复合乳酸菌发酵饲料对生长猪生长性能、粪便菌群、血清免疫和抗氧化指标的影响

本试验旨在研究复合乳酸菌发酵饲料对生长猪生长性能、粪便菌群、血清免疫和抗氧化指标的影响.选取平均体重(40.69±1.16)kg的健康"长×大"二元生长猪90头,随机分为3个组,每组3个重复,每个重复10头猪.对照组饲喂基础饲粮,试验Ⅰ组和试验Ⅱ组分别饲喂在基础饲粮中添加1％和3％复合乳酸菌发酵饲料的试验饲粮,试验期3...     

Effects of dietary rosemary extract supplementation on growth performance,nutrient digestibility,antioxidant capacity,intestinal morphology,and microbiota of weaning pigs

Rosemary (Rosmarinus officinalis L.) extract (RE) has multiple pharmacological and biological activities, including the use as a food additive and medicine. This study was conducted to investigate the effects of dietary RE supplementation on the growth performance, nutrient digestibility, antioxidant capacity, intestinal morphology, and microbiota of weaning piglets. A total of 192 crossbred weaned piglets [Duroc × (Large White × Landrace)] (initial body weight = 6.65 ± 0.33 kg, weaned days = 23 ± 1 d) were group housed (six pigs per pen; n = 8 pens/treatment). Pigs were fed a corn–soybean meal-based control diet or the basal diet supplemented with 100, 200, or 400 mg/kg RE. Pigs were allowed ad libitum access to fed for 21 d. The growth performance and apparent total tract digestibility of nutrients, and intestinal morphology and antioxidant status were evaluated. The components of the microbial microflora were also determined in the cecal samples. Compared with the control, dietary supplementation with RE increased the final body weight, average daily gain, and average daily feed intake (linear, P = 0.038, 0.016, and 0.009, respectively), and decreased the diarrhea ratio in piglets (linear, P < 0.05). The digestibility of crude protein (linear, P = 0.034) and gross energy (linear, P = 0.046) increased with treatment with RE. Piglets fed RE showed longer villus height (linear, P = 0.037 and 0.028, respectively) and villus height/crypt depth (linear, P = 0.004 and 0.012; quadratic, P = 0.023 and 0.036, respectively) in the jejunum and ileum, in addition to a lesser crypt depth in the jejunum (linear, P = 0.019) and ileum (quadratic, P = 0.042). The addition of RE increased the activity of superoxide dismutase (linear, P = 0.035 and 0.008, respectively) and glutathione peroxidase activity (linear, P = 0.027 and 0.039, respectively) and decreased the content of malondialdehyde (linear, P = 0.041 and 0.013; quadratic, P = 0.023 and 0.005, respectively) in the serum and liver. Dietary RE supplementation, compared with the control, increased the number of Bifidobacterium (linear, P = 0.034) and Bacteroidetes (linear, P = 0.029), while decreased Escherichia coli (linear, P = 0.008; quadratic, P = 0.014) in the cecal contents. Thus, dietary RE supplementation can improve growth performance, nutrient digestibility, antioxidant capacity, intestinal morphology, and the microbiota in weaned piglets, and 200 mg/kg may be considered the optimum dosage.     

Effect of trehalose supplementation in milk replacer on the incidence of diarrhea and fecal microbiota in preweaned calves

Trehalose, a nonreducing disaccharide consisting of d-glucose with α,α-1,1 linkage, was evaluated as a functional material to improve the gut environment in preweaned calves. In experiment 1, 173 calves were divided into two groups; the trehalose group was fed trehalose at 30 g/animal/d with milk replacer during the suckling period, and the control group was fed nonsupplemented milk replacer. Medication frequency was lower in the trehalose group (P < 0.05). In experiment 2, calves (n = 20) were divided into two groups (control group [n = 10] and trehalose group [n = 10]) based on their body weight and reared under the same feeding regimens as in experiment 1. Fresh feces were collected from individual animals at the beginning of the trial (average age 11 d), 3 wk after trehalose feeding (experimental day 22), and 1 d before weaning, and the fecal score was recorded daily. Fecal samples were analyzed for fermentation parameters and microbiota. The fecal score was significantly lower in the trehalose group than in the control group in the early stage (at an age of 14 to 18 d; P < 0.05) of the suckling period. Calves fed trehalose tended to have a higher proportion of fecal butyrate on day 22 than calves in the control group (P = 0.08). Population sizes of Clostridium spp. were significantly lower (P = 0.036), whereas those of Dialister spp. and Eubacterium spp. tended to be higher in the feces of calves in the trehalose group on day 22 (P = 0.060 and P = 0.083). These observations indicate that trehalose feeding modulated the gut environment and partially contributed to the reduction in medication frequency observed in experiment 1.     

甘草查尔酮A对副猪嗜血杆菌的体内外抑制作用

探讨甘草查尔酮A对副猪嗜血杆菌体内外生长的影响。将副猪嗜血杆菌于分别含10、20、50、100、200μg/mL甘草查尔酮A的TSA液体培养基中培养,采用分光光度法分析副猪嗜血杆菌生长和生物被膜形成的变化;以1、10、100mg/kg甘草查尔酮A经口灌胃小鼠,分别在3d、5d和7d称重,并计算脏器指数,Hiseq高通量测序技术分析肠道菌群等生长性能,Bliss法测定副猪嗜血杆菌对小鼠半数致死量(LD50);检测甘草查尔酮A对小鼠清除0.01×LD50副猪嗜血杆菌感染和抵抗100×LD50副猪嗜血杆菌感染的影响。结果表明,各浓度甘草查尔酮A对副猪嗜血杆菌的生长速率和生物被膜形成的影响差异均无显著差异。所有剂量组小鼠给予甘草查尔酮A处理后,一般临床症状、体重和脏器指数无统计学意义。灌喂甘草查尔酮A有增加小鼠肠道菌群丰富度的趋势,但降低拟杆菌门丰度而增加厚壁菌门丰度。小鼠清除0.01×LD50副猪嗜血杆菌感染的能力呈剂量依赖性,而100×LD50的副猪嗜血杆菌感染小鼠后随着甘草查尔酮A浓度增加可呈剂量依赖延迟小鼠死亡时间。表明甘草查尔酮A对副猪嗜血杆菌体外生长无显著的抑制作用,同时对小鼠生长性能亦无明显影响,但可增加肠道菌群丰富度而提高小鼠抵抗副猪嗜血杆菌感染的能力。     

Dietary hydrolysed yeast cell wall extract is comparable to antibiotics in the control of subclinical necrotic enteritis in broiler chickens

ABSTRACT

1. The aim of this study was to examine the effect of yeast cell wall (YCW) on performance and physiological responses of broiler chickens under subclinical necrotic enteritis challenge.

2. Six treatments in a 2 × 3 factorial arrangement (non-challenged or challenged plus no supplement, YCW or antibiotics (AB)) was used. Each treatment was replicated eight times with 12 birds per replicate. The treatments included: (1) Positive control (PC; no additive, not challenged); (2) Negative control (NC; no additive, with challenge); (3) YCWN = yeast cell wall (2.0 g/kg diet, not challenged; (4) YCWC = yeast cell wall (2.0 g/kg diet, challenged); (5) ABN = zinc bacitracin 50 ppm + Salinomycin 60 ppm, not challenged); (6) ABC = zinc bacitracin 50 ppm + Salinomycin 60 ppm, challenged).

3. Eimeria challenge at 9 d of age did not affect feed intake (FI), body weight gain (BWG), FCR or liveability at 10 d. The BWG and FCR at 10 d were greater (P < 0.05) in birds fed YCW or AB (AB) diets relative to the PC or NC groups. On 24 and 35 d, FI, BWG, FCR and flock uniformity (28 d) were greater (P < 0.05) in the challenged groups fed YCW or AB diets compared to NC group.

4. Supplementation with YCW ameliorated the negative effects of NE on liver, spleen and bursa weight of birds.

5. Necrotic enteritis challenge decreased (P < 0.05) caecal Lactobacillus and Bifidobacterium spp. counts, and increased ileum lesion score and caecal Clostridium perfirngens counts. This was reversed by the addition of either YCW or AB.

6. Supplementation with YCW and AB resulted to a greater (P < 0.05) dressing percentage and meat yield (35 d).

7. The results indicated that YCW plays a vital role in improving the physiological response and performance of broiler chickens under subclinical necrotic enteritis challenge.     

Intestinal microbiota of broilers submitted to feeding restriction and its relationship to hepatic metabolism and fat mass: Fast‐growing strain

The present study was conducted to verify how feed restriction affects gut microbiota and gene hepatic expression in broiler chickens and how these variables are related to body weight gain. For the experiment, 21‐d‐old Cobb500^TM birds were distributed in a completely randomized experimental design with three treatments: T1. Control (ad libitum—3.176 Mcal/kg ME—metabolizable energy—and 19% CP—crude protein); T2. Energetic restriction (2.224 Mcal/kg ME and 19% CP) from 22 to 42 days with consumption equivalent to control; T3. Quantitative restriction (70% restriction, i.e., restricted broilers ingested only 30% of the quantity consumed by the control group—3.176 Mcal/kg ME and 19% CP) for 7 days, followed by refeeding ad libitum from 28 to 42 days. Ileum and caecum microbiota collections were made at 21, 28 and 42 days of age. Hepatic tissue was collected at 28 and 42 days old for relative gene expression analyses. At 43‐d‐old, body composition was quantified by DXA (Dual‐energy X‐ray Absorptiometry). Both feed restriction programmes decreased Lactobacillus and increased Enterococcus and Enterobacteriaceae counts. No differences were found in the refeeding period. Energetic restriction induced the expression of CPT1‐A (Carnitine palmitoyltransferase 1A) gene, and decreased body fat mass. Quantitative feed restriction increased lipogenic and decreased lipolytic gene expression. In the refeeding period, CPT1‐A gene expression was induced, without changing the broilers body composition. Positive associations were found between BWG (Body Weight Gain) and Lactobacillus and Clostridium cluster IV groups, and negatively associations with Enterobacteriaceae and Enterococcus bacterial groups. In conclusion, differences found in microbiota were similar between the two feed restriction programmes, however, hepatic gene expression differences were only found in quantitative restriction. Higher counts of Lactobacillus and Clostridium cluster IV groups in ileum are likely to be related to better broiler performance and low expression of lipogenic genes.     

Effect of chicken egg yolk immunoglobulins on serum biochemical profiles and intestinal bacterial populations in early‐weaned piglets

This study was conducted to test the hypothesis that dietary supplementation with anti‐E. coli, chicken egg yolk immunoglobulins (IgY), may affect early weaned piglet (EWP) intestinal functions and enteric micro‐organisms. One hundred and forty‐eight ([Landrace × Yorkshire] × Duroc) piglets, weaned at age day 21, were randomly assigned to receive one of three diets for 14 days. Treatment group one (control group) was fed the base diet. Treatment group two (antibiotics group) was fed the base diet which was supplemented with 100 ppm colistin sulphate and 15 ppm enramycin; treatment group three (IgY group) was fed the base diet which was supplemented with 500 mg/kg anti‐E. coli IgY. The study evaluated the effects on EWPs of IgY on growth, serum biochemical, inflammatory profiles and also digestion content intestinal bacterial populations. Results showed no significant difference in diarrhoea rates between IgY‐fed EWPs and antibiotic‐treated EWPs. Serum biochemical analysis showed that EWPs fed an IgY‐containing diet had both lower (p < 0.05) cholesterol and low‐density lipoprotein compared to antibiotic‐treated EWPs. Escherichia coli populations measured in IgY‐fed EWP ileal contents, compared to the control group, were significantly reduced (p < 0.05). Enterococcus, Lactobacillus, Clostridium and Bifidobacterium populations were unaffected by the IgY treatment. Larger (p < 0.05) Enterococcus populations and lower (p < 0.05) expression levels of heat‐stable enterotoxin b (STb) were observed in IgY‐fed EWP caecal digesta compared to the control group. Enteric Lactobacillus significantly decreased (p < 0.05) in EWPs fed antibiotics while it was unaffected by IgY treatment. Dietary supplementation with anti‐E. coli IgY has the potential to suppress enteric E. coli growth, but not Lactobacillus, Clostridium and Bifidobacterium. This promotes and maintains a healthy EWP intestinal environment. These findings suggest that IgY may be used as an alternative to antibiotics in EWP diets.     

Relationships between woodlice (Isopoda: Oniscidea) and microbial density and activity in the field

 Field studies on microbial populations and their activity in soil and litter layers of different sites revealed statistically significant correlations with climatic factors, soil characteristics and the number of terrestrial isopods (Isopoda: Oniscidea). The number of captured Porcellio scaber was negatively correlated with the density of soil microbiota, but positively correlated with both respiration and cellulolytic activity of litter-colonizing microorganisms. By contrast, the number of Oniscus asellus was positively correlated with soil microbial density and respiration, and cellulolytic and respiratory activity of the litter. These interspecific differences were unexpected between species that frequently occur sympatrically, and, thus, probably have similar ecological requirements. Hence, the results suggested species-specific interactions of these species with soil and litter-colonizing microbiota. However, further field studies are required to prove this. Received: 16 December 1998     

Development of digestive biochemistry in the initial stages of three cultured Atherinopsids

The early development of the digestive biochemistry of three cultured Atherinopsids (two Odontesthes species and Chirostoma estor) was investigated. Relatively high lipolytic and high alkaline proteolytic activities were found in all species. In addition, gene expression of lipase and trypsin during the early development of C. estor not only indicates an early onset of the lipase activity but also demonstrates a major importance of protein digestion in this species. However, despite all of them share similar habitats, differences in their digestive activities were evident. The rise in the activities of brush border membrane enzymes correlated with the decrease in cytosolic activities, used as indicator of maturation of the digestive tract, was detected in both species of Odontesthes at 9 weeks after hatching. In contrast, no similar signs were measured in C. estor, this being in agreement to the long weaning period (nearly 5 months) reported for this species.