This study reveals the physicochemical, microbial, flavor, and sensory changes in sauced duck from the marinating phase to the end of storage, divided into six stages (stages A-F). The changes in color, total plate count, total volatile basic nitrogen, and thiobarbituric acid reactive substance at different stages were clarified. We utilized 16S rRNA gene sequencing, GC-IMS, and GC-MS to explore the changes in bacterial flora, fatty acid composition, and flavor characteristics. The dominant bacteria identified in stages A-C included Psychrobacter, Flavobacterium, and Pseudomonas, while Lactobacillus and Staphylococcus dominated during stages D-F. Aldehydes, esters, alcohols, and ketones emerged as the main flavor compounds. Several unsaturated fatty acids significantly (p < 0.05) decreased from stage A to stage F. The sensory quality of sauced duck improved. The potential reactions were determined, and correlation analysis of sauced duck samples across different stages was performed. 3-Methy-1-butanol could be a crucial indicator of sauced duck's overall quality. This research could support the treatment optimization of sauced duck products.

本试验采用混有发酵黄酒糟的日粮以及混有豆粕的常规日粮(作为对照)分别饲喂2组奶牛,每组各5头泌乳期荷斯坦牛,收集牛乳后将其制成马苏里拉奶酪.对收集到的牛乳的粗成分以及制作得到的马苏里拉奶酪的粗成分、理化性质、质构特性、功能特性以及气味差异进行分析,从而探究发酵黄酒糟饲喂的影响.结果表明,饲喂发酵黄酒糟对得到的原料乳粗成分没有造成显著性影响(P>0.05).但是由原料乳经过相同制作工艺后制成的马苏里拉奶酪出现了显著性差异.试验组的奶酪脂肪含量为16.1％,极显著低于对照组脂肪的含量(20.6％)(P<0.01).试验组奶酪的a*值和pH值显著低于对照组(P<0.01).试验组奶酪硬度、胶着性、咀嚼性的数值显著高于对照组(P<0.01),同时试验组的弹性值也显著高于对照组(P<0.05).试验组奶酪的拉伸性显著优于对照组(P<0.05),对照组奶酪的融化性以及流动性显著优于试验组(P<0.01).对试验组与对照组奶酪的气味差异通过电子鼻检测以及主成分分析,得到的第一主成分(PC1)贡献率为73.13％,第二主成分(PC2)贡献率为26.82％,累计贡献率高于80％,两组奶酪的气味存在明显差异.

In the yellow wine (YW) brewing industry, yellow wine lees (YWL) are the main by-product. YWL consists of high crude protein content at a lower price than soybean meal (SBM). Using whole re-sequencing, an abundance of genes and pathways relating to amino acid metabolism were detected in the genome of C. utilis KF01 and B. subtilis KF02. The genes and pathways related to fatty metabolism were relatively less. The fermentation of YWL was conducted with a specified ratio of C. utilis to B. subtilis, set at 2:1. The control group contained 28 volatiles (totaling 89.19 ng/mL); the YWL group contained 22 volatiles (41.36 ng/mL); 25 compounds (146.33 ng/mL) were detected in the FYWL group. Fatty acids and hydrolyzed amino acids significantly differed between each group. YWL and FYWL groups contained higher unsaturated fatty acid contents, while essential amino acids significantly increased. Feeding FYWL had a favorable impact on milk quality.

Yellow wine lees (YWL) are the main byproduct in the yellow wine brewing and can be used as animal feed. The deficiencies in fiber digestibility and amino acid equilibrium of YWL limited its utility value in animal feeding. The nutritional profile of YWL could be moderated after fermentation treatment. We fermented YWL with Candida utilis KF01 and Bacillus subtilis KF02, whose genomes were sequenced. We set three groups in the animal test with 15 Holstein cows: control, YWL, and fermented yellow wine lees (FYWL) group. 206 and 5 amino acid metabolism-related KEGG pathways, as well as 5257 (639 GO and 4618 eggNOG annotations) and 1579 (372 GO and 1207 eggNOG annotations) amino acid metabolism-related gene annotations were found in C. utilis KF01 and B. subtilis KF02. The collected milk samples were analyzed for composition. The contents of mono-unsaturated fatty acid (MUFA, 36.90% relative content), poly-unsaturated fatty acid (PUFA, 5.63% relative content), and essential amino acid (EAA, 2.01%) in the FYWL group milk were significantly (P < 0.05) higher. The content of flavor substances in the FYWL group (146.33 ng/mL) was the highest, followed by the control (89.19 ng/mL) and the YWL group (41.36 ng/mL). The principal component analysis (PCA) result presented the intra-group variations in flavor substances and differences in single substance among all groups. Feeding FYWL had significant effects (P < 0.05) in the Holstein cows on the milk composition.

本文主要介绍了微生态制剂、中草药制剂、发酵饲料、抗菌肽、酸化剂等替抗饲料添加剂的作用机制及其在蛋鸭生产中的应用研究进展,以期为替抗饲料添加剂在蛋鸭生产中的应用提供参考.

本试验将一株产朊假丝酵母(Candida utilis)JZ-1以及一株枯草芽孢杆菌(Bacillus subtilis)JZ-2混合后对鲜黄酒糟进行固态发酵.对发酵前后的黄酒糟进行蛋白营养成分、SDS-PAGE以及双向蛋白电泳分析,以探究发酵前后蛋白物质变化情况.结果表明,黄酒糟在发酵后有机物含量下降,粗蛋白以及多肽含量显著提高,除脯氨酸外的16种氨基酸在发酵48h后均显著增加(P<0.01).SDS-PAGE结果表明,发酵过程中分子质量25ku以上的大分子蛋白大量降解,小分子蛋白、多肽的含量显著上升.双向蛋白电泳成功鉴定了3个表达显著上调的差异蛋白并对其进行了GO功能注释.其中,1个差异蛋白(编号2930)分子的功能为抑制丝氨酸型内肽酶活性,1个差异蛋白(编号3014)分子的功能为GTP活性以及GTP连接,还有1个差异蛋白(编号3162)分子功能未知.综上表明,在混菌固态发酵过程中,黄酒糟中相当一部分大分子蛋白被降解为小分子蛋白、多肽、氨基酸等分子量较小的降解产物,这些营养物质对于奶牛而言易于消化吸收.黄酒糟中蛋白营养质量在发酵后得到了显著提高.

Salmonella is an essential food-borne pathogenic microorganism. Humans could get infected by consuming of Salmonella-contaminated foods, especially contaminated meat. In this study, a total of 580 retail meat samples (280 pork, 240 chicken, and 60 goose) were collected from slaughterhouses in Hangzhou to determine the prevalence and antimicrobial susceptibility patterns of Salmonella. Isolates were characterized by serotyping, PFGE (Pulsed-field gel electrophoresis), Polymerase chain reaction (PCR), and antibiotic susceptibility testing. The rates of Salmonella-positive pork, chicken, and goose samples were 21.1% (n = 59), 10.4% (n = 25) and 10.0% (n = 6), respectively. The prevalence of Salmonella was 15.5% in slaughterhouses. Thirteen different Salmonella serovars were identified, and 6 isolates could not be identified. The most commonly prevalent serovars are Salmonella Rissen (S. Rissen) (n = 20, 22.2%), S. Derby (n = 16, 17.8%) and S. Typhimurium (n = 12, 13.3%). The detection rate of the remaining serovars ranged from 1.1%-11.11%. All Derby, Corvallis, and Kentucky strains were from pork. Seventy-two isolates (80.0%) showed drug resistance (DR) to at least one antibiotics, 19 (21.1%) were multi-drug resistant strains, 2 (2.2%) showed seven or more. The detection rate of Trimethoprim/Sulfamethoxazole-resistance (70.0%) was highest, followed by Ampicillin (55.6%). Salmonella resistance was found related to serovar and origin. The positive rates of DR gene sul1, sul2, sul3, class I integrons and blaTEM were 92.2%, 95.6%, 86.7%, 83.3% and 62.2%, respectively. Fifty-seven different PFGE patterns and 7 main clusters were obtained. This study revealed the high positive rates of Salmonella resistance and related DR genes, especially for Sulfamethoxazole-resistance and its related gene.

Fifteen multiparous lactating Chinese Holstein dairy cows were used in a replicated 3 × 3 Latin Square Design to evaluate the effect of total mixed rations (TMR) containing unfermented and fermented yellow wine lees (YWL) on the oxidative status of heat-stressed lactating cows and the oxidative stability of the milk and milk fatty acids they produced. Cows were fed with three isonitrogenous and isocaloric diets as follows: (1) TMR containing 18% soybean meal, (2) TMR containing 11% unfermented YWL (UM), and (3) TMR containing 11% fermented YWL (FM). The rectal temperature (at 1300 h) and respiratory rate were higher in control cows than in cows fed UM or FM. Both types of YWL were greater in total phenolic and flavonoid contents, reducing power, and radical scavenging abilities than soybean meal. Cows fed UM or FM had higher blood neutrophil, white blood cell, and lymphocyte counts, as well as lower plasma malondialdehyde level, higher plasma superoxide dismutase, glutathione peroxidase, and 2,2-diphenyl-1-picryl-hydrazyl-hydrate levels, and higher total antioxidant capacity in the plasma than those fed control diet. The proportion of milk unsaturated fatty acids was higher and that of saturated fatty acids was lower in UM- and FM-fed animals than in the control animals. Milk from UM- and FM-fed cows had lower malondialdehyde content but higher 2,2-diphenyl-1-picryl-hydrazyl-hydrate content than the control cows. In conclusion, feeding TMR containing UM and FM to cows reduced both the oxidative stress in heat-stressed cows and improved the oxidative capacity of their milk.

Yellow wine lees (YWL) consist of a high content of crude protein with relatively low price. With microbial pretreatment, the increased crude protein content in the fermented YWL mix may be beneficial for the lactation performance of dairy cows. The current study was conducted to investigate lactation performance and nitrogen (N) utilization in lactating dairy cows receiving unfermented and fermented YWL mix as alternative protein source for soybean meal. Fifteen multiparous mid-lactation Chinese Holstein dairy cows with similar parity (2.30, SD 0.32), days-in-milk (190, SD 15.2) and milk yield (25.0, SD 0.45 kg) were used in a replicated 3 x 3 Latin square design. Diets were isonitrogenous and isocaloric, with a forage-to-concentrate ratio of 60:40 [dry matter basis]. Three dietary treatments were designed as follows (dry matter basis): (1) total mixed ration containing 18% soybean meal (Control), (2) total mixed ration containing 11% unfermented YWL mix (UM), and (3) total mixed ration containing 11% fermented YWL mix (FM). Each period lasted for 20 d, with the first 15 d used for adaptation and the next 5 d used for sampling. Dry matter intake (P = 0.04), milk yield (P = 0.02), milk protein yield (P = 0.02) and energy-corrected milk yield (P = 0.05) were higher in cows fed the control and FM diets than in those cows fed the UM diet. Milk composition, feed efficiency (milk yield/dry matter intake), and N conversion rate were not different (P > 0.05) among the three groups. The cows fed the UM diet showed lower N intake (P < 0.01), blood urea N (P = 0.02), urinary N (P = 0.04), microbial protein (P = 0.04) and metabolizable protein (P < 0.01) than the cows fed the control or FM diets. Feeding of the FM-fed cows tended to have greater IOFC than that of the control (P = 0.08), In summary, both unfermented and fermented YWL can be used as a protein source feed in the diets for lactating cows and inclusion of the fermented YWL had no adverse effects on lactation performance and N utilization but with greater profit.

This study was conducted to evaluate the effects of replacing soybean meal (SBM) with unfermented and microbially fermented yellow wine lees (YWL) mix on the in vitro rumen fermentation characteristics of substrate mixtures. Both types consisting of YWL at 400 g/kg were included in the mixtures at different ratios (1:0, 1:1, 1:2, 1:5 and 0:1, w/w) to replace SBM. Microbial fermentation of YWL did not have a negative impact on gas value (p> .05), increased microbial protein (MCP, p < .01) and in vitro crude protein (CP) digestibility (p < .01), and improved the efficiency of nitrogen utilisation (p < .01). The ratio of YWL replacing SBM had linear and quadratic effects on gas production (GP, p < .01), the rate of GP (p < .01), MCP (p < .01), total volatile fatty acids (VFAs, p < .01), in vitro CP digestibility and efficiency of nitrogen utilisation (p < .01), with the optimal ratio at 1:1. The in vitro digestibilities of dry matter and organic were slightly (p < .01) reduced with the increasing ratio of YWL. Besides, positive associative effects were observed on GP parameters, VFA and MCP at some replacement ratios. Considering the in vitro rumen characteristics and their associative effects, the optimal ratio at which to replace SBM with microbially fermented YWL was indicated to be 1:1.Highlights The in vitro rumen fermentation characteristics performed better with microbially fermented than unfermented yellow wine lees (YWL) replacing soybean meal (SBM). The positive associative effects were observed on gas production parameters, volatile fatty acid and microbial protein at replacing ratio of 1:1. The optimal ratio at which to replace SBM with microbially fermented YWL was 1:1.

Yellow wine lees (YWL) are the main co-products in yellow wine industry with unbalanced amino acid (AA) profiles. Solid-state fermentation was employed in this study to upgrade the YWL for ruminant animals. A 3 x 3 orthogonal design was conducted to optimize the fermentation condition for optimal crude protein (CP) yield as follows: ratio of water to total solid medium at 50 : 100 (v/w), temperature of 30 degrees C, and ratio of Candida utilis to Bacillus subtilis at 2 : 1. The contents of CP, peptides and AA of fermented products were 14 center dot 5, 40 center dot 9 and 26 center dot 1% higher than those of the unfermented respectively. In particular, the essential AA were highly improved, especially for lysine and methionine. The fermentation increased the in vitro microbial protein synthesis with higher CP digestibility and dramatically enhanced the ability of scavenging free radicals of the YWL. It is concluded that the microbial pretreatment can greatly improve the nutritional value of YWL, making these materials more suitable as feeds for animals, including ruminants.

The objectives of this study were to evaluate the effects of different supplemental levels of Saccharomyces cerevisiae fermentation product (SCFP; Original XP; Diamond V) on lactation performance in Holstein dairy cows under heat stress. Eighty-one multiparous Holstein dairy cows were divided into 27 blocks of 3 cows each based on milk yield (23.6±0.20 kg/d), parity (2.88±0.91) and day in milk (204±46 d). The cows were randomly assigned within blocks to one of three treatments: 0 (control), 120, or 240 g/d of SCFP mixed with 240, 120, or 0 g of corn meal, respectively. The experiment was carried out during the summer season of 2014, starting from 14 July 2014 and lasting for 9 weeks with the first week as adaption period. During the experimental period, average daily temperature-humidity index (measured at 08:00, 14:00, and 20:00) was above 68, indicating that cows were exposed to heat stress throughout the study. Rectal temperatures tended to decrease linearly (p = 0.07) for cows supplemented with SCFP compared to the control cows at 14:30, but were not different at 06:30 (p>0.10). Dry matter intake was not affected by SCFP supplementation (p>0.10). Milk yield increased linearly (p<0.05) with increasing levels of SCFP. Feed efficiency (milk yield/dry matter intake) was highest (p<0.05) for cows fed 240 g/d SCFP. Cows supplemented with SCFP gained (p<0.01) body weight, while cows in the control lost body weight. Net energy balance also increased linearly (p<0.01) with increasing levels of SCFP. Concentrations of milk urea nitrogen (p<0.01) decreased linearly with increasing levels of SCFP, while no difference (p>0.10) was observed among the treatments in conversion of dietary crude protein to milk protein yield. In summary, supplementation of SCFP alleviated the negative effect of heat stress in lactating Holstein dairy cows and allowed cows to maintain higher milk production, feed efficiency and net energy balance. Effects of SCFP were dose-dependent and greater effects were observed from higher doses.

The objectives of this study were to evaluate the effects of different supplemental levels of Saccharomyces cerevisiae fermentation product (SCFP; Original XP; Diamond V) on lactation performance in Holstein dairy cows under heat stress. Eighty-one multiparous Holstein dairy cows were divided into 27 blocks of 3 cows each based on milk yield (23.6±0.20 kg/d), parity (2.88±0.91) and day in milk (204±46 d). The cows were randomly assigned within blocks to one of three treatments: 0 (control), 120, or 240 g/d of SCFP mixed with 240, 120, or 0 g of corn meal, respectively. The experiment was carried out during the summer season of 2014, starting from 14 July 2014 and lasting for 9 weeks with the first week as adaption period. During the experimental period, average daily temperature-humidity index (measured at 08:00, 14:00, and 20:00) was above 68, indicating that cows were exposed to heat stress throughout the study. Rectal temperatures tended to decrease linearly (p = 0.07) for cows supplemented with SCFP compared to the control cows at 14:30, but were not different at 06:30 (p>0.10). Dry matter intake was not affected by SCFP supplementation (p>0.10). Milk yield increased linearly (p<0.05) with increasing levels of SCFP. Feed efficiency (milk yield/dry matter intake) was highest (p<0.05) for cows fed 240 g/d SCFP. Cows supplemented with SCFP gained (p<0.01) body weight, while cows in the control lost body weight. Net energy balance also increased linearly (p<0.01) with increasing levels of SCFP. Concentrations of milk urea nitrogen (p<0.01) decreased linearly with increasing levels of SCFP, while no difference (p>0.10) was observed among the treatments in conversion of dietary crude protein to milk protein yield. In summary, supplementation of SCFP alleviated the negative effect of heat stress in lactating Holstein dairy cows and allowed cows to maintain higher milk production, feed efficiency and net energy balance. Effects of SCFP were dose-dependent and greater effects were observed from higher doses.