The effect of salinomycin and lasalocid on laboratory cultures of Enterococcus faecium and Staphylococcus gallinarum strains.

The growth of Enterococcus faecium strains CCM 4231 and EF 26, and Staphylococcus gallinarum SG 31 was inhibited by salinomycin and lasalocid at concentrations of 25 and 50 mg/L. Staphylococcus gallinarum was more sensitive to the additives used than were enterococci. Maximum inhibition (90%) was measured after the growth with the SG 31 strain in the presence of both ionophores. Growth of organisms was more inhibited by salinomycin at 25 mg/L (67.5%) than at 50 mg/L (63%). The inhibitory effect in enterococcal strains reached after the addition of salinomycin and lasalocid (on average) 63 and 58%, respectively. The CCM 4231 strain was more inhibited by salinomycin as well as by lasalocid than was the EF 26 strain.

The effect of monensin on in vitro utilization of lactate in the rumen contents.

The effect of monensin on the in vitro utilization of lactate in the rumen contents of a steer, cow and two wethers was investigated. The rate of the utilization of lactate in monensin-treated cultures was on average only two thirds of that found in cultures without monensin. Monensin tended to increase acetate and to decrease butyrate in cultures with lactate. After 11-week adaptation of a wether to monensin the inhibitory effect of ionophore persisted, being, however, less pronounced and without influence on the molar percentages of VFA. Effects of monensin reported here seem to be caused by its inhibiting action against rumen lactilytic protozoa. There were no significant differences between monensin from Elanco and the Czechoslovak analogue.

[Effectiveness of the use of momensin for cattle fattening]. / Efektívnost pouzitia monenzínu vo výkrme hovädzieho dobytka.

Two groups of fattened bulls (125 bulls in each group) were investigated for the effect of monensin (125-175 mg per head/day) on live weight gains and for the effectiveness of monensin administration. After 160 days of fattening, the average daily weight gain was 713 g in the control group and 800 g in the monensin-treated group (an increase by 12.2%). After 11 months of fattening the daily weight gain was 702 g in the control group and 768 g in the monensin-treated group (an increase by 9.4%). Besides the control and experimental groups, monensin was administered to 1500 head of fattened cattle on the whole. Greater differences in the daily live weight gains (higher gains in the monensin-treated animals) were recorded mainly in the period when the feed ration contained high-quality bulk feeds. When the bulls were given feeds of lower quality (mainly late in winter), the differences in the average daily live weight gains decrease and the effect of monensin treatment is not so great. Throughout the fattening period, monensin had a favourable influence on the live weight gains and its use was economically advantageous.

[Use of the colonizing preparation Amylastin in the stimulation of rumen-type digestion in young ruminants]. / Pouzitie kolonizacného preparátu Amylastim v stimulácii bachorového typu trávenia mládat prezúvavcov.

In experiments with calves during the milk-nutrition period we tested the use of the colonisation preparation Amylastim, containing a bacterial strain of Streptococcus bovis AO 24/85, as a factor speeding up the development of the rumen microflora. We gave the preparation to the animals for a period of four weeks and studied its influence on the microflora adherent to the epithelium of the rumen wall. We ascertained a significant increase in the number of Streptococcus bovis germs (P less than 0.001) as well as of alpha-amylase activity (P less than 0.05). When giving the preparation Amylastim to calves in large-scale production conditions we ascertained a positive effect on the health condition, total losses being lower.

[The effect of monensin on rumen fermentation and weight gain in bulls fed a diet containing nontraditional feed]. / Vplyv monenzínu na bachorovú fermentáciu a prírastky hmotnosti býkov krmených diétou s podielom netradicných krmív.

Two groups of bullocks, each consisting of 125 animals, were subjected to a trial to study the effect of monensin (Rumensin premix) administered at doses from 125 to 175 mg per head/day on rumen fermentation and weight gains. For 135 days the animals were given a diet based on green juicy forage with a supplement of chopped straw and concentrate mixture; this mixture contained 20-30% of dried poultry droppings. In the experimental group with monensin, the concentration of total and protein nitrogen and the molar percentage of propionic acid significantly increased (23.7 and 28.5%, respectively, P less than 0.01) and the acetate: propionate ratio decreased four hours after feeding. Further, the energy yield of the production by volatile fatty acids (VFA) significantly increased in the rumen contents (76.89%, 78.64%, respectively, P less than 0.05). The levels of ammonia and non-protein nitrogen were not affected by the addition of monensin. The average daily live weight gains were 713 g in the control group and 800 g in the experimental group; this means that the gains of the experimental animals rose by 12.2%. Monensin had a positive influence on the proportions of the rumen-produced VFA in favour of propionic acid which, in turn, favourably influenced the energy balance of nutrient conversion and efficiency.

[Volatile fatty acids in the rumen of sheep fed a synthetic diet]. / Unikavé mastné kyseliny v bachore oviec krmených syntetickou diétou.

A trial was conducted with wethers to study the effect of the administration of a synthetic diet (composition: 30.125% starch, 30.125% sucrose, 25% cellulose, 5.25% urea, 8.125% mineral supplement, 1.25% maize oil and 0.125% cholinechloride) upon rumen fermentation. The adaptation to the synthetic diet lasted three months, the proportion of the synthetic diet increasing every week (by 10%) to the detriment of a traditional diet (composition: 0.5 kg meadow hay, 0.3 kg barley, 0.2 kg wheat bran, salt and straw ad libitum). In the 10th week the animals consumed 0.5 kg granular synthetic diet, 0.2 kg cellulose flakes and 0.01 kg polystyrene. After three weeks of the administration of the fully synthetic diet, the rumen fluid was sampled after morning feeding in intervals of 0, 1, 3, 5 and 7 hours. In the dynamics of fermentation, statistically significant differences were found only in isobutyric and isovaleric acid between the 0th and 1st and between the 5th and 7th hours (P less than 0.05--P less than 0.001). The data for all the time intervals were recalculated to average values. These were as follows: total volatile fatty acids 63.03 mmol/l, acetic acid 51.00 mol%, propionic acid 26.75 mol%, butyric acid 19.43 mol%, isobutyric acid 0.91 mol%, isovaleric 1.27 mol%, valeric acid 0.62 mol%, energy efficiency of VFA production 78.23%. The obtained data are confronted with literary data on synthetic diets which contained urea and various energy sources.

[The digestibility of unprocessed beech sawdust and its effect on the utilization of food by goats and rams]. / Strávitel'nost neupravených bukových pilín a ich vplyv na vyuzitie krmnej dávky u kôz a skopov.

Trials were performed with wethers and goats to study the effect of non-conditioned beech sawdust (NBS) on the digestibility of nutrients and energy in granular diets. Besides this, the effect of the administration of different diets on the digestibility of NBS was studied by the in vitro method after Méllenberger et al. (1970). NBS was used in diets for replacing hay at the rates of 0, 5, 10 and 20%. The inclusion of NBS in diets reduced nutrient and energy digestibility in diets given to wethers and goats; the larger the proportion of NBP, the higher the reduction. Goats showed higher values of nutrient and energy digestibility than wethers. The digestibility of NBS dry matter determined by the in-vitro method increased with higher NBS proportions in diets, as found from rumen fluid sampled from wethers and goats fed different diets.

[The effect of unprocessed beech sawdust on rumen fermentation in rams and goats]. / Vplyv neupravených bukových pilín na bachorovú fermentáciu skopov a kôz.

In a trial with wethers and goats the effect of non-conditioned beech sawdust (NBS) was studied as exerted on ammonia concentration, total VFA concentration, molar VFA percentage, energetic yield of VFA production, on the acetate : propionate ratio in rumen contents, and on urea concentration in blood. NBS was used in diets to replace bulk forage. The proportions of NBS in diets were 0, 5, 10, 15 and 20% (replacing hay). The results of the trials show that the administration of the different diets did not affect the concentration of ammonia and total VFA in the rumen content and the concentration of urea in blood. Goats showed an insignificant increase in the molar percentage of acetic acid, a decrease in the molar percentage of propionic acid and n-butyric acid when diets with gradated NBS proportions were administered, as well as an insignificant increase in the acetate : propionate ratio and a decrease in the energetic yield of VFA. In wethers the values of propionic and n-butyric acid were highly variable, which implied variation also in the acetate : propionate ration or in the energetic yield of VFA in the administration of different diets.

[The efficiency of hexose energy transformation into energy for volatile fatty acid production in the rumen of sheep fed diets containing sawdust]. / Výtaznost premeny energie hexóz na energiu tvorby unikavých mastných kyselín v bachore oviec krmených diétami s pilinami.

Based on the production and interrelationship of volatile fatty acids (VFA), the mathematical method according to Orskov et al. (1968) was used to determine the efficiency of VFA production, and/or conversion of the energy of hexoses contained in fodders into VFA energy in rumen. VFA were separated by gas chromatography. The energy yield of VFA production in the rumen contents of wethers was averaged from the samples taken one, three and five hours after feeding. Whethers were fed 11 experimental diets, in which a part of bulk fodder (5-20%) was replaced by treated or untreated sawdust, and/or a diet without sawdust. The energy yield varied from 73.12 to 76.51% and the maximum values were achieved with the diets containing no sawdust. Compared with the diets with sawdust addition, the differences are statistically significant (P less than 0.05). The addition of the treated beech sawdust to the same diet, in comparison with untreated sawdust resulted in a higher energy yield of VFA production, however, with no statistical significance. The ratio of acetate to propionate was in a direct but negative relationship to energy yield of VFA production (n = 44, r = -0.905, P less than 0.001). Therefore the diets rich in cellulose, which cause an increase in the molar percentage of acetic acid and a subsequent increase in the ratio of acetate to propionate, might be responsible for the energy losses in the form of methane and can result in the decrease in total energy balance (Orskov et al., 1968).

[Amino acid production in the isolated and perfused rumen wall of sheep]. / Produkcia aminokyselín izolovanou perfundovanou stenou bachora oviec.

The metabolism of amino acids and urea in an isolated perfused wall of sheep rumen was studied by the method of organ perfusion, using 3 kinds of perfusate. In experiments with semisynthetic perfusate containing urea (SPurea) the levels of lysine, valine, glutamic acid and alanine increased at a simultaneous decrease of levels of leucine, arginine, aspartic acid, threonine and methionine. In perfusions with the semisynthetic medium without urea (SP) the levels of lysine, valine, phenylalanine, isoleucine, glutamic acid, glycine and alanine increased, the level of threonine dropped. In perfusions with whole autologous blood (KP) the levels of valine, glutamic acid and alanine increased, the level of arginine decreased. The level of urea decreased sharply at using SPurea and KP, however, the equal cumulation of ammonia (200-400 mumol x 1(-1)) was found in all three types of perfusate after 2-hr perfusion. Moreover, in experiments with SP a low level of urea was found already after 5-min. of perfusion. The results of the experiments suggest that the rumen wall is capable of producing amino acids also without the contents of rumen, and that independently on the presence or absence of urea as a nitrogen source.