the effect of three levels of eucalyptus leaf (0, 28.65 or 57.37mg/200mg substrate), which were either oven, freeze or air dried on in vitro ruminal fermentation characteristics was assessed. the studied parameters were in vitro gas production (ivgp), methane production, ammonia (nh3-n) concentration, in vitro organic matter degradability, partitioning factor (pf) (ratio of substrate truly degr...

The electrical activity of the caecum was recorded during periods of two months in 5 ewes receiving different diets. For a similar amount of dry matter ingested, the frequency of caecal contractions was diminished on concentrates with urea versus hay ad libitum but not on concentrates without urea. The frequency also decreased when the level of food intake on hay diet or on concentrates without...

Oxalic acid (OA) is a secondary compound occurring in a wide range of plants consumed by ruminants, especially in saline lands or in arid and semi-arid regions. However, its impact on the rumen microbial community and its changes over time, as well as the potential consequences on ruminal function remains unknown. To examine this impact, five ewes fitted with a ruminal cannula and fed low quali...

Alfalfa hay was steam heated for an average of 47 min at 100 to 110°C; net ruminal protein escape (total escape minus ADIN x 6.25), estimated in vitro, was 50% versus 29% for control hay. Heating increased ADIN content from 4.6 to 15.3% of total N and increased NDF from 43 to 53% of DM. In trial 1, 14 cows averaging 81 DIM and 30 kg/d of milk were fed, in a switchback design, diets containing 1...

Microbial protein synthesis of steers (liveweight 286±9 kg) was compared with diets of ad libitum winter grass and fodder beet with 1 kg DM of lucerne silage. The experimental design was a four-by-two treatment comparison (experiment 1 and 2), using 11 day individual pen trials with total faecal and urinary collection. The trials assessed in vivo digestibility of diets, and diurnal variations i...

The utilization of nitrogen contained in soybean meal, casein, zein, and urea was studied in 12 mature wethers. Net microbial synthesis rates during the 6-hour period after feeding corresponded to ruminal ammonia concentrations, suggesting that the ruminal ammonia level in these experiments was a limiting factor in microbiol protein synthesis. Maximum conversion of dietary nitrogen to microbial...

An experiment was conducted to assess the impact of increasing levels of supplemental soybean meal (SBM; 45.7% CP) in cattle consuming tropical grass hay (Panicum maximum cultivar Gatton; 7.0% CP and 81.8% NDF) and drinking low salt water (LS) or high salt water (HS). Six ruminally fistulated beef steers (BW = 375 ± 43 kg) were used in a 6-treatment, 4-period crossover experiment. Treatments we...

The objective of this study was to determine the effects substituting barley grain with short-season, high-moisture shelled corn, and silage snaplage on ruminal fermentation site extent digestion in beef cattle fed finishing diets. Six ruminally duodenally cannulated heifers (420 ± 16.4 kg body weight) were a diet (BG), where half replaced corn (HC), or portion (SN) replicated 3 × Latin square ...

The effects of increasing concentrations of oregano (Origanum vulgare L.) and rosemary (Rosmarinus officinalis L.) essentials oil (EO) on ruminal gas emissions were tested in vitro using 50 mL serum bottles. Each bottle contained a 200 mg substrate (alfalfa hay and corn meal 1:1) and a 20 mL solution composed of a buffered medium and rumen fluid (1:2). The percentage of ruminal fermentation pro...

Eight lactating cows were fed 4 diets in which dietary crude protein (CP) was increased steps of approximately 2 percentage units from 11 to 17% DM by replacing high-moisture corn with soybean meal supplemented rumen-protected Met maintain a Lys:Met ratio 3:1 metabolizable protein. Trial design replicated × Latin square; experimental periods lasted 28 d, data and sample collection being perform...