Effects of dietary energy and protein content and lipid source on growth performance and carcass traits in Pekin ducks

MiR-106a-5p by Targeting MAP3K2 Promotes Repair of Oxidative Stress Damage to the Intestinal Barrier in Prelaying Ducks

Under caged stress conditions, severe disruptions in duck intestinal barrier function, which adversely affect economic performance, have been observed. MiRNAs play a crucial role in cellular processes, but the mechanisms underlying their involvement in repairing oxidative stress-induced damage to duck intestinal barriers have not been elucidated. We performed miRNA-seq and protein tandem mass tagging (TMT) sequencing and identified differentially expressed miRNAs and proteins in oxidative stress-treated ducks. Dual-luciferase reporter vector experiments, RT-qPCR, and Western blotting revealed the regulatory role of apla-miR-106a-5p/MAP3K2 in intestinal barrier damage repair. The results showed that oxidative stress led to shortened villi and deepened crypts, impairing intestinal immune function. Significant downregulation of apla-miR-106a-5p was revealed by miRNA-seq, and the inhibition of its expression not only enhanced cell viability but also improved intestinal barrier function. TMT protein sequencing revealed MAP3K2 upregulation in caged-stressed duck intestines, and software analysis confirmed MAP3K2 as the target gene of apla-miR-106a-5p. Dual-fluorescence reporter gene experiments demonstrated direct targeting of MAP3K2 by apla-miR-106a-5p. RT-qPCR showed no effect on MAP3K2 expression, while Western blot analysis indicated that MAP3K2 protein expression was suppressed. In summary, apla-miR-106a-5p targets MAP3K2, regulating gene expression at the transcriptional level and facilitating effective repair of intestinal barrier damage. This discovery provides new insights into the molecular mechanisms of physiological damage in ducks under caged stress, offering valuable guidance for related research.

Refining dietary metabolisable energy and crude protein levels in relation to duck performance and behaviour

1. The study evaluated the effect of dietary metabolisable energy (ME) content and crude protein (CP) level on the growth performance and behaviour of ducks.2. A total of 720, Cherry Valley ducks were allocated to 36 pens in groups of 20 birds. For the initial period, from 1 to 21 d age, six diets, containing a standard (SME), low (LME) and high (HME) ME of 12.14, 11.93 and 12.35 MJ/kg, and standard (SCP) or high (HCP) CP contents of 210 or 220 g/kg diet, respectively, were mixed. For the period from 22 to 42 d age, the diets contained ME of 12.98 (SME), 12.77 (LME), 13.19 (HME) MJ/kg and the levels of CP were 170 (SCP) or 180 (HCP) g/kg, respectively.3. An ME by CP interaction was seen from 1 to 21 d age in ducks fed HME + HCP diet, which had greater weight gain than those fed LME + SCP (P < 0.05). Compared to LME + SCP, dietary HME decrease feeding but increased walking behaviour compared to LME + SCP and SME + SCP (P < 0.05). High CP in LME and SME diets increased drinking behaviour (P < 0.05), but there was no change in HME diet. Compared to LME, feeding HME reduced ground pecking (P < 0.05). Feeding HME reduced feeding behaviour (P < 0.05) from 22 to 42 d age. During the same period, standing behaviour was reduced in HCP + LME (P < 0.05). Drinking was reduced in LME + SCP compared to SME + HCP and HME + HCP (P < 0.05).4. A diet formulated with HME and HCP is effective for enhancing growth performance of ducks aged 1-21 d and saving time for feeding or ground pecking, which may induce spending more time on other activities.

Analysis of growth performance and carcass and meat quality of different crossbreeds of Cherry Valley duck

Duck breeding and production are facing great opportunities in China, as the market for small-sized high-quality duck is rapidly expanding. Therefore, breeding the most suitable genetic stock has become an important goal.This study assessed body and carcass weight, slaughter rate and meat quality of offspring of three cross combinations; Cherry Valley duck (CV♂) × Small-sized Pekin duck (PK♀), CV♂×Taiwan white duck (TW♀), CV♂×Putian white duck (PT♀) and the corresponding pure lines at 56 d of age. These 420 ducks were raised in seven separate groups (10 pens/group, 3♂+3♀/pen).Body and carcass weights were significantly lower in the three cross combinations than CV ducks (P=0.042 and P=0.012). Abdominal fat and sebum weight were lowest in CV♂×PK♀, whereas the breast and the leg muscle weights were significantly higher in CV♂×PK♀ compared to CV♂×TW♀ and CV♂×PT♀ (P=0.018 and P=0.023). No difference was observed in the visceral tissues among the three cross combinations or compared to CV ducks.The performance indicators suggested that CV♂×PK♀, CV♂×TW♀ and CV♂×PT♀ cross combinations are best suited for segmented duck meat, featured duck meat and whole-duck processing, respectively.

Study on the Mechanism of MC5R Participating in Energy Metabolism of Goose Liver

Nutrition and energy levels have an important impact on animal growth, production performance, disease occurrence and health recovery. Previous studies indicate that melanocortin 5 receptor (MC5R) is mainly involved in the regulations of exocrine gland function, lipid metabolism and immune response in animals. However, it is not clear how MC5R participates in the nutrition and energy metabolism of animals. To address this, the widely used animal models, including the overfeeding model and the fasting/refeeding model, could provide an effective tool. In this study, the expression of MC5R in goose liver was first determined in these models. Goose primary hepatocytes were then treated with nutrition/energy metabolism-related factors (glucose, oleic acid and thyroxine), which is followed by determination of MC5R gene expression. Moreover, MC5R was overexpressed in goose primary hepatocytes, followed by identification of differentially expressed genes (DEGs) and pathways subjected to MC5R regulation by transcriptome analysis. At last, some of the genes potentially regulated by MC5R were also identified in the in vivo and in vitro models, and were used to predict possible regulatory networks with PPI (protein-protein interaction networks) program. The data showed that both overfeeding and refeeding inhibited the expression of MC5R in goose liver, while fasting induced the expression of MC5R. Glucose and oleic acid could induce the expression of MC5R in goose primary hepatocytes, whereas thyroxine could inhibit it. The overexpression of MC5R significantly affected the expression of 1381 genes, and the pathways enriched with the DEGs mainly include oxidative phosphorylation, focal adhesion, ECM-receptor interaction, glutathione metabolism and MAPK signaling pathway. Interestingly, some pathways are related to glycolipid metabolism, including oxidative phosphorylation, pyruvate metabolism, citrate cycle, etc. Using the in vivo and in vitro models, it was demonstrated that the expression of some DEGs, including ACSL1, PSPH, HMGCS1, CPT1A, PACSIN2, IGFBP3, NMRK1, GYS2, ECI2, NDRG1, CDK9, FBXO25, SLC25A25, USP25 and AHCY, was associated with the expression of MC5R, suggesting these genes may mediate the biological role of MC5R in these models. In addition, PPI analysis suggests that the selected downstream genes, including GYS2, ECI2, PSPH, CPT1A, ACSL1, HMGCS1, USP25 and NDRG1, participate in the protein-protein interaction network regulated by MC5R. In conclusion, MC5R may mediate the biological effects caused by changes in nutrition and energy levels in goose hepatocytes through multiple pathways, including glycolipid-metabolism-related pathways.

Dietary metabolizable energy and crude protein levels affect pectoral muscle composition and gut microbiota in native growing chickens

The experiment aimed to study effects of dietary metabolizable energy (ME) and crude protein (CP) levels alone and in interaction on performance, pectoral muscle composition and gut microbiota in native growing chickens. A total of 648 10-wks-old Beijing-You Chicken (BYC) female chickens were randomly allocated to 9 groups with 6 replicates per group and 12 chickens per replicate, and the chickens were fed with a 3 × 3 factorial diets (3 levels of dietary ME: 11.31 MJ/kg, 11.51 MJ/kg, 11.71 MJ/kg; and 3 levels of dietary CP: 14%, 15%, 16%). The results showed that dietary ME and CP levels didn't affect average feed intake (AFI), body weight gain, feed gain ratio (P > 0.05), but ME level significantly affected the AFI (P < 0.05); mortality rate of 11.31 MJ/kg group was the highest (P < 0.05). Dietary ME, CP levels, and the interaction significantly affected pectoral CP and crude fat (CF) content of the growing chickens (P < 0.01). Dietary CP level had opposite effects on pectoral CP and CF content (P < 0.01). The 16% CP increased the pectoral CF content, which may have a negative impact on meat flavor. Dietary ME level affected 11 types of pectoral free amino acids (FAA) contents, including aspartic acid, L-threonine (P < 0.05), also amino acid classification, for example, total amino acid (TAA) and essential amino acid (EAA) content (P < 0.05). The 11.51 MJ/kg group had the highest TAA, EAA, delicious amino acid (DAA) content and EAA percentage (P < 0.05), while 11.31 MJ/kg group had the lowest bitter amino acid (BAA) content and BAA percentage and the highest fresh and sweet amino acid (FSAA) percentage (P < 0.05). Dietary CP level significantly affected glutamine and tyrosine content (P < 0.05). The interaction of dietary ME and CP level affected C20:3n6 content, saturated fatty acid (SFA), and unsaturated fatty acid (UFA) percentage (P < 0.05). The CP level significantly affected SFA percentage (P < 0.05). The 16% CP level increased the diversity of gut microbiota, but at the same time increased the relative abundance of Proteobacteria (P < 0.05), which is a sign of microbiota disorder. The increase of dietary ME level resulted in a gradual decrease in the diversity and relative abundance of gut microbiota. In conclusion, the present study suggested that the medium dietary ME (11.51 MJ/kg) and low CP (14-15%) levels can be helpful for enhancing pectoral muscle composition, increase meat quality such as flavor and nutritional value, and benefit for gut microbiota in native growing chickens.

Effects of a high-fat diet on the growth performance, lipid metabolism, and the fatty acids composition of liver and skin fat in Pekin ducks aged from 10 to 40 days

This study aimed to investigate the effect of a high-fat diet on the growth performance, serum, liver, and skin lipid metabolism as well as the fatty acids composition of liver and skin fat in Pekin ducks from 10 to 40 d of age based on a pair-fed group. Two hundred forty healthy male ducks (10 d old, 470.53 ± 0.57 g) were randomly divided into 3 groups (8 replicates per cage of 10 ducks): a normal diet (ND, 3% fat), a high-fat diet (HFD, 9% fat), and a pair-fed diet (PFD, given the ND in an amount equal to that consumed of the HFD to eliminate the effects of feed intake). The results were as follows: compared to ND feeding, HFD feeding significantly decreased (P < 0.05) the feed intake and feed:gain ratio (F:G), along with serum triglyceride and nonesterified fatty acid contents. When compared with the ND and PFD, the HFD significantly decreased (P < 0.05) the liver weight and inhibited hepatic de novo lipogenesis (glucose-6-phosphate dehydrogenase and malate dehydrogenase activities), β-oxidation (carnitine palmitoyltransferase-1 content), and decreased saturated fatty acids and monounsaturated fatty acids deposition. Moreover, the HFD significantly increased (P < 0.05) the total fat content, lipid droplet area, and polyunsaturated fatty acids (PUFAs) content in the liver, as well as the abdominal fat weight, subcutaneous fat weight, the total fat and PUFAs content in skin fat. These results suggested that the HFD improved feed efficiency, which was related to HFD feeding inhibiting hepatic de novo lipogenesis and β-oxidation and promoting the deposition of fat in skin as well as altering the fatty acids composition of the liver and skin fat in Pekin ducks.

Effect of probiotic and Moringa oleifera extract on performance, carcass yield, and mortality of Peking duck

Background and Aim: Antibiotics have been used as growth promoters in poultry. However, continuous and long-term antibiotics can cause resistance, suppress the immune system, and accumulate toxic residue. To overcome these problems, feed additives that are safe for livestock and health for humans are needed, including probiotics. Therefore, the study aimed to determine the effect of probiotics (Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus lactis, and Bifidobacterium spp.) and Moringa oleifera extract on performance (body weight gain, body weight, feed intake, feed efficiency, and feed conversion ratio [FCR]), carcass yield (carcass weight and percentage of carcass) and mortality of Peking duck. Materials and Methods: This study used 48 Peking ducks, divided into four treatments and six replications. Each replication consisted of two ducks. The treatments were as follows: T0=control, T1=4 mL containing 1.2×108 CFU/mL of probiotic in drinking water, T2=4 mL containing M. oleifera extract in drinking water, and T3=2 mL containing 1.2×108 CFU/mL of probiotic in drinking water+2 mL containing M. oleifera extract in drinking water. The probiotics consist of L. acidophilus, L. casei, L. lactis, and Bifidobacterium spp. The data were statistically analyzed through analysis of variance. For the follow-up test, a multiple range test was conducted. Results: There was no significant difference (p>0.05) between body weight, feed intake, and mortality treatments. By contrast, control and treatment showed a significant difference (p<0.05) on feed efficiency, FCR, body weight gain, carcass weight, and percentage of carcass weight. Results of body weight gain statistics showed no significant difference (p>0.05) between T0 and T1, but T0 and T1 showed a significant difference with T2 and T3. The results of the feed efficiency statistic showed no significant difference (p>0.05) between T0, T1, and T2, but there was a significant difference between T0, T1, and T3. Feed efficiency at T2 showed no significant difference with T3, T1, and T0. The results of the FCR statistic showed no significant difference (p>0.05) between T0, T1, and T2, but there was a significant difference between T0, T1, and T3. FCR at T2 showed no significant difference with T3, T1, and T0. The carcass weight statistic showed no significant difference (p>0.05) between T0, T1, and T3, but there was a significant difference between T0 and T2. T2 showed no significant difference with T1 and T3. The carcass percentage statistic showed no significant difference (p>0.05) between T0 and T1, but T0 and T1 showed a significant difference (p<0.05) with T2 and T3. Conclusion: Based on the study results, it can be concluded that the use of a combination of probiotics (L. acidophilus, L. casei, L. lactis, and Bifidobacterium spp.) and M. oleifera extract can increase the production performance of Peking ducks and is safe for ducks' health.

Soybean Oil Replacement by Poultry Fat in Broiler Diets: Performance, Nutrient Digestibility, Plasma Lipid Profile and Muscle Fatty Acids Content

Simple Summary

The effect of partial or complete substitution of soybean oil (SO) by poultry fat (PF) on growth, nutrient digestibility, plasma lipids, and the pectoral muscle content of fatty acids (FAs) was examined in this study. Dietary PF supplementation improved breast muscle FA profile but did not affect muscle vitamin E content and liver thiobarbituric acid reactive substances (TBARS). By adding PF to the diet, economic efficiency was greatly improved in a dose-dependent manner. Therefore, the results of this study revealed that PF could be used as a partial or total replacement of SO in broiler nutrition without affecting their performance or physiological response with a tendency to improve their meat products.

Abstract

Continuous genetic improvements of commercial broiler strains has led to the necessity of using fats in their rations to fulfill a large portion of the energetic requirements. Several fat sources have been introduced in poultry nutrition, such as rendering poultry fat (PF) an available and cheap lipid source compared to conventional sources such as soybean oil (SO). The present study investigated the effect of partial or full replacement of SO by PF on performance, nutrient digestibility, blood lipids, and fatty acids (FAs) content of pectoral muscle. Four hundred and eighty one-day-old male Ross-308 chicks were distributed into four experimental groups (12 replicates each): the first group (control) was fed a diet formulated with soybean oil as a fat source while the second to fourth groups (PF25, PF50, and PF100) were fed diets formulated with 25, 50 and 100% of PF as a fat source instead of SO. Results revealed no synergistic effect between SO and PF in any of the studied parameters. Replacing SO by PF did not alter birds’ growth, carcass characteristics, and plasma indices of birds. Abdominal fat% was increased (p < 0.01) in PF50 and PF100. Dry matter digestibility was improved (p < 0.05) in PF50 and PF100, while crude fat and protein digestibility was not affected. Contents of palmitic and docosahexaenoic acids in the pectoral muscle of PF50 and PF100 were reduced (p < 0.01) while concentrations of oleic and linolenic acids, total unsaturated FAs, and polyunsaturated FAs/Saturated FAs ratio were elevated (p < 0.05) in the same groups. Liver thiobarbituric acid reactive substances (TBARS) and muscle vitamin E contents were not altered. The dietary addition of PF greatly improved economic parameters. In conclusion, PF can be used as a lipid source in broiler diets to produce inexpensive meat while maintaining its growth performance.

Gut Microbiota Dynamics, Growth Performance, and Gut Morphology in Broiler Chickens Fed Diets Varying in Energy Density with or without Bacitracin Methylene Disalicylate (BMD)

High-energy-density diet could increase body weight at the expense of the intestinal health of the animals. In order to optimize production without negatively influencing the gut health of chickens, dietary supplementation with bacitracin methylene disalicylate (BMD) is a common feeding strategy adopted to enhance production performance and intestinal health. Studies have suggested that BMD could improve chicken growth performance and gut health through modulation of the gut microbiota. The current study investigated the effect of BMD supplementation in a normal-energy (NE) or high-energy (HE) diet on growth performance, organ weights, jejunal morphology, and gut microbiota of broiler chickens at different growth stages. Birds were allocated to four treatments: normal-energy basal diet (NE-BAS), normal-energy BMD diet (NE-BMD), high-energy basal diet (HE-BAS), and high-energy BMD diet (HE-BMD). In the starter phase, body weight and body weight gain were reduced significantly (p < 0.05) in chickens fed HE diets compared to those fed NE diets. The FCR was significantly higher (p < 0.05) in birds fed HE-BMD diets in the starter phase but lower (p < 0.05) during the grower phase when compared to other treatments. Moreover, the relative bursa weight increased significantly (p = 0.0220) among birds that received HE diets. Birds fed HE-BMD had greater villus height (p = 0.054) than NE-BMD group. Among the chickens fed the HE diets, those that received BMD treatment had a significantly increased (p = 0.003) villus width (13.3% increase) compared to those that received the basal diet. Improved population of Firmicutes was observed in chickens fed HE-BMD diet when compared to HE-BAS. Our results imply that BMD may be more effective in improving intestinal health when supplemented in a high-energy diet for broiler chickens.

Effects of Achyranthes bidentata polysaccharides on performance, immunity, antioxidant capacity, and meat quality in Pekin ducks

This study was conducted to evaluate the effects of Achyranthes bidentata polysaccharide (ABP) on growth performance, antioxidant capacity, immune function, relative organ weight, ileal microflora, and meat quality in Pekin ducks. A total of 1,200 female 1-day-old Pekin ducklings (51.2 ± 0.2 g) were blocked based on body weight (BW) and randomly allocated into 3 treatments with 10 replicates of 40 birds each. The experiment lasted for 6 wk, and dietary treatments included corn–soybean meal–based diet supplemented with 0, 0.02, and 0.04% ABP. The supplementation of ABP increased (P < 0.05) body weight gain (BWG) and final BW linearly during day 22 to 42 and day 1 to 42, respectively, but decreased (P < 0.05) feed-to-gain ratio (F/G) linearly during day 22 to 42 and day 1 to 42. The inclusion of ABP increased (P < 0.05) serum superoxide dismutase, glutathione peroxidase, total antioxidative capacity, catalase, complement3, complement4, immunoglobin A, immunoglobin G, interleukin-2, interferon-γ, and tumor necrosis factor-α linearly. The relative weight of breast meat was increased (P < 0.05) linearly, but the relative weight of abdominal fat was decreased (P < 0.05) linearly with the increasing dietary ABP supplementation. The supplementation of ABP increased (P < 0.05) ileal Lactobacilli counts linearly, whereas decreased (P < 0.05) Escherichia coli counts linearly. Taken together, the inclusion of ABP promoted BWG and final BW during day 22 to 42 and the entire experiment, decreased F/G during day 22 to 42 and day 1 to 42, and partially improved antioxidant activities, immunity, and gut microflora in Pekin ducks.

Effects of grape seed extract on performance, immunity, antioxidant capacity, and meat quality in Pekin ducks

This study was conducted to evaluate the effects of grape seed extract (GSE) on growth performance, immunity, antioxidant capacity, relative organ weight, jejunum morphology, ileal microflora, and meat quality in Pekin ducks. A total of 1,500 female 1-day-old Pekin ducklings (52.0 ± 0.2 g) were blocked based on body weight (BW) and randomly allocated into 3 treatments with 10 replicates of 50 birds each. The experiment lasted for 6 wk, and dietary treatments included corn-soybean meal-based diet supplemented with 0, 0.01, and 0.02% GSE. The supplementation of GSE increased (P < 0.05) body weight gain (BWG) and final BW linearly but decreased (P < 0.05) feed-to-gain ratio (F/G) linearly during day (D) 22 to 42 and the entire experiment. The inclusion of GSE increased (P < 0.05) serum superoxide dismutase, glutathione peroxidase, total antioxidative capacity, catalase, complement4, immunoglobin G, interleukin-2, and interferon-γ linearly but decreased (P < 0.05) serum malondialdehyde linearly. The relative weight of carcass, breast meat, and spleen in GSE treatments was increased (P < 0.05) linearly, whereas the relative weight of abdominal fat was decreased linearly (P < 0.05). Birds fed GSE1 and GSE2 diets had lower (P < 0.05) cook loss, 2-thiobarbituric acid reactive substances, and drip loss on day 3 and 5 linearly but higher (P < 0.05) pH24h and water-holding capacity. The addition of GSE decreased (P < 0.05) jejunum crypt depth and ileal Escherichia coli counts linearly but increased (P < 0.05) jejunum villus height: crypt depth ratio and ileal Lactobacilli linearly. Taken together, the inclusion of GSE increased final BW and BWG, decreased F/G during day 22 to 42 and day 1 to 42, partially improved antioxidant activities, immunity, meat quality, and gut health in Pekin ducks.

β-Hydroxy-β-methylbutyrate-Induced Upregulation of miR-199a-3p Contributes to Slow-To-Fast Muscle Fiber Type Conversion in Mice and C2C12 Cells

The influence of β-hydroxy-β-methylbutyrate (HMB) on proliferation and differentiation of myogenic cells has been well-studied. However, the role of HMB in myofiber specification and potential mechanisms is largely unknown. Thus, the objective of this research was to explore the role of HMB supplementation in myofiber specification. Results showed that HMB treatment significantly increased the fast MyHC protein level (mice: 1.59 ± 0.08, P < 0.01; C2C12: 2.26 ± 0.11, P < 0.001), decreased the slow MyHC protein level (mice: 0.76 ± 0.05, P < 0.05; C2C12: 0.52 ± 0.02, P < 0.001), and increased the miR-199a-3p level (mice: 4.93 ± 0.37, P < 0.001; C2C12: 11.25 ± 0.57, P < 0.001). Besides, we also observed that HMB promoted the activity of glycolysis-related enzymes and reduced the activities of oxidation-related enzymes in mice and C2C12 cells. Overexpression of miR-199a-3p downregulated the slow MyHC protein level (0.71 ± 0.02, P < 0.01) and upregulated the fast MyHC protein level (2.13 ± 0.09, P < 0.001), while repression of miR-199a-3p exhibited the opposite effect. Target identification results verified that miR-199a-3p targets the 3'UTR of the TEA domain family member 1 (TEAD1) to cause its post-transcriptional inhibition (0.41 ± 0.07, P < 0.01). Knockdown of TEAD1 exhibited a similar effect with miR-199a-3p on myofiber specification. Moreover, suppression of miR-199a-3p blocked slow-to-fast myofiber type transition induced by HMB. Together, our finding revealed that miR-199-3p is induced by HMB and contributes to the action of HMB on slow-to-fast myofiber type conversion via targeting TEAD1.

Effects of dietary lipid sources on growth performance and carcass traits in Pekin ducks

This study was conducted to determine the influence of dietary lipid sources on growth performance, carcass traits and taste scores in Pekin ducks. A total of 1,500 fifteen-day-old ducks (820 ± 22 g) were blocked based on body weight (BW), and randomly allotted to 3 treatments with 10 replicates of 50 birds each (25 males and 25 females). The experiment lasted for 4 wk, and dietary treatments included 3 different lipid sources (soybean oil, duck fat, and palm oil), which were evaluated in corn-soybean meal diets (3250 kcal/kg metabolizable energy and 16.5% crude protein for grower diet and 3350 kcal/kg metabolizable energy and 15.5% crude protein for finisher diet). During days 15 to 28, feeding soybean oil and palm oil diets increased (P < 0.05) body weight gain (BWG), but decreased (P < 0.05) feed intake, feed-to-gain ratio (F/G) and caloric conversion compared with duck fat. During days 29 to 42, birds fed duck fat diet had higher BWG, but lower (P < 0.05) F/G and caloric conversion than those fed soybean oil and palm oil diets. Overall, feeding soybean oil diet increased (P < 0.05) BWG and final BW, but decreased (P < 0.05) F/G compared with palm oil. Birds fed duck fat diet had higher (P < 0.05) skin, subcutaneous fat and abdominal fat yield compared with palm oil. Left breast meat yield in soybean oil group was higher (P < 0.05) than that in duck fat and palm oil groups. Birds in soybean oil group had lower (P < 0.05) roasting loss, but higher (P < 0.05) comprehensive score compared with duck fat and palm oil. In summary, birds fed soybean oil diet had the best growth performance and taste scores for roasting, whereas the duck fat was better in abdominal fat and subcutaneous fat yield than soybean oil and palm oil in Pekin ducks from 15 to 42 d of age under the same nutritional level.

Carcass characteristics, chemical composition, physicochemical properties, texture, and microstructure of meat from spent Pekin ducks

The aim of the study was to compare P33 (Polish Pekin), P8 (Danish Pekin), and LsA (English Pekin) ducks after 2 reproductive seasons for carcass composition and some meat quality traits. A total of 48 duck carcasses (8 male carcasses and 8 female carcasses of each genotype) were studied. Whole carcasses were dissected, and pH and electrical conductivity of the breast and leg muscles were determined 24 h postmortem. After dissection, breast and leg muscles were sampled to determine proximate composition, some minerals, and physicochemical properties. Breast muscles were also analyzed for textural characteristics, microstructural characteristics, and rheological properties. At 112 wk of age, genotype and sex were found to have no significant effect on carcass weight and percentage of carcass components. The genotype of the birds had a significant effect on the water and fat content in the pectoral and leg muscles, as well as protein and collagen in the leg muscles. The origin of the ducks had a significant impact on the magnesium content in pectoral muscles and Warner–Bratzler shear force pectoralis muscle major, as well as the electrical conductivity of the leg muscles. The differences in duck genotype had a significant effect on the sum of elastic moduli, fiber cross-sectional area, fiber perimeter, and vertical fiber diameter of pectoralis major muscle. Regardless of the genetic origin, breast muscles from 112-week-old males had a lower fat content, and male leg muscles contained more water and protein and less fat and collagen than the female muscles. The genotype by sex interaction was significant for the content of breast muscles, skin with subcutaneous fat, and neck percentage and for the water and fat content in breast and leg muscles.

Effects of methylsulfonylmethane on growth performance, immunity, antioxidant capacity, and meat quality in Pekin ducks

This study was conducted to determine the effect of methylsulfonylmethane (MSM) on growth performance, immune function, antioxidant capacity, and meat quality in Pekin ducks. A total of 960 female 1-day-old Pekin ducklings (53.3 ± 0.4 g) were randomly allotted to 3 treatments with 8 replicates of 40 birds, based on their body weight (BW). The experiment lasted 6 wks, and dietary treatments included a corn–soybean meal–based diet supplemented with 0%, 0.15%, and 0.3% MSM, that is, CON, MSM1, and MSM2, respectively. Growth performance, serum profiles, and meat quality were determined. During the period of days 22–42, BW gain (BWG) in MSM2 treatment was higher (P < 0.05) and feed-to-gain ratio (F/G) was lower (P < 0.05) than those of CON and MSM1 treatments. BW gain and final BW in MSM2 treatment were increased (P < 0.05) compared with CON and MSM1 treatments during the period of days 1–42. Serum activities of superoxide dismutase and glutathione peroxidase, total antioxidative capacity, and concentrations of interleukin-2 and interleukin-6 were higher (P < 0.05) in MSM2 than in CON treatment. Ducks in the MSM2 treatment group had lower (P < 0.05) serum malondialdehyde, interferon gamma, and tumor necrosis factor-α levels than those in the CON treatment group. The supplementation of MSM increased (P < 0.05) water-holding capacity and redness (a*) and decreased (P < 0.05) values for 2-thiobarbituric acid and drip loss on day 5. Ducks in the MSM2 treatment group had higher (P < 0.05) pH_24h than those in the CON treatment group. Taken together, the inclusion of MSM (0.3%) increased final BW and BWG during periods of days 22–42 and days 1–42, reduced feed-to-gain ratio during the period of days 22–42, and resulted in positive effects on immunity, antioxidant capacity, and meat quality.

Butyrate promotes slow-twitch myofiber formation and mitochondrial biogenesis in finishing pigs via inducing specific microRNAs and PGC-1α expression1

The present study aimed to investigate the influence of dietary butyrate supplementation on muscle fiber-type composition and mitochondrial biogenesis of finishing pigs, and the underlying mechanisms. Thirty-two LY (Landrace × Yorkshire) growing pigs with BW of 64.9 ± 5.7 kg were randomly allotted to either control (basal diet) or butyrate diets (0.3% butyrate sodium). Compared with the control group, diet supplemented with butyrate tended to increase average daily gain (P < 0.10). Pigs fed butyrate diet had higher intramuscular fat content, marbling score and pH24 h, and lower shear force and L*24 h in longissimus thoracis (LT) muscle than that fed control diet (P < 0.05). Interestingly, supplemented with butyrate increased (P < 0.05) the mRNA level of myosin heavy chain I (MyHC-I) and the percentage of slow-fibers, and decreased (P < 0.05) the mRNA level of MyHC-IIb in LT muscle. Meanwhile, pigs in butyrate group had an increase in mitochondrial DNA (mtDNA) copy number and the mRNA levels of mtDNA-encoded genes (P < 0.05). Moreover, feeding butyrate diet increased PGC-1α (PPAR γ coactivator 1α) level, decreased miR-133a-3p level and increased its target gene level (TEAD1, TEA domain transcription factor 1), increased miR-208b and miR-499-5p levels and decreased their target genes levels (Sp3 and Sox6, specificity protein 3 and SRY-box containing gene 6; P < 0.05) in the LT muscle. Collectively, these findings suggested that butyrate promoted slow-twitch myofiber formation and mitochondrial biogenesis, and the molecular mechanism may be via upgrading specific microRNAs and PGC-1α expression, finally improving meat quality.

Effect of Dietary Inulin Supplementation on Growth Performance, Carcass Traits, and Meat Quality in Growing-Finishing Pigs

Inulin is one of the commercially feasible dietary fibers that has been implicated in regulating the gut health and metabolism of animals. This experiment was conducted to investigate the effect of dietary inulin supplementation on growth performance and meat quality in growing-finishing pigs. Thirty-six Duroc × Landrace × Yorkshire White growing barrows (22.0 ± 1.0 kg) were randomly allocated to two dietary treatments consisting of a basal control diet (CON) or basal diet supplemented with 0.5% inulin (INU). Results showed that inulin supplementation tended to increase the average daily gain (ADG) at the fattening stage (0.05 < p < 0.10). Inulin significantly increased the dressing percentage (p < 0.05) and tended to increase the loin-eye area. The serum concentrations of insulin and IGF-I were significantly higher (p < 0.05) in the INU group than in the CON group. Moreover, inulin supplementation significantly elevated the expression level of myosin heavy chain II b (MyHC IIb) in the longissimus dorsi (p < 0.05). Inulin significantly upregulated the expression of mammalian rapamycin target protein (mTOR) but decreased (p < 0.05) the expression level of muscle-specific ubiquitin ligase MuRF-1. These results show the beneficial effect of inulin supplementation on the growth performance and carcass traits in growing-finishing pigs, and will also facilitate the application of inulin in swine production.

MicroRNA-152 Promotes Slow-Twitch Myofiber Formation via Targeting Uncoupling Protein-3 Gene

The differences of pork quality characteristics among different pig breeds mainly came from the differences in myofiber type compositions. Growing evidence indicated the key role of miRNAs in myofiber specification. In the present study, we found that miR-152 is more abundant in the slow-twitch myofiber-enriched muscles. However, its role in myofiber type transformation and myogenesis is largely unknown. Overexpression of miR-152 in porcine myotubes promoted the formation of slow-twitch myofibers and myogenesis. While, inhibition of miR-152 expression showed the opposite effect to miR-152 mimics transfection. The luciferase reporter analysis confirmed that miR-152 straightly targets the 3'-untranslated region (3'-UTR) of uncoupling protein 3 (UCP3) to cause its post-transcriptional inhibition in the protein level. The knockdown of UCP3 by siRNA showed the similar effect of miR-152 on myofiber type transition. Furthermore, the rescue experiment in the porcine myotube transfected with miR-152 mimics or/and UCP3 overexpression plasmid with or without the 3'UTR revealed that UCP3 mediates the action of miR-152 in slow-twitch myofiber formation. Taken together, our findings proposed a novel molecular mechanism through which miR-152 epigenetically regulates meat quality via promoting slow-twitch myofiber formation and skeletal myogenesis.

Effect of arabinoxylan on colonic bacterial metabolites and mucosal barrier in high-fat diet-induced rats

The aim of this study was to demonstrate the effect of arabinoxylan on colonic mucosal barrier and metabolomic profiles in high-fat diet-induced rats. A total of 20 six-week-old male rats were arranged randomly to two groups (n = 10/group), including a high-fat diet (HFD) group and a high-fat supplemented with arabinoxylan diet (AXD) group. Results showed that feeding AXD reduced serum lipopolysaccharide in rats after 5 weeks. In colonic digesta, Escherichia coli population was reduced, while Lactobacillus, Bifidobacterium, and Bacteroidetes populations were increased in AXD group. Metabolomics assay found that the different abundances of 84 metabolites were observed, involving lipid, carbohydrate, and nitrogenous metabolism in colonic digesta. In colonic mucosa, AXD up-regulated gene level of tight-junction-related proteins. Meanwhile, lower TNF-α and IL-1β levels were related to TLR4/NF-κB/MyD88 pathway in AXD group. In conclusion, arabinoxylan could change colonic microbial metabolism and improve the colonic mucosal barrier via modulating intestinal microflora and tight junction proteins.

Enterococcus faecium NCIMB 10415 administration improves the intestinal health and immunity in neonatal piglets infected by enterotoxigenic Escherichia coli K88

Background

This study aimed to investigate the effects of oral administration of Enterococcus faecium NCIMB 10415 (E. faecium) on intestinal development, immunological parameters and gut microbiota of neonatal piglets challenged with enterotoxigenic Escherichia coli K88 (ETEC). A total of 96 1-day-old sow-reared piglets were randomly assigned to 2 groups, with 48 piglets in each group. The piglets were from 16 litters (6 piglets each litter), and 3 piglets each litter were allocated to the E. faecium-supplemented (PRO) group, while the other 3 piglets were allocated to the control (CON) group. After colostrum intake, piglets in the PRO group were orally administrated with 3 × 10⁹ CFU E. faecium per day for a period of one week. On day 8, one piglet per litter from each group was challenged (CON+ETEC, PRO+ETEC) or not (CON-ETEC, PRO-ETEC) with ETEC in a 2 × 2 factorial arrangement of treatments. On day 10 (2 days after challenge), blood and tissue samples were obtained from piglets.

Results

Before ETEC challenge, there were no significant differences for the average daily gain (ADG) and fecal score between the two groups of piglets. After ETEC challenge, the challenged piglets had greater fecal score compared to the non-challenged piglets, whereas E. faecium administration was able to decrease the fecal score. Piglets challenged with ETEC had shorter villous height, deeper crypt depth, and reduced number of goblet cells in the jejunum and decreased mRNA abundance of claudin-1 in the ileum, whereas increased the percentage of lymphocytes, concentrations of IL-1β in the plasma and TNF-α in the ileal mucosa, as well as increased the mRNA abundances of innate immunity-related genes in the ileum tissue. These deleterious effects caused by ETEC were partly alleviated by feeding E. faecium. In addition, piglets in PRO-ETEC group had decreased the percentage of CD8⁺ T cells of the peripheral blood when compared to those in CON-ETEC group. Moreover, E. faecium administration increased Verrucomicrobia at phylum level and decreased Bilophila at genus level.

Conclusions

These results suggest that oral administration of E. faecium alleviated the intestinal injury and diarrhea severity of neonatal piglets challenged by ETEC, partly through improving the intestinal microbiota and immune response. This offers a potential strategy of dietary intervention against intestinal impairment by ETEC in neonatal piglets.

Electronic supplementary material

The online version of this article (10.1186/s40104-019-0376-z) contains supplementary material, which is available to authorized users.

Effects of stale maize on growth performance, immunity, intestinal morphology and antioxidant capacity in broilers

OBJECTIVE

This study was conducted to determine the effects of stale maize on growth performance, immunity, intestinal morphology, and antioxidant capacity in broilers.

METHODS

A total of 800 one-day-old male Arbor Acres broilers (45.4±0.5 g) were blocked based on body weight, and then allocated randomly to 2 treatments with 20 cages per treatment and 20 broilers per cage in this 6-week experiment. Dietary treatments included a basal diet and diets with 100% of control maize replaced by stale maize.

RESULTS

The content of fat acidity value was higher (p<0.05) while the starch, activities of catalase and peroxidase were lower (p<0.05) than the control maize. Feeding stale maize diets reduced (p<0.05) average daily feed intake (ADFI) throughout the experiment, feed conversion ratio (FCR) during d 0 to 21 and the whole experiment as well as relative weight of liver, spleen, bursa of Fabricius and thymus (p<0.05) on d 21. Feeding stale maize diets decreased jejunum villus height (VH) and VH/crypt depth (CD) (p<0.05) on d 21 and 42 as well as ileum VH/CD on d 42. The levels of immunoglobulin G, acid α-naphthylacetate esterase positive ratios and lymphocyte proliferation on d 21 and 42 as well as lysozyme activity and avian influenza antibody H5N1 titer on d 21 decreased (p<0.05) by the stale maize. Feeding stale maize diets reduced (p<0.05) serum interferon-γ, tumor necrosis factor-α, interleukin-2 on d 21 and interleukin-6 on d 21 and 42. Broilers fed stale maize diets had lower levels of (p<0.05) total antioxidative capacity on d 42, superoxide dismutase and glutathione peroxidase on d 21 and 42, but higher (p<0.05) levels of malondialdehyde on d 21 and 42.

CONCLUSION

Feeding 100% stale maize decreased ADFI and FCR, caused adverse effects on immunity and antioxidant function and altered intestinal morphology in broilers.

Genomic Identification and Expression Analysis of the Cathelicidin Gene Family of the Forest Musk Deer

Simple Summary

Cathelicidins are a group of host defense peptides in vertebrates with both antimicrobial and immunomodulatory activities. In the present study, we identified the entire repertoire of the cathelicidin gene family from the forest musk deer genome. Sequence comparison, phylogenetic topology, and gene and genomic organizations collectively suggest that all cathelicidin genes have already been fixed in the genome of forest musk deer before the split of moschidae and bovidae, while independent pseudogenization events have occurred after species divergence. In addition, real-time PCR analysis suggested that all functional cathelicidins play important roles in the immune system. The results of this study will be helpful for further evolutionary and functional studies.

Abstract

The forest musk deer (Moschus berezovskii) is a small-sized artiodactyl species famous for the musk secreted by adult males. In the captive population, this species is under the threat of infection diseases, which greatly limits the increase of individual numbers. In the present study, we computationally analyzed the repertoire of the cathelicidin (CATHL) family from the genome of forest musk deer and investigated their expression pattern by real-time PCR. Our results showed that the entire genome of forest musk deer encodes eight cathelicidins, including six functional genes and two pseudogenes. Phylogenetic analyses further revealed that all forest musk deer cathelicidin members have emerged before the split of the forest musk deer and cattle and that forest musk deer CATHL3L2 and CATHL9 are orthologous with two cattle pseudogenes. In addition, the gene expression results showed that the six functional genes are not only abundantly expressed in the spleen and lung, but are also differently expressed in response to abscesses, which suggests that forest musk deer cathelicidins may be involved in infections. Taken together, identification and characterization of the forest musk deer cathelicidins provide fundamental data for further investigating their evolutionary process and biological functions.

Effects of absorbents on growth performance, blood profiles and liver gene expression in broilers fed diets naturally contaminated with aflatoxin

Objective

The study was conducted to evaluate the effects of the absorbent (a mixture of activated carbon and hydrated sodium calcium aluminosilicate) on growth performance, blood profiles and hepatic genes expression in broilers fed diets naturally contaminated with aflatoxin.

Methods

A total of 1,200 one-day-old male chicks were randomly assigned to 6 treatments with 10 replicate cages per treatment. The dietary treatments were as follows: i) control (basal diets); ii) 50% contaminated corn; iii) 100% contaminated corn; iv) control+1% adsorbent; v) 50% contaminated corn+1% absorbent; vi) 100% contaminated corn+1% absorbent.

Results

During d 1 to 21, feeding contaminated diets reduced (p<0.05) body weight (BW), average daily gain (ADG), and average daily feed intake (ADFI), but increased (p<0.05) feed-to-gain ratio (F/G). The absorbent supplementation increased (p<0.05) BW, ADG, and ADFI. There were interactions (p<0.05) in BW, ADG, and ADFI between contaminated corn and absorbent. Overall, birds fed 100% contaminated diets had lower (p<0.05) final BW and ADG, but higher (p<0.05) F/G compared to those fed control diets. The absorbent addition increased (p<0.05) serum albumin concentration on d 14 and 28 and total protein (TP) level on d 28, decreased (p<0.05) alanine transaminase activity on d 14 and activities of aspartate aminotransferase and alkaline phosphatase on d 28. Feeding contaminated diets reduced (p<0.05) hepatic TP content on d 28 and 42. The contaminated diets upregulated (p<0.05) expression of interleukin-6, catalase (CAT), and superoxide dismutase (SOD), but downregulated (p<0.05) glutathione S-transferase (GST) expression in liver. The absorbent supplementation increased (p<0.05) interleukin-1β, CAT, SOD, cytochrome P450 1A1 and GST expression in liver. There were interactions (p<0.05) in the expression of hepatic CAT, SOD, and GST between contaminated corn and absorbent.

Conclusion

The results suggest that the naturally aflatoxin-contaminated corn depressed growth performance, while the adsorbent could partially attenuate the adverse effects of aflatoxin on growth performance, blood profiles and hepatic genes expression in broilers.

L-tryptophan Enhances Intestinal Integrity in Diquat-Challenged Piglets Associated with Improvement of Redox Status and Mitochondrial Function

Simple Summary

In the present study, three groups of piglets were treated with diquat, a bipyridyl herbicide which can utilize molecular oxygen to generate superoxide anion radicals and is widely considered as an effective chemical agent for inducing oxidative stress. The three groups were fed a 0, 0.15%, and 0.30% tryptophan (Trp) supplemented diet, and one control group without diquat treatment was used to study the protective effects of supplemented Trp on growth performance and intestinal barrier function of piglets exposed to oxidative stress. The results showed that 0.15% Trp supplementation alleviated diquat-induced impaired growth performance, intestinal barrier injury, redox imbalance, and mitochondrial dysfunction. These findings from the current study suggest that piglets under the condition of stress might need more Trp to maintain intestinal integrity and optimal growth performance, but the proper dosage of Trp supplementation is needed to determine for different conditions or models.

Abstract

Tryptophan (Trp) supplementation has been shown to improve growth performance and enhance intestinal integrity in piglets. However, the effects of dietary Trp supplementation on the intestinal barrier function in piglets exposed to oxidative stress remain unknown. This study was conducted to evaluate whether dietary Trp supplementation can attenuate intestinal injury, oxidative stress, and mitochondrial dysfunction of piglets caused by diquat injection. Thirty-two piglets at 25 days of age were randomly allocated to four groups: (1) the non-challenged control; (2) diquat-challenged control; (3) 0.15% Trp-supplemented diet + diquat; (4) 0.30% Trp supplemented diet + diquat. On day seven, the piglets were injected intraperitoneally with sterilized saline or diquat (10 mg/kg body weight). The experiment lasted 21 days. Dietary supplementation with 0.15% Trp improved growth performance of diquat-challenged piglets from day 7 to 21. Diquat induced an increased intestinal permeability, impaired antioxidant capacity, and mitochondrial dysfunction. Although dietary supplementation with 0.15% Trp ameliorated these negative effects induced by diquat challenge that showed decreasing permeability of 4 kDa fluorescein isothiocyanate dextran, increasing antioxidant indexes, and enhancing mitochondrial biogenesis. Results indicated that dietary supplementation with 0.15% Trp enhanced intestinal integrity, restored the redox status, and improved the mitochondrial function of piglets challenged with diquat.