Pectin alleviates the pulmonary inflammatory response induced by PM2.5 from a pig house by modulating intestinal microbiota.

This study aimed to investigate whether dietary fiber pectin can alleviate PM2.5-induced pulmonary inflammation and the potential mechanism. PM2.5 samples were collected from a nursery pig house. The mice were divided into three groups: the control group, PM2.5 group and PM2.5 + pectin group. The mice in the PM2.5 group were intratracheally instilled with PM2.5 suspension twice a week for four consecutive weeks, and those in the PM2.5 + pectin group were subject to the same PM2.5 exposure, but fed with a basal diet supplemented with 5% pectin. The results showed that body weight and feed intake were not different among the treatments (p > 0.05). However, supplementation with pectin relieved PM2.5-induced pulmonary inflammation, presenting as slightly restored lung morphology, decreased mRNA expression levels of IL-1ß, IL-6 and IL-17 in the lung, decreased MPO content in bronchoalveolar lavage fluid (BLAF), and even decreased protein levels of IL-1ß and IL-6 in the serum (p < 0.05). Dietary pectin altered the composition of the intestinal microbiota, increasing the relative abundance of Bacteroidetes and decreasing the ratio of Firmicutes/Bacteroidetes. At the genus level, short-chain fatty acid (SCFA)-producing bacteria, such as Bacteroides, Anaerotruncus, Prevotella 2, Parabacteroides, Ruminococcus 2 and Butyricimonas, were enriched in the PM2.5 +pectin group. Accordingly, dietary pectin increased the concentrations of SCFAs, including acetate, propionate, butyrate and valerate, in mice. In conclusion, dietary fermentable fiber pectin can relieve PM2.5-induced pulmonary inflammation via alteration of intestinal microbiota composition and SCFA production. This study provides a new insight into reducing the health risk associated with PM2.5 exposure.

Requirements of metabolizable protein by Dorper × thin-tailed Han crossbred ewe lambs.

The requirement of net protein (NP) and metabolizable protein (MP) by Dorper crossbred ewe lambs grown from 35 to 50 kg of body weight (BW) was assessed by comparative slaughter experiment. Thirty-five ewe lambs (33.5 ± 0.6 kg BW) of F1 crosses of Dorper × thin-tailed Han sheep were used: 7 lambs were slaughtered as reference animals at the start of the trial, and the remaining 28 lambs were randomly divided into 4 groups of 7 lambs each. Three of the 4 groups were fed a pelleted mixed diet (concentrate/roughage = 44:56, dry matter basis) for ad libitum intake or 65% or 45% of ad libitum intake, and they were all slaughtered when the lambs that were fed ad libitum reached 50 kg BW. The lambs from the fourth group were also fed ad libitum and slaughtered at 43 kg BW as the intermediate group. The intake of MP by the animals of these 4 groups was estimated, and their total body protein and protein retention were measured. The daily requirements of NP and MP for maintenance were 1.52 and 3.98 g/kg BW0.75 , respectively, with a partial efficiency of MP utilization for maintenance of 0.38. The MP requirement for growth ranged from 77.4 to 124.5 g/day for average daily gains from 100 to 250 g BW, and the partial efficiency of MP utilization for growth was 0.66. The Dorper crossbred ewe lambs required more MP for both maintenance and growth in comparison with the recommendations of the US nutritional system.

Growth performance, nutrient digestibility, and slaughter traits of male fattening lambs under different feeding standards.

This study compared the growth performance, nutrient utilization, and slaughter traits of Dorper crossbred male lambs fed as per the established nutrition recommendations for sheep, with an aim to verify the efficacy of different feeding standards. A total of 576 lambs (4 months of age, 28.3 ± 0.86 kg BW) were randomly allotted to 3 treatments with 12 replicates per treatment (16 lambs per replicate). The lambs were fed diets formulated according to the following 3 nutritional systems: the nutrient requirements of Dorper crossbred lambs established by Chinese Academy of Agricultural Sciences (CAAS), NRC (National Research Council), (2007), and AFRC (Agricultural and Food Research Council) (1993). The experiment lasted for 81 d. Feed intake was recorded every 3 days, and lambs were weighed every 20 days. Digestibility trials were conducted with 6 lambs each group from d 42 to 53 and d 70 to 81. At the end of the experiment, 10 lambs randomly chosen from each group were sacrificed to determine the carcass traits and meat quality. The results indicated that the lambs in the NRC group had the highest dry matter intake (DMI), followed by those in the AFRC and CAAS groups (P < 0.05). The average daily gain, carcass weight, and dressing percentage were higher for lambs in the CAAS group than those in the NRC group (P < 0.05). The lambs in the CAAS group had the lowest feed conversion ratio, followed by those in the AFRC and NRC groups (P < 0.05). The apparent digestibility of DM was higher for the lambs in the CAAS group than those in the NRC group (P < 0.05). Water losing rate, as well as the lightness (L*), redness (a*), and yellowness (b*) values of the longissimus thoracis were not different among groups (P > 0.05). In conclusion, Dorper crossbred lambs fed diets formulated according to the CAAS recommendations exhibited superior growth performance than those fed diets formulated according to the American or British feeding standards.

Prediction of methane emission from sheep based on data measured in vivo from open-circuit respiratory studies

Objectives: The current study analysed the relationships between methane (CH4) output from animal and dietary factors. Methods: The dataset was obtained from 159 Dorper × thin-tailed Han lambs from our seven studies, and CH4 production and energy metabolism data were measured in vivo by an open-circuit respiratory method. All lambs were confined indoors and fed pelleted diet during the whole experimental period in all studies. Data from two-thirds of lambs were used to develop linear and multiple regressions to describe the relationship between CH4 emission and dietary variables, and data from the remaining one third of lambs were used to validate the established models. Results: CH4 emission (g/d) was positively related to dry matter intake (DMI) and gross energy intake (GEI) (P < 0.001). CH4 energy/GEI was negatively related to metabolizable energy/gross energy (ME/GE) and metabolizable energy/digestible energy (ME/DE) (P < 0.001). Using DMI to predict CH4 emission (g/d) resulted in a coefficient of determination (R2) of 0.80. Using GEI, DEI, and MEI predict CH4 energy/GEI resulted in a R2 of 0.92. Conclusion: the prediction equations established in the current study are useful to develop appropriate feeding and management strategies to mitigate CH4 emissions from sheep.

Effects of Tea Saponin Supplementation on Nutrient Digestibility, Methanogenesis, and Ruminal Microbial Flora in Dorper Crossbred Ewe.

Two experiments were conducted using Dorper × thin-tailed Han crossbred ewes. In experiment 1, eighteen ewes were randomly assigned to two dietary treatments (a basal diet, or the same basal diet supplemented with 2.0 g tea saponin (TS)/head/day) to investigate the effects of TS supplementation on nutrient digestibility and methane emissions. In experiment 2, six ewes with ruminal cannulae were assigned to the same two dietary treatments as in experiment 1 to investigate the effects of TS supplementation on rumen fermentation and microbial flora. TS supplementation increased the apparent digestibility of organic matter (OM) (p = 0.001), nitrogen (N) (p = 0.036), neutral detergent fibre (NDF) (p = 0.001), and acid detergent fibre (ADF) (p < 0.001). Urinary N (p = 0.001) and fecal N (p = 0.036) output were reduced, and N retention (p = 0.001) and nitrogen retention/nitrogen intake (p = 0.001) were increased. Supplementary TS did not decrease absolute methane emissions (p = 0.519) but decreased methane emissions scaled to metabolic bodyweight by 8.80% (p = 0.006). Ammonia levels decreased (p < 0.001) and total volatile fatty acid levels increased (p = 0.018) in response to TS supplementation. The molar proportion of propionate increased (p = 0.007), whereas the acetate:propionate ratio decreased (p = 0.035). Supplementation with TS increased the population of Fibrobacter succinogenes (p = 0.019), but the population of protozoans tended to decrease (p = 0.054). Supplementation with TS effectively enhanced the apparent digestibility of OM, N, NDF, and ADF, and decreased methane emissions scaled to metabolic bodyweight.

Effects of rearing system on meat quality, fatty acid and amino acid profiles of Hu lambs.

To determine the effects of early rearing system on meat quality traits, fatty acid and amino acid profiles of meat, 48 Hu lambs were selected and randomly divided into four treatments: control lambs were ewe-reared from birth to 60 days of age (ER), while treatment lambs were segregated from their dams at 10, 20 and 30 days of age, then artificially reared with milk replacer until 60 days of age (EW10, EW20 and EW30, respectively). All lambs had no access to the milk replacer or their dams from 61 to 90 days. Creep feed was supplied ad libitum to all lambs from 15 to 90 days of age. Artificially reared lambs (EW10, EW20 and EW30) had higher (p < .05) creep feed intake, average daily gain, slaughter weight, hot carcass weight, meat ether extract content, bright meat color (lightness and yellowness) than ewe-reared lambs. The content of unsaturated fatty acids and monounsaturated fatty acids in EW10 and EW20 were greater (p < .05) than that in ER, whereas the proportions of saturated fatty acids in EW10 and EW20 were lower than that in ER (p < .05). The percentages of C18:0, C18:2, C18:3 and the ratio of polyunsaturated fatty acids and saturated fatty acids of artificially reared lambs were greater than ewe-reared lambs (p < .05). The meat proportions of leucine, alanine and proline were higher (p < .05) in artificially reared lambs than ewe-reared ones. Finally, the artificially reared system increased meat production and changed the fatty acid and amino acid profiles of meat, and it would be appropriate to rear Hu lambs artificially from 10 days with milk replacer.

Effects of feeding a Moringa oleifera rachis and twig preparation to dairy cows on their milk production and fatty acid composition, and plasma antioxidants.

BACKGROUND: We determined how supplementing the diet of lactating, multiparous Holstein dairy cows with a preparation of Moringa oleifera rachises and twigs affected their milk production and quality and the levels of plasma antioxidants. RESULTS: We found that milk yield increased in cows receiving the 6% (w/w) moringa supplement compared with that of the control. Addition of the moringa supplement increased the concentration of milk fat and decreased the somatic cell count in the milk. However, protein, glucose and total solid and urea nitrogen concentrations in the milk were the same for all treatments. The concentration of glutathione peroxidase increased for cows fed the moringa supplement compared with the control. The percentages of total unsaturated fatty acids, mono-unsaturated fatty acids, and polyunsaturated fatty acids including n-3 polyunsaturated fatty acid increased in the milk of cows fed the moringa supplement compared with those of the controls. CONCLUSION: Addition of the moringa supplement into the diet of lactating multiparous cows improved milk production and health status and modified milk fatty acid profile positively. The results suggested that moringa supplement could be used as a diet supplement for producing high quality and healthier milk. © 2017 Society of Chemical Industry.

Net protein and metabolizable protein requirements for maintenance and growth of early-weaned Dorper crossbred male lambs.

BACKGROUND: Dorper is an important breed for meat purpose and widely used in the livestock industry of the world. However, the protein requirement of Dorper crossbred has not been investigated. The current paper reports the net protein (NP) and metabolizable protein (MP) requirements of Dorper crossbred ram lambs from 20 to 35 kg BW. METHODS: Thirty-five Dorper × thin-tailed Han crossbred lambs weaned at approximately 50 d of age (20.3 ± 2.15 kg of BW) were used. Seven lambs of 25 kg BW were slaughtered as the baseline animals at the start of the trial. An intermediate group of seven randomly selected lambs fed ad libitum was slaughtered at 28.6 kg BW. The remaining 21 lambs were randomly divided into three levels of dry matter intake: ad libitum or 70% or 40% of ad libitum intake. Those lambs were slaughtered when the lambs fed ad libitum reached 35 kg BW. Total body N and N retention were measured. RESULTS: The daily NP and MP requirements for maintenance were 1.89 and 4.52 g/kg metabolic shrunk BW (SBW0.75). The partial efficiency of MP utilization for maintenance was 0.42. The NP requirement for growth ranged from 12.1 to 43.5 g/d, for the lambs gaining 100 to 350 g/d, and the partial efficiency of MP utilization for growth was 0.86. CONCLUSIONS: The NP and MP requirements for the maintenance and growth of Dorper crossbred male lambs were lower than the recommendations of American and British nutritional systems.

Oral administration of Lactobacillus plantarum and Bacillus subtilis on rumen fermentation and the bacterial community in calves.

The objective of this study was to assess the effect of dietary probiotics on rumen fermentation and the bacterial community in dairy calves. Twelve Holstein calves were randomly allocated to three treatments: a basal diet, the basal diet supplemented with Lactobacillus plantarum GF103 (LB) or basal diet supplemented with a mixture of Lactobacillus plantarum GF103 and Bacillus subtilis B27 (LBS). A milk replacer was fed to calves from 8 days of age. A starter and alfalfa hay was offered ad libitum from 21 and 28 days of age, respectively, and the orts were weighted daily. The ruminal fluid was sampled at 56 and 83 days of age to determine the rumen fermentation characteristics. The bacterial community was analyzed by denaturing gradient gel electrophoresis (DGGE) and the number of certain bacteria was quantified by real-time polymerase chain reaction. The ratio of total dry matter intake to average body wieght was higher in the control (P < 0.05). The DGGE fingerprint of the 16S ribosomal RNA gene was affected by the blended probiotics at 83 days of age. The number of Ruminococcus albus was lower in the LB and LBS treatment (P < 0.05). Oral administration of the probiotics affected the rumen bacterial community and the numbers of cellulolytic bacteria decreased.

Effect of supplementation of allicin on methanogenesis and ruminal microbial flora in Dorper crossbred ewes.

BACKGROUND: Garlic extracts have been reported to be effective in reducing methanogenesis. Related mechanisms are not well illustrated, however, and most studies have been conducted in vitro. This study investigates the effects of supplementary allicin (AL) in sheep diet on in vivo digestibility, rumen fermentation, and shifts of microbial flora. METHODS: Two experiments were conducted using Dorper × thin-tailed Han crossbred ewes. In experiment 1, eighteen ewes (60.0 ± 1.73 kg BW) were randomly assigned for 29 days to either of two dietary treatments: a basal diet or the basal diet supplemented with 2.0 g AL/head·day to investigate supplementary AL on nutrient digestibility and methane emissions. In experiment 2, six ewes (65.2 ± 2.0 kg BW) with ruminal canulas were assigned to the same two dietary treatments as in experiment 1 for 42 days to investigate supplementary AL on ruminal fermentation and microbial flora. The methane emissions were determined using an open-circuit respirometry system and microbial assessment was done by qPCR of 16S rRNA genes. RESULTS: Supplementary AL increased the apparent digestibility of organic matter (P < 0.001), nitrogen (P = 0.006), neutral detergent fiber (P < 0.001), and acid detergent fiber (P = 0.002). Fecal nitrogen output was reduced (P = 0.001) but urinary nitrogen output was unaffected (P = 0.691), while nitrogen retention (P = 0.077) and nitrogen retention/nitrogen intake (P = 0.077) tended to increase. Supplementary AL decreased methane emissions scaled to metabolic bodyweight by 5.95 % (P = 0.007) and to digestible organic matter intake by 8.36 % (P = 0.009). Ruminal pH was unaffected (P = 0.601) while ammonia decreased (P = 0.024) and total volatile fatty acids increased (P = 0.024) in response to supplementary AL. Supplementary AL decreased the population of methanogens (P = 0.001) and tended to decrease that of protozoans (P = 0.097), but increased the populations of F. succinogenes (P < 0.001), R. flavefaciens (P = 0.001), and B. fibrisolvens (P = 0.001). CONCLUSIONS: Supplementation of AL at 2.0 g/head·day effectively enhanced OM, N, NDF, and ADF digestibility and reduced daily methane emissions (L/kg BW(0.75)) in ewes, probably by decreasing the population of ruminal protozoans and methanogens.

Effect of Dietary Concentrate:forage Ratios and Undegraded Dietary Protein on Nitrogen Balance and Urinary Excretion of Purine Derivatives in Dorper×thin-tailed Han Crossbred Lambs.

THIS STUDY AIMED TO INVESTIGATE DIETARY CONCENTRATE: forage ratios (C:F) and undegraded dietary protein (UDP) on nitrogen balance and urinary excretion of purine derivatives (PD) in lambs. Four Dorper×thin-tailed Han crossbred castrated lambs with 62.3±1.9 kg body weight at 10 months of age were randomly assigned to four dietary treatments in a 2×2 factorial arrangement of two levels of C:F (40:60 and 60:40) and two levels of UDP (35% and 50% of CP), according to a complete 4×4 Latin-square design. Each experimental period lasted for 19 d. After a 7-d adaptation period, lambs were moved into individual metabolism crates for 12 d including 7 d of adaption and 5 d of metabolism trial. During the metabolism trial, total urine was collected for 24 h and spot urine samples were also collected at different times. Urinary PD was measured using a colorimetric method and creatinine was measured using an automated analyzer. Intake of dry matter (DM) (p<0.01) and organic matter (OM) (p<0.01) increased as the level of UDP decreased. Fecal N was not affected by dietary treatment (p>0.05) while urinary N increased as the level of UDP decreased (p<0.05), but decreased as dietary C:F increased (p<0.05). Nitrogen retention increased as dietary C:F increased (p<0.05). As dietary C:F increased, urinary excretion of PD increased (p<0.05), but was not affected by dietary UDP (p>0.05) or interaction between dietary treatments (p>0.05). Daily excretion of creatinine was not affected by dietary treatments (p<0.05), with an average value of 0.334±0.005 mmol/kg BW(0.75). A linear correlation was found between total PD excretion and PDC index (R(2) = 0.93). Concentrations of creatinine and PDC index in spot urine were unaffected by sampling time (p>0.05) and a good correlation was found between the PDC index (average value of three times) of spot urine and daily excretion of PD (R(2) = 0.88). These results suggest that for animals fed ad libitum, the PDC index in spot urine is effective to predict daily excretion of PD. In order to improve the accuracy of the spot sampling technique, an appropriate lag phase between the time of feeding and sampling should be determined so that the sampling time can coincide with the peak concentration of PD in the urine.

Net Phosphorus Requirements of Dorper×Thin-tailed Han Crossbred Ram Lambs.

A comparative slaughter trial was conducted to estimate the phosphorus (P) requirement for maintenance and growth of crossbred lambs of Dorper with a Chinese indigenous sheep breed, thin-tailed Han sheep. Thirty-five Dorper×thin-tailed Han crossbred, noncastrated ram lambs (20.3±0.22 kg of shrunk body weight (SBW)) were used. Seven lambs were randomly chosen and slaughtered at 20 kg SBW as the baseline group for measuring initial body composition. Another seven lambs were also randomly chosen and offered a pelleted mixed diet for ad libitum intake and slaughtered at 28 kg SBW. The remaining 21 sheep were randomly divided into 3 groups with 7 sheep each and subject to the same diet of either 70 or 40% of ad libitum intake. The 3 groups were slaughtered when the sheep fed ad libitum reached 35 kg of SBW. Body P contents were determined after slaughter. The results showed that the net P requirement for maintenance was 30.0 mg/kg of empty body weight (EBW) or 23.4 mg/kg body weight (BW), and the P requirement for growth decreased from 5.3 to 5.0 g/kg of EBW gain as the lamb grew from 20 to 35 kg. The net P requirement for growth of Dorper×thin-tailed Han crossbred ram lambs was lower than that of sheep adopted by the American nutritional system.

Laboratory culture of the freshwater benthic gastropod Bellamya aeruginosa (Reeve) and its utility as a test species for sediment toxicity.

This study aimed to develop original laboratory culture and sediment toxicity testing protocols for the freshwater gastropod Bellamya aeruginosa (Reeve), a new potential species for sediment toxicity testing. B. aeruginosa was successfully cultured with an effective culture system under proposed laboratory conditions. Optimal ad libitum feeding levels for larvae, juveniles, and adults were 2.0, 6.0, and 16.0 mg fish food/(snail x day), respectively. Mean survival rates of juveniles were higher than 90%. The snails could be sexed at 9 weeks of age, and their generation time is approximately 4 months. Reproduction continued all year around; the mean fecundity was 0.55 newborn/(female x day). The utility of this species for bioassays was evaluated in both 10-day and 28-day case studies with artificial sediments. The 10-day LC50 of Cu for larvae was 480 gg/g dry weight (dw), and the lowest observed effects concentration of Cu for survival and growth of larvae was 195 microg/g dw. Survival and growth are reliable indicators of acute toxicity. Larvae accumulated more Cu than adults. B. aeruginosa exhibited a higher sensitivity to Cu exposure than standard test species (Hyalella azteca and Chironomus tentans). The 28-day test of sediment toxicity with adults showed that fecundity was a robust endpoint indicator of reproductive toxicity, and the biochemical endpoints of superoxide dismutase, catalase, and glutathione could be used as sensitive biomarkers for Cu-induced oxidative damage. B. aeruginosa can be therefore recommended as a candidate for the standardization of the freshwater sediment toxicity test protocol.

[Theoretical model for rocky desertification control in karst area].

Based on the basic principles of restoration ecology, the trigger-action model for rocky desertification control was proposed, i. e. , the ability that an ecosystem enables itself to develop was called dominant force, and the interfering factor resulting in the deviation of the climax of ecological succession from its preconcerted status was called trigger factor. The ultimate status of ecological succession was determined by the interaction of dominant force and trigger factor. Rocky desertification was the result of serious malignant triggers, and its control was the process of benign triggers in using the ecological restoration method of artificial designs to activate the natural designing ability of an ecosystem. The ecosystem of Karst rocky desertification in Fenghuang County with restoration measures was taken as a case to test the model, and the results showed that the restoration measures based on trigger-action model markedly improved the physical and chemical properties of soil and increased the diversity of plant. There was a benign trigger between the restoration measures and the Karst area. The rationality of the trigger-action model was primarily tested by the results in practice.