Comparison of Fecal Methanogenic Archaeal Community Between Erhualian and Landrace Pigs Using Denaturing Gradient Gel Electrophoresis and Real-Time PCR Analysis

Erhualian and Landrace breeds are typical genetically obese and lean pigs, respectively. To compare the fecal methanogenic Archaeal community between these two pig breeds, fecal samples from different growth phase pigs were collected and used for PCR-denaturing gradient gel electrophoresis （DGGE） with two primer pairs （344fGC/519r and 519f/915rGC） and real-time PCR analysis. Results showed that a better separation and higher quality of bands pattern were obtained in DGGE proifles using primers 344fGC/519r as compared with primers 519f/915rGC. Sequencing of DGGE bands showed that the predominant methanogens in the feces of Erhualian and Landrace pigs belonged to Methanobrevibacter spp. and Methanosphaera spp. Real-time PCR analysis revealed that there was no signiifcant difference in the numbers of fecal total methanogens between Erhualian and Landrace pigs;however, pig growth phase affected the numbers of 16S rRNA genes of total methanogens and Methanobrevibacter smithii. Dissociation curves of methyl coenzyme-M reductase subunit A （mcrA） gene fragments ampliifed with real-time PCR showed all samples possessed a single peak at 82＆#176;C, which might be associated with M. smithii. Samples from the same growth phase of each breed showed good replicative dissociation curves. The results suggest that the growth phase （including diet factor） other than genotype of pig may affect the fecal methanogenic Archaeal community of pigs.

Optimal Nutritional Levels for New America-Line Landrace Pigs during Fattening Period

[ Objective] To investigate the effects of different nutritional levels on production performance, apparent digestibility of nutrients and car- cass quality, and determine the optimal levels of energy, crude protein, calcium and phosphorus in diet for the Landrace pigs at fattening stage. [ Method] A total of 36 healthy Landrace pigs at the same parity with close weaning age and similar body weight [ （70 ± 1 ） kg ~ were selected. They were divided into nine experimental groups randomly. The experiment was carried out according to the L9 （3^4） orthogonal design. Then the production performance, apparent digestibility of nutrients and carcass quality were determined, respectively. The preliminary trial lasted for 7 d, and the trial lasted for 42 d. [ Result] The levels of crude protein and calcium had significant effects on the average daily gain （ P 〈 0.05）, and the energy level had extremely significant effects on the average daily gain （ P 〈 0.01 ）. The levels of energy, crude protein, calcium and phosphorus had effects on the apparent digestibility of nutrients in various degrees. The crude protein level had significant effects on the backfat P2 （P 〈 0.05） ; the energy level had significant effects on the backfat P2 and backfat P1 （P 〈 0.05） ; and the calcium level had significant effects on backfat P2 and lean meat percentage （P 〈 0.05）. [ Condasion] During the fattening period, the requirement of digestible energy, crude protein, calcium and phosphorus for the new America-line Landrace pills was 13.39 MJ/ka. 16.00%. 1.45% and 0.90%. respectively.

Detection and Analysis of Routine Blood Indexes in Guike Pig

[Objectives] In this study,routine blood indexes of Guike pig were detected to clarify quantity variation and morphology distribution of different functional cells（ red blood cells,white blood cells and platelets）,thus providing reference data for immunological evaluation and disease resistance research of Guike pig. [Methods] Blood samples were collected from forty-four 49-day-old healthy Guike pigs（ 22 males and 22 females） once a week for seven consecutive weeks to detect routine blood indexes,and the results were compared with routine blood indexes of Landrace pig and Enshi black pig. [Results]Among red blood cell indexes of Guike pig at different day ages,red blood cell count（ RBC） and hemoglobin count（ HGB） both reached the lowest levels（ 6. 85 × 10^12/L and 97. 1 g/L）at 70 days of age,which were significantly lower than the corresponding indexes at 49,56,63,84 and 91 days of age（ P 〈 0. 05,similarly hereinafter）; mean corpuscular hemoglobin（ MCH） and mean corpuscular hemoglobin concentration（ MCHC） demonstrated basically the same variation pattern,which both reached the lowest levels（ 15. 11 pg and 275. 70 g/L） at 70 days of age and reached the highest levels（ 16. 40 pg and 314. 30 g/L） at 91 days of age; hematocrit（ HCT）,mean corpuscular volume（ MCV） and red blood cell distribution width（ RDW） exhibited relatively stable changes with no significant differences among different day ages（ P 〉 0. 05,similarly hereinafter）. Among white blood cell indexes of Guike pig at different day ages,white blood cell count（ WBC） reached the lowest level（ 13. 71 × 10^9/L） at 63 days of age and reached the highest level（ 17. 52 × 10^9/L） at 84 days of age,with significant differences; neutrophil count（ NEUT）reached the lowest level（ 3. 61 × 10^9/L） at 70 days of age,which was significantly lower than that at 49,56 and 77 days of age; lymphocyte count（ LYMPH） exhibited relatively stable changes and was not significantly affected by the increase in day age. Among platelet indexes of Guike pig at different day ages,platelet count（ PLT）,thrombocytocrit（ PCT） and platelet volume distribution width（ PDW） exhibited relatively stable changes among different day ages,which were not significantly affected by the increase in day age. Compared to 35-day-old Landrace pig and 5-month-old Enshi black pig,most routine blood indexes of Guike pig were similar to or ranged between those of Landrace pig and Enshi black pig except HCT,mean platelet volume（ MPV）,PCT and PDW. [Conclusions]Guike pig has a certain uniqueness in routine blood indexes,which has developed a stable immune system at 49-91 days of age.