炎热条件下助长素对断奶仔猪生产性能及血液指标的影响

在高温和高噪音的不良饲养环境条件下，选择体重１０ｋｇ左右杜浙猪４０头，随机分成四组，即对照组、试验Ⅰ、Ⅱ、Ⅲ组。在同一日粮基础上分别添加０％、０．０５％、０．１０％．０．１５％猪用助长素，以探讨不同浓度的猪用助长素对断奶仔猪的生产性能和部分血液指标的影响。结果表明，添加０．０５％、０．１０％、０．１５％猪用助长素均能明显提高断奶仔猪的日增重，提高饲料利用率。经统计分析，添加０．１５％猪用助长素组猪的日增重与对照组之间存在极显著差异（ｐ＜０．０１）。试验组猪只血液中红细胞总数、血色素和碱性磷酸酶含量也明显高于对照组。添加０．１０％猪用助长素的血液碱性磷酸酶含量与对照组之间存在极显著差异（ｐ＜０．０１）。     

Genetic diversity among some cattle breeds in the Alpine area

Seven autochthonous Italian cattle breeds bred in the alpine area (Aosta Black Pied, Aosta Red Pied, Aosta Chestnut, Oropa Red Pied, Grey Alpine, Rendena and Burlina) were investigated in order to characterise their genetic structure and to study their phylogenetic origin. Two cattle breeds from Germany (Original German Brown and Holstein) and four from Switzerland (Simmental, Herens, Evolene and Brown Swiss) were included in the study in order to determine the genetic diversity existing among Italian local breeds, similar breeds bred on the other side of the Alps and in the well known Holstein.
Seventeen microsatellites, of the internationally accepted panel for the study of cattle biodiversity, were used for the analysis.
Microsatellites were highly polymorphic with a mean number of 5,5 alleles (ranging from 2 to 12 per locus). For each locus, allelic frequencies, heterozygosity (H) and the Polymorphism Information Content (PIC) were computed. The genetic equilibrium according to Hardy–Weinberg was calculated for each population and for each locus. Allele frequencies were used to estimate genetic distances and to draw a phylogenetic tree. The two closest breeds were Aosta Red Pied and Aosta Black Pied, while the two genetically most different were Holstein and Aosta Chestnut. Aosta valley breeds, Evolene and Herens constituted a tight cluster in the phylogenetic consensus tree. Principal component analysis showed a similar pattern for all the alpine breeds, while Holstein and Original German Brown were far away. The genetic differences among breeds were in accordance with their geographical and historical origins.     

Sows infected in pregnancy with porcine respiratory coronavirus show no evidence of protecting their sucking piglets against transmissible gastroenteritis

Eighteen litters of sucking piglets were challenged with one of two strains of transmissible gastroenteritis virus (TGEV). During pregnancy, their seronegative dams had been either inoculated intranasally with porcine respiratory coronavirus (PRCV), inoculated orally with TGEV or left untreated. On the basis of weight gain, clinical signs and survival, no differences in response to challenge was detected when piglets suckled by PRCV inoculated sows were compared with those suckled by uninoculated sows. Such a difference was evident when the litters of sows successfully pre-immunized with TGEV were compared with those of unicoculated or PRCV-inoculated sows. The possibility of transplacental transmission of PRCV was investigated in two litters born to sows that had been inoculated with this virus in late pregnancy. All sixteen live-born piglets were seronegative for the virus at birth and PRCV was not isolated from tissues taken from two stillborn piglets.     

The Effect of Prolonged Supplementation of Dietary Zinc on Weight Gain,Tissue Storage of Zinc and some Serum Variables in Fattening Pigs

The effect of prolonged administration of dietary zinc in fattening pigs from 50 to 95 kg body weight was studied. No effect on daily weight gain was recorded. The concentration of zinc in different tissues did not increase. A slight increase of serum zinc was noted, but no other changes of the serum variables tested could be demonstrated. It was concluded that the amounts of zinc which are recommended for treatment of pigs with wasting syndrome do not introduce any significant accumulation of zinc in organs or tissues.     

Comparative Analysis of Different Implementation Strategies on Genomic Selection in Large White Pigs

At present, genomic selection (GS) has been applied in pigs breeding, but some implementation strategies, such as the determination of genotyping ratios or early selection rates for piglets, are required to obtain a higher benefit using this technology. The Large White pigs born from 2011 to 2016 at WENS Foodstuff Group Co.,Ltd were chose as the research objects, including more than 45 000 growth measurement records, more than 70 000 reproduction records and 2 090 individuals with genotyping-by-sequencing (GBS) data. The 440 individuals born from July to December in 2016 were used as the candidate individuals. The traits included two growth traits, age at 100 kg and backfat thickness at 100 kg, and one reproduction trait, number of total born. To compare the prediction effects, four prediction scenarios were designed according to including or ignoring the phenotypic or genotypic information of candidate individuals when predicting their breeding values. The predictive reliability of different scenarios and rankings of selection indices of individuals would be compared. The results showed that the results using the phenotypic and genotypic information was more reliable than ignoring them to predict the breeding values of candidate individuals. When genomic selection indices were calculated before and after performances testing for the growth traits, the individuals ranking in the top 30% of indices after testing were all found in the individuals ranking in the top 60% of indices before testing. If the piglets with the top 60% of traditional BLUP indices were only selected, around 15% of individuals with good genetic potentials would be omitted. This study suggests that all healthy piglets after birth are genotyped and their genomic selection indices are calculated, and then the individuals ranking in the top 60% of indices are chose to perform growth measurement.     

Pharmacokinetics of Sulfadimethoxine and Sulfamethoxazole in Combination with Trimethoprim after Oral Single- and Multiple-Dose Administration to Healthy Pigs

The pharmacokinetics were studied of sulfadimethoxine (SDM) or sulfamethoxazole (SMX) in combination with trimethoprim (TMP) administered as a single oral dose (25 mg + 5 mg per kg body weight) to two groups of 6 healthy pigs. The elimination half-lives of SMX and TMP were quite similar (2–3 h); SDM had a relatively long half-life of 13 h. Both sulfonamides (S) were exclusively metabolized to N4-acetyl derivatives but to different extents. The main metabolic pathway for TMP was O-demethylation and subsequent conjugation. In addition, the plasma concentrations of these drugs and their main metabolites after medication with different in-feed concentrations were determined. The drug (S:TMP) concentrations in the feed were 250:50, 500:100, and 1000:200 mg per kg. Steady-state concentrations were achieved within 48 h of feed medication, twice daily (SDM+TMP) or three times a day (SMX+TMP). Protein binding of SDM and its metabolite was high (>93%), whereas SMX, TMP and their metabolites showed moderate binding (48–75%). Feed medication with 500 ppm sulfonamide combined with 100 ppm TMP provided minimum steady-state plasma concentrations (C _ss,min) higher than the concentration required for inhibition of the growth of 90% of Actinobacillus pleuropneumoniae strains (n = 20).     

The Control of Parasitic Nematodes in Commercial Piggeries in Kenya as Reflected by a Questionnaire Survey on Management Practices

Tropical Animal Health and Production -     

日粮铜水平对猪生长性能影响的研究

60头军牧 1号生长猪 (19.2 6± 1.2 0kg) ,随机分成 6组 ,公母各半。基础饲料为玉米 -豆粕型饲料。使用硫酸铜作为铜源 ,对照组铜添加浓度为 0mg/kg ,试验各组铜添加浓度为 10 0、15 0、2 0 0、2 5 0和 30 0mg/kg。试验开始时称重 ,之后每隔 2 0d称重一次。测定长性能指标。试验结果如下 :在日粮中添加不同水平的铜 (≥15 0mg/kg和≤ 30 0mg/kg)可明显提高平均日增重 (ADG) ,降低料重比 (F/G)。但增重效应表现出明显的阶段性差异 ,前期 (0d～ 6 0d)效果优于后期 (6 0d～ 10 0d)。整个试验期 ,试验组与对照组相比 ,ADG平均提高 9.9% ,增幅在 5 %～ 14 % ,其中以 2 0 0和 2 5 0mg/kg铜组最佳 ,分别达到 72 0 .77g/d(P <0 .0 1)和 72 5 .8g/d(P <0 .0 1) ;试验组比对照组F/G平均降低了 5 .4 % ,降幅为 3%～ 8% ,其中以 2 0 0和 2 5 0mg/kg铜组最低 ,分别为 3.0 8(P <0 .0 1)和 3.0 6 (P <0 .0 1)。采食量未见有显著变化 (P >0 .0 5 )。本试验结果表明 :15 0mg/kg～ 30 0mg/kg铜添加量对生长猪具有明显促生长作用 ,其中以 2 0 0和 2 5 0mg/kg铜组最佳     

重组猪生长激素对猪脂肪组织GH-R、IGF-1、IGF-R和Leptin基因表达的影响

选用体质量 5 0 kg左右的去势长白×大约克公猪 16头 ,随机分为试验组和对照组 ,试验组猪每日肌肉注射重组猪生长激素 (rp GH) 4 m g/头 ,2 8d后屠宰采集背部皮下脂肪 ,用 RT- PCR方法 ,以 18S r RNA作内标 ,定量分析脂肪组织中生长激素受体 (GH- R)、胰岛素样生长因子 - 1(IGF- 1)、胰岛素样生长因子 型受体 (IGF- R)和瘦蛋白(L eptin)的 m RNA丰度。结果显示 ,试验猪脂肪细胞 GH- R m RNA丰度比对照猪增加了 5 0 .9% (P<0 .0 5 ) ,IGF- 1m RNA丰度增加 2 7.8% (P<0 .0 5 ) ,IGF- R m RNA丰度增加 4 8.1% (P<0 .0 1) ,而 L eptin m RNA丰度则比对照猪减少 2 8.2 % (P<0 .0 5 )。结果提示 ,生长激素不仅可以直接调节脂肪组织 ,还可能通过脂肪 GH- R介导产生 IGF- 以旁 (自 )分泌形式调节脂肪组织的代谢     

Reduced intake of dietary lysine promotes accumulation of intramuscular fat in the Longissimus dorsi muscles of finishing gilts

The present study was conducted to elucidate the effect of dietary lysine levels on the intramuscular fat (IMF) content in the Longissimus dorsi (L. dorsi) muscles of finishing gilts. Eleven gilts in total from two litters of pigs aged 110 days were used. The average initial bodyweight of the pigs was 61.7 kg. Six pigs were assigned to the low lysine (LL) diet group (lysine content: 0.43 or 0.40%) and five pigs were assigned to the control group (lysine content: 0.65 or 0.68%). The diets were iso‐energetic and iso‐protein, and contained all essential amino acids (apart from lysine) in the recommended amounts. The pigs were fed these diets until their live weights reached 110 kg. Live weight gain and feed efficiency tended to be lower in the LL group (P = 0.118 and P = 0.052, respectively). Pigs from the LL group took 5 days longer to reach 110 kg (P < 0.01). The IMF content in the L. dorsi of the LL group was twice as high as that of the control group (6.7 vs 3.5%; P < 0.01). The percentage of oleic acid in the L. dorsi of the LL group tended to be higher than that of the control group (P = 0.052), whereas the percentage of linoleic acid and the total percentage of polyunsaturated fatty acids in the L. dorsi were lower (P < 0.05) in the LL group. Free L‐carnitine content in the L. dorsi was lower (P < 0.05) in the LL group. The average abundance of peroxisome proliferator‐activated receptor gamma mRNA in the L. dorsi of the LL group was threefold higher than that of the control group. The leptin mRNA abundance in the L. dorsi of the LL group was 3.3‐fold higher than that of the control group (P < 0.01). These results suggest that a higher activity of adipogenesis may have been involved in the promoted accumulation of IMF in the L. dorsi muscles of pigs, induced by a dietary LL level.