生长猪低磷日粮添加植酸酶和有机酸以及维生素D_3的研究

本试验通过添加植酸酶、有机酸(柠檬酸、抗坏血酸)和维生素D3、木聚糖酶来减少无机磷的添加量,提高饲料中植酸磷的利用率,降低磷的排泄量。选择30 kg左右的"斯格"纯种猪70头,随机分成7组:常磷组、低磷日粮组(NC)、NC+600 U/kg植酸酶组、NC+600 U/kg植酸酶+10 g/kg的柠檬酸、NC+600 U/kg植酸酶+10 g/kg的柠檬酸+200 mg/kg抗坏血酸、NC+600 U/kg植酸酶+10 g/kg的柠檬酸+200 mg/kg抗坏血酸+100μg/kg的维生素D3、不添加磷酸氢钙。所有日粮中都添加50 mg/kg木聚糖酶。结果表明:低磷日粮添加植酸酶、有机酸(柠檬酸、抗坏血酸)和维生素D3,平均日采食量无显著影响(P0.05),日增重显著提高(P0.05),料重比显著降低(P0.05);养分消化率均显著提高;血液指标着中,白蛋白显著降低(P0.05),碱性磷酸酶、总蛋白、谷草、谷丙转氨酶无影响(P0.05)。     

可消化钙水平对饲喂不同磷含量日粮生长猪生长性能和骨成分的影响

本研究开展了30 d的饲养试验以确定可消化钙水平对饲喂不同磷含量日粮生长猪生长性能和骨成分的影响。试验选择平均体重为(50.21±2.1)kg的生长猪180头,随机分为15组,每组12头猪,每个重复4头猪。试验日粮采用3×5因子设计,可消化磷水平分别为1.4、2.7、4.1 g/kg,可消化钙水平分别为1.3、2.5、3.8、5.0,和6.3 g/kg。结果表明,日粮可消化钙和可消化磷水平对生长猪末重、日增重、饲料报酬、骨钙和骨磷含量的影响具有显著交互作用(P<0.05)。在可消化钙磷比值分别为1.20∶1和1.25∶1,可消化磷水平为2.7 g/kg时,预测的最大体重为87.20 kg,日增重为1.23 kg。但由于方程的线性性质,没有得到预测的最大饲料报酬。随着日粮可消化钙水平的增加,无论饲粮中可消化磷水平是多少,平均日采食量均表现为显著降低(P<0.05)。可消化磷含量为2.7和4.1 g/kg时,预测的骨骼灰分最大值分别为55.8和60.1 g/kg,对应的可消化钙磷比值分别为2.03∶1和1.59∶1。综上所述,当日粮磷水平达到或低于需要水平时,过量的钙对50~85 kg猪生长性能具有负面影响。而当可消化钙水平高于需要水平时,饲粮中含有高于需要水平的可消化磷可以使猪的生长性能最大化。骨灰分最大化所需的可消化钙水平大于生长性能最大化需要的可消化钙水平,同时当磷水平达到需要量时,保证足够的骨矿化而不影响生长性能所需的可消化钙磷比为1.23∶1。     

Performance and nutrient digestibility in growing pigs fed wheat dried distillers’ grain with solubles‐containing diets supplemented with phytase and multi‐carbohydrase

Effect of supplementing wheat dried distillers’ grain with solubles (DDGS)‐containing diet with enzymes on nutrient utilization by growing pigs was evaluated in two experiments. In Experiment 1, 60 pigs weighing ~30 kg were fed five diets that included a corn‐based diet (Control), Control with 10% wheat DDGS (DDGS‐PC), DDGS‐PC without inorganic P source (DDGS‐NC), and DDGS‐NC plus phytase alone or with multi‐carbohydrase for 4 weeks to determine average daily gain (ADG), average daily feed intake (ADFI) and gain‐to‐feed ratio (G:F). In Experiment 2, 30 barrows weighing 22 kg were fed five diets fed in Experiment 1 to determine nutrient digestibility and retention. Pigs fed DDGS‐PC and Control diets had similar ADG and G:F. The ADG and G:F for DDGS‐PC diet were higher (P < 0.05) than those for DDGS‐NC diet. Phytase improved (P < 0.05) ADG, G:F, total tract P digestibility and P retention by 6.6, 8.7, 86.0 and 85.5%, respectively. Addition of multi‐carbohydrase to phytase‐supplemented diet did not affected growth performance, but reduced (P < 0.05) P retention. In conclusion, inclusion of 10% wheat DDGS in growing pig diet may not affect growth performance of growing pigs. Phytase supplementation to wheat DDGS‐containing diet can eliminate the need for inorganic P supplement in pig diets.     

BGB饲料对生长猪和肥育猪生长性能的影响

本试验旨在评估BGB饲料对生长猪和肥育猪生长性能的影响。试验分两期进行,试验1选用初始体重为19.02±0.04kg的阉公猪72头,随机分为3组。以玉米-豆粕型日粮为基础日粮,对照组添加60mg/kg盐霉素,试验组分别添加5%、10%的BGB饲料。试验期28d,计算日采食量(ADFI)、日增重(ADG)和饲料转化率(FCR)。试验2选用初始体重为57.01±0.6kg的阉公猪54头,试验期35d,试验期日粮处理与饲养管理同试验1。试验1结果表明:处理组与对照组各项测定指标无显著差异(P>0.05),但在饲喂后期,5%BGB添加组的ADG比对照组提高7.8%,饲料转化率改善10.8%。试验2结果表明:处理组与对照组各项测定指标无显著差异(P>0.05),在饲喂后期,5%、10%BGB添加组的ADG分别比对照组改善了10.7%和4.0%。从全期结果来看,处理组的效果要优于对照组,5%BGB添加组效果最好。以上两个试验表明:添加BGB可以达到与添加抗生素相似的生产水平,对生长性能有一定的促进作用,最适添加量为5%。     

Determination of net energy content of soybean oil fed to growing pigs using indirect calorimetry

The objectives of this experiment were: (i) to determine the net energy (NE) of soybean oil (SBO) fed to growing pigs using indirect calorimetry (IC); and (ii) to evaluate the effects of inclusion rate of SBO on heat production, oxidative status and nutrient digestibility in growing pigs. Eighteen growing barrows were allotted to three diets based on completely randomized design with six replicate pigs (period) per diet. Diets included a corn‐soybean meal basal diet and two test diets containing 5% or 10% SBO at the expense of corn and soybean meal. During each period, pigs were individually housed in metabolism crates for 14 days, including 7 days to adapt to feed, metabolism crate and environmental conditions. On day 8, pigs were transferred to the open‐circuit respiration chambers for measurement of daily O₂ consumption and CO₂ and CH₄ production. During this time, pigs were fed one of the three diets at 2.4 MJ metabolizable energy/kg body weight (BW)^0.6/day. Total feces and urine were collected and daily total heat production (THP) was measured from days 9 to 13 and fasted on day 14 to evaluate their fasting heat production (FHP). The results show that trends of decreased apparent total tract digestibility of neutral detergent fiber (linear, P = 0.09) and acid detergent fiber (linear, P = 0.07) were observed as the content of dietary lipids increased. The average THP for the three diets were 1326, 1208 and 1193 kJ/kg BW^0.6/day, respectively. The FHP of pigs averaged 843 kJ/kg BW^0.6/day and was not affected by diet characteristics. A reduction of the respiratory quotients in the fed state as the inclusion level of SBO increased was observed. In conclusion, the NE values of SBO we determined by indirect calorimetry were 33.45 and 34.05 MJ/kg dry matter under two inclusion levels. THP could be largely reduced when SBO is added in the feed, but the THP of SBO included at 5% in a corn‐soybean meal diet is not different from the THP of SBO included at 10%.     

牛至油对育肥猪生长性能和肉品质的影响

文章旨在研究不同浓度的牛至油对肥育猪生长性能和肉质特性的影响。试验选择32头阉割公猪和32头后备母猪随机分成4个组,对照组饲喂基础日粮,试验组分别在基础日粮中添加0.2、0.4和0.8mg/kg牛至油,试验共开展5周。试验结束后禁食12h,称重后屠宰。经过一夜的冷却,从屠体上取50cm的腰肌(每组8头,4头公猪、4头母猪)。日粮中添加牛至精油对生长猪末重、日增重、屠宰率均无显著差异(P>0.05),同时各组最长肌嫩度、屠宰后45min和24h后的pH、肉色及感官特性也无显著差异(P>0.05)。此外,脂质氧化试验结果显示,日粮添加牛至油对肌肉无明显的抗氧化作用(P>0.05)。综上所述,由于胴体和肉质属性均无显著变化,说明本试验中日粮添加不同水平牛至油对猪的肉质参数没有影响。     

硒代蛋氨酸对断奶仔猪生长性能、抗氧化及免疫性能的影响

文章旨在研究日粮添加有机硒(硒代蛋氨酸)对断奶仔猪生长性能、血清抗氧化和免疫性能的影响。试验选择26 d断奶的杜×长×大仔猪1080头[平均体重(9.82±1.18)kg],随机分为6组,每组4个重复,每个重复45头。对照组饲喂基础日粮(硒含量为0.03 mg/kg),无机组饲喂在基础日粮中添加0.4 mg/kg硒(亚硒酸钠),有机硒组在基础日粮中分别添加0.2、0.4、0.6和0.8 mg/kg硒(硒代蛋氨酸),试验共进行42 d。结果显示:日粮添加0.4和0.8 mg/kg有机硒较对照组显著降低了断奶仔猪22～42 d的料重比(P <0.05)。0.4 mg/kg有机硒组较对照组和0.4 mg/kg无机硒组显著提高了血清GSH-Px和T-AOC活力(P <0.05)。与对照组相比,0.2和0.4 mg/kg有机硒组显著提高了肝脏GSH-Px活力(P <0.05),而0.2 mg/kg有机组肝脏T-AOC活力最高(P <0.05)。与对照组相比,无机硒组和有机硒组显著降低了肝脏和肌肉MDA含量(P <0.05)。与对照组相比,无机硒组和有机硒组显著降低了肝脏MDA含量(P <0.05)。0.6 mg/kg有机硒组较对照组、0.4 mg/kg无机硒组和0.2、0.4 mg/kg有机硒组显著提高了断奶仔猪21 d血清硒含量(P <0.05);与对照组相比,0.4和0.6 mg/kg有机硒组显著提高了仔猪42 d血清硒含量(P <0.05)。0.8 mg/kg有机硒组较对照组和0.4 mg/kg无机硒组显著提高了仔猪42 d血清硒含量(P <0.05)。结论 :日粮添加硒代蛋氨酸可以改善断奶仔猪的生长性能,提高其抗氧化性能和血清硒含量,断奶仔猪适宜的硒代蛋氨酸添加水平为0.2～0.4 mg/kg(以硒计)。     

液态酶解发酵豆粕对生长育肥猪生产性能及部分营养物质粪排泄量的影响

将豆粕加入木瓜蛋白酶和酵母菌在40℃条件下进行液态酶解发酵处理24h制备液态酶解发酵豆粕并进行营养成分分析。72头体质量（31.25±0.22）kg健康阉公猪,随机分为3组,每组4个重复,每个重复6头猪,分别为对照料、添加10%液态酶解发酵豆粕和添加20%液态酶解发酵豆粕组,预饲期7d,正试期28d。结果表明,豆粕经过液态酶解发酵后粗蛋白含量有所提高,但是差异不显著（P〉0.05）,钙和磷的含量均没有显著变化（P〉0.05）,水溶性蛋白、小肽、小分子蛋白含量显著提高（P〈0.05）,大分子蛋白含量显著降低（P〈0.05）,脲酶活性显著降低（P〈0.05）。饲养试验表明,添加10%液态酶解发酵豆粕和20%液态酶解发酵豆粕的试验组和对照组相比平均日采食量分别提高了12.14%和20.81%（P〈0.05）,平均日增重分别提高了11.33%和22.29%（P〈0.05）;粪中氮的排泄量分别降低了11.11%和8.80%（P〈0.05）;粪中磷的排泄量分别降低了3.59%（P〉0.05）和23.95%（P〈0.05）,粪中铜的排泄量分别降低了2.22%（P〉0.05）和7.52%（P〉0.05）,粪中锌的排泄量3个组之间均没有显著性差异（P〉0.05）。综上,豆粕经木瓜蛋白酶和酵母菌酶解发酵后蛋白质成分有所改善,饲喂生长育肥猪可以提高生产性能,降低粪中部分营养物质的排泄量。     

中草药复合制剂对热应激条件下猪生产性能和血液生化指标的影响

本文研究了藿香、苍术、黄柏和石膏提取物对高温下猪生产性能和血清生化指标的影响。选用2月龄农大I系实验用小型猪48头,分为常温组、高温应激组(高温组)、高温中草药复合制剂组(复合制剂组)3个处理,每组16头猪。于试验的第1、3、6和10天,每组选4头猪,用数字体温表测定肛温,称重,静脉采血后分离血清,测定血清皮质醇、热休克蛋白70含量。结果显示:高温组猪日采食量和日增重显著下降(P<0.05),血清皮质醇、热休克蛋白70含量显著升高(P<0.05)。复合制剂组的日增重和日采食量显著增高(P<0.05),血清皮质醇、热休克蛋白70含量均显著降低(P<0.05)。以上结果提示,复合制剂可以显著改善高温条件下猪的生产性能。     

Effect of probiotic bacteria‐fermented medicinal plants (Gynura procumbens,Rehmannia glutinosa,Scutellaria baicalensis) as performance enhancers in growing pigs

This study was conducted to investigate the effect of dietary supplementation of mixed fermented medicinal plants (FMP) obtained from exudates of Gynura procumbens, Rehmannia glutinosa and Scutellaria baicalensis fermented with Lactobacillus plantarum, Saccharomyces cerevisiae and Bacillus licheniformis, respectively, on growth performance in growing pigs in order to assess the feasibility of using FMP as an alternative to antibiotic growth promoters (AGP), such as tiamulin. A total of 150 growing pigs (body wieght 25.50 ± 2.50 kg) were used in a 6 weeks experiment and randomly divided into five groups with six replicates of five growing pigs each. The treatments were NC (basal diet), basal diet with 33 ppm tiamulin (PC), basal diet with FMP 0.05% (FMP 0.05), basal diet with FMP 0.1% (FMP 0.1) and basal diet with FMP 0.2% (FMP 0.2). Overall, body weight gain, feed conversion rate, the digestibility of dry matter and gross energy, noxious gas emission all improved with FMP supplementation as compared to NC. Taken together, these results suggest the feasibility of using FMP as an alternative to AGP for enhancing the growth performance, nutrient digestibility and excreta noxious gas emission of growing pigs.     

Effect of heat stress and feeding management on growth performance and physiological responses of finishing pigs

This study aimed to determine whether pig responses to heat stress (HS) were directly due to heat exposure (regardless of feeding level and pattern) or were indirectly due to the reduction of feed intake (FI) and to determine if increasing feeding frequency (splitting heat increments) can improve pig response to HS. A total of 48 pigs (66.1 ± 1.7 kg) were allocated to four groups in three replicates. After 7 d in thermoneutral (TN) conditions (22 °C; period 1 [P1; day −7 to −1]), pigs were placed in either TN or HS (32 °C) conditions for 20 d (period 2 [P2; day 0 to 19]). The diet was provided either ad libitum (AL; 2 distributions/d) or pair-fed (PF8; 8 distributions/d) using HS–AL pigs as the reference group. Thus, the four experimental groups were TN–AL, HS–AL, TN–PF8, and HS–PF8. The daily ration of PF8 pigs was distributed at every 90-min intervals from 0900 to 1930 hours. Data were analyzed using the PROC MIXED procedure with replicate (n = 3), experimental group (n = 4), and their interactions as fixed effects, and the REPEATED statement was used for repeated measures data. Pigs had a similar average daily feed intake (ADFI) during P1 (P > 0.05). In P2, HS–AL and PF8 pigs had lower ADFI (−19%), average daily gain (−25%), and final body weight (−6.1 kg) than TN–AL pigs (P < 0.01). TN–AL pigs had thicker backfat than TN–PF8 pigs (P < 0.05), while the HS pigs had intermediate results. HS pigs had a higher perirenal fat percentage based on the contrast analysis between PF8 pigs (P < 0.05). Thermoregulatory responses of pigs increased with HS exposure but did not differ between HS or between TN groups (P > 0.05). For TN pigs, variation in muscle temperature (T_muscle) depended on feeding and physical activity, while for HS pigs, T_muscle gradually increased throughout the day. The T_muscle of PF8 pigs increased with each additional meal but plateaued earlier for HS–PF8 than TN–PF8 pigs; an increase in T_muscle per meal was also lower in HS–PF8 than TN–PF8 (P < 0.05). Exposure to HS decreased plasma T3 and T4 (P < 0.05) and increased plasma creatinine (P < 0.05). Between the PF8 groups, HS pigs also had a transient increase in plasma insulin on day 8 (P < 0.05). The effect of HS on FI decreased the growth rate of pigs but there are heat-induced effects, such as altered physiological responses, which might explain the direct HS effects seen in other literature especially in terms of increased adiposity. The increased feed provision frequency in the present study did not improve the HS response of pigs.     

松针粉对生长猪生长性能及免疫功能的影响

为探究饲料中添加松针粉对生长猪生长性能及免疫功能的影响,选择品种、胎次相近,平均体重为(60.92±0.46)kg的杜×长×大(Duroc×Landrace×large white)三元杂交猪108头,按完全随机设计法分为3组,每组6个重复,每个重复6头猪,试验周期41 d。对照组饲喂基础日粮,试验A组饲喂基础日粮+2%松针粉(等量替代麸皮),试验B组饲喂基础日粮+2%松针粉(直接添加)。结果表明:与对照组相比,试验A组的日增重提高2.88%,采食量提高1.94%,料肉比降低3.91%(P > 0.05);试验组B日增重降低3.43%,采食量降低3.91%,料肉比降低 0.53%(P > 0.05);试验A组与B组的咳嗽率均有所降低,分别降低64.22%和53.43%(P > 0.05);试验A组与B组血清中免疫球蛋白IgG和IgM含量较高,但三个试验组之间差异不显著。因此,在饲料中用2%松针粉等量替代麸皮或直接添加2%松针粉均有提高猪只生长性能、降低咳嗽率、提高免疫功能的趋势(P > 0.05)。     

SSTR和IGFBP对生长猪生产性能的影响

选用 9周龄 1 9kg左右约·杜·长·宁四元杂种猪 60头 ,随机分为 3组 ,试验组I、试验组II和对照组各 2 0头。试验组I在 1 0、 1 3和 1 5周龄颈部皮下注射生长激素抑制激素受体 (SSTR)疫苗 ;试验组II在 1 0周龄颈部皮下注射SSTR +IGFBP (胰岛素样生长因子结合蛋白 )疫苗 ,1 3及 1 5周龄注射SSTR疫苗 ;对照组注射相同剂量的生理盐水。结果表明 :SSTR组平均日增重较对照组提高 5 73% ,采食量提高 3 88%。SSTR +IGFBP组平均日增重较对照组提高 9 74% ,采食量提高 1 1 1 6%。     

Advances in the mechanism of high copper diets in restraining pigs growth

High copper feed has been widely used as an inexpensive and highly effective feed additive to promote growth performance of pigs. However, long-term feeding of high copper feed may reduce the growth-promoting effects of copper, time-dependent accumulation of copper in animal tissues and organs, and copper toxicity thereby reducing the growth performance of pigs. Due to the widespread effects of high copper supplementation in animals' diets, the benefits and drawbacks of high copper feeding in pigs have been reported in several studies. Meanwhile, few of these studies have systematically described the mechanism by which high copper diets restrain pig growth. Therefore, to address the concerns and give a better understanding of the mechanism of high copper diet in restraining pig growth in different systems, this paper reviews the research progress of long-term supplementation of high copper on the growth of pigs and provides some suggestions and further research directions.     

吡啶甲酸铬对生长猪生产性能和组织中铬残留的影响

选用96头体重(24.67±0.36)kg,公母各半达兰猪,随机分为4组,每组4个重复,每个重复6头。对照组饲喂基础日粮,3个试验组分别添加200、400μg/kg和800μg/kg吡啶甲酸铬(以铬计)。另外,选用8头体重(24.98±0.56)kg达兰猪,随机分为2组,添加1600μg/kg和3200μg/kg吡啶甲酸铬(以铬计),试验期28d。结果表明,添加200～800μg/kg吡啶甲酸铬对猪平均日增重和饲料转化效率无显著影响(P>0.05),但可提高饲料采食量,800μg/kg处理组的采食量显著高于其他3个处理组(P=0.01)。添加200～3200μg/kg吡啶甲酸铬猪组织中铬残留量为0.08～0.35mg/kg。     

小肽添加剂对生长猪生长性能的影响

试验研究三种不同的小肽添加剂制品对生长猪生长性能的影响。试验选用72头初始体重在(34.64±8.32)kg的杜×长×大三元阉公猪,随机分为4个处理,每个处理6个重复,每个重复3头猪试验各组分别饲喂基础日粮(对照组),基础日粮加100mg/kg小肽A(小肽A组),基础日粮加100mg/kg小肽B(小肽B组),基础日粮加50mg/kg小肽C(小肽C组),试验期28d。测定其对生长猪的生长性能的影响,结果表明,与对照组相比,小肽A组、小肽B组和小肽C组的生长猪的平均采食量分别提高了9.8%、7.0%和12.5%(P0.05),平均日增重分别提高了15.8%、12.8%和21.7%(P0.05),料肉比分别降低了5.1%、6.3%和8.5%(P0.05)。     

Genetic relationships between efficiency traits and gut microbiota traits in growing pigs being fed with a conventional or a high-fiber diet

In pigs, the gut microbiota composition plays a major role in the process of digestion, but is influenced by many external factors, especially diet. To be used in breeding applications, genotype by diet interactions on microbiota composition have to be quantified, as well as their impact on genetic covariances with feed efficiency (FE) and digestive efficiency (DE) traits. This study aimed at determining the impact of an alternative diet on variance components of microbiota traits (genera and alpha diversity indices) and estimating genetic correlations between microbiota and efficiency traits for pigs fed a conventional (CO) or a high-fiber (HF) diet. Fecal microbes of 812 full-siblings fed a CO diet and 752 pigs fed the HF diet were characterized at 16 weeks of age by sequencing the V3-V4 region of the 16S rRNA gene. A total of 231 genera were identified. Digestibility coefficients of nitrogen, organic matter, and energy were predicted analyzing the same fecal samples with near infrared spectrometry. Daily feed intake, feed conversion ratio, residual feed intake and average daily gain (ADG) were also recorded. The 71 genera present in more than 20% of individuals were retained for genetic analyses. Heritability (h²) of microbiota traits were similar between diets (from null to 0.38 ± 0.12 in the CO diet and to 0.39 ± 0.12 in the HF diet). Only three out of the 24 genera and two alpha diversity indices with significant h² in both diets had genetic correlations across diets significantly different from 0.99 (P < 0.05), indicating limited genetic by diet interactions for these traits. When both diets were analyzed jointly, 59 genera had h² significantly different from zero. Based on the genetic correlations between these genera and ADG, FE, and DE traits, three groups of genera could be identified. A group of 29 genera had abundances favorably correlated with DE and FE traits, 14 genera were unfavorably correlated with DE traits, and the last group of 16 genera had abundances with correlations close to zero with production traits. However, genera abundances favorably correlated with DE and FE traits were unfavorably correlated with ADG, and vice versa. Alpha diversity indices had correlation patterns similar to the first group. In the end, genetic by diet interactions on gut microbiota composition of growing pigs were limited in this study. Based on this study, microbiota-based traits could be used as proxies to improve FE and DE in growing pigs.     

双低菜粕及添加复合酶制剂对生长猪生长性能及血清指标的影响

选取健康"杜×长×大"三元杂交生长猪36头,按饲养试验要求分为3组,每组3个重复,每重复4头猪(公、母各半)。对照组饲喂玉米-豆粕型日粮;试验1组(双低菜粕组)在对照组饲粮基础上,用8%的双低菜粕代以配方中7%的豆粕;试验2组(双低菜粕+酶组)在试验1组基础上添加0.03%专用复合酶制剂。预试期7 d,正试期32 d。结果表明,不同处理日粮对生长猪的生长和饲料利用无显著影响(P>0.05);添加酶制剂使生长猪血清FT3水平提高了17.01%(P<0.05);双低菜粕组生长猪血清IgA含量提高了14.08%(P<0.01),加酶后生长猪血清IgGI、gM、补体C3和C4含量分别提高了12.59%(P<0.01)、20.59%(P<0.01)、36.18%(P<0.01)和24%(P<0.01);不同处理日粮对生长猪血清抗氧化指标及Ca、P、BUN(尿素氮)含量均无显著影响(P>0.05)。     

Dose–response and functional role of whey permeate as a source of lactose and milk oligosaccharides on intestinal health and growth of nursery pigs

Two experiments were conducted to evaluate dose–response and supplemental effects of whey permeate on growth performance and intestinal health of nursery pigs. In experiment (exp.) 1, 1,080 pigs weaned at 6.24 kg body weight (BW) were allotted to five treatments (eight pens/treatment) with increasing levels of whey permeate in three phases (from 10% to 30%, 3% to 23%, and 0% to 9% for phase 1, 2, and 3, respectively) fed until 11 kg BW and then fed a common phase 4 diet (0% whey permeate) until 25 kg BW in a 48-d feeding trial. Feed intake and BW were measured at the end of each phase. In exp. 2, 1,200 nursery pigs at 7.50 kg BW were allotted to six treatments (10 pens/treatment) with increasing levels of whey permeate from 0% to 18.75% fed until 11 kg BW. Feed intake and BW were measured during 11 d. Six pigs per treatment (1 per pens) were euthanized to collect the jejunum to evaluate tumor necrosis factor-alpha, interleukin-8 (IL-8), transforming growth factor-beta 1, mucin 2, histomorphology, digestive enzyme activity, crypt cell proliferation rate, and jejunal mucosa-associated microbiota. Data were analyzed using contrasts in the MIXED procedure and a broken-line analysis using the NLIN procedure of SAS. In exp. 1, increasing whey permeate had a quadratic effect (P < 0.05) on feed efficiency (G:F; maximum: 1.35 at 18.3%) in phase 1. Increasing whey permeate linearly increased (P < 0.05) average daily gain (ADG; 292 to 327 g/d) and G:F (0.96 to 1.04) of pigs in phase 2. In exp. 2, increasing whey permeate linearly increased (P < 0.05) ADG (349 to 414 g/d) and G:F (0.78 to 0.85) and linearly increased (P < 0.05) crypt cell proliferation rate (27.8% to 37.0%). The breakpoint from a broken-line analysis was obtained at 13.6% whey permeate for maximal G:F. Increasing whey permeate tended to change IL-8 (quadratic, P = 0.052; maximum: 223 pg/mg at 10.9%), to decrease Firmicutes:Bacteroidetes (P = 0.073, 1.59 to 1.13), to increase (P = 0.089) Bifidobacteriaceae (0.73% to 1.11%), and to decrease Enterobacteriaceae (P = 0.091, 1.04% to 0.52%) and Streptococcaceae (P = 0.094, 1.50% to 0.71%) in the jejunal mucosa. In conclusion, dietary inclusion of whey permeate increased the growth of nursery pigs from 7 to 11 kg BW. Pigs grew most efficiently with 13.6% whey permeate. Improvement in growth performance is partly attributed to stimulating intestinal immune response and enterocyte proliferation with positive changes in jejunal mucosa-associated microbiota in nursery pigs.     

有机微量元素对生长猪生长性能及微量元素排出量的影响

选用96头平均体重为（19.13±1.18）kg生长猪,分为处理1组（高剂量无机微量元素组）、处理2组（高剂量有机元素组）、处理3组（低剂量无机元素组）、处理4组（高剂量有机元素组）,每个处理3个重复,每个重复8头仔猪,试验期50 d,研究有机微量元素对生长猪生长性能及微量元素排出量的影响力。结果表明：处理1、2、4组的日增重分别比处理3组提高5.83%、7.03%、7.70%,均显著高于处理3组（P＜0.05）,其他处理组之间的日增重差异不显著。处理1、2、4组的料重比分别比处理3组降低5.28%、6.79%、7.92%,均达差异显著（P＜0.05）,处理1、2、4组之间的料重比差异不显著,处理4组的料重比最低。处理1组和处理2组粪中铜、铁、锌、锰的排泄量差异均不显著,处理3组和处理4组粪中铜、铁、锌、锰的排泄量差异均不显著,处理3组和处理4组粪中铜、铁、锌、锰的排泄量比处理1组和处理2组显著降低（P＜0.05）。