Effect of replacement of antibiotics with thyme and celery seed mixture on the feed intake and digestion, ruminal fermentation, blood chemistry, and milk lactation of lactating Barki ewes.

The study investigated the effect of in-feed administration of dried thyme leaf and celery seed mixture (at 1 : 1 DM basis) compared with salinomycin ionophore on milk production and milk nutritive value of Barki ewes. Thirty ewes (37.5 ± 1.8 kg), divided into 3 treatment groups, were fed: (1) a complete control diet comprising concentrates and fodder maize (Zea mays L.) at 60 : 40 dry matter basis, (2) the control diet plus 20 g of thyme and celery mixture supplementation and (3) the control diet supplemented with 1 g of salinomycin per ewe daily for 90 days. Inclusion of thyme-celery treatment increased (P < 0.05) weight gain, average daily gain, milk yield, milk component yields, and feed efficiency, without affecting milk composition. In addition, the thyme-celery treatment enhanced (P < 0.05) nutrient intake and digestibility, total ruminal volatile fatty acids, branched chain fatty acids, and acetate proportions and decreased ammonia-N concentration. Thyme-celery treatment increased (P < 0.05) serum glucose, thyroxine, and glutamate-pyruvate transaminase concentrations. It is concluded that the thyme and celery mixture (1 : 1 DM basis) at 20 g per lactating ewe daily can replace the salinomycin ionophore. Enhanced feed utilization and lactational performance as well as milk nutritive value for human consumption were observed with the natural additive mixture supplementation.

Effects of dietary linseed oil and propionate precursors on ruminal microbial community, composition, and diversity in Yanbian yellow cattle.

The rumen microbial ecosystem is a complex system where rumen fermentation processes involve interactions among microorganisms. There are important relationships between diet and the ruminal bacterial composition. Thus, we investigated the ruminal fermentation characteristics and compared ruminal bacterial communities using tag amplicon pyrosequencing analysis in Yanbian yellow steers, which were fed linseed oil (LO) and propionate precursors. We used eight ruminally cannulated Yanbian yellow steers (510 ± 5.8 kg) in a replicated 4 × 4 Latin square design with four dietary treatments. Steers were fed a basal diet that comprised 80% concentrate and 20% rice straw (DM basis, CON). The CON diet was supplemented with LO at 4%. The LO diet was also supplemented with 2% dl-malate or 2% fumarate as ruminal precursors of propionate. Dietary supplementation with LO and propionate precursors increased ruminal pH, total volatile fatty acid concentrations, and the molar proportion of propionate. The most abundant bacterial operational taxonomic units in the rumen were related to dietary treatments. Bacteroidetes dominated the ruminal bacterial community and the genus Prevotella was highly represented when steers were fed LO plus propionate precursors. However, with the CON and LO diet plus malate or fumarate, Firmicutes was the most abundant phylum and the genus Ruminococcus was predominant. In summary, supplementing the diets of ruminants with a moderate level of LO plus propionate precursors modified the ruminal fermentation pattern. The most positive responses to LO and propionate precursors supplementation were in the phyla Bacteriodetes and Firmicutes, and in the genus Ruminococcus and Prevotella. Thus, diets containing LO plus malate or fumarate have significant effects on the composition of the rumen microbial community.

Sulfated gastrin stimulates ghrelin and growth hormone release but inhibits insulin secretion in cattle.

This study was designed to determine the effects of gastrin on the circulating levels of ghrelin, growth hormone (GH), insulin, glucagon and glucose in ruminants. Two experiments were done in eight Holstein steers. Animals were randomly assigned to receive intravenous bolus injections: (1) 0.1% bovine serum albumin in saline as vehicle, 0.8, 4.0 and 20.0 µg/kg body weight (BW) of bovine sulfated gastrin-34; (2) vehicle, 0.53 µg/kg BW of bovine sulfated gastrin-17 alone or combined with 20.0 µg/kg BW of [D-Lys(3)]-GHRP-6, the selective antagonist of GHS-R1a. Blood samples were collected from -10 to 150 min relative to injection time. Concentrations of acyl and total ghrelin in response to gastrin-34 injection were significantly increased in a dose-dependent manner. Concentrations of GH were also markedly elevated by gastrin-34 injection; however, the effect of 20.0 µg/kg was weaker than that of 4.0 µg/kg. The three doses of gastrin-34 equally decreased insulin levels within 15 min and maintained the level until the time of last sampling. Gastrin-34 had no effect (P > 0.05) on the levels of glucagon and glucose. Levels of acyl ghrelin increased after administration of gastrin-17 alone or combined with [D-Lys(3)]-GHRP-6; however, [D-Lys(3)]-GHRP-6 did not block the elevation of GH by gastrin-17. The present results indicate that sulfated gastrin stimulates both ghrelin and GH release, but the GHS-R1a may not contribute to the release of GH by gastrin. Moreover, sulfated gastrin seems to indirectly maintain the homeostasis of blood glucose through the down-regulation of insulin in ruminants.

Poisoning of goats by the pods of Luetzelburgia auriculata.

Farmers report that the pods of Luetzelburgia auriculata cause digestive signs and death when ingested by goats. To demonstrate the toxicity of the pods of this plant 12 goats were divided into 4 groups of 3 goats each. Groups 1, 2, 3 and 4 were administered 2.5, 1, 0.5 and nil g of pods per kg body weight, respectively. Goats in Groups 1 and 2 developed decreased ruminal movements followed by anorexia, depression and soft feces or diarrhea. Goats in Group 1 died 59-106 h after first showing clinical signs. Goats in Group 2 also regurgitated rumen content, but all recovered 65-90 h after first showing clinical signs. The only clinical sign shown by goats in Group 3 was regurgitation of rumen content, and all goats recovered 5.5-24 h after first regurgitating. All goats in Group 4 remained normal. The goats that died were necropsied and found to have a reddish mucosa of the forestomachs that detached easily from the underlying tissues. Other lesions included diffuse reddening of the mucosa of the abomasum and intestine. Histological examination of the mucosa of the forestomachs showed diffuse ballooning degeneration of keratinocytes, with necrosis and vesicle and pustule formation in the epithelium. In some areas there was sloughing of the ruminal epithelium. These results demonstrate that the pods of L. auriculata are toxic and responsible for field outbreaks of poisoning in goats in the state of Piaui.

Dose response to cinnamaldehyde supplementation in growing beef heifers: ruminal and intestinal digestion.

The objective of this study was to determine if cinnamaldehyde (CIN) could be used to improve feed intake, digestion, and immune status in growing beef heifers fed high-concentrate diets. The experiment was designed as a 4 x 4 Latin square using 4 ruminally and duodenally cannulated beef heifers with 4 treatments: control (no CIN added), 400 mg/d of CIN (low), 800 mg/d of CIN (medium), and 1,600 mg/d of CIN (high), and four 21-d periods. Feed intake, rumen pH and fermentation characteristics, site and extent of digestion, microbial N synthesis, blood metabolites, and acute phase protein response were measured. The diets consisted of 15% barley silage, 80% dry-rolled barley grain, and 5% supplement (DM basis). Intakes (kg/d) of DM, OM, NDF, starch, and N were quadratically (P = 0.04) changed with increasing CIN supplementation. The amount of OM fermented in the rumen quadratically (P = 0.02) decreased with increasing CIN. Digestibilities (% of intake) of OM, NDF, and N in the rumen were not affected by supplementing with low and medium CIN, but they were reduced by 8% (P = 0.10), 31% (P = 0.05), and 17% (P = 0.05), respectively, with high CIN. Similarly, digestibilities of OM and NDF in the total tract also tended to be reduced by 7% (P = 0.10) and 20% (P = 0.10), respectively, with high CIN because supplementation of CIN had minimal effects on intestinal digestibility. Flows (g/d) of microbial N and other nutrients to the duodenum were not affected by CIN supplementation, even though the amount of ruminal fermented OM varied with level of CIN supplementation. Rumen pH, total VFA concentration, and molar proportions of individual VFA were not affected by CIN. Although concentrations of NEFA (P = 0.06) and triglyceride (P = 0.01) were quadratically changed with increasing CIN supplementation, blood concentrations of glucose and urea N, white blood cell counts, serum amyloid A, and lipopolysaccharide in plasma were not affected by CIN. Plasma haptoglobin numerically (P = 0.11) decreased with the medium dose of CIN fed compared with control. The results indicate that supplementation of a high-concentrate diet with a low dose of CIN resulted in small increases in nutrient availability in the rumen due to increased feed intake and greater ruminal digestion of OM. However, feed intake and ruminal digestion of feeds were adversely affected when a high dose of CIN was used.

Central and peripheral serotonergic influences on viscerovisceral inhibitory reflex during duodenal distension in sheep.

The effects of duodenal distension on forestomach and abomasal motility were investigated in conscious sheep chronically fitted with intraparietal electrodes, a duodenal cannula, and an intracerebroventricular cannula. Duodenal distensions with a balloon inflated with 40 ml (DD40) of water reduced the frequency of forestomach and abomasal contractions by 45 and 32%, respectively, while distension with 80 ml (DD80) induced a total inhibition. Methysergide, a mixed 5HT1-5HT2 antagonist administered intravenously (200 micrograms/kg) or intracerebroventricularly (20 micrograms/kg) suppressed the DD40-induced inhibition and reduced that induced by DD80. Spiroxatrine, a selective 5HT1A antagonist, intravenously (100 micrograms/kg) or intracerebroventricularly (10 micrograms/kg), suppressed the DD40 and DD80-induced inhibition, which was also attenuated by the 5HT2 antagonist ritanserin given intravenously (200 micrograms/kg) or intracerebroventricularly (20 micrograms/kg). Granisetron, a 5HT3 antagonist, injected intravenously (150 micrograms/kg), abolished the effects of DD40 and DD80 while it had no antagonistic action on DD40 and DD80 when given intracerebroventricularly (15 micrograms/kg). It is concluded that in sheep, duodenal distension inhibits forestomach and abomasal motility through 5HT1A and 5HT2 receptors at the level of the central nervous system and 5HT3 receptors located peripherally.

[The effect of flavomycin on digestion in fattening bulls]. / Einfluss von Flavomycin auf die Verdauung bei Mastbullen.

Three friesian bulls (Genotype 31) were fitted with re-entrant cannulas at the duodenum to investigate the influence of a flavomycin supplement of the digestion in the forestomachs and the other parts of the digestive tract. The supplement of flavomycin increased the total digestibility of the organic matter. The digestibility of starch and sugar was between 97% and 98%. The balance of the nutrients in the digestive tract shows, that by flavomycin supplementation the degradation of organic matter and crude protein in the fore stomach was decreased and the amount of the organic matter and crude protein in the gut was increased. The balance of the amino acids in the gut showed that after flavomycin ca. 30 g more amino acids were found in the gut. The synthesis of bacterial protein in the forestomachs was, after flavomycin application, slightly reduced as was the degradation rate of the feed protein.

Effect of flunixin meglumine and cimetidine hydrochloride on the pH in the third compartment of the stomach of llamas.

A Tigon fistula was surgically implanted into the third compartment of the stomach of 5 llamas to allow measurement of gastric pH. The llamas were allotted into 2 groups and given flunixin meglumine or cimetidine hydrochloride for 3 days. After 4 days without treatment, the drugs given to each group were reversed. Measurements of gastric pH were taken every 30 minutes for 6 hours, using an automated pH meter. The pH measurements after drug administration were compared with measurements obtained during a pretreatment control period. Gastric pH during pretreatment control periods had a mean of 1.43 +/- 0.063 (mean +/- SE). The use of flunixin did not significantly decrease gastric pH, compared with pretreatment controls. Gastric pH was significantly higher within the first 30 minutes after administering cimetidine, compared with pretreatment controls, but this difference disappeared at all later times.

Opioid inhibitory control of the ruminant stomach motility: functional importance of the hypothalamus.

In conscious sheep, Leu-enkephalin (10 and 20 micrograms.kg-1) administered into the third cerebral ventricle caused a psychosedative action and a significant inhibition of the frequency of rumen contractions. The amplitude of the first rumen contractions, following immediately after the end of the Leu-enkephalin's infusion (at a dose of 20 micrograms) and the average amplitude of primary rumen contractions were also significantly inhibited. The hypothalamic isolation prevented both the inhibitory effect of Leu-enkephalin on the rumen motility and the drug induced psychosedative action. In contrast, Leu-enkephalin (20 micrograms.kg-1), significantly enhanced phasic contractions of the rumen after hypothalamic isolation. However the hypothalamic isolation did not prevent Leu-enkephalin induced inhibition of the mean amplitude of rumen contractions, but this inhibition was not significant (NS). The character of the histopathological changes induced by the isolation of the hypothalamus showed descending degenerative changes of the neuronal pathways connecting the hypothalamus to the pons and lower to the medulla. These results do suggest that the isolation of the hypothalamus causes the degeneration of the descending inhibitory opioid pathways connecting the hypothalamus to the gastric centers of the medulla and point act out the functional importance of descending tonic opioid inhibitory control of ruminant forestomach motility.

Oral administration of calcium chloride-containing products: testing for deleterious side-effects.

Two products that contain CaCl2 and that are intended for oral administration were tested for safety aspects. One product contained CaCl2 as a gel, the other contained CaCl2 in an oil emulsion. Oral administration of the CaCl2-containing products caused minor to severe damage to the mucosa of the forestomach and abomasum. The gel solution especially proved to be highly caustic, while the oil emulsion appeared to be relatively safe.

The evocation of rumination in sheep by the close-arterial injection of catecholamines, cholinergic drugs, autacoids and gastrointestinal hormones into the forestomach.

The effect of alpha-2 adrenoreceptor agonists, cholinergic drugs, autacoids and some gastrointestinal hormones upon the evocation of rumination in sheep when injected by close-arterial injection into the forestomach was examined. Apart from adrenaline, noradrenaline, dopamine and xylazine only one alpha-2 agonist (BHT933) evoked rumination effectively. Acetylcholine, neostigmine, the gastrointestinal hormones and the autacoids examined did not evoke rumination consistently. Tyramine did not usually evoke rumination and guanethidine injected before adrenaline did not prevent the latter from evoking rumination. The evocation of rumination by catecholamines does not appear to involve sympathetic, cholinergic or non-sympathetic non-cholinergic neurones in the enteric nervous system to activate the nervous sensory receptors involved in the reflex evocation of rumination.

Pathophysiological effects of endotoxins in ruminants. 1. Changes in body temperature and reticulo-rumen motility, and the effect of repeated administration.

Data from the literature on the clinical effects of bacterial endotoxins in ruminants are reviewed. Special attention is paid to the effects on body temperature and reticulo-rumen motility. Furthermore, the effects of repeated intravenous injection of endotoxin are summarised. Pathophysiological disturbances after intramammary infusion of endotoxins proved to be identical to those found after intravenous injection of non-lethal doses. Strikingly, however, no marked inhibitory effect on rumen motility nor abortion was observed after intramammary infusion of endotoxins. Moreover, in cows that were made tolerant to endotoxin by daily intravenous injections, intramammary infusion of one-fifth of this daily dose produced a maximum effect on body temperature and plasma Zn concentrations. This suggests that inflammatory endogenous mediators were released in the udder and then absorbed into the blood circulation, rather than the absorption of endotoxin.

Alleviation of excessive gas accumulation in the ruminant stomach by ritanserin.

The relationships between forestomach motility and eructation rate were studied in sheep and cattle. Three ewes and 2 heifers were implanted with strain gauges on the reticulo-rumen and fitted with a cannula in the dorsal sac of the rumen. Studies were performed in sheep after induction of hypocalcemia by Na2EDTA infusion and cattle were studied after ruminal distension. Experiments were performed by measuring the rate and volume of eructated ruminal gases, using a technique by which the trachea is transected. The frequency of reticulo-ruminal contractions decreased 40% within 30 minutes of Na2EDTA infusion to the sheep. The volume of eructated gas (for 30-minute periods) decreased from 10.7 L to 5.5 L at the end of the 60-minute infusion period. Pretreatment with ritanserin (0.1 mg/kg, subcutaneously) not only prevented bloating during the ruminal stasis induced by hypocalcemia, but also significantly increased the eructated volume of gas. In cattle, ritanserin given at the same dose level (0.1 mg/kg, subcutaneously) significantly increased the volume of eructated gas after ruminal distension. This study supports the hypothesis that the caudal esophageal sphincter has a role in the rate of ruminal gas eructation and indicates that its relaxation may be due to a 5-hydroxytryptamine antagonist.

Electro-mechanical coupling in the complex stomach smooth muscles.

In the majority of experiments the ruminal preparations did not exhibit spontaneous electrical and contractile activity but showed a Ca-dependent spike-free myogenic tone. Ba2+ or Sr2+ evoked spike activity and phasic contractions and increased the muscle tonic tension. Tetraethylammonium (TEA) exerted no effect on the ruminal preparations but potentiated the effect of Ba2+. Acetylcholine (ACh) induced dose-dependent spike-free tonic contractions which were verapamil resistant and were suppressed by sodium nitroprusside. When applied to BaCl2- or TEA-pretreated preparations ACh caused spike activity and phasic contractions. The antral abomasum exhibited a spontaneous electrical activity--slow waves on which spike potentials were superimposed. ACh and TEA induced membrane depolarization and increased the spike activity and the phasic contraction amplitude.

Proglumide: selective antagonism of the rumination but not gastric motor effects induced by pentagastrin in sheep.

The effect of intravenous (IV) vs intracerebroventricular (ICV) administrations of pentagastrin on gastro-intestinal motility and rumination were investigated by electromyography in sheep; these effects were compared to those obtained after a previous IV or ICV injection of proglumide. When ICV administered at a dose of 20 ng X kg-1, pentagastrin did not significantly affect the frequency of reticular and abomasal spiking activity but elicited a 13 to 37 min period of rumination after a delay of 23 +/- 7 min. In contrast, when IV infused at a rate of 20 ng X kg-1 X h-1 during 20 min, pentagastrin inhibited significantly the frequency of reticular and abomasal contractions for 30 to 40 min but did not induce rumination. Proglumide ICV administered (0.8 mg X kg-1) abolished the rumination induced by central injection of pentagastrin whereas a 10 times higher dose administered systemically (8 mg X kg-1 IV) did not block these effects. Both of ICV and IV administrations of proglumide at respectively 0.8 and 8 mg X kg-1 were unable to antagonize the inhibitory effects of pentagastrin on reticulum and abomasum motility. It was concluded that (i) pentagastrin acts centrally to induce rumination and that (ii) proglumide selectively blocks these effects but not the pentagastrin induced gastro-intestinal hypomotility.

[Role of sodium ions in gastric absorption of calcium in ruminants (author's transl)]. / Röle des ions sodium dans l'absorption gastrique du calcium chez les ruminants.

The influence of sodium ions on gastric absorption of calcium in ruminants was studied with regard to the accompanying anions. Bags made of the surviving mucous membrane of different compartments of bovine stomach were used for this purpose. The epithelial side of the mucous membrane always faced towards the inside of the bags. The bags were filled with a combined solution of a calcium salt (chloride, carbonate or phosphate) and sodium chloride. The concentration of calcium was always the same (10 mg/100 ml) while the concentration of sodium varied, amounting to 102.5, 205 and 1025 mg/100 ml. The external face of the bags was placed in Tyrode's solution. In general, calcium absorption became more and more intensive when the concentration of sodium in the contents increased, regardless of the solubility and dissociability of the calcium salt used. When chloride was the accompanying anion, this effect appeared in the rumen and omasum at a physiological concentration of sodium (205 mg/100 ml), and in the abomasum it appeared only at a concentration which widely exceeded the limits of the normal (1025 mg/100 ml). When either carbonate or phosphate were used for this purpose, this effect generally appeared at the highest concentration of sodium, and only in the abomasum, with phosphate as the accompanying anion, at a concentration of 205 mg/100 ml. On the basis of these results, it was concluded that the presence of sodium ions in the contents stimulates gastric absorption of calcium, but the concentration of sodium at which this stimulative effect appears depends, at least to a certain degree, on the accompanying anion of calcium. The possibility of improving the absorption of calcium in the digestive tract of ruminants is discussed in view of the results obtained.

H1- and H2-receptors in the smooth muscle of the ruminant stomach.

1 The effects of histamine on the longitudinal and circular smooth muscle from the rumen and reticulum of the bovine stomach have been analyzed by the use of H1- and H2-receptor antagonists. 2 Histamine caused three different types of response of the smooth muscle preparations: a contraction, contraction followed by relaxation, and a relaxation. These responses were resistant to the effect of tetrodotoxin, atropine, combined treatment with alpha- and beta- adrenoceptor blocking agents, hexamethonium and also to guanethidine. 3 Mepyramine antagonized the contractile responses and metiamide antagonized the relaxation responses in a highly selective and competitive manner. 4 It is concluded that histamine-induced excitatory and inhibitory responses of the smooth muscles from the bovine forestomach are mediated by histamine H1- and H2-receptors, respectively.

Effects of Serotonin and Histamine on the contractile activity of smooth-muscle strips of sheep complex stomach.

The effect of histamine and serotonin is studied on strips of the two smooth-muscle layers from the different sections of the complex stomach. Histamine in concentration of 10(-9) to 10(-4) g/ml has no visible effect on preparations from the rumen and reticulum. In strips from the omasum as well as from the proximal and antral regions of the abomasum inhibitory effect is observed mainly with respect to the spontaneous phasic activity of the strips. Serotonin in concentrations of 10(-8) to 10(-4) g/ml has an excitatory effect in almost all preparations studied. Of the forestomach strips it is mostpronouced in rumen strips. The effect consists in an increase of the tone of the preparations. In the proximal region of the abomasum is effect also consists in a rise of the tone, while in strips from the antral region it causes a rise in the amplitude and frequency of the phasic contractions. Serotonin in the concentrations tested has an inhibitory effect only on omasum preparations.