The combination of deoxynivalenol and zearalenone at permitted feed concentrations causes serious physiological effects in young pigs

This study was to investigate the effects of the combination of deoxynivalenol (DON) and zearalenone (ZON) on pigs. Twenty-four weaning piglets were divided into a control group fed a diet free of mycotoxins and a toxin group fed a diet containing 1 mg/kg DON and 250 µg/kg ZON. The results showed that supplementation of DON and ZON in diets had extensive effects on pigs. More specifically, DON and ZON caused levels of total protein, albumin, and globulin in sera to decrease (p < 0.05) by 14.5%, 6.5% and 11.3%, respectively, and at the same time increased (p < 0.05) the serum enzyme activities of γ-glutamyltransferase, aspartate aminotransferase and alanine aminotransferase by 72.0%, 32.6% and 36.6%, respectively. In addition, DON and ZON decreased (p < 0.05) the level of anti-classical swine fever antibody titers by 14.8%. Real-time PCR showed that DON and ZON caused the mRNA expression levels of IFN-γ, TNF-α, IL-2, to decrease (p < 0.05) by 36.0%, 29.0% and 35.4%, respectively. Histopathological studies demonstrated that DON and ZON caused abnormalities in the liver, spleen, lymph nodes, uterus, and kidney. The concentrations of DON and ZON used in this study are in line with the published critical values permitted by BML. Our study clearly put the standard and adequacy of safety measures for these toxins into question. The authors suggest that with the increasing availability of cellular and molecular technologies, it is time to revisit the safety standards for toxins in feeds so as to make feeds safer, providing consumers with safer products.     

Effect of feed intake level and dietary protein content on the body temperature of pigs housed under thermo neutral conditions

Feed intake and diet composition appear to affect the body temperature of pigs. Two trials were conducted to analyse the effect of feed intake level and dietary protein content on the intestinal temperature (IT) of pigs housed under thermo neutral conditions. Ten pigs (64.1 ± 1.3 kg initial body weight) fitted with an ileal cannula were used. A thermometer set to register the IT at 5‐min intervals was implanted into the ileum through the cannula. In both trials, the ambient temperature ranged from 19.1 to 21.6°C and the pigs were fed at 07:00 and 19:00 hr (same amount each time). In trial 1, the pigs were fed daily 1.2 or 1.8 kg of a wheat–soybean meal diet. The IT followed a similar pattern along a 24‐hr period regardless the feed intake level. The IT rapidly increased up to 0.61 and 0.74°C after the morning meal and up to 0.53 and 0.47°C after the evening meal in pigs fed 1.2 and 1.8 kg/d respectively. The postprandial IT was higher in pigs fed 1.8 kg after each meal (p < .05). In trial 2, pigs were fed daily 1.8 kg of a low (11%) or a high (22%) crude protein diet. The IT followed a similar pattern along the 24‐hr period regardless the dietary protein level. The postprandial IT did not differ between pigs fed the low protein or the high protein (p > .10). The IT rapidly increased up to 0.66 and 0.62°C after the morning meal in pigs fed the high‐ and low‐protein diet (p < .05), but there was no change after the evening meal (p > .10). In conclusion, the feed intake level affected the IT of pigs housed under TN conditions, but the dietary protein content had no effect.     

The administration of diets contaminated with low to intermediate doses of deoxynivalenol and supplemented with antioxidants and binding agents slightly affects the growth,antioxidant status,and vaccine response in weanling pigs

This study aimed to evaluate the impact of grading levels of deoxynivalenol (DON) in the diet of weaned pigs, as well as the effects of a supplementation with antioxidants (AOX), hydrated sodium calcium aluminosilicates (HSCAS), and their combination on the growth, AOX status, and immune and vaccine responses against the porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2). At weaning, 336 piglets were allocated to six dietary treatments according to a randomized complete block design. Treatments were as follows: basal diet (CTRL); basal diet containing DON at 1.2 mg/kg (DON1.2); basal diet containing DON at 2.4 mg/kg (DON2.4); DON2.4 diet + a mix of AOX which included vitamins A and E at 20,000 IU and 200 IU/kg feed respectively, selenized yeast at 0.3 mg/kg, and a grape seed extracts at 100 mg/kg feed (DON2.4 + AOX); DON2.4 diet + the mix of AOX and the modified HSCAS mentioned above (DON2.4 + AOX + HSCAS); DON2.4 + AOX + HSCAS. Pigs were vaccinated against PRRSV and PCV2 at 7 d; on 0, 14, and 35 d, growth performance was recorded, and blood samples were collected in order to evaluate the oxidative status, inflammatory blood markers, lymphocyte blastogenic response, and vaccine antibody response. Increasing intake of DON resulted in a quadratic effect at 35 d in the lymphocyte proliferative response to concanavalin A and PCV2 as well as in the anti-PRRSV antibody response, whereas the catalase activity decreased in DON2.4 pigs compared with the CTRL and DON1.2 groups (P ≤ 0.05). Compared with the DON2.4 diet, the AOX supplementation slightly reduced gain to feed ratio (P = 0.026) and increased the ferric reducing ability of plasma as well as α-tocopherol concentration (P < 0.05), whereas the association of AOX + HSCAS increased the anti-PRRSV IgG (P < 0.05). Furthermore, the HSCAS supplement reduced haptoglobin levels in serum at 14 d compared with the DON2.4 group; however, its concentration decreased in all the experimental treatments from 14 to 35 d and particularly in the DON2.4 + AOX pigs, whereas a different trend was evidenced in the DON2.4 + HSCAS group, where over the same period haptoglobin concentration increased (P < 0.05). Overall, our results show that the addition of AOX and HSCAS in the diet may alleviate the negative effects due to DON contamination on the AOX status and immune response of vaccinated weanling pigs.     

东祁连山亚高山草地土壤微生物功能群数量动态及其与土壤环境关系

选取东祁连山亚高山草地植被6种典型群落类型(嵩草草甸,金露梅灌丛草地,珠芽蓼-嵩草草地,高山柳-金露梅灌丛草地,禾草草地,沼泽草地),对各样地的土壤微生物生理功能群数量的季节动态及其与土壤环境因子之间的关系进行了分析。结果表明,1)土壤微生物生理类群的数量大小顺序为:好气性纤维素分解菌>嫌气性纤维素分解菌>反硝化细菌>嫌气性固氮菌>硝化细菌;2)主要生理功能群季节动态变化总体趋势为随季节变化(5-11月)数量有所下降,从土壤剖面层次来看,0~10 cm土层数量大于10~20 cm土层;3)除嫌气性纤维素分解菌外,其余各种微生物生理功能群与土壤C、N关系紧密,表现出不同显著水平的正相关或负相关。     

高温期日粮电解质与铬对肥育猪生长与代谢的影响

将来源相同、体重相近的 (72kg) 杜长大肥育猪 32头 ,公母各半 ,随机分为 4个处理 ,每处理设 2个重复 (各组间差异不显著 ) ,每组公母各 2头 ,在试验日粮中分别添加碳酸氢钠、氯化钾、烟酸铬 ,研究日粮电解质与铬对持续高温期肥育猪生长性能与生化反应的影响。研究结果表明 ,持续高温期肥育猪采食含电解质日粮后 :(1 )日增重显著增加 (p <0 0 5) ;料肉比变化不显著 (p>0 0 5) ,试验组平均体重为1 0 0kg,平均日增重为 91 0g,分别比对照组高 5 %、7% ;(2 )血液葡萄糖、总蛋白、球蛋白、白蛋白含量普遍升高 ,但只有血清球蛋白水平变化差异显著 (p<0 0 5) ,肌酸激酶、尿素氮含量普遍降低(p >0 0 5) ;(3)Na+ 含量显著升高 (p<0 0 5) ,Cl- 明显降低 (p <0 0 5) ;血清K+ 的浓度变化不是很明显 ,但试验组K+ 平均浓度高于对照组     

A between‐experiment analysis of relationships linking dietary protein intake and post‐weaning diarrhea in weanling pigs under conditions of experimental infection with an enterotoxigenic strain of Escherichia coli

Numerous experiments have demonstrated that feeding a lower protein diet decreases protein fermentation in the gastrointestinal tract (GIT) and reduces the incidence of post‐weaning diarrhea (PWD). However, there is a lack of holistic evidence underpinning the relationship between feeding a lower protein diet and PWD in relation to physiological responses and protein fermentation in the GIT. The scope of this article, therefore, will: (i) focus on the impact of dietary protein levels on selected indices of GIT health in weaned pigs without and with experimental infection with an enterotoxigenic strain of Escherichia coli; and (ii) attempt to conduct regression analysis to examine the relationships between dietary‐origin protein intake, nitrogen fermentation indices, fecal consistency and the incidence of PWD. We used datasets generated from a series of four intensive experiments in weaned pigs. The collective results derived from these datasets indicate that restriction of daily protein intake to less than 60 g through feeding a lower protein diet for as little as 7 days after weaning reduced the incidence of PWD commensurate with a reduction in protein fermentation indices.     

The effects of early‐age thermal manipulation and daily short‐term fasting on performance and body temperatures in broiler exposed to heat stress

This study was conducted to investigate the effects of thermal manipulation at 5 days of age and short‐term fasting during the warmest part of the day on responses to prolonged heat stress of broilers. A total of 240‐day‐old Ross 308 female broiler chicks were divided into three groups: control, thermal manipulation (chicks were exposed to 36 °C for 24 h at 5 days of age) and short‐term fasting during the warmest part of the day (10.00–17.00 h). Prolonged heat stress was induced daily from 28 to 42 days by heating until the ambient temperature reached 32–35 °C between 10.00 and 17.00 h. Both thermal manipulation and short‐term fasting resulted in a decrease in rectal temperatures and haematocrit values at 35 and 41 days of age. Thermal manipulation improved body weight, feed consumption and feed conversion. However, short‐term fasting caused a reduction in body weight and a deterioration in feed conversion. Short‐term fasting lowered the percentages of carcass, whereas thermal manipulation highered breast yield. Both thermal manipulation and short‐term fasting decreased heart mass and abdominal fat.