy cows. Bovine oligopeptide transporter 1(bP epT 1) is involved in the peptide transport process in the gastrointestinal tracts of dairy cows. However,little information is known in the characteristics of bP epT 1. Therefore, the purpose of this study was to characterize bP epT 1 functional y using a mammalian cel expression system. The uptake of radiolabeled dipeptide glycyl-sarcosine([3 H]-Gly-Sar)into the bP epT 1-transfected Chinese hamster ovary cel s was measured at various pH and substrate concentrations and with or without 15 other smal peptides that contained Met or Lys.Results: Western blot results showed that the abundance of bP epT 1 protein in the jejunum and ileum are the highest in the gastrointestinal tract of dairy cows. The uptake of [3 H]-Gly-Sar by b Pep T1-Chinese hamster ovary cells was dependent on time, p H, and substrate concentration, with a low Kmvalue of 0.94 ± 0.06 mmol/L and a maximum velocity of 20.80 ± 1.74 nmol/(mg protein · 5 min). Most of the di-and tripeptides were the substrates of b Pep T1,based on substrate-competitive studies. However, bP epT 1 has a higher affinity to the peptides with shorter chains, greater hydrophobicity, and negative or neutral charges.Conclusions: These results demonstrated for the first time the functional characteristics of bP epT 1, and they provide a new insight and better understanding into its vital role in absorbing a wide range of peptides from the digestive tract of dairy cows.     

Dairy sheep production research at the University of Wisconsin-Madison,USA-a review

Commercial milking of sheep is a new agricultural industry in the United States starting approximately 30 yr ago. The industry is still small, but it is growing. The majority of the sheep milk is used in the production of specialty cheeses. The United States is the major importer of sheep milk cheeses with 50 to 60% of annual world exports coming to the United States during the past 20 yr. Therefore, there is considerable growth potential for the industry in the United States. The only dairy sheep research flock in North America is located at the Spooner Agricultural Research Station of the University of Wisconsin-Madison. The research program started in 1993 and has been multifaceted; dealing with several areas important to commercial dairy sheep farmers. The East Friesian and Lacaune dairy breeds were compared and introduced to the industry through the research program. Both dairy breeds produced significantly more milk than traditional meat-wool breeds found in the U.S., but the two breeds differed in their production traits. East Friesian-cross ewes produced more lambs and slightly more milk than Lacaune-cross ewes whereas Lacaune-cross ewes produced milk with a higher percentage of fat and protein than East Friesian-cross ewes. Lactation physiology studies have shown that ewes with active corpora lutea have increased milk yields, oxytocin release during milking is required to obtain normal fat percentages in the milk, large udder cisterns of dairy ewes can allow for increased milking intervals, and short daylengths during late pregnancy results in increased milk yield. In the nutrition area, legume-grass pastures and forages with a higher percentage of legume will result in increased milk production. Grazing ewes respond to additional supplementation with increased milk yield, but it is important to match the supplement to the quality of the grazing. Ewes on high quality legume-grass pastures that are high in rumen degradable protein respond with increased milk production to supplements high in energy and/or     

Effects of omega-3 supplementation on components of the endocannabinoid system and metabolic and inflammatory responses in adipose and liver of peripartum dairy cowsOA

Background: Dietary supplementation of omega-3 fatty acids can reduce the activation of the endocannabinoid system(ECS) by decreasing the availability of arachidonic acid, thus lowering endocannabinoids(e CBs) levels. The ECS is a modulator of energy metabolism, stress response and inflammation in mammals, yet there is little information on the roles of the ECS in transition dairy cows. During the periparturient period, the adipose tissue and liver are the main metabolic organs that participate ...     

TLR7/8 signalling affects X-sperm motility via the GSK3α/β-hexokinase pathway for the efficient production of sexed dairy goat embryos

Background:Goat milk is very similar to human milk in terms of its abundant nutrients and ease of digestion.To derive greater economic benefit,farmers require more female offspring(does);however,the buck-to-doe offspring sex ratio is approximately 50%.At present,artificial insemination after the separation of X/Y sperm using flow cytometry is the primary means of controlling the sex of livestock offspring.However,flow cytometry has not been successfully utilised for the separation of X/Y sperm aimed at sexing control in dairy goats.Results:In this study,a novel,simple goat sperm sexing technology that activates the toll-like receptor 7/8(TLR7/8),thereby inhibiting X-sperm motility,was investigated.Our results showed that the TLR7/8 coding goat Xchromosome was expressed in approximately 50%of round spermatids in the testis and sperm,as measured from cross-sections of the epididymis and ejaculate,respectively.Importantly,TLR7/8 was located at the tail of the Xsperm.Upon TLR7/8 activation,phosphorylated forms of glycogen synthase kinaseα/β(GSK3α/β)and nuclear factor kappa-B(NF-κB)were detected in the X-sperm,causing reduced mitochondrial activity,ATP levels,and sperm motility.High-motility Y-sperm segregated to the upper layer and the low-motility X-sperm,to the lower layer.Following in vitro fertilisation using the TLR7/8-activated sperm from the lower layer,80.52±6.75%of the embryos were XX females.The TLR7/8-activated sperm were subsequently used for in vivo embryo production via the superovulatory response;nine embryos were collected from the uterus of two does that conceived.Eight of these were XX embryos,and one was an XY embryo.Conclusions:Our study reveals a novel TLR7/8 signalling mechanism that affects X-sperm motility via the GSK3α/β-hexokinase pathway;this technique could be used to facilitate the efficient production of sexed dairy goat embryos.     

Regulation Mechanism of Silent Information Regulator 2 Related Enzyme 3 and Its Role in Dairy Cow Mastitis北大核心CSCD

silent information regulator 2 related enzyme 3 (SIRT3) is a member of the Sirtuin family of nicotinamide adenine dinucleotide (NAD+) dependent deacetylases, SIRT3 mainly regulates cell metabolism, bio-synthesis, apoptosis and oxidative stress etc. In this paper, we reviewed the regulatory mechanisms of SIRT3 with nuclear factor-κB (NF-κB), adenosine monophosphate-activated protein kinase (AMPK), non-esterified fatty acids (NEFA) and reactive oxygen species (ROS) pathways and the role of SIRT3 in dairy cow mastitis, to provide theoretical support for targeted treatment of dairy cow mastitis. © 2023 Chinese Journal of Animal Science and Veterinary Medicine Co., Ltd. All rights reserved.