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Developing alternatives to antibiotics is an urgent need in livestock production. Antimicrobial peptides (AMPs) are regarded as powerful antibiotic substitutes (ASs) because AMPs have broad-spectrum antimicrobial activities and growth-promoting ability. Here, we aimed to comprehensively assess the effects of AMPs on the growth performance, diarrhea rate, intestinal morphology and immunity of healthy or challenged piglets, compared with an antibiotics group or negative control group. We performed a set of meta-analyses of feeding trials from database inception to 27 May 2019. Among the 1379 identified studies, 20 were included in our meta-analyses (56 arms and 4067 piglets). The meta-analyses revealed that (1) compared with the negative control group, AMPs significantly improved the healthy piglets’ average daily gain (ADG), average daily feed intake (ADFI), gain : feed ratio (G/F), levels of immune globulin (Ig) IgM and IgG, and intestinal villus height : crypt depth ratio (V/C) (P < 0.05). Meanwhile, AMPs significantly increased the challenged piglets’ ADG, ADFI, G/F and V/C of the jejunum and ileum, and notably deceased the diarrhea rate (P < 0.05); (2) compared with antibiotics group, the effects of AMPs were slightly weaker than those of antibiotics in the healthy piglets, but AMPs have similar effects to those of antibiotics in challenged piglets. In a higher purity, the optimal dose of AMPs may be approximately 0.01%. Our findings indicate that AMPs can improve piglet growth performance, enhance immunity, benefit intestinal morphology and decrease the diarrheal rate. AMPs could be great ASs especially under infection conditions.
In this paper, the generation of relativistic electron mirrors (REM) and the reflection of an ultra-short laser off the mirrors are discussed, applying two-dimension particle-in-cell simulations. REMs with ultra-high acceleration and expanding velocity can be produced from a solid nanofoil illuminated normally by an ultra-intense femtosecond laser pulse with a sharp rising edge. Chirped attosecond pulse can be produced through the reflection of a counter-propagating probe laser off the accelerating REM. In the electron moving frame, the plasma frequency of the REM keeps decreasing due to its rapid expansion. The laser frequency, on the contrary, keeps increasing due to the acceleration of REM and the relativistic Doppler shift from the lab frame to the electron moving frame. Within an ultra-short time interval, the two frequencies will be equal in the electron moving frame, which leads to the resonance between laser and REM. The reflected radiation near this interval and corresponding spectra will be amplified due to the resonance. Through adjusting the arriving time of the probe laser, a certain part of the reflected field could be selectively amplified or depressed, leading to the selective adjustment of the corresponding spectra.
Small intestinal epithelium homeostasis involves four principal cell types: enterocytes, goblet, enteroendocrine and Paneth cells. Epidermal growth factor (EGF) has been shown to affect enterocyte differentiation. This study determined the effect of dietary EGF on goblet, enteroendocrine and Paneth cell differentiation in piglet small intestine and potential mechanisms. Forty-two weaned piglets were used in a 2 × 3 factorial design; the major factors were time post-weaning (days 7 and 14) and dietary treatment (0, 200 or 400 µg/kg EGF supplementation). The numbers of goblet and enteroendocrine cells were generally greater with the increase in time post-weaning. Moreover, the supplementation of 200 µg/kg EGF increased (P < 0.01) the number of goblet and enteroendocrine cells in villus and crypt of the piglet small intestine as compared with the control. Dietary supplementation with 200 µg/kg EGF enhanced (P < 0.05) abundances of differentiation-related genes atonal homologue 1, mucin 2 and intestinal trefoil factor 3 messenger RNA (mRNA) as compared with the control. Piglets fed 200 or 400 µg/kg EGF diet had increased (P < 0.05) abundances of growth factor-independent 1, SAM pointed domain containing ETS transcription factor and pancreatic and duodenal homeobox 1 mRNA, but decreased the abundance (P < 0.01) of E74 like ETS transcription factor 3 mRNA as compared with the control. Animals receiving 400 µg/kg EGF diets had enhanced (P < 0.05) abundances of neurogenin3 and SRY-box containing gene 9 mRNA as compared with the control. The mRNA abundance and protein expression of lysozyme, a marker of Paneth cell, were also increased (P < 0.05) in those animals. As compared with the control, dietary supplementation with 200 µg/kg EGF increased the abundance of EGF receptor mRNA and the ratio of non-phospho(p)-β-catenin/β-catenin (P < 0.05) in villus epithelial cells at days 7 and 14. This ratio in crypt epithelial cells was higher (P < 0.05) on the both 200 and 400 µg/kg EGF groups during the same period. Our results demonstrated that dietary EGF stimulated goblet, enteroendocrine and Paneth cell differentiation in piglets during the post-weaning period, partly through EGFR and Wnt/β-catenin signalling.
Some studies have shown that the excessive metabolic heat production is the primary cause for dead chicken embryos during late embryonic development. Increasing heat shock protein (HSP) expression and adjusting metabolism are important ways to maintain body homeostasis under heat stress. This study was conducted to investigate the effects of in ovo injection (IOI) of vitamin C (VC) at embryonic age 11th day (E11) on HSP and metabolic genes expression. A total of 320 breeder eggs were randomly divided into normal saline and VC injection groups. We detected plasma VC content and rectal temperature at chick’s age 1st day, and the mRNA levels of HSP and metabolic genes in embryonic livers at E14, 16 and 18, analysed the promoter methylation levels of differentially expressed genes and predicted transcription factors at the promoter regions. The results showed that IOI of VC significantly increased plasma VC content and decreased rectal temperature (P < 0.05). In ovo injection of VC significantly increased heat shock protein 60 (HSP60) and pyruvate dehydrogenase kinase 4 (PDK4) genes expression at E16 and PDK4 and secreted frizzled related protein 1 (SFRP1) at E18 (P < 0.05). At E16, IOI of VC significantly decreased the methylation levels of total CpG sites and −336 CpG site in HSP60 promoter and −1137 CpG site in PDK4 promoter (P < 0.05). Potential binding sites for nuclear factor-1 were found around −389 and −336 CpG sites in HSP60 promoter and potential binding site for specificity protein 1 was found around −1137 CpG site in PDK4 promoter. Our results suggested that IOI of VC increased HSP60, PDK4 and SFRP1 genes expression at E16 and 18, which may be associated with the demethylation in gene promoters. Whether IOI of VC could improve hatchability needs to be further verified by setting uninjection group.
Force-feeding was considered as a traditional high-efficiency approach to improve growth performance and accelerate fat deposition of Pekin ducks. However, force-feeding is a serious violation of international advocacy on animal welfare, because it can induce serious injuries to animals, such as damages to the digestive tract, effects on immunity and even severe oxidative stress. Therefore, it is urgent to stop force-feeding. The aim of this study was to determine the effects of force feeding on immune function, digestive function and oxidative stress in the mucosa of duodenum and jejunum of Pekin ducks. A total of 500 ducks were randomly divided into two groups. The control group was allowed to feed freely on a basal diet. The experimental group was force-fed by inserting a plastic feeding tube 8 to 10 inches long down the esophagus for 6 days. Compared with the control group, there was a significant (P<0.05) increase in serum diamine oxidase, d-lactic acid, endotoxin and corticosterone levels in the force-feeding group. The crypt depth in duodenum and jejunum showed significant differences (P<0.05) between the two groups and the intestinal villus epithelium cell was severely damaged in force-feeding group. Similarly, the activities of digestive enzymes as well as the levels of immune function in the duodenal and jejunal mucosa in the force-feeding group were significantly higher than the control group (P<0.05). However, there was a significant decrease in the superoxide dismutase, glutathione peroxidase and catalase levels with a marked increase in malondialdehyde level in duodenal and jejunal mucosa (P<0.05). In summary, at the end of the fattening period with force-feeding for 6 days, Pekin ducks experienced an adverse effect on the integrity of their duodenal and jejunal mucosa epithelium cell as well as their immune function and antioxidant capacity of Pekin ducks but also had improvement in digestive enzyme activities.
To solve the on-ground lateral direction control problem of the unswept flying-wing unmanned aerial vehicle (UAV) without rudder, steering system or breaking system, a control approach which uses differential propeller thrust to control the lateral direction is proposed. First, a mathematical model of the unswept flying-wing UAV on-ground moving is established. Second, based on the active disturbance rejection control (ADRC) theory, a yaw angle controller is designed by using the differential propeller thrust as the control output. Finally, a straight line trajectory tracking control law is designed by improving the vector field path following method. Experiment results show that the proposed control laws have a shorter response time, better robustness and better control precision compared with proportional integral derivative (PID) controller. The proposed controller has small computational complexity, simple parameter setting process, and uses practical measurable physical quantities, providing a reference solution for further engineering applications.
Hypoimmunity and numerous stresses are two major challenges in broiler industry. Nutrient intervention at the specific time of embryonic stage is a feasible way to improve animal performance. This study was conducted to investigate the possible effects of in ovo feeding (IOF) of vitamin C at embryonic age 15th day (E15) on growth performance, antioxidation and immune function of broilers. A total of 240 broiler fertile eggs were randomly divided into two groups (0 and 3 mg injected dose of vitamin C at E15), and new-hatched chicks from each treatment were randomly allocated into six replicates with 10 chicks per replicate after incubation. The results indicated that in ovo vitamin C injection improved the hatchability (P < 0.05) and increased immunoglobulin M (IgM) (at the broiler’s age 1st day, D1), IgG and IgM concentrations (D21), as well as lysozyme activity (D21, P < 0.05) and total antioxidant capacity (D42, P < 0.01) in plasma of broilers. On D21, the splenic expression level of DNA methyltransferase 1 (DNMT1) was up-regulated in vitamin C (VC) group, whereas interleukin (IL)-6, interferon-γ, ten-eleven translocation protein 1 and thymine-DNA glycosylase were down-regulated (P < 0.05). On D42, in ovo vitamin C injection up-regulated splenic expression levels of DNMT1, DNA methyltransferase 3B (DNMT3B) and growth arrest and DNA-damage-inducible protein beta (P < 0.05), whereas down-regulated splenic expression levels of IL-6, tumour necrosis factor-α and methyl-CpG-binding domain protein 4 (P < 0.05). Our findings suggested that IOF of 3 mg vitamin C at E15 could improve, to some extent, the antioxidant activity and immune function in plasma, corresponding with the lower expression of pro-inflammatory cytokines in spleen. However, IOF of vitamin C leading to the changes in the expression of DNA methyltransferases and demethylases may suggest an increased trend of DNA methylation level in spleen and whether DNA methylation variation is associated with the lower expression of pro-inflammatory cytokines in spleen warrants future study.
A multichannel calorimeter system is designed and constructed which is capable of delivering single-shot and broad-band spectral measurement of terahertz (THz) radiation generated in intense laser–plasma interactions. The generation mechanism of backward THz radiation (BTR) is studied by using the multichannel calorimeter system in an intense picosecond laser–solid interaction experiment. The dependence of the BTR energy and spectrum on laser energy, target thickness and pre-plasma scale length is obtained. These results indicate that coherent transition radiation is responsible for the low-frequency component (
1 THz) of BTR. It is also observed that a large-scale pre-plasma primarily enhances the high-frequency component (
3 THz) of BTR.
Hepatitis E is an important zoonosis that is prevalent in China. Hepatitis E virus (HEV) is a pathogen that affects humans and animals and endangers public health in China. In this study, the detection of HEV epidemics in swine in Sichuan Province, China, was carried out by nested real-time PCR. A total of 174 stool samples and 160 bile samples from swine in Sichuan Province were examined. In addition, software was used to analyse the biological evolution of HEV. The results showed that within 2 years of swine HEV (SHEV) infection in China, SHEV was first detected in Sichuan Province. HEV was endemic in Sichuan; the positive rate for pig farms was 11.1%, and the total positive sample rate was 10.5%. The age of swine with the highest positive rate (17.9%) was 5–9 weeks. The examined swine species in order of highest to lowest HEV infection rates were Chenghua pig, Large White, Duroc, Pietrain, Landrace and Hampshire. Nucleotide and amino acid sequence analysis showed that the HEV epidemic in swine in Sichuan Province was related to genotype IV, which had the highest homology to HEV in Beijing. Sichuan strains have greater variation than Chinese representative strains, which may indicate the presence of new HEV strains.
The distribution of human papillomaviruses (HPVs) must be understood for the control and prevention of cervical cancer. Community-based Papanicolaou and HPV DNA tests were performed on 41 578 women. The prevalences of HPV genotypes 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68 were assessed. In total, 10% women were infected/co-infected by these HPVs. The infection rate increased from 7.1% in women aged ⩽30 years to 10.4% in those aged 50–60 years, and then decreased slightly to 9.9% in those aged >60 years. The HPV 16 and 58 positivity rates were significantly higher among women with high-grade squamous intraepithelial lesions (HSILs) than among those with cervicitis/negativity for intraepithelial lesion or malignancy (NILM) or low-grade SILs (LSILs). The HPV 18, 52 and 68 infection rates were significantly lower in women with HSILs than in those with NILM or LSILs. The proportion of women infected by multiple HPV strains was higher among those with HSILs. The proportions of the five most common genotypes, HPV 16, 18, 33, 52 and 58, increased with the number of co-infecting strains. HPV 16 and 58 were the high-risk HPVs in the Shanghai community and should be the focus in HPV screening and vaccination.
To investigate the effects of soybean isoflavone (SI) on immunity in infectious bursal disease virus (IBDV)-infected broilers, chicks were fed the same basal diet supplemented with 0 (non-infected control), 0 (infected control), 10, 20 or 40 mg/kg SI for 44 days. At 21 days old, chickens were inoculated with bursal infectious dose causing 50% morbidity of the IBDV BC 6/85 strain by the eye-drop and nasal route (except for non-infected controls). Results showed that, over 1–23 days post-infection (dpi), there was a significant interaction between SI supplementation level and time: high-level SI supplementation increased peripheral T lymphocyte proliferation, percentages of CD3+, CD4+ and CD8+ T lymphocytes, CD4+ to CD8+ ratio, serum concentrations of IgA, IgM and IgG, and IBDV antibody titres. Except for serum IgA and IgM, these variables increased over time with far higher values at 23 dpi than earlier. Compared with non-infected controls, IBDV inoculation decreased peripheral T lymphocyte proliferation at 3 dpi, percentages of CD3+, CD4+ and CD8+ T lymphocytes, and serum IgG, IgM concentration at 23 dpi, and increased IBDV antibody titres at 7, 15 and 23 dpi. Supplemental SI quadratically increased peripheral T lymphocyte proliferation, CD4+ to CD8+ ratio and serum IgA concentration at 3 dpi, percentages of CD3+, CD4+ and CD8+ T lymphocytes at 3 and 23 dpi, and serum IgM concentration and IBDV antibody titres at 23 dpi. These results indicate that dietary SI improved cellular and humoral immunity of IBDV-infected birds and may enhance resistance of Yellow-feathered broilers to infectious diseases.
Multiple Attribute Decision Analysis (MADA), known to be simple and convenient, is one of the most commonly used methods for Effectiveness Evaluation of Fighter (EEF), in which the attribute weight assignment plays a key role. Generally, there are two parts in the index system of MADA, i.e. performance index and decision index (or label), which denote the specific performance and the category of the object, respectively. In some index systems of EEF, the labels can be easily obtained, which are presented as the generations of fighters. However, the existing methods of attribute weight determination usually ignore or do not take full advantage of the supervisory function of labels. To make up for this deficiency, this paper develops an objective method based on fuzzy Bayes risk. In this method, a loss function model based on Gaussian kernel function is proposed to cope with the drawback that the loss function in Bayes risk is usually determined by experts. In order to evaluate the credibility of assigned weights, a longitudinal deviation and transverse residual correlation coefficient model is designed. Finally, a number of experiments, including the comparison experiments on University of California Irvine (UCI) data and EEF, are carried out to illustrate the superiority and applicability of the proposed method.
Litter size has a great impact on the profit of swine producers. Uterine development is an important determinant of reproduction efficiency and could hence affect litter size. Chinese Erhualian pig is one of the most prolific breeds in the world, even though large phenotypic variation in litter size was observed within Erhualian sows. To dissect the genetic basis of the phenotypic variation, we herein conducted genome-wide association studies for total number born and number born alive (NBA) of Erhualian sows. In total, one significant single nucleotide polymorphism (SNP) (P<1.78e−06) and 11 suggestive SNPs (P<3.57e−05) were identified on 10 chromosomes, confirming seven previously reported quantitative trait loci (QTL) and uncovering six QTL for litter size or uterus length. One locus on Sus scrofa chromosome (SSC) 13 (79.28 to 90.43 Mb) harbored a cluster of suggestive SNPs associated with multiparous NBA. The SNP (rs81447100) within this region was confirmed to be significantly (P<0.05) associated with litter size in Erhualian (n=313), Sutai (n=173) and Yorkshire (n=488) populations. Retinol binding protein 2 and retinol binding protein 1 functionally related to the development of uterus were located in a region of 2 Mb around rs81447100. Moreover, four genes related to embryo implantation and development were also detected around other significant SNPs. Taken together, our findings provide a potential marker (rs81447100) for the genetic improvement of litter size not only in Chinese Erhualian pigs but also in European commercial pig breeds like Yorkshire, and would facilitate the final identification of causative variant(s) underlying the effect of SSC13 QTL on litter size.
Protocols designed for the adipogenic differentiation of human and mouse cells are commonly used for inducing the adipogenesis of bovine stromal vascular cells. However, likely due to metabolic differences between ruminant and non-ruminant animals, these methods result in only few cells undergoing complete adipogenesis with minimal lipid droplet accumulation. Here, we discuss the development of an adipogenic differentiation protocol for bovine primary cells through a three-dimensional spheroid culture. Stromal vascular cells derived from bovine intramuscular fat were isolated and stored in liquid nitrogen before culturing. Cells were cultured in hanging drops for 3 days to allow for the formation of spherical structures. The spheroids were then transferred to cell culture plates with endothelial basal medium-2 for 3 days and in Dulbecco’s Modified Eagle’s Medium (DMEM) supplemented with a standard adipogenic cocktail for 3 additional days, which were then allowed to fully differentiate for 3 days in DMEM supplemented with insulin. Compared with conventional two-dimensional culture, cells in a three-dimensional spheroid culture system had higher adipogenic gene expression and consequently contained more adipocytes with larger lipid droplets. In addition, endothelial induction of spheroids prior to adipogenic differentiation is essential for efficient induction of adipogenesis of bovine stromal vascular cells, mimicking in vivo adipose development. In summary, the newly developed three-dimensional spheroid culture method is an efficient way to induce adipogenic differentiation and study adipose development of cells derived from ruminant animals, which also can be used for studying the role of angiogenesis in adipose development.
Giant electromagnetic pulses (EMP) generated during the interaction of high-power lasers with solid targets can seriously degrade electrical measurements and equipment. EMP emission is caused by the acceleration of hot electrons inside the target, which produce radiation across a wide band from DC to terahertz frequencies. Improved understanding and control of EMP is vital as we enter a new era of high repetition rate, high intensity lasers (e.g. the Extreme Light Infrastructure). We present recent data from the VULCAN laser facility that demonstrates how EMP can be readily and effectively reduced. Characterization of the EMP was achieved using B-dot and D-dot probes that took measurements for a range of different target and laser parameters. We demonstrate that target stalk geometry, material composition, geodesic path length and foil surface area can all play a significant role in the reduction of EMP. A combination of electromagnetic wave and 3D particle-in-cell simulations is used to inform our conclusions about the effects of stalk geometry on EMP, providing an opportunity for comparison with existing charge separation models.
l-Arginine is a nutritionally essential amino acid for spermatogenesis and plays versatile roles in animal health and can be utilized as a potential agent to improve reproductive performance of boars under high ambient temperature. The present study aimed to determine whether dietary l-arginine could alleviate heat stress-induced infertility in boars. In all, 20 boars (PIC 1040; 248.59±3.84 kg BW and 407.65±6.40 days of age) were selected and randomly assigned to four groups (group 0.0%, basal diet; group 0.6%, 0.8% or 1.0%, basal diet added with 0.6%, 0.8% or 1.0% l-arginine (wt:wt), respectively.) The four diets were made isonitrogenous by addition of appropriate amounts of l-alanine. Boars were pre-fed the corresponding experimental diet for 42 days. Then, the semen characteristics and libido were accessed for 6 weeks during the hot summer period (25.5° to 33.0°C). Results show that dietary l-arginine remarkably improved sperm motility, normality, total sperm number and effective total sperm number. Also, dietary l-arginine improved semen antioxidant capacity, such as decrease of malondialdehyde and 8-Hydroxy-2'-deoxyguanosine content in sperm (P<0.05), increase of the ratio of glutathione and oxidized glutathione, total antioxidant capacity, glutathione peroxidase and catalase activities in seminal plasma (P<0.05). Most of mitochondria contained intact ultrastructure in l-arginine-supplemented group which also accompany with higher ATP content than the 0.0% group. The boars fed 0.8% l-arginine show increased levels of estradiol-17β and testosterone and exhibit improved libido performance than boars in the 0.0% group. Adding dietary l-arginine linearly increased (P=0.002) nitric oxide content (as l-arginine increased). The scrotal surface temperature in the 0.6%, 0.8% and 1.0% group were decreased by 0.9°C, 0.9°C and 0.4°C, respectively, compared with the 0.0% group. l-Arginine levels caused linear effect on semen quality and antioxidant capacity, also caused quadratic effect on libido performance. During the hot summer months, the predicted optimal l-arginine levels for best semen quality and antioxidant capacity was 0.8% to 1.0% and for best libido performance was 0.8%. It can be concluded that l-arginine can be used as an effective agent to alleviate heat stress-induced infertility of boar, and that 0.8% to 1.0% can be considered as the optimum dosage.
A liquid chromatography mass spectrometry method for determination of clothianidin in brown rice, straw, rice hull, paddy water and paddy sediment was developed and residue levels were determined in the different components. The limit of quantification was set at 0·01 mg/kg for the matrices studied. Clothianidin degradation in straw, paddy water and soil was studied, and clothianidin residues in brown rice, straw, hull and paddy soil were determined. Concurrent recoveries were between 85·6 and 92·5%, with relative standard deviations ranging from 1·3 to 6·8% at three fortification levels between 0·01 and 5·0 mg/kg. The half-lives in straw, paddy water and paddy sediment were found to be 1·9–4·9, 4·1–5·0 and 4·9–6·3 days, respectively. The maximum residues in brown rice, straw, hull and paddy soil samples were 0·38, 1·88, 1·38 and 0·14 mg/kg, respectively.
Diarrhea is a common cause of morbidity and mortality and the incidence of diarrhea in the world has changed little over the past four decades. To assess the prevalence of and healthcare practices for diarrhea, a cross-sectional study was conducted in Pudong, Shanghai, China. In October 2014, a total of 5324 community residents were interviewed. Respondents were asked if they had experienced diarrhea (defined as ⩾3 passages of watery, loose, bloody, or mucoid stools within a 24-h period) in the previous month prior to the interview. The monthly prevalence of diarrhea was 4·1% (95% CI: 3·3–4·8), corresponding to an incidence rate of 0·54 episodes per person-year. The proportion of individuals with diarrhea who sought healthcare was 21·2% (95% CI: 13·4–29·0). Diarrhea continues to impose a considerable burden on the community and healthcare system in Pudong. Young age and travel were identified as predictors of increased diarrhea occurrence.
An outbreak of acute hepatitis recently occurred in a nursing home in Zhejiang Province, China. The objectives of this study were to confirm the outbreak and identify the aetiology, source and transmission patterns. All residents and staff in or near the nursing home during the period from 1 October 2014 to 21 May 2015 were investigated regarding hygiene and for epidemiological information including water and food (eating meat especially pork products). Serum and stool specimens were collected for detection of hepatitis E virus (HEV) antibodies using ELISA and RNA using RT–PCR. Samples that were RNA positive were genotyped. Of 185 senior residents and 24 staff in the nursing home, there were 37 laboratory-confirmed cases during the outbreak. Of these cases, 12 patients (three deaths) were symptomatic with jaundice, a common clinical symptom for hepatitis E infection. HEV strains were isolated from three cases and they formed a single cluster within genotype 4d. A case-control study was conducted to investigate potential risk factors for the outbreak and the results revealed that cases more often washed their dishes and rinsed their mouths using tap water than the controls (P < 0·05). Based on hygiene investigation and meteorological information, it is likely that HEV-infected sewage and faeces contaminated the water network on rainy days. Collectively, these results suggest that the outbreak of HEV genotype 4 infection was most likely caused by contaminated tap water rather than food.
It has been demonstrated that microRNAs (miRNAs) play important roles in the control of melanogenesis and hair color in mammals. By comparing miRNA expression profiles between brown and white alpaca skin, we previously identified miR508-3p as a differentially expressed miRNA suggesting its potential role in melanogenesis and hair color formation. The present study was conducted to determine the role of miR508-3p in melanogenesis in alpaca melanocytes. In situ hybridization showed that miR508-3p is abundantly present in the cytoplasma of alpaca melanocytes. miR508-3p was predicted to target the gene encoding microphthalmia transcription factor (MITF) and a luciferase reporter assay indicated that miR508-3p regulates MITF expression by directly targeting its 3′UTR. Overexpression of miR508-3p in alpaca melanocytes down-regulated MITF expression both at the messenger RNA and protein level and resulted in decreased expression of key melanogenic genes including tyrosinase and tyrosinase-related protein 2. Overexpression of miR508-3p in melanocytes also resulted in decreased melanin production including total alkali-soluble melanogenesis, eumelanogenesis and pheomelanogenesis. Results support a functional role of miR508-3p in regulating melanogenesis in alpaca melanocytes by directly targeting MITF.