Effect of nitrogen fertilisation on the amino acid digestibility of different triticale genotypes in caecectomised laying hens.

Background: The influence of nitrogen fertilisation and genotype on the amino acid (AA) digestibility of triticale grain was investigated in caecectomised laying hens. Three genotypes, Grenado, EAW6002 and Lasko, were cultivated with and without nitrogen fertilisation at the end of the heading stage. The six triticale variants as well as a basal diet were each used to feed seven laying hens in a 7 × 7 Latin square design.

Changes in Rumen Microbial Community Composition during Adaption to an In Vitro System and the Impact of Different Forages.

This study examined ruminal microbial community composition alterations during initial adaption to and following incubation in a rumen simulation system (Rusitec) using grass or corn silage as substrates. Samples were collected from fermenter liquids at 0, 2, 4, 12, 24, and 48 h and from feed residues at 0, 24, and 48 h after initiation of incubation (period 1) and on day 13 (period 2). Microbial DNA was extracted and real-time qPCR was used to quantify differences in the abundance of protozoa, methanogens, total bacteria, Fibrobacter succinogenes, Ruminococcus albus, Ruminobacter amylophilus, Prevotella bryantii, Selenomonas ruminantium, and Clostridium aminophilum.

Studies on potential effects of fumaric acid on rumen microbial fermentation, methane production and microbial community.

The greenhouse gas methane (CH4) contributes substantially to global climate change. As a potential approach to decrease ruminal methanogenesis, the effects of different dosages of fumaric acid (FA) on ruminal microbial metabolism and on the microbial community (archaea, bacteria) were studied using a rumen simulation technique (RUSITEC). FA acts as alternative hydrogen acceptor diverting 2H from methanogenesis of archaea towards propionate formation of bacteria.

Influence of apple and citrus pectins, processed mango peels, a phenolic mango peel extract, and gallic Acid as potential feed supplements on in vitro total gas production and rumen methanogenesis.

Several food processing byproducts were assessed as potential feed and feed supplements. Since their chemical composition revealed a high nutritional potential for ruminants, the Hohenheim in vitro gas test was used to investigate total gas, methane, and volatile fatty acid production as well as protozoal numbers after ruminal digestion of different substrate levels. Processing byproducts used were low- and high-esterified citrus and apple pectins, integral mango peels, and depectinized mango peels.

Effect of monensin on in vitro fermentation of silages and microbial protein synthesis.

The objective of the study was to investigate the effects of monensin on silage fermentation and microbial net protein synthesis. In Experiment 1, monensin (0.5, 1, 2, 4, 6, or 10 µg) was added to syringes that contained 120 mg of grass silage (GS), grass silage and concentrate (GS + C), or maize silage (MS), resulting in concentrations of 4.

Investigations on the effect of forage source, grinding, and urea supplementation on ruminal fermentation and microbial protein flow in a semi-continuous rumen simulation system.

The objective of the present study was to compare the effect of maize silage and grass silage on microbial fermentation and protein flow in a semi-continuous rumen simulation system (Rusitec) when milling screen size (MSS) during grinding was varied. Oven-dried silages were milled through screens of 1, 4 or 9 mm pore size and incubated for 48 h in a Rusitec system. Furthermore, the effect of N supplementation to maize silage (MSS: 4 mm) was investigated and single dose vs.

Effects of concentrate proportion in the diet with or without Fusarium toxin-contaminated triticale on ruminal fermentation and the structural diversity of rumen microbial communities in vitro.

The objective of this study was to investigate the effects of the concentrate proportion and Fusarium toxin-contaminated triticale (FCT) in the diet on nutrient degradation, microbial protein synthesis and structure of the microbial community, utilising a rumen simulation technique and single-strand conformation polymorphism (SSCP) profiles based on PCR-amplified small subunit ribosomal RNA genes. Four diets containing 60% or 30% concentrates on a dry matter basis with or without FCT were incubated. The fermentation of nutrients and microbial protein synthesis was measured.

Determination of titanium dioxide supplements in different matrices using two methods involving photometer and inductively coupled plasma optical emission spectrometer measurements.

Titanium dioxide (TiO2) is a viable marker in digestibility studies using different animal species. The photometrical analysis is based on an intense orange colour following the addition of hydrogen peroxide to an acid solution. The measurement using inductively coupled plasma optical emission spectrometry (ICP-OES) is a method for analysing more than one element from the same sample preparation.

Description of the structural diversity of rumen microbial communities in vitro using single-strand conformation polymorphism profiles.

Changes of the rumen microbial community structure, as it can be established with a rumen simulation technique (RUSITEC) were studied using PCR and single-strand conformation polymorphism (SSCP) of small subunit rDNA genes (SSU rDNA). Four total mixed rations were incubated and two ammonia levels in the artificial saliva were applied. Three replicated vessels were used for each treatment.

Ruminal fermentation patterns and parameters of the acid base metabolism in the urine as influenced by the proportion of concentrate in the ration of dairy cows with and without Fusarium toxin-contaminated triticale.

Feeding a total mixed ration with 50% concentrate and a mean deoxynivalenol (DON) concentration of 5.3 mg/kg DM to 13 German Holstein cows in early lactation (Myco group) resulted in alterations in the ruminal fermentation patterns (lower molar percentage of acetate and isobutyrate, higher molar percentage of valerate) compared to the 14 control cows (Period 1, 11 weeks). In the Myco group, significantly lower ruminal pH value occurred in weeks 4 and 8 and lower minimum pH values critical for developing subacute ruminal acidosis were detected.

On the effects of the concentrate proportion of dairy cow rations in the presence and absence of a fusarium toxin-contaminated triticale on cow performance.

The aim of the present study was to investigate the effects of a deoxynivalenol (DON) contaminated ration with a concentrate proportion of 50%, on the performance of dairy cows (Period 1), and to examine the effects when the concentrate proportion was elevated to 60% compared to a ration with 30% concentrates (Period 2). In Period 1, 13 lactating German Holstein cows (Myco group, on average 29 days in milk) were fed the experimental diet (on average 5.3 mg DON/kg DM) as total mixed ration over 11 weeks, while another 14 cows (on average 33 days in milk) received a control diet.

Nutrient digestibility and prediction of metabolizable energy in total mixed rations for ruminants.

The aim of the present study was to determine equations that predict ME in total mixed rations (TMR) based on routine methods. The ME content of 30 TMR for dairy cows was determined based on digestible crude nutrients obtained with wether sheep. Concentrations in the TMR (in g/kg DM) varied between 118 and 234 for crude protein, 26 and 48 for crude lipid, 131 and 250 for crude fibre, 281 and 488 for NDF, and 173 and 304 for ADF.