Ruminal Organisms Research Articles

The effect of the rumen washing mechanism in sheep differs with concentration and size of abrasive particles

Measures of tooth wear have widespread use as proxies in palaeobiological reconstructions. In order to apply these proxies, an understanding of potential influence factors on wear is important. The processes during the digestion in the ruminant organism lead, possibly inadvertently, to a washing of material before it is regurgitated for rumination chewing. Therefore, ruminants might experience less tooth wear from external abrasives such as dust and grit, which can be washed off, compared to nonruminant herbivores. Details of the washing mechanism, including its efficiency in relation to abrasive size, have not been explored so far. Here, we describe the location and quantity of external abrasives in the gastrointestinal tract of sheep fed seven diets containing external silica abrasives varying in concentration (0, 4, and 8%) and size (4, 50, and 130 μm). As typical for ruminants, external abrasives accumulated mainly in the fourth stomach section, the abomasum. Compared to the diet, the dorsal rumen contents – from where material for regurgitation and rumination is recruited – were depleted of external abrasives for the 130 μm silicates, and for the 8% concentration of 50 μm silicates, but not for the 4 μm silicates or the 4% concentration of 50 μm silicates. These results suggest that the rumen washing mechanism is probably more protective against abrasion from grit and sand, and potentially less efficient against fine dust.

THE PERIOD OF THE CATTLE BUNOSTOM DEVELOPMENT OF THE IN THE AMUR REGION

The authors focus on the fight against the most common helminthic diseases of agricultural animals as they see it as an important part of the veterinary science. Bunostomosis is one of such diseases; it is a helminthiasis of ruminants caused by vipostomum trigonocephalum nematodes (in sheep and goats) and vipostomum phlebotomum (mainly in the cattle), which are parasitic in the small intestines. The disease is characterized by diarrhea, exhaustion and death of ruminants. The disease is widespread and causes great economic damage. The authors explored the prevalence of tuberculosis and age-related infection with tuberculosis by ovoscopy and levoscopy in the Amur region. They examined 2655 animals, including 1415 small ruminants and 1240 cattle from five districts of the Amur region. The researchers examined 4 calves and 4 lambs aged 4 inorder to study the period of bunostom development in the organism of animals, which were infected with percutaneously and orally. Brown larvae received from faeces of spontaneously infested animals is considered to be the material for infection. The development and survival of larvae in the environment were investigated in 2016-2017. The authors found out that in the Amur region larvae develop at the temperatures above 40С. The period of development at the temperature from 40С tо 9 0С was 23 days. When the temperature was increasing, the development period was reduced to 5-7 days. In October larvae stop their development. The underdeveloped eggs and larvae left die in winter. At the farms of the Amur region, the infection rate of cattle and sheep is 31.9 and 49.6%. The bunostome infection of the cattle aged 1-11 months is 59,8%; 1-2 years - 26,0; 3 years and more - 19,9; sheep aged 4-11 months infection rate is 52,9; 1 year - 60,9, 3 years and more - 38,7%. The authors observed bunostomes development during 89-102 days in the ruminant organism before the sexually mature stage in the conditions of the Amur region.

The effects of feeding monensin on rumen microbial communities and methanogenesis in bred heifers fed in a drylot

Drylot beef cow-calf systems are viable alternative management systems to traditional forage-based systems. In such confinement, adding ionophores such as monensin to the diets of beef cattle is common, and has been shown to improve feed efficiency and increase average daily gain. The addition of monensin is also commonly utilized as a strategy for methane mitigation, as this ionophore class antimicrobial acts to interfere with ion flux primarily within Gram-positive cells through its action as an ion carrier. It is widely accepted that suppression of these ruminal organisms results in the reduction of substrates for rumen methanogenic archaea, reducing methane production. However, several studies have indicated that cattle may adapt to monensin, and within weeks of feeding, may return to prior levels of methane production. Our hypothesis is that feeding monensin to bred beef heifers in confinement will temporarily decrease methane production from shifts in the methanogenic archaeal and bacterial communities. Sixteen fall-born bred heifers were randomly assigned to 2 treatment groups (n = 8 per treatment) and were fed a control diet or a diet containing monensin for 70 days using headgates. In vivo gas exchange of oxygen consumption, carbon dioxide and methane production were measured for 24-h periods throughout the trial using individual calorimeter head boxes. Rumen content sampling was conducted on day 0, 18 and 53 of the trial through oral lavage. Upon completion of sampling, DNA was isolated for ruminal bacteriome composition utilizing deep, next-generation sequencing of the V1-V3 hypervariable regions of the 16S bacterial rRNA gene. Level of methanogen 16S rRNA was quantified using qPCR. There was a significant reduction in phylum SR1 (P < 0.05). The abundance of several OTUs was reduced between treatment with monensin, including Anaerofustis (P < 0.0001), Shuttleworthia (P < 0.0001) and Order Bacteroidales (P = 0.003). No significant shifts in key ruminal methanogenic archaeal groups as a percentage of total methanogen 16S rRNA occurred (P > 0.05). Heifers fed monensin did not produce significantly less methane than the control (P > 0.05) on a liters per day basis, which was consistent throughout the study. These data suggest methane production is not reduced long-term when animals are fed monensin in confinement. Additionally, the data suggest that monensin supplementation does not suppress all classical Gram-positive populations, rather it influences finer shifts in bacterial species that may be key in ruminant function. Determining the stability of the ruminal microbiome over time in heifers fed monensin may provide further insights to long-term methane mitigation in cow-calf systems.

Effects of different non-protein amino acids on in vitro dry matter digestibility of lucerne chaff

Some plants not only contain various nutrients which support the growth of animals, but also contain anti-nutritional factors which have adverse effects on animals. NPAAs, such as ODAP and DABA, are among those compounds. In addition to the direct adverse effects on animals by NPAAs, studies also have shown that ODAP, a major non-protein amino acid in some forage legumes, inhibited the growth of some non-ruminal microorganisms. Experiments were conducted to determine the effects of ODAP and DABA on in vitro dry matter (DM) digestibility of lucerne chaff as means to test their effects on ruminal microorganisms. The results showed the in vitro DM digestibility of lucerne chaff at 24, 48 and 72 h was significantly reduced by 18.6, 11.0 and 8.6% when three levels of ODAP (40.67, 81.34 and 122 μg/ml, C18 reverse phase chromatography-fractionated extracts from L. sativus) were included in the medium. No inhibitory effect of diaminobutyric acid on in vitro DM digestibility of lucerne chaff was observed when pure DABA was used at a concentration of up to 300 μg/ml. The results indicated that although ODAP and DABA are similar in structure, they have different effects on ruminal organisms. Therefore, the use of DABA-containing plants as a feed supplement is not likely to cause any adverse effect on feed utilization, whereas the use of ODAP-containing plants may have some adverse effects on feed digestibility.

Sulfur supplementation of lupin grain diets fed to young sheep

Summary. We examined the effects of supplementation of lupins with limestone or gypsum on liveweight change and wool production of young Merino wethers [age 10 months; starting liveweight (mean s.e.m.) 34.8 0.33 kg]. Lupins with the added compounds were fed in amounts estimated to provide metabolisable energy at 0.8, 1.0, 1.5 and 2.0 times maintenance requirements. The remainder of the ration was cereal straw fed at 10% of the weight of lupins given. Lupins coated with limestone or gypsum had a dry matter digestibility of 880 g/kg, and contained (g/kg DM) nitrogen 56.1 v. 57.4, sulfur 2.3 v. 4.6 and calcium 7.9 v. 5.4 respectively. As the amount of the ration fed was increased, there were linear increases (P&lt;0.001) in liveweight gain (–9 to 226 g/day), clean wool growth rate (5.3–10.2 g/day), and fibre diameter of wool grown (18.0–21.6 m). There were no significant differences between lupins coated with limestone or gypsum in liveweight change (97 v. 105 g/day) or clean wool growth rate (7.6 v. 7.5 g/day). While the addition of sulfur to the diet reduced fibre diameter of wool grown (19.4 v. 20.0 m; P&lt;0.01), this is not consistent with the effects of increased sulfur amino acid supply which would be expected to increase fibre diameter. It is concluded that the supply of inorganic sulfur to ruminal organisms was not limiting production responses to lupins or that there were other more limiting nutrients.

Enzyme and microbial systems involved in starch processing

This article reviews, in brief, the important industrial uses of starch and starch processing in industry. The other aspects discussed include the main enzymes involved in starch degradation, commercially available amylolytic enzymes, thermostable enzymes from mesophilic and thermophilic microorganisms, microbial fermentation systems used in amylolytic enzyme biosynthesis, amylolytic yeasts in ethanol production from starch, and amylolytic ruminal organisms.

Introduction of Tn916 and pAM beta 1 into Streptococcus bovis JB1 by conjugation.

The transposon Tn916 and self-mobilizing plasmid pAM beta 1 were conjugated from Enterococcus faecalis to the ruminal bacterium Streptococcus bovis JB1. Transconjugants were identified by resistance to tetracycline (Tn916) or erythromycin (pAM beta 1) and by Southern hybridization analyses. Transfer frequencies were 7.0 x 10(-6) and 1.0 x 10(-6) per recipient cell for Tn916 and pAM beta 1, respectively. The transconjugants JB1/Tn916 and JB1/pAM beta 1 were used as donors for matings with E. faecalis, Bacillus subtilis, and the ruminal bacterium Butyrivibrio fibrisolvens. While pAM beta 1 was successfully transferred to all three organisms, Tn916 was transferred only into B. subtilis and B. fibrisolvens at very low frequencies. This is the first report of conjugal DNA transfers between two ruminal organisms.

Effects of alkaline hydrogen peroxide treatment on in vitro degradation of cellulosic substrates by mixed ruminal microorganisms and Bacteroides succinogenes S85.

The effects of sodium hydroxide (NaOH) and alkaline hydrogen peroxide (AHP) treatments on wheat straw (WS) and various cellulosic substrates were determined by measuring susceptibility to degradation by mixed ruminal organisms or Bacteroides succinogenes S85. In vitro incubations were used to measure differences in fermentation resulting from each successive step in the AHP treatment process. In vitro incubations through 48 or 108 h were conducted to measure these differences. The AHP treatment of WS increased (P less than 0.05) dry matter, neutral detergent fiber, and acid detergent fiber degradation over control WS when these substrates were incubated with mixed ruminal microorganisms or B. succinogenes S85. Fermentations containing AHP-treated WS had greater (P less than 0.05) microbial purine (RNA) and volatile fatty acid concentrations by 12 h compared with those containing untreated or NaOH-treated WS. Xylose in AHP-treated WS was utilized more extensively (P less than 0.05) by 12 h compared with the xylose of untreated or NaOH-treated WS. Treatment with AHP removed 23% of the alkali-labile phenolic compounds from WS. When substrates with high levels of crystalline cellulose (raw cotton fiber, Solka floc, and Sigmacell-50) were treated with NaOH or AHP and incubated for 108 h with B. succinogenes S85, extent of acid detergent fiber degradation of cotton fiber and Sigmacell-50 was similar to that of their respective controls. Sodium hydroxide and AHP treatments were effective in increasing acid detergent fiber degradation of the Solka floc which contained, on average, 3.3 and 4.8 percentage units more acid detergent lignin and hemicellulose, respectively, than cotton fiber and Sigmacell-50.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term feeding of acetyl urea to dairy cows

After an introductory survey of investigations dealing with the conversion of acetyl urea in the ruminant organism, a feeding trial using dairy cattle is described in which the effects of long-term acetyl urea feeding on the clinical picture and various performance parameters have been studied. Five Black-Pied cows of medium milk yield were fed a natural diet and received, over at least 14 months, a daily acetyl urea supplementation of 430 g (= 40 to 44% of the digestible crude protein). The clinical control, including the analysis of blood parameters, did not produce any deviation from normal. As to milk and butterfat yields, the experimental group reached results comparable to those of the control group. Over the entire experimental period the experimental group and the control averaged per cow and day of milking 11.1 and 11.3 kg FCM, respectively. The reproductive behaviour proved normal for all the cows under study. Postmortem findings of 4 cows revealed, among other things, chronic kidney alterations that cannot be safely exluded to be caused by the experiments. A stress over several months of two cows fed 850 g acetyl urea per day was not found to affect animal performance and health.

Rumen Digestion Studies: II. Studies in the Chemistry of Rumen Digestion

Studies of the chemical changes in the rumen suggest the following salient features regarding the fate of roughage in the ruminant digestive tract: During the first 6 hours after feeding the predominant phenomenon was the rapid digestion of proteins and carbohydrates. Decomposition of cellulose began during this period but was not extensive. The predominant phenomenon during the second 6 hours was the rapid disintegration of cellulose. Digestion of proteins and carbohydrates in this period paralleled the digestion of cellulose. Although small amounts of lignin may be attacked in the rumen, functionally the rumen is not a factor in lignin digestion. Rumen digestion was observed to come to a standstill within 12 hours after feeding. Prolonging the digestion periods to 24 hours did not increase rumen digestion coefficients. Lignin apparently protects plant fragments from further action by rumen microflora. Average rumen digestion coefficients for 8 trials at 12–14 hours after feeding were: dry matter 48.4, protein 59.6, nitrogen-free extract 65.2, crude fiber 27.2, cellulose 43.4, other carbohydrates 83.0 and lignin 3.1%. After plant fragments pass from the rumen variable amounts of lignin may be digested, thereby exposing varying amounts of cellulose and protein to further digestion. Fecal digestion was observed to be quite variable even though rumen digestion of the same lots of hay was very constant. The caecum plays only a supplementary role in the disintegration of roughage within the ruminant organism. An average of 11.6% of the cellulose and possibly 9.5% protein was observed to be digested in the caecum. The production of fatty acids in the rumen was demonstrated. Maximum increases, after the increase due to digestion was eliminated, were 54.9% on an alfalfa hay ration and 281.7% on a beet pulp ration. The rapid dissipation of fatty acids from the rumen together with the marked increases noted suggests that fatty acids may make a highly significant contribution to the nutrition of the ruminant either as an intermediate or end product of digestion.

The mechanism of cellulose digestion in the ruminant organism: IV. Further observations fromin vitrostudies of the behaviour of rumen bacteria and their bearing on the problem of the nutritive value of cellulose

Further studies of the behaviour of cellulose-splitting bacteria in artificial media have been made in an attempt to account for the manner in which cellulose is utilized for fat production in the ruminant. The behaviour of thermophilic bacteria, with an optimum temperature of fermentation in the neighbourhood of 65°C, has been compared with that of the micro-organisms capable of fermenting at 37°C. In both cases the cultures were obtained from the rumen contents of sheep.By the addition of toluene at the “head” stage of fermentation, it was possible to demonstrate, both at 37 and 65°C., the production of small amounts of glucose during subsequent incubation. Glucose is clearly a primary breakdown product in the bacterial fermentation of cellulose.An investigation has been made of the nature of the volatile fatty acids produced by bacterial decomposition of shredded filter paper. No consistent differences from this standpoint were noted between the reactions as carried out at 37 and 65°C., but the nature and proportions of the acids varied considerably from culture to culture. In some cases acetic acid was produced almost exclusively, whilst in others the fatty acids consisted of butyric and formic acids, with but traces of acetic acid. The findings in this regard apparently afford no clue to the manner in which cellulose is used for fat production, since propionic acid, the only recognized fat-former among the lower normal fatty acids, was not detected.

The Mechanism of Cellulose Digestion in the Ruminant Organism. III. The Action of Cellulose-Splitting Bacteria on the Fibre of Certain Typical Feeding Stuffs

The present communication deals with the results of quantitative investigations into the action of thermophilic cellulose-splitting bacteria on the fibre of a number of typical feeding stuffs. The primary object was to ascertain whether such measurements could form the basis of a quick in vitro method for estimating the digestibility of the fibrous constituent of feeding stuffs and, in addition, could lead to a method for following the process of lignification in herbage and in forage crops.

The mechanism of cellulose digestion in the ruminant organism: II. The transformation of cellulose into glucose by the agency of cellulose-splitting bacteria

An attempt was made in a recent communication (1) to propound a theory in connection with the digestion of cellulose in the ruminant organism which should be compatible with Kellner's findings as to the value of digestible fibre in the fattening of ruminants. It was shown that the generally accepted theory, that cellulose is digested by bacterial agency in the rumen with the production of organic acids and gaseous products, such as methane, hydrogen and carbon dioxide, failed entirely to account for the equal values of digestible fibre and starch for fat production in the ruminant animal. This could only be explained by assuming that glucose (or some other sugar capable of hydrolysis to glucose) was formed as a primary product of the action of bacteria on cellulose, and that, as with digestible carbohydrates originally present in the food, only about 8 per cent, of the sugar so formed underwent further bacterial breakdown into organic acids and gases, the remainder being available for absorption into the organism in the form of glucose. On this assumption, it would follow that every gram of fibre so digested would yield to the organism as much glucose as would a gram of starch, and in this way Kellner's practical finding would be capable of explanation.

The mechanism of cellulose digestion in the ruminant organism

During the carrying out of the series of researches which led to the formulation of the well-known expression for calculating the starch equivalent of a feeding stuff, Kellner(1) was led to investigate the value of crude fibre in the fattening ration of oxen. For this purpose he used material which had resulted from the boiling of rye straw with an alkaline solution under pressure, the object of this treatment being to free the cellulose of the straw from incrusting substances. This fibre-rich preparation was added to a basal ration which was slightly in excess of maintenance requirements. The result produced by the addition to the basal ration of the digestible matter derived from the fibre of the treated straw was found by Kellner to be equal to that produced by the addition of an equal weight of pure starch. The conclusion was therefore warranted that the digestion products of cellulose in the ruminant organism are equal, for purposes of fat formation in the body, to those derived from the digestion of starch. This finding is given practical expression in Kellner1s formula for calculating the starch value of a feeding stuff, an equal value being attached to digestible fibre and digestible carbohydrate.It is clear that any theory which is put forward to explain the breakdown of cellulose in the ruminant tract must be compatible with the experimentally demonstrated fact that the products of such digestion of a given weight of digestible fibre are equal in nutritive value to the products derived from the digestion of the same weight of starch.