The objective of this experiment was to evaluate the effects of supplementing a rumen-protected source of Met, N-acetyl-l-methionine (NALM), on lactational performance and nitrogen metabolism in ...early- to mid-lactation dairy cows. Sixty multiparous Holstein dairy cows in early lactation (27 ± 4.3 d in milk, SD) were assigned to 4 treatments in a randomized complete block design. Cows were blocked by actual milk yield. Treatments were as follows: (1) no NALM (control); (2) 15 g/d of NALM (NALM15); (3) 30 g/d of NALM (NALM30); and (4) 45 g/d of NALM (NALM45). Diets were formulated using a Cornell Net Carbohydrate and Protein System (CNCPS) v.6.5 model software to meet or exceed nutritional requirements of lactating dairy cows producing 42 kg/d of milk and to undersupply metabolizable Met (control) or supply incremental amounts of NALM. The digestible Met (dMet) supply for control, NALM15, NALM30, and NALM45 were 54.7, 59.8, 64.7, and 72.2 g/d, respectively. The supply of dMet was 88, 94, 104, and 115% of dMet requirement for control, NALM15, NALM30, and NALM45, respectively. Milk yield data were collected, dry matter intake (DMI) was measured daily, and milk samples were collected twice per week for 22 wk. Blood, ruminal fluid, urine, and fecal samples were collected during the covariate period and during wk 4, 8, and 16. Data were analyzed using the GLIMMIX procedure of SAS (SAS Institute) using covariates in the model for all variables except body weight. Linear, quadratic, and cubic contrasts were also tested. Treatments did not affect DMI, milk yield, and milk component concentration and yield; however, feed efficiency expressed as milk yield per DMI and 3.5% fat-corrected milk per DMI were quadratically affected, with greater response observed for NALM15 and NALM30 compared with control. Acetate proportion linearly increased, whereas propionate proportion linearly decreased with NALM supplementation. Blood urea nitrogen linearly decreased with NALM supplementation. Total plasma essential AA concentrations were quadratically affected, as greater values were observed for control and NALM45 than other treatments. Plasma Met concentration was quadratically affected as lower levels were observed with NALM15, whereas Met concentrations increased with NALM45 compared with control. Nitrogen utilization efficiency and apparent total-tract nutrient digestibility were not affected by treatment. Supplementation of NALM at 15 or 30 g/head per day resulted in the greatest improvements in feed efficiency without affecting N metabolism of early- to mid-lactation dairy cows.
We evaluated the effects of supplementing bacterial direct-fed microbial (DFM) on performance, apparent total-tract digestibility, rumen fermentation, and immune parameters of lactating dairy cows. ...One hundred fourteen multiparous Holstein cows (41 ± 7 DIM) were used in a randomized complete block design with an experiment comprising 14 d of a covariate (pre-experimental sample and data collection) and 91 d of an experimental period. Cows were blocked based on energy-corrected milk (ECM) yield during the covariate period and the following treatments were randomly assigned within each block: (1) control (CON), corn silage-based total mixed ration without DFM; (2) PRO-A, basal diet top-dressed with a mixture of Lactobacillus animalis and Propionibacterium freudenreichii at 3 × 10
cfu/d; and 3) PRO-B, basal diet top-dressed with a mixture of L. animalis, P. freudenreichii, Bacillus subtilis, and Bacillus licheniformis at 11.8 × 10
cfu/d. Milk yield, dry matter intake (DMI), and body weight were measured daily, while milk samples for component analysis were taken on 2 consecutive days of each week of data collection. Feces, urine, rumen, and blood samples were taken during the covariate period, wk 4, 7, 10, and 13 for estimation of digestibility, N-partitioning, rumen fermentation, plasma nutrient status and immune parameters. Treatments had no effect on DMI and milk yield. Fat-corrected milk (3.5% FCM) and milk fat yield were improved with PRO-B, while milk fat percent and feed efficiency (ECM/DMI) tended to increase with PRO-B compared with PRO-A and CON. Crude fat digestibility was greater with PRO-B compared with CON. Feeding CON and PRO-A resulted in higher total volatile fatty acid concentration relative to PRO-B. Percentage of neutrophils tended to be reduced with PRO-A compared with CON and PRO-B. The mean fluorescence intensity (MFI) of anti-CD44 antibody on granulocytes tended to be higher in PRO-B compared with CON. The MFI of anti-CD62L antibody on CD8+ T cells was lower in PRO-A than PRO-B, with PRO-A also showing a tendency to be lower than CON. This study indicates the potential of DFM to improve fat digestibility with consequential improvement in fat corrected milk yield, feed efficiency and milk fat yield by lactating dairy cows. The study findings also indicate that dietary supplementation with DFM may augment immune parameters or activation of immune cells, including granulocytes and T cells; however, the overall effects on immune parameters are inconclusive.
Many organisms undergo dormancy as a stress response to survive under unfavorable conditions that might impede development. This is observed in seeds and buds of plants and has been proposed as a ...mechanism of drug evasion and resistance formation in
We explored the effects of the phytohormones abscisic acid (ABA) and gibberellic acid (GA) on dihydroartemisinin (DHA)-induced dormant erythrocytic stages of
parasites. Dormant ring stages exposed to ABA and GA recovered from dormancy up to 48 h earlier than parasites exposed to DHA alone. Conversely, fluridone, an herbicide inhibitor of ABA synthesis, blocked emergence from dormancy. Additionally, the role of the apicoplast was assessed in dormant parasite recovery. Apicoplast-deficient
remained viable for up to 8 days without the organelle and recrudesced only when supplemented with isopentyl pyrophosphate (IPP). IPP was not required for survival in the dormant state. Fosmidomycin inhibition of isoprenoid biosynthesis did not prevent dormancy release from occurring in parasites with an intact apicoplast, but IPP or geranylgeranyl pyrophosphate was needed for complete recrudescence. In addition, the apicoplast and specifically the isoprenoids it produces are essential for recovery of dormant parasites. In summary, ABA and GA have significant effects on dormant parasites, and the phenotypes produced by these phytohormones and the herbicide fluridone also provide a means to explore the mechanism(s) underlying dormancy and the regulatory network that promotes cell cycle arrest in
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This retrospective study was conducted to analyze the recurrence of ear lobe keloids in 36 patients after surgical excision followed by radiation therapy. In all the cases keloids were excised and ...the surgical wound closed primarily. Following surgery, patients underwent 1800 cGy of radiation therapy in three equally divided doses over five to seven days. Most of our patients were young black females who developed keloids secondary to ear lobe piercing. Of the 36 patients followed for a mean period of 5.6 years, we noted only one (2.8%) recurrence. All the patients were followed for a minimum of two years. No serious complications were observed in our series. However, one patient developed radiation dermatitis followed by patchy hypopigmentation. We conclude that surgical excision followed by radiation therapy is a safe and effective method to control keloid recurrence in the ear lobe region.
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