藏仔猪粪便真菌菌群多样性分析

为探究西藏地区藏仔猪粪便中真菌菌群结构,本研究采用ITS1序列分析新生藏仔猪和断奶藏仔猪新鲜粪便中真菌的多样性。结果表明：从5头新生藏仔猪新鲜粪便中,共鉴定出5个门、13个纲、 25个目、33个科和38个属的真菌;从5头断奶藏仔猪新鲜粪便中,共鉴定出5个门、12个纲、20个目、24个科和28个属的真菌。子囊菌门和担子菌门为优势门,占门级分类的86.35%;布勒担菌科、虫草科、丛赤壳科、曲霉科、丝孢酵母菌科、肉杯菌科、酵母菌科和毕赤酵母菌科为优势科,占科级分类的54.38%。随着藏仔猪的生长,其粪便中真菌菌群的数量和优势真菌的相对丰度均发生变化,这说明不同生长发育阶段会影响藏仔猪粪便中真菌的多样性。     

Genetic parameters for haemoglobin levels in sows and piglets as well as sow reproductive performance and piglet survival

Genetic parameters were estimated for haemoglobin (Hb) levels in sows and piglets as well as sow reproductive performance and piglet survival. Reproductive traits were available between 2005 and 2014 for 7857 litters from 1029 Large White and 858 Landrace sows. In 2012 and 2013, Hb levels, sow BW and sow back fat depth were measured on 348 sows with 529 litters 5 days prior to farrowing. In addition, Hb levels were available for 1127 one-day-old piglets from 383 litters (a maximum of three piglets per litter) of 277 sows with Hb levels. The average Hb levels in sows (sow Hb), their litters (litter Hb, based on average Hb of three piglets) and individual piglets (piglet Hb) were 112 ± 12.6 g/l, 103 ± 15.3 g/l and 105 ± 21.7 g/l, respectively. Heritabilities for Hb levels were 0.09 ± 0.07 for sow Hb, 0.19 ± 0.11 for litter Hb and 0.08 ± 0.05 for piglet Hb. Estimates for the permanent environment effect of sows were 0.09 ± 0.09 for sow Hb, 0.11 ± 0.12 for litter Hb and 0.12 ± 0.03 for piglet Hb. In comparison, heritabilities for both number of stillborn piglets and pre-weaning survival were lower (0.05 ± 0.01 and 0.04 ± 0.01). Sow BW had no significant heritability, while sow back fat depth was lowly heritable (0.10 ± 0.08). Positive genetic correlations were found between sow Hb and litter Hb (0.64 ± 0.47) and between litter Hb and sow back fat depth (0.71 ± 0.53). Higher litter Hb was genetically associated with lower number of stillborn piglets (−0.78 ± 0.35) and higher pre-weaning survival (0.28 ± 0.33). Negative genetic correlations between sow Hb and average piglet birth weight of the litter (−0.60 ± 0.34) and between piglet Hb and birth weight of individual piglets (−0.37 ± 0.32) indicate that selection for heavier piglets may reduce Hb levels in sows and piglets. Similarly, selection for larger litter size will reduce average piglet birth weight (r_g: −0.40 ± 0.12) and pre-weaning survival (−0.57 ± 0.13) and may lead to lower litter Hb (−0.48 ± 0.27). This study shows promising first results for the use of Hb levels as a selection criterion in pig breeding programs, and selection for higher Hb levels may improve piglet survival and limit further reduction in Hb levels in sows and piglets due to selection for larger and heavier litters.     

Disappearance of immunoreactive glycinin and 𝛃-conglycinin in the digestive tract of piglets

Soybean allergy represents a health threat to human and animals. Glycinin and β-conglycinin, the main storage proteins in soybean, have been identified as major food/feed allergens. The present study was conducted to investigate the disappearance of immunoreactive glycinin and β-conglycinin in the digestive processes of piglets. Twelve crossbred piglets, weaned at 21 days of age, were allocated to three dietary treatments in a complete block design, each treatment with four replicates (female/male = 1:1). From day 22–28, the control group was fed diets without leguminous products, while the two treatment groups received diets containing 2.2% purified glycinin or β-conglycinin. All piglets were slaughtered at 29 days of age and digesta was sampled from stomach, middle jejunum, caecum and colon. Results indicated that immunoreactive glycinin and β-conglycinin decreased as the digesta descended down the digestive tract to 0.12% and 0.47%, respectively. Little immunoreactive glycinin was found in the digesta of caecum and colon, while immunoreactive β-conglycinin was detected in the colon. Along the whole digestive tract the disappearance of immunoreactive glycinin was significantly higher than β-conglycinin (p < 0.05).     

Growth performance, digestibility and faecal coliform bacteria in weaned piglets fed a cereal-based diet including either chicory (Cichorium intybus L) or ribwort (Plantago lanceolata L) forage

Twenty-five weaned 35-day-old piglets were used in a 35-day growth experiment to evaluate the effect of inclusion of chicory and ribwort forage in a cereal-based diet on growth performance, feed intake, digestibility and shedding of faecal coliform bacteria. A total of seven experimental diets were formulated, a cereal-based basal diet (B), and six diets with inclusion of 40, 80 and 160 g/kg chicory (C40, C80 and C160) or ribwort (R40, R80 and R160). Piglets had ad libitum access to feed and water throughout the experiment. Three and five weeks post-weaning faeces samples for determination of digestibility were collected once a day for five subsequent days. Additional faeces samples for determination of coliform counts were collected at days 1, 16 and 35 post-weaning. Piglets fed diet R160 had the lowest average daily feed intake (DFI) and daily weight gain (DWG), and differed (P < 0.05) from piglets fed diets B, R40 and R80. There were no differences in DFI and DWG between the chicory diets and diet B. Inclusion of chicory or ribwort had a minor negative impact on the coefficient of total tract apparent digestibility (CTTAD) of dry matter, organic matter and crude protein, whereas inclusion of both chicory and ribwort resulted in higher CTTAD of non-starch polysaccharides and neutral detergent fibre (NDF). The CTTAD of arabinose were higher for diets C160 and R160 than for diet B (P < 0.05), and the CTTAD of uronic acid was higher for diets C40, C80, C160, R80 and R160 than for diet B (P < 0.05). Age affected the CTTAD for all parameters (P < 0.05) except for NDF, with higher values at 5 than at 3 weeks post-weaning. The coliform counts decreased with increasing age (P < 0.05), but was not affected by treatment. The results indicate that inclusion of up to 160 g/kg of chicory do not negatively affect performance, whereas high inclusion of ribwort have a negative impact on feed consumption and consequently on growth rate. Both herbs have a higher digestibility of fibre compared to cereal fibre. Chicory and ribwort are both promising as feedstuffs to weaned piglets, but the low palatability of ribwort limits the inclusion level.     

Effects of the antimicrobial peptide cecropin AD on performance and intestinal health in weaned piglets challenged with Escherichia coli

This study was conducted to determine the effects of the antimicrobial peptide cecropin on performance and intestinal health in piglets. Newly weaned barrows were randomly assigned to one of three treatments (n=8), including a corn-soybean basal diet or similar diets supplemented with antibiotics (100 mg/kg kitasamycin plus 800 mg/kg colistin sulfate) or 400 mg/kg cecropin AD. On day 13, all piglets were orally challenged with 10(9)CFU/mL of Escherichia coli K88. On day 19, all piglets were euthanized and sampled. Before challenge, piglets fed antibiotics had greater weight gain, feed efficiency, nitrogen and energy retention than the control (P<0.05). E. coli challenge decreased weight gain, feed intake and feed efficiency for the control piglets (P<0.05) but not for the antibiotic or cecropin AD treated piglets. The incidence of diarrhea post-challenge in the antibiotic and cecropin AD treatments decreased compared with the control piglets. The total viable counts of cecal E. coli were lower while the Lactobacilli counts were higher in the antibiotic and cecropin AD treatments compared with the control (P<0.05). Cecropin AD treatment decreased total aerobes while increasing total anaerobes in the ileum (P<0.05). A higher villus height to crypt depth ratio in the jejunum and ileum as well as a deeper crypt depth in the jejunum and higher villus height in the ileum were observed in piglets fed antibiotics or cecropin AD compared with control piglets (P<0.05). Piglets fed the control diet had lower levels of secretory IgA in their jejunum and lower serum IgA, IgG, interleukin-1β and interleukin-6 compared with the other treatments (P<0.05). Overall, these data suggest that cecropin AD enhances pig performance through increasing immune status and nitrogen and energy retention as well as reducing intestinal pathogens in weaned piglets.     

小肽营养素对断奶仔猪生产性能及血液生化指标的影响

本试验将40头21 d断奶的三元杂交猪随机分为4组,用4组不同日粮组成及营养水平的饲料(I:基础日粮+2%喷雾干燥血浆蛋白粉(SDPP);Ⅱ、Ⅲ和Ⅳ组分别在基础日粮中添加1%,2%和3%小肽营养素)饲养21 d后称重、测定血液生化指标并进行统计分析.结果表明:添加小肽营养素对断奶仔猪的生产性能无显著影响;各处理组的血清总蛋白、血糖和血清尿素差异不显著,2%小肽组的球蛋白、免疫球蛋白含量显著高于其它组;小肽产品可以部分等蛋白取代断奶仔猪日粮中的血浆蛋白粉.通过了解小肽营养素替代喷雾干燥血浆蛋白粉对21 d断奶仔猪的生产性能和血液生化指标的影响,为肽类产品在断奶仔猪日粮中的应用提供了依据.     

Dietary supplementation with a nucleotide-rich yeast extract modulates gut immune response and microflora in weaned pigs in response to a sanitary challenge

An experiment was carried out to evaluate the short-term effect of supplementing a nucleotide-rich yeast extract (NRYE) on growth performance, gut structure, immunity and microflora of piglets raised under sanitary and unsanitary conditions. A total of 84, 21-day old piglets were used in this study; 42 piglets were raised in a room designated as the clean room that was washed once per week, whereas the other 42 piglets were raised in a room designated as the unclean room in which 7 kg of manure from the sow herd was spread on each pen floor on day 1 and 7 and the room was not washed throughout the experiment. The pigs were fed a corn–soybean meal-based diet without or with 0.1% NRYE. Each treatment had 7 replicate pens in each room, and each pen housed 3 pigs. Feed disappearance and BW were recorded on day 1 and 14. On day 14, one pig per pen was euthanized to collect ileum, mesenteric lymph nodes and spleen tissues, and cecum and colon digesta. Overall, NRYE supplementation did not affect growth performance in both clean and unclean conditions, improved kidney weight in both clean (P=0.0002) and unclean room (P<0.0001) and tended to improve the villus height/crypt depth ratio in the clean room (P=0.073). Supplementing NRYE was associated with upregulation of Ileal programmed cell death gene-1 (P=0.0003), interleukin (IL)-1β (P<0.0001), IL-6 (P=0.0003), IL-10 (P<0.0001) and tumor necrosis factor-α (TNF-α) (P<0.0001) in pigs raised in the unclean room. Supplementing the NRYE in pigs raised in the clean room suppressed growth of cecal Enterobacteriacea (P<0.0001) members and colonic Enterococcus spp. (P<0.019), improved proliferation of cecal Lactobacillus spp. (P<0.002) and colonic Clostridium cluster IV (P<0.011) and XVIa members (P<0.0002). Supplementing the NRYE in the unclean room improved proliferation of cecal Clostridium cluster IV (P<0.026) and suppressed proliferation of colonic Enterococcus spp. (P<0.037). In conclusion, supplementing the NRYE to piglets under unsanitary conditions improved ileal immune response by upregulating inflammatory cytokines, and positively modulated proliferation of beneficial gut bacteria and suppression of harmful ones in both clean and unclean rooms.