Dietary nucleotide supplementation as an alternative to in-feed antibiotics in weaned piglets.

Nucleotides are important to cell growth and division and are crucial to the rapid proliferation of such cells as the intestinal mucosa and immune cells. Accordingly, the nucleotide requirements of animals are high during periods of rapid growth and periods of stress like post-weaning period. Thus, nucleotide supplementation may be a possible alternative to in-feed antibiotics as growth promoter in this phase. The study aimed to evaluate dietary nucleotide supplementation as an alternative to in-feed antibiotics on performance and gut health of weaned piglets. Ninety-six 21-day-old piglets, weighing 7.44 ±â€¯0.65 kg, were allocated into 1 of 3 treatments (8 pens per treatment; 4 pigs per pen) in a 14-day trial. Dietary treatments consisted of control: corn-soybean meal-based diet; nucleotides: control +2 g/kg of a nutritional additive with purified nucleotides; and antibiotic: control +0.8 g/kg of antibiotic growth promoter based on colistin and tylosin. Performance variables and fecal score were not affected (P > 0.05) by supplementing nucleotide or antibiotic. Nucleotides treatment had similar effect to antibiotic and superior to control (P < 0.05) on enhancing duodenum villus height, jejunum crypt depth, and reduction of Paneth cellular area. Duodenum and ileum of animals supplemented with nucleotides or antibiotics had higher (P < 0.05) number of proliferating cells than did those of control animals, whereas the jejunum of animals that received antibiotic diets presented more (P < 0.05) proliferating cells than either the nucleotides or control animals. Jejunum of nucleotide-treated piglets showed a greater number of apoptotic cells than those fed antibiotic or control diets (P < 0.05). Nucleotides and antibiotic treatments decreased the B lymphocyte counts in duodenum and ileum (P < 0.05) but increased in the jejunum (P < 0.05), when compared to the control treatment. Relative abundance of mitogen-activated protein kinases-6, haptoglobin, and tumor necrosis factor-α mRNA was not influenced (P > 0.05) by treatments. In the ileal, antibiotic supplementation reduced total bacteria quantification compared to nucleotide supplementation or the control (P < 0.05), whereas nucleotides supplementation increased enterobacteria proliferation compared to the antibiotic or control diets (P < 0.05). However, nucleotides and antibiotic reduced (P < 0.05) colon total bacteria quantification when compared to control. These results suggest that the nucleotides source used to weaned piglets improved gut health by modulating the local immune response and modulating intestinal mucosa development, and, therefore, nucleotides may be an alternative to antibiotics as growth promoters.

Chromium, CLA, and ractopamine for finishing pigs.

This study aimed to evaluate the effects of dietary chromium, CLA, and ractopamine on performance, carcass traits, and pork quality of finishing pigs slaughtered at 115 kg BW. Ninety-six crossbred barrows (initial BW = 70.21 ± 1.98 kg) were randomly assigned to 1 of 6 dietary treatments. There were 8 replicates per treatment (48 pens; 2 pigs/pen). A diet formulated according to the nutritional requirements was used as the control (CON). The other 5 diets were based on the CON and supplemented as follows: 0.4 mg/kg Cr yeast (CrY); 0.5% CLA; 0.4 mg/kg CrY and 0.5% CLA (CrY + CLA); 20 mg/kg ractopamine (RAC); 0.4 mg/kg CrY and 20 mg/kg RAC (CrY + RAC). Lysine levels on diets containing ractopamine were raised by 20% compared to CON to meet the greater requirements of pigs fed ractopamine. Pigs fed RAC and CrY + RAC were fed CON for the first 17 d, and then the respective diets for the last 28 d on trial. Data were analyzed in a model including the fixed effect of treatment (6 levels) and initial BW as a covariate for all characteristics, with the exception of carcass traits, in which final BW was used as a covariate. Least-squares means were separated using Tukey-Kramer's method. Differences were considered when probability values were lower than 0.05. Pigs fed RAC and CrY + RAC had the greatest ( < 0.001) final BW and ADG. Pigs fed CrY + RAC had greater ( < 0.001) G:F than pigs within the other groups, except for those fed RAC. Pigs fed CrY + RAC and RAC had similar G:F, both greater ( < 0.001) than pigs fed CON. Average daily feed intake was similar ( = 0.83) for all diets. Pigs fed CrY + RAC had greater LM area ( = 0.01) and carcass yield ( < 0.02) than pigs fed CON, CrY, CLA, and CrY + CLA. Loin muscle area and carcass yield of pigs fed RAC were not different from pigs fed the others diets. Pigs fed CON diets had greater BF ( = 0.02) than pigs fed CLA diet. Additives did not affect ( > 0.05) pork quality, except for color. No differences ( > 0.05) were observed for carcasses pH and temperature. The values for pigs fed RAC were greater ( = 0.01) than pigs fed other diets. Pigs fed RAC had lower ( < 0.01) values compared to pigs fed other experimental diets. Serum urea nitrogen concentration (SUN) was lower ( = 0.02) in pigs fed CrY + RAC than in pigs fed CON and RAC and similar to pigs fed the other feeding additives. In summary, it was demonstrated that, when combined, CrY and RAC increase LM area and carcass yield, and reduce SUN, suggesting that chromium could improve nutrient utilization by muscle cells in RAC-fed pigs. Additionally, the additives have no major effects on pork quality.

Evaluation of Acid Digestion Procedures to Estimate Mineral Contents in Materials from Animal Trials.

Rigorously standardized laboratory protocols are essential for meaningful comparison of data from multiple sites. Considering that interactions of minerals with organic matrices may vary depending on the material nature, there could be peculiar demands for each material with respect to digestion procedure. Acid digestion procedures were evaluated using different nitric to perchloric acid ratios and one- or two-step digestion to estimate the concentration of calcium, phosphorus, magnesium, and zinc in samples of carcass, bone, excreta, concentrate, forage, and feces. Six procedures were evaluated: ratio of nitric to perchloric acid at 2:1, 3:1, and 4:1 v/v in a one- or two-step digestion. There were no direct or interaction effects (p>0.01) of nitric to perchloric acid ratio or number of digestion steps on magnesium and zinc contents. Calcium and phosphorus contents presented a significant (p<0.01) interaction between sample type and nitric to perchloric acid ratio. Digestion solution of 2:1 v/v provided greater (p<0.01) recovery of calcium and phosphorus from bone samples than 3:1 and 4:1 v/v ratio. Different acid ratios did not affect (p>0.01) calcium or phosphorus contents in carcass, excreta, concentrate, forage, and feces. Number of digestion steps did not affect mineral content (p>0.01). Estimated concentration of calcium, phosphorus, magnesium, and zinc in carcass, excreta, concentrated, forage, and feces samples can be performed using digestion solution of nitric to perchloric acid 4:1 v/v in a one-step digestion. However, samples of bones demand a stronger digestion solution to analyze the mineral contents, which is represented by an increased proportion of perchloric acid, being recommended a digestion solution of nitric to perchloric acid 2:1 v/v in a one-step digestion.

Effects of dietary soybean meal concentration on growth and immune response of pigs infected with porcine reproductive and respiratory syndrome virus.

An experiment was conducted to determine the effects of dietary soybean meal (SBM) concentration on the growth performance and immune response of pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV). Four experimental treatments included a 2 × 2 factorial arrangement of 2 dietary SBM concentrations, 17.5% (LSBM) or 29% (HSBM), and 2 levels of PRRSV infection, uninfected sham or PRRSV infected. Sixty-four weanling pigs of split sex (21 d of age, 7.14 ± 0.54 kg) were individually housed in disease containment chambers. Pigs were provided a common diet for 1 wk postweaning before being equalized for BW and sex and allotted to 4 treatment groups with 16 replicate pigs per group. Pigs were fed experimental diets for 1 wk before receiving either a sham inoculation (sterile PBS) or a 1 × 10 50% tissue culture infective dose of PRRSV at 35 d of age (0 d postinoculation, DPI). Pig BW and feed intake were recorded weekly, and rectal temperatures were measured daily beginning on 0 DPI. Blood was collected on 0, 3, 7, and 14 DPI for determination of serum PRRSV load, differential complete blood cell counts, and haptoglobin and cytokine concentrations. Infection with PRRSV increased (P < 0.01) rectal temperatures of pigs throughout the infection period, with no influence of dietary SBM concentration. Pigs in the PRRSV-infected group had lower (P < 0.01) ADFI and G:F from 0 to 14 DPI compared with uninfected pigs. In the PRRSV-infected group, pigs fed HSBM tended to have improved ADG (P = 0.06) compared with pigs fed LSBM, whereas there was no influence of SBM concentration on growth of pigs in the uninfected group. At 14 DPI, PRRSV-infected pigs fed HSBM had a lower serum PRRSV load (P < 0.05), a higher (P = 0.02) hematocrit value, and a tendency for greater hemoglobin concentration (P = 0.09) compared with pigs fed LSBM. Serum haptoglobin and tumor necrosis factor-α concentrations of PRRSV-infected pigs were lower (P < 0.05) in pigs fed HSBM at 3 and 14 DPI, respectively, than in pigs fed LSBM. Overall, increasing the dietary SBM concentration modulated the immune response and tended to improve the growth of nursery pigs during a PRRSV infection.

Effect of grinding with diamond-disc and -bur on the mechanical behavior of a Y-TZP ceramic.

This study compared the effects of grinding on the surface micromorphology, phase transformation (t→m), biaxial flexural strength and structural reliability (Weibull analysis) of a Y-TZP (Lava) ceramic using diamond-discs and -burs. 170 discs (15×1.2mm) were produced and divided into 5 groups: without treatment (Ctrl, as-sintered), and ground with 4 different systems: extra-fine (25µm, Xfine) and coarse diamond-bur (181µm, Coarse), 600-grit (25µm, D600) and 120-grit diamond-disc (160µm, D120). Grinding with burs was performed using a contra-angle handpiece (T2-Revo R170, Sirona), while for discs (Allied) a Polishing Machine (Ecomet, Buehler) was employed, both under water-cooling. Micromorphological analysis showed distinct patterns generated by grinding with discs and burs, independent of grit size. There was no statistical difference for characteristic strength values (MPa) between smaller grit sizes (D600 - 1050.08 and Xfine - 1171.33), although they presented higher values compared to Ctrl (917.58). For bigger grit sizes, a significant difference was observed (Coarse - 1136.32>D120 - 727.47). Weibull Modules were statistically similar between the tested groups. Within the limits of this study, from a micromorphological point-of-view, the treatments performed did not generate similar effects, so from a methodological point-of-view, diamond-discs should not be employed to simulate clinical abrasion performed with diamond-burs on Y-TZP ceramics.

Crab louse infestation in pre-Columbian America.

Until now, Pthirus pubis infestation in ancient human populations had only been recorded in the Old World. We found crab lice on South American mummified bodies from the Atacama Desert region. Crab louse eggs were found attached to the pubic hairs of a 2,000-yr-old Chilean mummy. Well-preserved adults were found in sediment and clothing from a Peruvian mummy dated 1,000 yr ago. Paleoparasitological evidence expands the knowledge of the distribution of this ectoparasite in ancient populations. As with many other parasites, pubic lice recorded in Andean populations show the antiquity of this parasite in the New World. It is likely that P. pubis entered the continent with early human migration to the New World.