Effects of urea plus nitrate pretreated rice straw and corn oil supplementation on fiber digestibility,nitrogen balance,rumen fermentation,microbiota and methane emissions in goats

Background: Urea pretreatment is an efficient strategy to improve fiber digestibility of low quality roughages for ruminants. Nitrate and oil are usually used to inhibit enteric methane(CH_4) emissions from ruminants. The objective of this study was to examine the combined effects of urea plus nitrate pretreated rice straw and corn oil supplementation to the diet on nutrient digestibility, nitrogen(N) balance, CH_4 emissions, ruminal fermentation characteristics and microbiota in goats. Nine female goats were used in a triple 3 × 3 Latin Square design(27 d periods). The treatments were: control(untreated rice straw, no added corn oil), rice straw pretreated with urea and nitrate(34 and 4.7 g/kg of rice straw on a dry matter [DM] basis, respectively, UN), and UN diet supplemented with corn oil(15 g/kg soybean and15 g/kg corn were replaced by 30 g/kg corn oil, DM basis, UNCO).Results: Compared with control, UN increased neutral detergent fiber(NDF) digestibility(P 0.001) and copies of protozoa(P 0.001) and R. albus(P 0.05) in the rumen, but decreased N retention(-21.2%, P 0.001), dissolved hydrogen concentration(-22.8%, P 0.001), molar proportion of butyrate(-18.2%, P 0.05),(acetate + butyrate) to propionate ratio(P 0.05) and enteric CH_4 emissions(-10.2%, P 0.05). In comparison with UN, UNCO increased N retention(+34.9%, P 0.001) and decreased copies of protozoa(P 0.001) and methanogens(P 0.001). Compared with control, UNCO increased NDF digestibility(+8.3%, P 0.001), reduced ruminal dissolved CH_4 concentration(-24.4%, P 0.001) and enteric CH_4 emissions(-12.6%, P 0.05).Conclusions: A combination of rice straw pretreated with urea plus nitrate and corn oil supplementation of the diet improved fiber digestibility and lowered enteric CH_4 emissions without negative effects on N retention. These strategies improved the utilization of rice straw by goats.     

Poultry fat decreased fatty acid transporter protein mRNA expression and affected fatty acid composition in chickens

Background: A study was undertaken to examine the effects of poultry fat (PF) compared with those of soybean oil (SBO) on intestinal development, fatty acid transporter protein (FATP) mRNA expression, and fatty acid composition in broiler chickens. A total of 144 day-old male commercial broilers were randomly allocated to 2 treatment groups (6 replicates of 12 chicks for each treatment) and fed isocaloric diets containing 3.0% PF or 2.7% SBO at 0 to 3 wk and 3.8% PF or 3.5% SBO at 4 to 6 wk, respectively. Results: PF had no influence on intestinal morphology, weight, or DNA, RNA, or protein concentrations at 2, 4, and 6 wk of age. However, compared with SBO, PF significantly decreased FATP mRNA abundance at 4 wk (P=0.009) and 6 wk of age (P<0.001); decreased liver fatty acid-binding protein (L-FABP) mRNA abundance at 6 wk of age (P=0.039); and decreased C18:2 (P=0.015), C18:3 (P<0.001), C20:2 (P=0.018), Σ-polyunsaturated fatty acids (Σ-PUFA) (P = 0.020), and the proportion of PUFA (P<0.001) in the intestinal mucosa and decreased C18:2 (P=0.010), C18:3 (P<0.001), C20:2 (P<0.001), Σ-PUFA (P=0.005), and the proportion of PUFA (P<0.001) in breast muscle at 6 wk of age. Conclusions: PF decreases FATP and L-FABP mRNA expression and decreased the proportion of PUFA in the intestinal mucosa and breast muscle.     

Antioxidant efficiency of lycopene on oxidative stress-induced damage in bovine spermatozoa

Background: Lycopene(LYC) is a natural carotenoid with powerful reactive oxygen species(ROS) scavenging activities. The aim of this study was to investigate if lycopene has the ability to reverse ROS-mediated alterations to the motility, viability and intracellular antioxidant profile of bovine spermatozoa subjected to ferrous ascorbate(Fe AA). Spermatozoa were washed out of fresh bovine semen, suspended in 2.9 % sodium citrate and subjected to LYC treatment(0.25, 0.5, 1 or 2 mmol/L) in the presence or absence of Fe AA(150 μmol/L Fe SO_4 and 750 μmol/L ascorbic acid) during a 6 h in vitro culture. Spermatozoa motion characteristics were assessed using the Sperm Vision?computer-aided sperm analysis(CASA) system. Cell viability was examined with the metabolic activity(MTT) assay,ROS generation was quantified via luminometry and the nitroblue-tetrazolium(NBT) test was applied to quantify the intracellular superoxide formation. Cell lysates were prepared at the end of the in vitro culture to investigate the intracellular activity of superoxide dismutase(SOD), catalase(CAT), glutathione peroxidase(GPx) as well as the concentrations of glutathione(GSH) and malondialdehyde(MDA).Results: FeA A treatment led to a reduced spermatozoa motility(P 0.001), viability(P 0.001) and a decline of the antioxidant capacity of spermatozoa(P 0.001) but increased the ROS generation(P 0.001), superoxide production(P 0.001) and lipid peroxidation(P 0.001). LYC administration resulted in a preservation of the spermatozoa motion parameters(P 0.001), mitochondrial activity(P 0.001) and antioxidant characteristics(P 0.001 with respect to SOD;P 0.01 in relation to CAT; P 0.05 as for GPx and GSH) with a concentration range of 1 and 2 mmol/L LYC revealed to be the most effective.Conclusions: Our results suggest that LYC exhibits significant ROS-scavenging and antioxidant properties which may prevent spermatozoa alterations caused by oxidative stress, and preserve the functionality of male reproductive cells.     

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 q PCR of 16 S r RNA 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 p H 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 BW0.75) in ewes, probably by decreasing the population of ruminal protozoans and methanogens.     

Effect of dietary canthaxanthin and 25-hydroxycholecalciferol supplementation on the performance of duck breeders under two different vitamin regimens

Background: Dietary canthaxanthin(CX), 25-hydroxycholecalciferol(25-OH-D3) and vitamins have been widely reported to be involved in productive and reproductive performance of broiler breeders. However, limited information is available for duck breeders. In this study, a total of 1,560 Cherry Valley SM3 duck breeder females and 312 males were used to assess if the addition of CX and 25-OH-D3 could increase the performance of duck breeders under two different dietary vitamin regimens. Four diets were used under a 2 × 2 factorial arrangement with 2 kinds of vitamin premixes(REGULAR and HIGH; HIGH premix had higher levels of all vitamins except K3 than REGULAR premix), and with or without the supplementation of the mixture of CX(6 mg/kg) and 25-OH-D3(0.069 mg/kg). The ducks were fed ad libitum with pelleted diets based on corn-soybean meal from 38 to 77 wk of age.Results: HIGH vitamin premix decreased malondialdehyde(MDA) level(P 0.001) of egg yolk, increased hatchability of fertile eggs(P = 0.029), increased hatchability of total eggs(P = 0.029), and decreased serum protein carbonyl level(P = 0.037) of breeder males. The mixture of CX and 25-OH-D3 increased serum calcium of breeder females(P = 0.010), decreased the cracked egg rate(P = 0.001), increased the pigmentation of egg yolk(P 0.001)and male bill(P 0.001), and decreased MDA level of egg yolk(P 0.001) and male serum(P = 0.034). Interactive effects were observed in cracked egg rate(P = 0.038), shell thickness(P = 0.011) and serum phosphorus(P = 0.026)of breeder females. HIGH vitamin premix together with the mixture of CX and 25-OH-D3 decreased cracked egg rate and increased shell thickness of duck breeders. Serum phosphorus was decreased in duck breeder females fed REGULAR vitamin premix without the addition of the CX and 25-OH-D3 mixture.Conclusions: Dietary HIGH vitamin premix increased antioxidant status of eggs and breeder males, and increased hatchability. The mixture of CX and 25-OH-D3 enhanced egg shell quality, and promoted pigmentation and antioxidant status of eggs and breeder males.     

亚洲牛奶和乳制品消费猛增

根据TNS亚太固定样组(第一个泛亚地区连续性消费者固定样组 )的数据表明:亚洲人牛奶和其他乳制品的消费量在增长。此外 ,液态奶比奶粉更受亚洲人的青睐。在乳制品消费量方面领亚洲之先的是日本和韩国 ,在调查的每一个季度里 ,几乎所有的家庭户都购买了乳制品。与此相反的是:马来西亚的乳制品消费量仍是亚洲最低的国家之一 ,过半数 (58 % )的家庭户购买了任何一种乳制品 ,这当中仅74 %的家庭户购买了牛奶。尽管不是一个传统上就和乳制品消费有关联的国家 ,但中国的乳品市场与前一年度相比有了两位数的增长速度 ,尤其在液态奶的销售上。液态…     

鲤鱼饲料中2种大豆蛋白源替代鱼粉蛋白的比较研究

将初始体质量为(100.25±0.98)g的健康鲤鱼180尾随机分为3组,每组3个重复,分别饲喂以鱼粉为动物蛋白源(对照组)和以全脂豆粉(全脂豆粉组)、去皮豆粕(去皮豆粕组)分别替代20%鱼粉蛋白配制的等蛋白(36%)、等能(15.2kJ/g)的半精制饲料,在室内单循环控温养殖系统中进行6周生长试验,探讨2种大豆蛋白部分替代鱼粉对鲤鱼生长及饲料利用的影响。结果表明:全脂豆粉组鲤鱼的特定生长率、蛋白质效率、蛋白质沉积率极显著下降(P0.01),饲料效率显著降低(P0.05);而去皮豆粕组鲤鱼的特定生长率、蛋白质效率、蛋白质沉积率与对照组差异不显著(P0.05),饲料效率显著升高(P0.05)。     

全脂米糠部分替代玉米对四川白鹅器官指数和胸肌中氨基酸组成影响的研究

试验目的是研究全脂米糠部分替代玉米后对四川白鹅器官指数和胸肌中氨基酸组成的影响。204只四川白鹅[公鹅,28日龄,(984±15)g]随机分配到4个处理组,进行为期42 d的饲养试验。其全脂米糠的添加量分别为0、6%、12%和18%。每个处理有6个重复,每个重复8~9只鹅。研究结果表明,四川白鹅饲粮中部分添加全脂米糠有降低肌胃指数和心肌指数的趋势(线性0.05P0.1),且四川白鹅胸肌中丝氨酸的含量最高可提高3.6%(线性0.05P0.1),但对其它氨基酸含量均没有影响(线性P0.05;二次P0.05)。说明全脂米糠部分替代玉米后对四川白鹅的器官指数和胸肌的氨基酸组成均没有影响。     

Dose-response effects of in-feed antibiotics on growth performance and nutrient utilization in weaned pigs fed diets supplemented with yeast-based nucleotides

Dietary nucleotides are bioactive compounds with the potential to mitigate weaning-associated challenges in piglets. An experiment was conducted to determine the interaction effect of antimicrobial growth promoters(AGP) and a nucleotide-rich yeast extract(NRYE) on growth performance and apparent total tract digestibility(ATTD) of dry matter(DM), crude protein(CP) and gross energy(GE),and to establish whether NRYE supplementation may completely or partially replace AGP in diets for weaned pigs. In phase 1 and 2, corn, wheat, canola meal and soybean meal based diets, which were formulated to contain 0.0 or 0.1% NRYE with 0, 25, 50, 75 or 100% of the recommended AGP dosage, were fed to 108 twenty-one day old piglets(initial body weight 7.11 ± 0.9 kg; mean ±SD) from d 1 to 14 and15 to 28, respectively. Overall, increasing AGP level in NRYE supplemented diets linearly decreased average daily gain(ADG)(P = 0.002) and gain-to-feed ratio(G:F)(P = 0.007); and quadratically decreased ATTD of DM(P = 0.001), CP(P =0.003) and G:F(P = 0.017) during phase 2. Compared with control and pigs fed NRYE with 100% of recommended AGP dosage, pigs fed 0.1% NRYE without AGP had greater(P 0.05) ADG and G:F in phase 2 and overall. In conclusion, supplementing 0.1% NRYE improved growth performance of pigs but this beneficial effect was reduced by increasing dietary AGP dosage.     

国际科技资讯

巴西及葡萄牙研究表明Coalho奶酪制作中加入牛奶不会影响营养及风味Coalho奶酪是著名的拉丁传统美食,一种烧烤奶酪,通常由羊奶制作。近期有巴西及葡萄牙研究人员对由山羊奶、牛奶及期混合物制作的Coalho奶酪在冷冻储藏28d过程中的营养、质地及感官特性进行比较(拟发表于Food Science and Technology2013年2期)。     

河北坝上地区生鲜乳主要指标变化规律研究

为了解河北坝上地区奶牛乳产品质量的变化规律,对某规模化牛场2015—2016年的乳成分数据进行整理,并采用SPSS 17.0软件进行分析,以得出该地区生鲜乳的主要指标变化规律。结果表明:乳脂率8月份最低(3.14%),1月份最高(4.20%);乳蛋白率6月份最低(3.06%),8月份最高(3.9%);乳糖含量10月份最低(4.85%),8月份最高(5.43%);全脂乳固体含量6月份最低(12.27%),9—10月份最高(12.97%);非脂乳固体含量6月份最低(8.44%),11月份最高(8.81%);酸度含量3月份最低(13.79°T),9月份最高(14.37°T)。乳脂率与乳蛋白率、全脂乳固体和非脂乳固体呈极显著正相关(P0.01),与乳糖呈极显著负相关(P0.01);乳蛋白率与全脂乳固体、非脂乳固体呈极显著正相关(P0.01),与酸度呈显著正相关(P0.05);乳糖与全脂乳固体和非脂乳固体呈极显著负相关(P0.01);全脂乳固体与非脂乳固体呈极显著正相关(P0.01)。     

Maternal antibiotic treatment affects offspring gastric sensing for umami taste and ghrelin regulation in the pig

Background: Scarce is knowledge on the process regulating the development of acid secretion, orexigenic signaling, and chemosensing in the stomach of young pigs. Changes of early microbial encounters by suckling pigs can interact with the gut maturation, by the induction of different molecular signaling. Our goal was to assess if the age of offspring and the maternal environment, influenced by sow antibiotic treatment peripartum, could affect gastric morphology and the expression of genes involved in the control of hydrochloric secretion, feed intake, taste,and inflammation in offspring stomach.Methods: 84 pigs from sows fed a diet with amoxicillin(on –d10 to +d21 from farrowing, ANT) or without(CON)were sacrificed at d14, d21, d28(weaning) or d42. Samples of oxyntic(OXY), pyloric(PY) and cardiac mucosae close to OXY were collected and parietal and enteroendocrine cells(EECs) were counted. Relative gene expression of a set of 11 key genes(ATP4 A, SSTR2, GAST, GHRL, MBOAT4, PCSK1, GNAT1, TAS1 R1, TAS1 R3, IL8 and TNF) was assessed by qRT-PCR. In addition, 40 offspring obtained from the same ANT and CON sows were offered a normal or a fatenriched diet for 4 weeks between 140 and 169 d of age, and then OXY and PY were sampled.Results: The number of parietal and EECs increased with age(P 0.001). ATP4 A increased with age(within suckling,P = 0.043, post-weaning vs. suckling, P 0.001), SSTR2 increased only after weaning(P 0.001). In OXY, GHRL increased during suckling(P = 0.012), and post-weaning as a trend(P = 0.088). MBOAT4 tended to increase during suckling(P = 0.062). TAS1 R1 increased from suckling to post-weaning period(P =0.001) and was lower in ANT offspring(P = 0.013). GNAT1 in PY was higher in ANT offspring(P = 0.041). Antibiotic treatment of sows peripartum increased expression of GHRL and MBOAT4 in OXY of growing-finishing offspring aged 5 months.Conclusions: Data show that sensing for umami taste and ghrelin regulation can be affected by maternal environment, but the development of acid secretion, orexigenic signaling and taste perception in the stomach are mostly developmentally controlled.     

饲料中膨化全脂大豆粉添加蛋氨酸替代鱼粉对乌鳢生长和代谢的影响

以乌鳢鱼种(8.25±1.30)g为试验对象,分别以膨化全脂大豆蛋白替代0%、20%、40%、60%、80%、100%的鱼粉蛋白配制等氮、等能的饲料,饲养8周,探讨饲料中补充限制性蛋氨酸的膨化全脂大豆粉替代鱼粉对乌鳢生长和代谢的影响。结果表明,当替代20%鱼粉蛋白时,乌鳢的增重率显著高于80%和100%替代组(P0.05),与对照组相比差异不显著;当替代量为100%时,乌鳢的增重率显著低于对照组和其它各组。20%替代组的蛋白质效率显著高于对照组和其他各试验组(P0.05),100%替代组的蛋白质效率显著低于对照组和其他各试验组(P0.05)。80%和100%替代组乌鳢肠道蛋白酶活性显著低于对照组(P0.05),而80%和100%替代组乌鳢肝脏AST和ALT、血清AST和ALT与之正好相反。60%、80%和100%替代组乌鳢的氮排泄显著高于对照组(P0.05)。在本试验条件下,饲料中膨化全脂大豆添加蛋氨酸可替代乌鳢饲料鱼粉蛋白的60%~80%。     

水牛奶干酪功能活性肽的研究

以水牛奶为原料,研制不同凝乳酶的水牛奶干酪,利用单因素试验、二次通用旋转方案筛选奶酪蛋白肽提取工艺,并研究蛋白肽的抗氧化功能及抑菌活性。结果表明,水牛奶奶酪蛋白肽最佳提取工艺为料液比26∶1、匀浆时间5min、转速10×1000r/min;4种水牛奶奶酪蛋白肽均具有较好的功能活性,其中贯筋藤凝乳酶奶酪的ABTS清除活性为82.22%、还原能力(RP)为52.96%、DPPH自由基清除能力为52.63%,对李斯特菌抑菌率达到86.33%、对沙门氏菌抑菌率达到55.36%。水牛奶干酪含有较丰富的功能活性物质,开发前景较好。     

甘油代替大麦对泌乳中后期奶牛采食量、产奶量和乳质量的影响

文章旨在确定在不影响牛奶产量、牛奶成分、乳脂肪酸组成和牛奶感官质量的情况下,用不同水平甘油代替大麦对泌乳中后期奶牛的影响。试验选择了40头荷斯坦奶牛,采用4×4拉丁方试验设计。在部分混合日粮中,粗甘油替代大麦的含量分别为日粮干物质的0、6%、12%和18%。每天记录个体产奶量、采食量和挤奶频率,每周分析牛奶成分。对新鲜牛奶和贮藏7 d的牛奶样品进行感官分析。部分混合日粮的摄入量随甘油添加水平由0升高至12%,增加近1 kg,甘油由12%升高至18%,减少约1 kg。甘油水平由0升高至6%时,精料摄入量下降0.5 kg。随着日粮中甘油比例的增加,牛奶产量呈线性下降(P<0.05),而牛奶中的脂肪和蛋白质含量呈上升趋势(P=0.08),导致能量校正乳水平随甘油水平的升高表现为二次曲线效应,其中6%甘油组产量最高,18%甘油组产量最低。蛋白质和乳糖产量随日粮中甘油比例的增加线性下降(P<0.05)。随着日粮甘油比例的增加,牛奶中棕榈酸、油酸、亚油酸、亚麻酸和共轭亚油酸的比例线性下降(P<0.05),而短链和中链脂肪酸的比例大部分呈上升趋势。综上所述,甘油作为一种能量饲料可以在不影响牛奶品质的前提下,在泌乳中后期奶牛日粮中替代大麦的水平高达18%。但日粮甘油水平超过12%时可能会降低能量校正乳的产量。     

Dietary arachidonate in milk replacer triggers dual benefits of PGE_2 signaling in LPS-challenged piglet alveolar macrophages

Background: Respiratory infections challenge the swine industry, despite common medicinal practices. The dual signaling nature of PGE_2(supporting both inflammation and resolution) makes it a potent regulator of immune cell function. Therefore, the use of dietary long chain n-6 PUFA to enhance PGE_2 effects merits investigation.Methods: Day-old pigs(n = 60) were allotted to one of three dietary groups for 21 d(n = 20/diet), and received either a control diet(CON, arachidonate = 0.5% of total fatty acids), an arachidonate(ARA)-enriched diet(LC n-6,ARA = 2.2%), or an eicosapentaenoic(EPA)-enriched diet(LC n-3, EPA = 3.0%). Alveolar macrophages and lung parenchymal tissue were collected for fatty acid analysis. Isolated alveolar macrophages were stimulated with LPS in situ for 24 h, and m RNA was isolated to assess markers associated with inflammation and eicosanoid production.Culture media were collected to assess PGE_2 secretion. Oxidative burst in macrophages was measured by: 1)oxygen consumption and extracellular acidification(via Seahorse), 2) cytoplasmic oxidation and 3) nitric oxide production following 4, 18, and 24 h of LPS stimulation.Results: Concentration of ARA(% of fatty acids, w/w) in macrophages from pigs fed LC n-6 was 86% higher than CON and 18% lower in pigs fed LC n-3(P 0.01). Following LPS stimulation, abundance of COX-2 and TNF-α mRNA(P 0.0001), and PGE_2 secretion(P 0. 01) were higher in LC n-6 PAM vs. CON. However, ALOX5 abundance was1.6-fold lower than CON. Macrophages from CON and LC n-6 groups were 4-fold higher in ALOX12/15 abundance(P 0.0001) compared to LC n-3. Oxygen consumption and extracellular acidification rates increased over 4 h following LPS stimulation(P 0.05) regardless of treatment. Similarly, increases in cytoplasmic oxidation(P 0.001)and nitric oxide production(P 0.002) were observed after 18 h of LPS stimulation but were unaffected by diet.Conclusions: We infer that enriching diets with arachidonic acid may be an effective means to enhance a stronger innate immunologic response to respiratory challenges in neonatal pigs. However, further work is needed to examine long-term safety, clinical efficacy and economic viability.     

Gas stunning with CO_2 affected meat color,lipid peroxidation,oxidative stress,and gene expression of mitogen-activated protein kinases,glutathione S-transferases,and Cu/Zn-superoxide dismutase in the skeletal muscles of broilers

Background: Meat color and lipid peroxidation are important traits related to meat quality. CO_2 concentration is a critical factor that can affect meat quality in the commercial use of gas stunning(GS). However, the effect and mechanism of CO_2 stunning on meat color and lipid peroxidation during long-term storage remain poorly studied. We aimed to study the effects of GS methods, especial y CO_2 concentration, on meat color and meat lipid peroxidation in broilers during long-term storage at 4 °C and to explore the potential mechanism of meat color change via lipid peroxidation and the inner lipid peroxide scavenging system.Methods: Eighteen broilers were sacrificed after exposure to one of the following gas mixtures for 90 s: 40% CO_2+21% O_2+ 39% N2(G40%), 79% CO_2+ 21% O_2(G79%), or no stunning(0% CO_2, control). Meat color, serum variables,enzyme activities, and the gene expression of mitogen-activated protein kinase(MAPK), nuclear factor-erythroid2-related factor 2(Nrf2), glutathione S-transferase(GST) and superoxide dismutase(SOD) were determined.(Continued on next page)Results: The concentrations of serum triiodothyronine(T3, P = 0.03) and the ratio of serum free triiodothyronine/free thyroxine(FT3/FT4, P 0.01) were decreased, whereas levels of serum cortisol(P 0.01) were increased in the 40%CO_2 group compared with the control group. Additionally, the thiobarbituric acid-reactive substances(TBARS)3 d(P 0.01) and TBARS6 d(P = 0.01) in breast meat and the TBARS3 din thigh meat(P 0.01) were increased in the40% CO_2 group compared with the control group. Serum T3 was negatively correlated with TBARS6 dboth in the breast and thigh meat(r =-0.63, P 0.01 and r =-0.47, P = 0.05 respectively). T3/T4 was negatively correlated with TBARS6 din the breast meat and in the thigh meat(r =-0.57, P = 0.01; and r =-0.53, P = 0.03 respectively). Compared with the control group, Lightness(L*)1 d(P = 0.03) and L*9 d(P 0.01) were increased, whereas total chromatic aberration(E*)1 d(P = 0.05) and E*3 d(P 0.01) were decreased in the breast meat of both the G40% and G79% groups. The values of yel owness(b*)3 d(P = 0.01), b*6 d(P 0.01) and E*6 d(P 0.01) in the thigh meat were lower in both the G40% and G79% groups than in the control group. In the breast muscle, the m RNA levels of c-Jun N-terminal kinase 2(JNK2, P = 0.03),GSTT1(P = 0.04), and SOD1(P = 0.05) were decreased, and the m RNA levels of JNK1(P = 0.07), Nrf2(P = 0.09), and GSTA3(P = 0.06) were slightly lower in both the G40% and G79% groups compared with the control group. However, among these genes, only the m RNA level of JNK1 was decreased in the G40% group compared with the control group and the G79% group(P = 0.03) in the thigh muscle.Conclusions: Compared with the control group, meat color quality in the breast meat was decreased, and the expression of genes in the MAPK/Nrf2/ARE(antioxidant responsive element) antioxidant pathway in breast muscle was partly suppressed by GS of both 40% and 79% CO_2. However, oxidative stress and meat lipid peroxidation during storage were aggravated by GS with 40% CO_2 compared to GS with 79% CO_2 and no GS.     

Effect of Poly-β-Hydroxybutyrate on the Activity of Nonspecific Immunity Related Enzymes in Fenneropenaeus chinensis

[Objective] This study was carried out to explore the effect of poly-β-hydroxybutyrate(PHB) on the performance of the nonspecific immune system in Fenneropenaeus chinensis. [Method] F. chinensis individuals were assigned into six groups, and each group was fed with a diet containing 0(Control), 0.5%(Group E_(0.5)), 1.0%(Group E_(1.0)), 2.5%(Group E_(2.5)), 5.0%(Group E_(5.0)) or 10.0% PHB(Group E_(10.0)). The mortality rate and relative percent of survival(RPS) of each group were calculated after 6 weeks. Meanwhile, the total antioxidant capacity(T-AOC), the activity of acid phosphatase(ACP), peroxidase(POD) and catalase(CAT), and the content of malondialdehyde(MDA) in hepatopancreas and serum were measured,and their correlation with PHB concentration was analyzed. [Result] The RPS in PHB treated shrimps increased initially and decreased subsequently with increasing PHB concentration. RPS of Group E_(1.0) was the highest, showing significant difference from that of other groups( P 0.05).With the increase in PHB concentration, the activity of immunity related enzymes changed in a similar pattern with RPS: increasing at first and decreasing subsequently. In addition, the activity of the enzymes was elevated in the 2~(nd) and 3~(rd) weeks of PHB administration. Among them, T-AOC in serum of groups E_(1.0) and E_(2.5), T-AOC in hepatopancreas of Group E_(1.0), ACP activity in serum of groups E_(1.0) and E_(2.5), ACP activity in hepatopancreas of Group E_(1.0), CAT activity in groups E_(0.5), E_(1.0) and E_(2.5), CAT activity in hepatopancreas of groups E_(0.5), E_(1.0) and E_(10.0), POD activity in both serum and hepatopancreas of groups E_(0.5), E_(1.0) and E_(2.5), SOD activity in both serum and hepatopancreas of Group E_(1.0), MDA content in serum of Group E_(1.0) and MDA content in hepatopancreas of groups E_(0.5) and E_(1.0) showed significant difference from those of other groups(P0.05). [Conclusion] PHB can improve the immunity of F. chinensis, 1.0% in feed has the best effect, and the total enzyme activity reaches the highest level in the 2~(nd) and 3~(rd) weeks of PHB administration.     

Dietary supplementation of Rosmarinus officinalis L.leaves in sheep affects the abundance of rumen methanogens and other microbial populations

Background: Rumen microbiome has a great influence on ruminant health and productivity. Different plant extracts have been tested for their ability to modulate the rumen microbiome to improve feed digestion and fermentation. Among the evaluated plant extracts, essential oils, tannins, and saponins appeared to have positive effects on rumen protein metabolism, volatile fatty acids production, and methane and ammonia production.Methods: The objective of this study was to evaluate the effect of rosemary(Rosmarinus officinalis L.) leaves and essential oils on rumen microbial populations. Four ruminally cannulated sheep were used in a 4×4 Latin square design fed(21 d/period): 1) a control diet composed of alfalfa hay and concentrate pellet(CTR), 2) CTR supplemented with 7 g/d/sheep of rosemary essential oil adsorbed on an inert support(EO), 3) CTR with 10 g/d/sheep of dried and ground rosemary leaves(RL), and 4) CTR with 10 g/d of dried and ground rosemary leaves pelleted into concentrate(RL pellet). Abundance of total bacteria, archaea, protozoa, and some select bacterial species or groups was quantified using q PCR, while the community of bacteria and archaea was profiled using denaturing gradient gel electrophoresis.Results: No difference in abundance was noted for total bacteria, protozoa, or Ruminococcus flavefaciens between the control and the treatments, but the rosemary leaves, either in loose form or in pellet, decreased the abundance of archaea and the genus Prevotella(P 0.001). The rosemary leaves in loose form also decreased(P 0.001) the abundance of Ruminococcus albus and Clostridium aminophilum, while the EO increased(P 0.001) the abundance of Fibrobacter succinogenes. The community of bacteria and archaea was not affected by any of the supplements.Conclusions: Being able to affect the abundance of several groups of rumen microbes that are known to be involved in degradation of protein and fiber and production of methane and ammonia, rosemary leaves may be used to modulate rumen microbiome and its function.