Ruminal fermentation pattern of acidosis-induced cows fed either monensin or polyclonal antibodies preparation against several ruminal bacteria

This study was designed to evaluate a spray-dried multivalent polyclonal antibody preparation (PAP) against lactate-producing bacteria as an alternative to monensin (MON) to control ruminal acidification. Holstein cows (677 ± 98 kg) fitted with ruminal cannulas were allocated in an incomplete Latin square design with two 20 days period. Cows were randomly assigned to control (CTL), PAP, or MON treatments. For each period, cows were fed a forage diet in the first 5 days (d−5 to d−1), composed of sugarcane, urea and a mineral supplement, followed by a 74% concentrate diet for 15 days (d 0 to d 14). There were no treatment main effects (P > 0.05) on dry matter intake (DMI) and microbial protein synthesis. However, there was a large peak (P < 0.01) of intake on d 0 (18.29 kg), followed by a large decline on d 1 (3.67 kg). From d2, DMI showed an increasing pattern (8.34 kg) and stabilized around d 8 (12.96 kg). Higher mean pH was measured (P < 0.01) in cattle-fed MON (6.06 vs. PAP = 5.89 and CTL = 5.91). The ruminal NH3-N concentration of CTL-fed cows was lower (P < 0.01) compared to those fed MON or PAP. The molar concentration of acetate and lactate was not affected (P > 0.23) by treatments, but feeding MON increased (P = 0.01) propionate during the first 4 days after the challenge. Feeding MON and PAP reduced (P = 0.01) the molar proportion of butyrate. MON was effective in controlling pH and improved ruminal fermentation of acidosis-induced cows. However, PAP was not effective in controlling acidosis. The acidosis induced by the challenge was caused by the accumulation of SCFAs. Therefore, the real conditions for evaluation of this feed additive were not reached in this experiment, since this PAP was proposed to work against lactate-producing bacteria

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery

Effects of adding a spray-dried polyclonal antibody preparation on ruminal fermentation patterns and digestibility of cows fed high concentrate diets

The present study aimed to evaluate the effects of different doses of a spray-dried polyclonal antibody preparation against specific ruminal bacteria on rumen fermentation parameters as well as protozoa counts, in situ degradability of sugarcane neutral detergent fibre (NDF) and total tract apparent digestibility of total diet in cows fed high concentrate diets. Eight ruminally-cannulated cows were used in a replicated 4 4 Latin square design with four experimental periods of 21 days. The treatments were: T1 (control), 0.0 g/d of multivalent polyclonal antibody preparation (PAP-MV); T2, 1.5 g/d of PAP-MV; T3, 3.0 g/d of PAP-MV; T4, 4.5 g/d of PAP-MV. Sample collection for rumen fermentation parameters was carried out the last day of each period at 0, 2, 4, 6, 8, 10 and 12 h after morning meal. For protozoa counts, samples were collected the last day of each period at 0 and 4 h after feeding. In situ degradability of sugarcane NDF was performed the last 5 days of each period, while total tract apparent digestibility of total diet was assessed the last 10 days of each period. Regardless of sampling time, there was no linear or quadratic effect on rumen pH, total concentration of short chain fatty acids, molar proportion of acetate, propionate and butyrate, ammonia nitrogen (NH3-N) or lactate. No treatment effects were detected for protozoa counts, in situ degradability of sugarcane NDF and total tract apparent digestibility of total diet. In conclusion, different levels of spray-dried PAP-MV were not sufficient to alter rumen environment.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Shelf-life characteristics of longissimus muscle of feedlot bullocks supplemented with vitamin D and E.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Effect of Vitamin D and E supplementation on attributes of meat tenderness of feedlot bullocks.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP