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.

Draft genome sequence of Lactobacillus delbrueckii subsp. bulgaricus LBP UFSC 2230: a tool for preliminary identification of enzymes involved in CLA metabolism.

Several Lactobacillus ssp. are recognized as potential conjugated linoleic acid (CLA) producers. We have previously reported the ability of a range of Lactobacillus delbrueckii subsp. bulgaricus strains to produce CLA in fermented milk, being a potential candidate for the fermented dairy food chain. This study reports the draft genome sequence of L. bulgaricus strain LBP UFSC 2230, isolated from Italian Grana Padano cheese. Draft genome sequence originated in a total of 4,310,842 paired-end reads that were quality trimmed and assembled into 135 contigs with a total length of 604,745,873 bp, including 2086 protein coding genes and an average GC content of 49.7%. Draft genome sequence represents an important tool to identify the enzymes involved in this strain's CLA metabolism. We identified a gene encoding an enzyme involved in biohydrogenation of linoleic acid pathway, oleate hydratase.

Application of exopolysaccharide-forming lactic acid bacteria in cooked ham model systems.

The meat industry often applies hydrocolloids (not label-free) to improve quality attributes of meat products including reconstructed cooked ham. A new approach to improve product quality could be the usage of in-situ Exopolysaccharide (EPS)- forming lactic acid bacteria (LAB) provided that these strains are able to produce EPS in meat matrices under typical processing conditions (here: cooked ham). Two homopolysaccharide- (L. curvatus TMW 1.624 and L. sakei TMW 1.411; 106CFUmL) and heteropolysaccharide-forming LABs (L. plantarum TMW 1.1478 and TMW 1.25; 106CFUmL) were hence examined for EPS formation in a cooked ham model system consisting of minced pork topside (<2% fat) and 16.67% brine containing either 0.5% sucrose or dextrose. Samples were stored for 48 h at either 2 °C to simulate typical tumbling conditions, or at 15 °C to examine in-situ EPS production under reduced stress conditions. Microbial growth behavior and pH development (48 h) were monitored and EPS qualitatively as well as semi-quantitatively analyzed using both confocal laser scanning microscopy and MATLAB enabling a better comparison of the investigated strains. All LAB were able to tolerate the suboptimal growth conditions in the cooked ham model systems (2 °C, 1.92% nitrite curing salt) and were found to already produce EPS within 10 h of storage at 2° and 15 °C. EPS amounts detected after 24 h of incubation were significantly (p < 0.05) higher than those determined after sample preparation. EPS were found to be predominately located at the outer edge of meat proteins. All investigated strains seem to be promising for prospective studies in cooked ham.