Search

Calcium nitrate supplementation has recently been suggested to provide potential benefits to sows and, in particular, their offspring when administered at a level of 1,200 ppm in feed shortly before farrowing through lactation. More specifically, nitrate supplementation has been suggested as one opportunity for improved placental and/or fetal blood flow and has been hypothesized in previous work to be important to the swine industry in light of the global trend toward larger litter sizes. The benefit is likely manifested through exposure to the nitrate moiety, but interestingly, nitrate has historically been considered a compound of concern for swine. High levels of nitrate once metabolized to nitrite can interfere with the oxygen-carrying capacity of hemoglobin, resulting in increased methemoglobin and, subsequently, methemoglobinemia (MetHb) if the animal is deprived of significant amounts of oxygen; however, the level of nitrate exposure necessary to induce MetHb in sows is not clearly defined. This work was undertaken to examine methemoglobin levels in sows and piglets exposed to the potentially beneficial levels of 1,200 and 6,000 ppm nitrate added to their diets over the course of the periparturient period. Other oxygen capacity blood variables were evaluated (e.g. hemoglobin, hematocrit, and various measures of hemoglobin and red blood cell volumes and concentrations), as well as performance endpoints (weight changes and feed intake) and general observations over the 27-d period. No evidence of treatment-related toxicity manifestation was observed at these supplemental levels. Nearly all oxygen-related variables were affected by time (independent of treatment), indicating adaptive general effects of farrowing. These findings support the hypothesis that MetHb is not a concern up to at least 6,000 ppm supplemental nitrate exposure, even in combination with additional nitrate in the sow's daily diet. This work is important to help swine producers understand that consideration of nitrate benefit should outweigh concern for risk of nitrate-induced toxicity. [ABSTRACT FROM AUTHOR]

Superior bioavailability of organic selenium (Se) has been extensively studied. However, limited research has been conducted to evaluate the effect of organic forms on intestinal redox potential to support gut health and animal well-being. Two experiments (Exp) were conducted to compare the effect of either hydroxy-selenomethionine (OH-SeMet) or Se-enriched yeast (Se-yeast) on ameliorating hydrogen peroxide (H2O2)-induced oxidative stress in a rat intestinal epithelial cell line (IEC-6). A cell viability test was initially performed to validate the Se level (0.15, 0.3, 0.6 ug/mL) used for the reactive oxygen species (ROS) assay. In both studies, OH-SeMet or Se-yeast promoted cell viability and attenuated cell apoptosis indicating no negative impact on cell growth. However, the Se-yeast sources showed considerably greater effectiveness than OH-SeMet. To quantify redox potential, confluent cells were treated with DCFDA, an indicator of ROS production. Briefly, IEC-6 cells were seeded into 96-well plates (4 ×104 cells per well) with 3 replicates per treatment (Trt) and incubated with a fresh solution of DCFDA. The ROS production, in response to 30μM H2O2, was quantified by fluorescence emission at 485 nm. Data were analyzed with GLIMMIX procedure of SAS. In both Exp, Se inclusion in all Se-Trts was 0.3 ppm. In Exp 1, Trts included: Non treated (cells only), H2O2, H2O2 + 2mM Trolox (Vit. E analog), H2O2 + sodium selenite, H2O2 + OH-SeMet, H2O2 + Se-yeast product A, H2O2 + Se-yeast product B. Cells treated with H2O2 had 4.6-fold increase (P < 0.05) in ROS production relative to non-H2O2 treated cells. Trolox reduced ROS 7.6-fold (P < 0.05) relative to H2O2 only cells, OH-SeMet and sodium selenite did not ameliorate (P > 0.35) the negative impact of H2O2 on ROS production. However, cells treated with H2O2 + Se-yeast product A or B reduced ROS production by 15% (P = 0.07) and 32% (P < 0.01), respectively, compared with cells treated with H2O2 only. To validate the redox potential of OH-SeMet, Exp 2 included a pure form of selenomethionine. Treatments in Exp 2. were similar to Exp 1 with the inclusion of H2O2 + seleno-L-methionine. Selenomethionine, either as a pure source or the hydroxy analog, did not prevent (P > 0.40) H2O2-induced oxidative stress. However, Exp 2 confirmed the effectiveness of Se-Yeast products on reducing ROS production. More specifically, Se-Yeast product B (52% reduction, P = 0.04) was superior to product A (32% reduction, P = 0.17) in comparison to cells treated with H2O2 only. These findings suggest that the type of organic Se source differs in their ability to regulate intestinal redox potential, with Se-yeast sources being more effective than hydroxy analogs. Selenomethionine content in Se-yeast does not appear to be the main driver in reducing ROS in intestinal cells, suggesting that livestock fed Se-yeast can support better intestinal health during oxidative stress. [ABSTRACT FROM AUTHOR]

An experiment was conducted to test the hypothesis that supplementing diets with a blend of medium chain fatty acids (MCFA) and a phytogenic feed additive (Fresta Protect, Delacon, Linz, Austria), together or separately, would improve growth performance and stool quality of nursery pigs challenged with Escherichia coli (ETEC). A total of 200 pigs [5.52 ± 0.17 kg body weight (BW)] were weaned at 17 to 19 days of age, allotted to 40 pens (5 pigs/pen), and allowed to acclimate for 2 days before initiation of dietary treatments. Pens were blocked by BW and randomly assigned to 1 of 5 treatments: negative control (NC), NC + 55 mg/kg carbadox (Positive control; PC), NC + 1.0% MCFA, NC + 0.1% phytogenic, or NC + 1.0% MCFA and 0.1% phytogenic. All pigs were administered an oral gavage of 5 mL ETEC (blend of K88+ and F18+) with a final titer of 1010 CFU/pig on day 5 and 6. Body weights were recorded on days 0, 4, 11, and 18, whereas feed intake was recorded for the overall trial (day 0 - 18). Fecal scores were assessed daily on an ordered likert scale to determine the joint probability of more normal stool quality. Data were analyzed using the lme4 package of R 4.1.2, and the statistical models included the fixed effect of treatment and random effect of BW block. Growth performance data were assumed to be normally distributed, whereas mortality and stool quality were analyzed using generalized linear mixed models specifying binomial and multinomial distributions, respectively. Contrasts were used to test for effects of dietary additive (carbadox, MCFA, phytogenic, or MCFA and phytogenic) compared with NC (Table 1). Results indicated postchallenge BW, post-challenge and overall average daily gain (ADG), and overall gain:feed (G:F) were greater (P < 0.05) for PC than for NC. In the pre-challenge phase, dietary inclusion of MCFA reduced (P < 0.05) final BW and ADG compared with NC, but overall G:F was greater (P < 0.05) than NC when the MCFA blend was fed. Inclusion of the phytogenic increased (P < 0.05) ADG in the post-challenge period and G:F in the overall trial compared with NC. The combination of MCFA blend and phytogenic resulted in increased (P < 0.05) post-challenge final BW, post-challenge ADG, and overall ADG compared with NC. All treatments, except MCFA blend, tended (P < 0.10) to reduce mortality compared with NC. The PC, MCFA blend, and combination treatments resulted in a greater (P < 0.05) probability of normal stool quality than NC. In conclusion, supplementation of the phytogenic and the combination of MCFA with phytogenic improved growth performance and tended to reduce mortality of nursery pigs under ETEC challenge. Furthermore, the combination improved stool quality. [ABSTRACT FROM AUTHOR]

An experiment was conducted to determine the impact of dietary SID Ile to Lys ratio on the performance pigs from 11 to 80 kg of BW. A total of 1,092 pigs (initial BW = 11.1, SEM = 0.6 kg; 14 pens/treatment; 13 pigs/pen) were used in an 80d trial with a randomized complete block design. Dietary treatments were in a 2 x 3 factorial arrangement containing 2 levels of DDGS (0 and 25%) and 3 levels of SID Ile/Lys (0.54, 0.58, and 0.62). Energy and nutrient levels of all treatments were formulated at equal levels that met or exceeded NRC (2012) requirements. The SID Ile/Lys ratio was controlled by crystalline Ile. The MIXED procedures of SAS 9.4 were employed for statistical analysis. Orthogonal contrasts were used to test for main effects of DDGS and SID Ile/Lys. In the results, formulating with 25% DDGS decreased FBW, ADG, and ADFI (P < 0.05) of growing pigs. The average FBW of treatments without and with 25% DDGS were 81.7 and 78.6 kg, respectively. The ADG of diets without and with DDGS were 0.88 vs 0.84 kg/d, respectively. The ADFI of treatments without DDGS were 1.85 kg/day, while the counterparts of treatments fed diets containing 25% DDGS were 1.79 kg/d. Feeding diets containing 25% DDGS tended to decrease Gain:Feed (0.477 vs. 0.472; P < 0.10). Increasing the level of SID Ile/Lys (from 0.54 to 0.62) linearly increased Gain:Feed in pigs fed diets containing 25% DDGS (0.467, 0.471, 0.477, respectively; P < 0.05). In summary, this study demonstrated feeding diets containing 25% DDGS decreased the performance of growing pigs by reducing ADG and ADFI. Greater SID Ile/Lys in diets may help reduce the negative impact of DDGS diets in growfinishing pigs by improving feed efficiency. [ABSTRACT FROM AUTHOR]