Effect of peripartal administration of mycobacterium cell wall fraction on health and fertility of Holstein cows under organic-certified management

The main objective of this study was to evaluate the effect of peripartal administration of a commercially available nonspecific immune stimulant (mycobacterium cell wall fraction; MCWF [Amplimune, NovaVive Inc., Napanee, ON, Canada]) on the incidence of disease during early lactation and subsequent fertility of dairy cows. A second objective was to characterize the dynamics of circulating white blood cells (WBC) and metabolic markers following treatment administration. Cows in an United States Department of Agriculture (USDA) organic-certified dairy herd were blocked by parity and, based on sequential calving dates, randomly assigned to receive two injections (5 mL s.c.) of either a placebo (saline solution) as a control (CON; n = 71) or MCWF (n = 65) at enrollment (7 d before expected calving) and within 24 h after calving. Blood samples were collected from a subsample of the study population (MCWF = 16; CON = 18) for WBC count at enrollment, at day 2 post enrollment, and at days 1, 3, 7, and 14 after calving. Serum fatty acids, beta-hydroxybutyrate, and Ca concentrations were determined at days 1 and 7 postpartum (MCWF = 21; CON = 21). Main outcome variables included incidence risk of peripartal and early lactation health disorders and pregnancy at first artificial insemination (AI), at 100, and at 150 days in milk (DIM). In addition, the average daily milk yield up to 90 DIM and death and live culling before 305 DIM were compared. Treatment effects were assessed using multivariable logistic regression, time-to-event analyses, and repeated measures analysis of variance (ANOVA). A treatment effect on the incidence risk of some of the health disorders in the study was established. Incidence risk of metritis and clinical mastitis <28 DIM was smaller in MCWF than in CON cows (36.9% vs. 50.7% and 6.3% vs. 19.7%, respectively). On the contrary, the incidence risk of respiratory disease <28 DIM was smaller in CON (0%) than in MCWF (7.7%). Reproductive performance of multiparous cows was affected by MCWF administration: pregnancy at first AI and pregnancy at 100 and 150 DIM were greater in MCWF than in CON (35.6% vs. 19.2%; 51.1% vs. 25.0%; and 64.4% vs. 40.4%, respectively). Overall, median intervals from calving to pregnancy were 90 vs. 121 d in MCWF and CON cows, respectively. No treatment effects on the dynamics of circulating WBC or in postpartum metabolic status were established. No differences for milk yield or for the proportion of cows that survived up to 305 DIM were determined, although cows in MCWF left the herd earlier than cows in CON. In conclusion, incidence risks of metritis and mastitis in early lactation were smaller in cows receiving MCWF, whereas the incidence risk of respiratory disease was smaller in CON. Fertility significantly improved in MCWF compared with CON cows. As this study was performed in an organic-certified dairy, specific health and reproductive management practices may affect the external validity of the current findings.

Phytoremediation of Uranium-Contaminated Soil by Perennial Ryegrass (Lolium Perenne L.) Enhanced with Citric Acid Application

Perennial ryegrass (Lolium perenne L.) was planted in uranium-contaminated soil mixture (river sand and vermiculite mixed with equal volume ratio) supplemented with different amounts of citric acid (0, 1, 5, and 10 mmol/kg) and divided into 4 treatments (Con+0, Con+1, Con+5, and Con+10) to investigate the effects of citric acid concentrations on the remediation efficiency and enhanced mechanism of perennial ryegrass in the lab. The uranium content in the plant tissues showed that the roots were the predominant tissue for uranium accumulation, and the subcellular distributions of uranium in the root cells was in the order: cell wall fraction > cytosol fraction > organelle fraction. However, in the shoot cells the order was cell wall fraction > organelle fraction > cytosol fraction. In this study, the optimal concentration of citric acid added was 5 mmol/kg, and the removal efficiency of U in the shoots and roots increased by 47.37% and 30.10% respectively. The treatment with 5 mmol/kg citric acid had the highest contents of photosynthetic pigment and soluble protein, the highest activity of antioxidant enzymes, and the lowest content of MDA (malondialdehyde) and relative electrical conductivity. Moreover, the damage to the cell ultrastructure of perennial ryegrass observed by TEM (transmission electron microscope) was significantly alleviated when 5 mmol/kg citric acid was added. All results indicate that perennial ryegrass can accumulate uranium with elevated uranium tolerance and enrichment ability when 5 mmol/kg citric acid is added under uranium stress. These results suggest that citric acid has significant effects on improving the uranium phytoremediation potential of perennial ryegrass.

Mitigation of AFB1-Related Toxic Damage to the Intestinal Epithelium in Broiler Chickens Consumed a Yeast Cell Wall Fraction

In vivo experiments were conducted to evaluate the effectiveness of a yeast cell wall fraction (YCW) to reduce the negative impact of aflatoxin B1 (AFB1) to the intestinal epithelium in broiler chickens. Zeta potential (ζ-potential), point of zero charge (pHpzc), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) techniques were used to characterize the YCW. Two hundred one-day-old male Ross 308 broiler chickens were randomly allocated into four treatments: (1) control, chickens fed an AFB1-free diet; (2) AF, chickens feed an AFB1-contaminated diet (500 ng AFB1/g); (3) YCW, chickens fed an AFB1-free diet + 0.05% YCW; and (4) AF + YCW, chickens fed an AFB1-contaminated diet (500 ng AFB1/g) + 0.05% YCW. At the end of the 21-day feeding period, fluorescein isothiocyanate dextran (FITC-d) was administered to chicks by oral gavage to evaluate gastrointestinal leakage. Blood and duodenum samples were collected to assess serum biochemistry and histomorphology, respectively. Compared to the control group, chicks of the AF group significantly diminished weight gain (WG) and average daily feed intake (ADFI), and increased feed conversion ratio (FCR), mortality rate (MR), and intestinal lesion scores (p < 0.05). Alterations in some serum biochemical parameters, and damage to the intestinal integrity were also evident in the AF-intoxicated birds. YCW supplementation improved WG and FCR and increased villus height, villus area, crypt depth, and the number of goblet cells in villi. The effects of YCW on growth performance were not significant in chicks of the AF + YCW group; however, the treatment decreased MR and significantly ameliorated some biochemical and histomorphological alterations. The beneficial effect of YCW was more evident in promoting gut health since chickens of the AF + YCW group presented a significant reduction in serum FITC-d concentration. This positive effect was mainly related to the changes in negative charges of YCW due to changes in pH, the net negative surface charge above the pHpzc, the higher quantities of negative charged functional groups on the YCW surface, and its ability to form large aggregates. From these results, it can be concluded that YCW at low supplementation level can partially protect broilers' intestinal health from chronic exposure to AFB1.

75 Effect of mycobacterium cell wall fraction immunostimulant on conception rates in heifer recipients

In cattle, the average pregnancy for IVF embryos around Days 45 to 90 is 35% (Ealy et al. 2019 J. Anim. Sci. 97, 2555–2568). Among other factors, uterine contamination with pathogens from the vagina during embryo transfer may affect pregnancy success. Prophylactic antibiotic treatment for this purpose in embryo recipients is considered malpractice. An alternative to antibiotics is the use of mycobacterium cell wall fraction (MCWF) immunostimulant (Amplimune, NovaVive Inc.) against these pathogens. Therefore, the objective was to determine the effect of MCWF on conception rates in heifer recipients. For this purpose, Holstein heifers were synchronized with 2 injections of prostaglandin F2α 14 days apart and randomly allocated to 2 groups: (1) MCWF (n=292), single intramuscular injection of 5mL of Amplimune on the day of pretransfer oestrus; (2) Control (n=296): no Amplimune treatment. Embryo transfers using quality 1 frozen IVF embryos were performed in all recipients 7 to 8 days after oestrus and with a corpus luteum ≥22mm, using a double sanitary sheath technique. Data were analysed using the generalized linear mixed model (GLMM). Results are shown in Table 1. In conclusion, treatment with MCWF increased the number of recipients to be used for embryo transfer and improved the conception rate at Day 60. Importantly, MCWF treatment was more efficient for getting a recipient pregnant by Day 60 per total of synchronized recipients. Table 1. Effect of mycobacterium cell wall fraction (MCWF) on pregnancy in heifer recipients transferred frozen embryos (quality 1) Variable MCWF Control Utilisation rate 227/292a 174/296b (No. of transferred recipients/no. of synchronized recipients) (78%) (59%) Pregnancy Day 30 144/227 94/174 (No. of pregnant recipients at Day 30/no. of transferred recipients) (63%) (54%) Pregnancy Day 60 131/227a 83/174b (No. of pregnant recipients at Day 60/no. of transferred recipients) (58%) (48%) Embryo mortality 13/144 11/94 (No. of embryo loss at Day 60/no. of pregnant recipients at Day 30) (9%) (12%) Pregnancy Day 60 per total of synchronized 131/292a 83/296b (No. of pregnant recipients/no. of synchronized recipients) (45%) (28%) a,bValues with different superscripts within a row are different (P ≤ 0.05).

Chemical and thermal characteristics of soluble polysaccharides from fruit pericarps of the Algerian Argania spinosa

Soluble polysaccharides were isolated from fruit pericarps of the Algerian Argania spinosa. The cell wall fraction was subjected to sequential extractions with H2O (2 × 2 h at 100°C), EDTA (1%, 6 h at 80°C) and KOH (1 and 4 M, 14 h at 25°C). The structures of the obtained polysaccharide fractions were characterized using gas chromatography (GC), infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The presence of arabinose, galactose and rhamnose in the pectin fractions suggests the presence of rhamnogalacturonan, while the abundance of xylose in the hemicellulosic fractions indicates the presence of xylan. The DSC data revealed the endothermal behavior of all the soluble polysaccharides and only two thermal transitions, the glass transition (Tg) and the fusion transition (Tf) have been recorded.