Abomasal Cannulas Research Articles

Pharmacokinetic and pharmacodynamic properties of pantoprazole in calves.

Development of abomasal ulceration is a large concern, especially within calves; however, there is a paucity of research into the use of gastro protectants in ruminant species. Proton pump inhibitors, such as pantoprazole, are widely used in humans and companion animals. Their efficacy in ruminant species is undetermined. The objectives of this study were to 1) estimate the plasma pharmacokinetic parameters for pantoprazole in neonatal calves after three days of intravenous (IV) or subcutaneous (SC) administration, and 2) measure the effect pantoprazole had on abomasal pH over the treatment period. Pantoprazole was administered to 6 Holstein-Angus cross bull calves at a dose of 1 mg/kg (IV) or 2 mg/kg (SC), once a day (every 24 h) for three days. Plasma samples were collected over a 72 h period and analyzed via HPLC-UV for determining pantoprazole concentrations. Pharmacokinetic parameters were derived via non-compartmental analysis. Abomasal (n= 8) samples were collected via abomasal cannulas over a 12 h period, per calf per day. Abomasal pH was determined via a bench top pH analyzer. Following Day 1 of IV administration, plasma clearance, elimination half-life, and volume of distribution of pantoprazole were estimated at 199.9 mL/kg/h, 1.44 h, and 0.51 L/kg, respectively. On Day 3 of IV administration, the reported values were 192.9 mL/kg/h, 2.52 h, and 1.80 L/kg mL, respectively. Elimination half-life and volume of distribution (V/F) of pantoprazole following SC administration were estimated at 1.81 h and 0.55 L/kg, respectively, on Day 1; and 2.99 h and 2.82 L/kg, respectively, on Day 3. The reported values for IV administration were similar to those previously reported in calves. SC administration appears to be well absorbed and tolerated. The sulfone metabolite was detectable for 36 h after the last administration for both routes. Abomasal pH was significantly higher than the pre-pantoprazole pH 4, 6, and 8 h after administration in both the IV and SC groups. Further studies of pantoprazole as a treatment/preventative for abomasal ulcers are warranted.

Abomasal ulcers: Do ranitidine or omeprazole prevent phenylbutazone-induced lesions in sheep?

Treatment and prevention of gastric ulcers are well known in monogastric animals; however, there are uncertainties about the preventive effects of acid-reducer drugs, their dosages and the best route of administration to ruminants. The object of this research was to test the preventive actions of ranitidine and omeprazole on abomasal ulcer development in sheep treated with a high dosage of non-steroidal anti-inflammatory drug. Eight healthy adult sheep with abomasal cannula were distributed in two contemporary and balanced 4 × 4 Latin squares (eight animals per group). For seven days, animals in the control group received high doses of phenylbutazone (4.4 mg/kg, every 12 h) while the treated groups received the same high doses of phenylbutazone plus an acid-reducer drug, namely 2 mg/kg of intravenous ranitidine every 12 h; 0.4 mg/kg of intravenous omeprazole; 4 mg/kg of oral paste omeprazole, both once a day. Intravenous omeprazole caused phlebitis, increasing serum fibrinogen content, and 75 % of the treated animals were diagnosed with type 1a ulcers in abomasal mucosa. Oral omeprazole showed no adverse effects, but was not effective in preventing type 1a ulcer in 50 % of animals, which was the same amount as diagnosed in control group. Despite of a minor heart rate increase, ranitidine treated animals showed only 37.5 % of abomasal injuries. Based on clinical findings, intravenous ranitidine is apparently better than omeprazole in prevention of abomasal ulcers, but another kind of experimental design comparing group by group is required and strongly recommended to ensure the beneficial effect of ranitidine.

Investigation on daily or every three days supplementation with protein or protein and starch of cattle fed tropical forage

Effects of daily or every three days supplementation with protein or protein and starch on intake, digestion, rumen dynamics, urinary excretion characteristics, nitrogen (N) balance and, liver function of cattle fed high-quality tropical forage were evaluated. Five Nellore heifers (299 ± 7.5 kg of body weight) fitted with ruminal and abomasal cannulas were used in a 5 × 5 Latin square design. Treatments included: control; 200 g of crude protein (CP) daily; 200 g of CP and 400 g of starch daily; 600 g of CP every three days; 600 g of CP and 1,200 g of starch every three days. Supplements enhanced (P < 0.02) CP and digested organic matter intake. Among supplemented animals, every three days (infrequent) supplementation decreased (P < 0.05) forage intake. Supplements enhanced (P < 0.01) total organic matter and CP digestibility. Ruminal N balance was also enhanced (P < 0.01) by supplements, changing from negative in control to positive in supplemented animals. On average, supplements enhanced (P < 0.01) rumen ammonia nitrogen (RAN) compared to the control. However, an interaction (P < 0.01) between treatments and days pointed out that RAN levels were constant over days for control and frequently supplemented animals, but for infrequent supplemented animals it was greater on supplementation day and then decreased in the two following days. Supplements improved (P < 0.01) N balance, but without (P ≥ 0.43) differences among them. On average, supplemented animals presented greater (P < 0.01) urinary-N excretion (UNE) than control. Supplements, on average, also enhanced (P < 0.01) serum urea-N (SUN). Among supplemented animals, addition of starch to supplements reduced (P < 0.04) UNE, but it did not result in greater N retention. There was (P < 0.01) an interaction between days and treatments for SUN and the urinary excretion characteristics. Non-supplemented and daily supplemented animals presented constant values for these variables along the three-day-supplementation cycle. However, in animals supplemented every three days changes in SUN levels resulted in an untypical decoupling between SUN and RAN throughout the supplementation cycle. While RAN peaked on supplementation day, SUN peaked a day latter, which seem to be supported by a greater urea-N salvage in kidneys on day after supplementation. The changes in SUN and urinary excretion pointed out that the day after supplementation seem to be important for N salvage in ruminants infrequently supplemented. In summary, supplemented animals have greater N balance. Starch addition to protein supplements does not enhance N balance.

Ruminal biohydrogenation and abomasal flow of fatty acids in lactating cows fed diets supplemented with soybean oil, whole soybeans, or calcium salts of fatty acids

Ruminants have a unique metabolism and digestion of unsaturated fatty acids (UFA). Unlike monogastric animals, the fatty acid (FA) profile ingested by ruminants is not the same as that reaching the small intestine. The objective of this study was to evaluate whole raw soybeans (WS) in diets as a replacer for calcium salts of fatty acids (CSFA) in terms of UFA profile in the abomasal digesta of early- to mid-lactation cows. Eight Holstein cows (80 ± 20 d in milk, 22.9 ± 0.69 kg/d of milk yield, and 580 ± 20 kg of body weight; mean ± standard deviation) with ruminal and abomasal cannulas were used in a 4 × 4 Latin square experiment with 22-d periods. The experiment evaluated different fat sources rich in linoleic acid on ruminal kinetics, ruminal fermentation, FA abomasal flow, and milk FA profile of cows assigned to treatment sequences containing a control (CON), with no fat source; soybean oil, added at 2.68% of diet dry matter (DM); WS, addition of WS at 14.3% of diet DM; and CSFA, addition of CSFA at 2.68% of diet DM. Dietary fat supplementation had no effect on nutrient intake and digestibility, with the exception of ether extract. Cows fed fat sources tended to have lower milk fat concentration than those fed CON. In general, diets containing fat sources tended to decrease ruminal neutral detergent fiber digestibility in relation to CON. Cows fed WS had lower ruminal digestibility of DM and higher abomasal flow of DM in comparison to cows fed CSFA. As expected, diets containing fat supplements increased FA abomasal flow of C18:0 and total FA. Cows fed WS tended to present a higher concentration of UFA in milk when compared with those fed CSFA. This study suggests that under some circumstances, abomasal flow of UFA in early lactation cows can be increased by supplementing their diet with fat supplements rich in linoleic acid, regardless of rumen protection, with small effects on ruminal DM digestibility.

Protein dietary efficiency and methane emission in cattle fed soybean meal treated with tannins

Adding tannins to the dietary protein source will cause complexation between the tannin and protein, which may increase dietary ruminal undegraded protein. Thus, this study aimed to evaluate the effects of replacing soybean meal (SM) with soybean meal treated with tannin (SMT) on the intake, partial and total nutrient digestibility, and protein dietary efficiency of young cattle fed a high-concentrate diet. Five Nellore bulls with bodyweights of 290 ± 11.2 kg were fitted with ruminal and abomasal cannulas and were used in the study. The experimental diets included 7.5% SM, with a proportion of that SM (0%, 33%, 66% or 100%) replaced with SMT. Another treatment (SMT+urea) with only 2.5% SM treated with tannins was tested. The intake of ether extract and the intake of neutral detergent fibre ash and protein were the only parameters related to feed intake that were affected by the replacement of SM with SMT. Ruminal and intestinal digestibility each showed a linear effect on crude protein, which decreased with ruminal digestibility and increased with intestinal digestibility. The intake of ruminal undegraded protein and metabolisable protein showed a positive linear correlation with the amount of SMT in the diet. SMT substitution showed no effect on methane emission. The replacement of traditional SM with SM treated with 2.5% tannins (85% condensed tannins and 15% hydrolysable tannins) for cattle that were fed high-concentrate diets showed increased amounts of metabolisable protein and decreased nitrogen loss per unit of crude protein, without changing the methane emission.

Abomasal dysfunction and cellular and mucin changes during infection of sheep with larval or adult Teladorsagia circumcincta.

This is the first integrated study of the effects on gastric secretion, inflammation and fundic mucins after infection with L3 T. circumcincta and in the very early period following transplantation of adult worms. At 3 months-of-age, 20 Coopworth lambs were infected intraruminally with 35,000 L3; infected animals were killed on Days 5, 10, 15, 20 and 30 post-infection and 6 controls on either Day 0 or 30 post-infection. Another 15 Romney cross lambs received 10,000 adult worms at 4–5 months-of-age though surgically-implanted abomasal cannulae and were killed after 6, 12, 24 and 72 hours; uninfected controls were also killed at 72 hours. Blood was collected at regular intervals from all animals for measurement of serum gastrin and pepsinogen and abomasal fluid for pH measurement from cannulated sheep. Tissues collected at necropsy were fixed in Bouin’s fluid for light microscopy, immunocytochemistry and mucin staining and in Karnovsky's fluid for electron microscopy. Nodules around glands containing developing larvae were seen on Day 5 p.i., but generalised effects on secretion occurred only after parasite emergence and within hours after transplantation of adult worms. After L3 infection, there were maximum worm burdens on Days 10–15 post-infection, together with peak tissue eosinophilia, inhibition of gastric acid secretion, hypergastrinaemia, hyperpepsinogenaemia, loss of parietal cells, enlarged gastric pits containing less mucin and increased numbers of mucous neck cells. After adult transplantation, serum pepsinogen was significantly increased after 9 hours and serum gastrin after 18 hours. Parallel changes in host tissues and the numbers of parasites in the abomasal lumen suggest that luminal parasites, but not those in the tissues, are key drivers of the pathophysiology and inflammatory response in animals exposed to parasites for the first time. These results are consistent with initiation of the host response by parasite chemicals diffusing across the surface epithelium, possibly aided by components of ES products which increased permeability. Parietal cells appear to be a key target, resulting in secondary increases in serum gastrin, pit elongation, loss of surface mucins and inhibition of chief cell maturation. Inflammation occurs in parallel, and could either cause the pathology or exacerbate the direct effects of ES products.

Effect of protein supplementation in the rumen, abomasum, or both on intake, digestibility, and nitrogen utilisation in cattle fed high-quality tropical forage

Effects of differing proportions of ruminal and abomasal protein infusion on intake, digestion, ruminal dynamics and the metabolic parameters of nitrogen (N) compounds were evaluated in beef bulls fed high-quality tropical forage (98.6 g crude protein, CP/kg dry matter) for ad libitum intake. Four Nelore bulls (280 ± 10 kg bodyweight) fitted with ruminal and abomasal cannulas were studied in a 4 × 4 Latin square. Treatments included: Control (no supplement) or 230 g/day of supplemental CP (as casein), with ratios of abomasal : ruminal infusion of 0 : 100, 50 : 50 or 100 : 0. Organic matter intake was not affected by treatments (P ≥ 0.30), though N intake increased by supplementation (P &lt; 0.001). Total CP and organic matter digestibility were increased (P &lt; 0.02) by protein supplementation. Nitrogen balance was 43% greater (P &lt; 0.02) in the treatments with supplementation. Although supplementation did not affect (P = 0.98) the efficiency of absorbed N, a tendency towards a positive linear effect (P = 0.08) was observed when modifying the site of supplementation from the rumen to the abomasum. Supplementation increased (P &lt; 0.01) ruminal ammonia-N, serum urea-N, urinary N and urea-N excretion, which subsequently decreased linearly (P &lt; 0.01) by the displacement of supplementation from the rumen to the abomasum. The results indicate that protein supplementation, either in the rumen or abomasum produces similar effects on N retention. However, the metabolic mechanisms responsible for the improved N retention appear to differ between supplementation sites. Additionally, the efficiency of N utilisation increases with infusion of protein into the abomasum.

The Effect of Marshallagia marshalli on Serum Gastrin Concentrations in Experimentally Infected Lambs.

: Because there appeared to be no data available on serum gastrin concentrations in animals infected with Marshallagia marshalli, and considering the high prevalence of this parasite in livestock throughout many countries, we decided to perform research in the field using experimental infection. After surgical implantation of abomasal cannula into 10 male Baluchi sheep, each animal was orally infected with 5,000 M. marshalli larvae. Serum gastrin concentrations and abomasal pH were measured with a human ELISA kit and a PHM LE438 standard pH electrode, respectively. According to the results obtained from the study, serum gastrin increased after 14 and 21 days post-infection (dpi), while abomasal pH increased after 7 dpi and reached a maximal value 16 dpi. The increase in serum gastrin concentration was revealed 6 days after elevation in abomasal pH, which could be the result of reduced acid secretion. Generally, the present study pointed out that a limited number of M. marshalli could increase serum gastrin concentrations.

Laparoscopic abomasal cannulation in sheep

Abomasal cannulation, an important research tool in experimental procedures, provides a method for the placement of an abomasal cannula in sheep. The aim of this study was to describe a technique for laparoscopic abomasal cannulation in sheep. It was performed in six anaesthetised sheep positioned in dorsal recumbency using three portals in the abdomen. The first absorbable traction suture was placed 1 cm cranial to the determined abomasal cannula site. A stab incision was made with a laparoscopic monopolar hook electrode in the middle of a purse-string suture placed around the abomasal cannula site. The T-shaped cannula was inserted into the abomasum lumen through the stab incision, and the second traction suture was then placed 1 cm caudal to the abomasal cannula site. The T-shaped abomasal cannula was pulled out of the abdominal cavity through the exit wound located 3-5 cm lateral and 10-12 cm cranial to the right side of the umbilicus. The two traction sutures were tied. The T-shaped cannula was secured to the skin with a finger-trap suture. Repeat laparoscopy was performed 1 month later. Firm adhesion between the abomasum and abdominal wall was observed in all sheep, with no evidence of leakage or peritonitis. No major intraoperative or postoperative complications were encountered. The median surgical time was 49 min, with a range from 42 to 58 min. The abomasal contents were collected easily. In conclusion, laparoscopic abomasal cannulation is safe and easy to perform. Its low complication rates and the "ideal" placement of the tube into the abomasum make it an especially attractive alternative to traditional surgical abomasal cannulation in veterinary practice.

Metabolic profile and ruminal and abomasal pH in sheep subjected to intravenous ranitidine

Resumo: Brazilian sheep production has intensified, predisposing sheep to an increased incidence of digestive disorders, such as abomasal ulcers. Ranitidine is used to prevent and treat this disease; however, there is little information on the parenteral use of this drug in adult ruminants. Few data exist on the concomitant metabolic changes and the behavior of the digestive system associated with its use. For this study, five healthy male sheep with ruminal and abomasal cannulas were used. A 5x5 Latin square experiment with a 2x2+1 factorial arrangement of the treatments was performed. Sheep treated with drug doses of 1 or 2mg/kg ranitidine administered intravenously every 8 or 12 hours were compared with the control group, was treated intravenously with 1 mL of physiological solution per 25 kg every 12 hours. Higher total protein concentrations, hemoglobin levels, as well as increased aspartate aminotransferase activity and increased abomasal pH for up to 150 min following drug administration were observed in all animals that received the drug, regardless of dose and frequency. The animals treated every 12 hours showed a decrease in leukocyte number compared with the control group and with the animals treated every 8 hours. Increased serum creatinine concentrations were observed in the animals treated every 8 hours. Treatments of 1mg/kg every 8 hours and 2mg/kg every 12 hours increased the red blood cell count and decreased the serum pepsinogen. All protocols studied were safe for healthy sheep, but 1mg/kg ranitidine every 8 hours and 2mg/kg ranitidine every 12 hours were the most effective protocols for gastric protection.

Effect of tulathromycin on abomasal emptying rate in healthy lactating goats

Tulathromycin is a long-acting semi-synthetic macrolide antibiotic that is synthesized from erythromycin. Macrolides have pharmacodynamic properties beyond their antimicrobial effects, including anti-inflammatory and immunomodulatory properties that are perceived to be clinically beneficial. An additional pharmacodynamic property of macrolides is a prokinetic effect, which is marked in adult cattle and calves administered erythromycin and less prominent in calves administered spiramycin, tilmicosin, and tylosin. Based on structural similarities to erythromycin, the hypothesis was that parenteral administration of tulathromycin would increase abomasal emptying rate in healthy adult goats. Accordingly, five adult lactating goats (30–36 months of age) received each of the following 3 treatments: IM injection of 2mL of 0.9% NaCl (control); IM injection of tulathromycin (2.5mg/kg body weight); IV injection of tulathromycin (2.5mg/kg body weight). Abomasal emptying rate was assessed by acetaminophen absorption, which was injected into the abomasum through a surgically placed abomasal cannula at 50mg/kg BW, 15min after each treatment. Jugular venous blood samples were obtained periodically after injection and plasma acetaminophen concentrations determined using a colorimetric nitration assay. The maximum observed plasma acetaminophen concentration (Actual Cmax) and time of actual Cmax (Actual Tmax) were determined, and pharmacokinetic modeling was used to calculate model Cmax and model Tmax and abomasal emptying half-time (T50). Results showed that tulathromycin (IM and IV) increased abomasal emptying rate, as indicated by a shorter time to actual Tmax and model Tmax, and shorter T50, than control. The clinical relevance of these findings remains to be determined.

Comparison of purine bases and 15N for quantifying microbial nitrogen yield using three marker systems and different sampling sites in zebu cross breed bulls

The present experiment was designed to evaluate the use of microbial markers (MM), sampling sites (SS), and marker systems (MS) to estimate microbial nitrogen (MN) synthesis in bulls and to develop equations to correct MN estimates when only one of the aforementioned techniques was utilized. The MM systems evaluated were (1) purine bases (PB) and (2) 15N labeling. The SS evaluated were: (1) reticulum, (2) omasum, and (3) abomasum, and the single, double and triple MS were evaluated. Eight crossbred (Holstein×Zebu) bulls (353±36.9kg of BW; 24±1mol) with ruminal and abomasal cannulas were utilized in this experiment. The following experimental diets were used: (1) 60% corn silage+40% concentrate, (2) 40% corn silage+60% concentrate, (3) 60% fresh sugarcane+40% concentrate, and (4) 40% fresh sugarcane+60% concentrate. Four experimental periods lasting 16d each were completed with 10d for adaptation to the experimental diet and 6d for sampling. Bulls were randomly distributed into two 4×4 Latin squares balanced for residual effects. Data were analyzed in a Latin square design using PROC MIXED. Interactions were observed (P<0.05) in MN, microbial crude protein/total digestible nutrients (MCP/TDN), microbial nitrogen/rumen fermented organic matter (MN/RFOM), microbial nitrogen/rumen truly fermented organic matter (MN/RTFOM), and microbial dry matter/rumen fermented total carbohydrates (MDM/RFTCHO) between SS and MM. For PB, the greatest (P<0.01) values of MN were observed for the digesta sampled in the reticulum and abomasum. In contrast, for 15N, the greatest (P<0.01) values were observed for digesta sampled in the omasum and abomasum. Microbial nitrogen yield was only different (P<0.05) when using reticulum and 15N from those estimated using abomasum and 15N. Thus, the equation developed to correct MN value was: MN (g/d)=27.93±2.46+0.99±0.09×reticulum 15N. The triple MS exhibited the greatest (P<0.01) value of MN compared to the single and double MS. No interactions (P>0.05) were observed between MS and MM or SS; thus, the equation established to correct MN value used only the MS. In conclusion, we have demonstrated that there is no difference using 15N to estimate MN yield if omasum or abomasum are used. Therefore, the omasum can be used as an accurate SS to predict MN. The triple MS presented higher values than the single and double MS. Thus, if single or double MS is used the value must be corrected by the equation obtained using the triple MS.

Soybean meal replaced by slow release urea in finishing diets for beef cattle

Eight crossbred steers (average body weight of 418kg) fitted with ruminal and abomasal cannula were used to evaluate the effects of replacing soybean meal (SBM) with slow-release urea (SRU) in beef cattle diets containing two concentrate levels. The experimental design included two 4×4 Latin squares, which were run simultaneously. Each Latin square received one level of concentrate [400 or 800g/kg on a dry matter (DM) basis]. Within each Latin square, the four replacement levels of soybean meal protein with slow-release urea were applied to the animals (0%, 33%, 66% and 100% of substitution on N basis). The DM intake as well as organic matter (OM) intake and crude protein (CP) intake decreased linearly (P<0.05) as SBM was replaced with SRU. Ruminal digestibility coefficient of OM tended to be greater (P=0.074) for the 40 % concentrate diet. DM and OM passage rate (kp) were greater (P<0.05) on the 80% concentrate diet. A cubic effect (P<0.10) of SBM replacement with SRU on ruminal ammonia (NH3–N) concentration in relation to time was detected. A quadratic effect on pH was observed (P<0.10) when replacing SBM with SRU. Nitrogen intake, nitrogen excreted in the feces, nitrogen balance and efficiency of nitrogen use decreased linearly (P<0.10) as SRU increased in the diet, whereas the total nitrogen excreted in urine increased linearly (P=0.007). The production of microbial nitrogen and microbial efficiency were not affected by the experimental treatments (P>0.10). A lower intake of DM, OM, and CP was observed when cattle were fed SRU compared to SBM. However, the use of SRU did not change the digestibility and digestion rate (kd) and kp of DM, OM, CP and neutral detergent fiber corrected for ash and protein (NDFap). In summary, SRU provides higher concentrations of NH3–N throughout a day than SBM in cattle fed low concentrate diets.

Digesta sampling sites and marker methods for estimation of ruminal outflow in bulls fed different proportions of corn silage or sugarcane.

The objective of this experiment was to assess ruminal outflow and apparent total-tract digestibility using digesta samples from 3 sites (reticulum, omasum, and abomasum) and 3 marker methods (single marker: indigestible NDF [iNDF; sample without separation]; double marker: iNDF + Co-EDTA [filtered sample]; and triple marker: iNDF + ytterbium [Yb] acetate + Co-EDTA [filtered and centrifuged]) in bulls fed corn silage and sugarcane-based diets. Eight crossbred (Holstein × Zebu) bulls (353 ± 37 kg of BW; 24 ± 1 mo of age) with ruminal and abomasal cannulas were randomly distributed into two 4 × 4 Latin squares that were balanced for residual effects. The following experimental diets were used: 1) 60% corn silage + 40% concentrate, 2) 40% corn silage + 60% concentrate, 3) 60% fresh sugarcane + 40% concentrate, and 4) 40% fresh sugarcane + 60% concentrate. Reticular, omasal, and abomasal digesta samples were collected at 9-h intervals over 3 d. At the end of the experiment, a composite sample was prepared for each bull, and these samples were subsequently assigned to the 3 marker methods. The concentrations of CP, NDF, and iNDF of reticular digesta differed (P < 0.01) from those of the omasum and abomasum. Use of omasal and abomasal samples led to similar estimates of ruminal outflow and ruminal digestibility for DM (P = 0.65), OM (P = 0.68), CP (P = 0.85), and NDF (P = 0.57). In contrast, the ruminal outflow of digesta based on reticular sampling appeared to be underestimated. We recommend sampling from the omasum because sampling from this region is less invasive than sampling from the abomasum. Although we did not observe differences in ruminal NDF digestibility among the different marker methods, we did observe that ruminal digestibility of CP was greater for the single marker method than for the double and triple marker methods; we therefore recommend the use of the double or triple marker method.

Nutritional performance of cattle grazing on low-quality tropical forage supplemented with nitrogenous compounds and/or starch

The objective of this work was to evaluate the effects of protein and/or starch supplementation on the nutritional performance of cattle grazing on low-quality tropical forage. Five crossbred steers (Holstein × Gyr) with an average body weight (BW) of 397 kg that were fitted with ruminal and abomasal cannulae were used. The animals were kept in individual signal-grass (Bracharia decumbens) paddocks. Five treatments were evaluated: 1 - control (without supplementation); 2 - supplementation with 1 g of crude protein (CP) per kg of BW; 3 - supplementation with 2.5 g of starch per kg of BW; 4 - supplementation with CP and starch as described for treatments 2 and 3; and 5 - supplementation as described for treatment 4 but replacing the corn starch with a mixture of corn starch and nitrogenous compounds, thereby resulting in an energy supplement of 150 g CP/kg of dry matter. The experiment was performed according to a 5 × 5 Latin square design in a 2 × 2 + 1 factorial arrangement. The forage intake was not affected by any of the factors evaluated in this study. The production of microbial nitrogen in the rumen was not affected by nitrogen or starch supplementation. The apparent nitrogen balance was only increased when both starch and nitrogen were supplied. Supplementation with both starch and nitrogenous compounds for cattle grazing on low-quality tropical forage is characterized by an interactive metabolic effect that increases nitrogen accretion by the animals.

Effects of forage intake level on nitrogen net flux by portal-drained viscera of mature sheep with abomasal infusion of an amino acid mixture

This study aimed to investigate the pattern of nitrogen (N) metabolites flux across the portal-drained viscera (PDV) of mature sheep over a wide range of forage intake, and to determine the effect of dry matter intake (DMI) on the PDV recovery of an abomasally infused amino acids (AA) mixture. Four Suffolk mature sheep (61.4 ± 3.6 kg BW) surgically fitted with abomasal cannulae and multi-catheters were fed four levels of DMI of lucerne hay cubes ranging from 0.4 to 1.6 fold the metabolizable energy requirements for maintenance. Each period lasted for 17 days: 7 days for diet adaptation, 5 days for measurement of N balance and N metabolites flux under basal pre-infusion conditions (basal phase) and 5 days for determining the recovery of the infused AA (584 mmol/day) across the PDV (infusion phase). Six sets of blood samples were collected on the last day of both basal and infusion phases. Increasing DMI increased portal release of AA and enhanced N retention. At 0.4 M and as a proportion of digested N, there was a marked drop in total AA-N release accompanied by greater ammonia-N release and urea-N uptake across the PDV. The incremental recovery ratio of infused AA across the PDV was altered with increasing DMI accounting for 0.88, 1.12, 1.23 and 1.31 at 0.4, 0.8, 1.2 and 1.6 M, respectively. In addition, across the individual AA, the net portal recovery ratio of infused methionine and valine increased linearly (P < 0.05) while that of phenylalanine, branched-chain AA and total essential AA tended to increase linearly (P < 0.10) with increasing DMI. These results indicated that DMI affects the net portal recovery of AA available in the small intestine of mature sheep.

Effect of orally administered electrolyte solution formulation on abomasal luminal pH and emptying rate in dairy calves

To determine the effects of 3 commercially available, orally administered electrolyte solutions (OAEs) on abomasal luminal pH and emptying rate in dairy calves, compared with the effect of orally administered milk replacer. Randomized crossover study. 6 male dairy calves (age, 12 to 31 days). Calves were surgically instrumented with an abomasal cannula and were administered 4 treatments in randomized order: all-milk protein milk replacer, high-glucose high-bicarbonate OAE, high-glucose high-bicarbonate OAE containing glycine, and low-glucose OAE containing acetate and propionate. Abomasal luminal pH was measured with a miniature glass pH electrode prior to treatment administration and every second afterward for 24 hours. Feeding of orally administered milk replacer resulted in a rapid increase in mean abomasal luminal pH from 1.3 to 5.8, followed by a gradual decrease to preprandial values by 8 hours afterward (mean 24-hour pH, 3.2). High-glucose high-bicarbonate OAEs caused a large and sustained increase from 1.3 to 7.5 (mean 24-hour pH, 4.1 for the solution without glycine and 3.5 for the solution with glycine). In contrast, feeding of the acetate-containing OAE was followed by only a mild and transient increase (mean 24-hour pH, 2.1); luminal pH returned to preprandial values by 3 hours after ingestion. Ingestion of a bicarbonate-containing OAE resulted in sustained abomasal alkalinization in dairy calves. Because persistently high abomasal luminal pH may facilitate growth of enteropathogenic bacteria, administration of OAEs containing a high bicarbonate concentration (> 70mM) is not recommended for calves with diarrhea.

Effects of pistachio by-product in replacement of lucerne hay on microbial protein synthesis and fermentative parameters in the rumen of sheep

This study was conducted to evaluate the effect of partial and total substitution of lucerne hay with pistachio by-product on nutrient intake, apparent digestibility, rumen fermentation, digesta kinetics, blood metabolites, nitrogen retention and microbial protein synthesis in Baloochi sheep. Six sheep with a bodyweight of 40.1 ± 1.77 kg fitted with ruminal and abomasal cannulae were assigned at random to three diets in a double 3 × 3 Latin-square design. The dietary treatments included a control (basal diet), low pistachio by-product diet (50% of the lucerne hay in the basal diet was replaced by pistachio by-product), and high pistachio by-product diet (all of the lucerne hay in the basal diet was replaced by pistachio by-product). The daily basal diet was 500 g/kg DM lucerne hay, 250 g/kg DM wheat straw, 210 g/kg DM barley grain, 30 g/kg DM cotton seed meal, 8 g/kg DM vitamin–mineral supplement and 2 g/kg DM salt. Faeces and urine were collected for 8 days and used to estimate digestibility, nitrogen retention and microbial protein synthesis. Sheep were dosed ruminally with Cr-EDTA (2.27 g/L) and rumen samples were evaluated for pH, volatile fatty acids, ammonia nitrogen concentrations and digesta kinetics. The intake of neutral detergent fibre, purine derivatives excretion, volatile fatty acid concentrations in the rumen and ammonia nitrogen in the abomasum decreased (P &lt; 0.05). Ether extract intake and ruminal pH was increased at 5 h after feeding (P &lt; 0.05) as the level of pistachio by-product in the diet increased. Total pistachio by-product replacement for lucerne hay increased (P &lt; 0.05) apparent digestibility of nitrogen, ether extract, organic matter and nitrogen retention and decreased (P &lt; 0.05) microbial protein synthesis, efficiency of microbial protein synthesis and ammonia nitrogen in the rumen. The inclusion of pistachio by-product had no effect on blood metabolites and digesta kinetics. Based on these results it was concluded that pistachio by-product can be considered as a useful replacement for lucerne hay in the diet of Baloochi sheep without any negative impacts on their responses. Moreover, pistachio by-product inclusion in diet improved nitrogen metabolism in Baloochi sheep.

Fontes proteicas em suplementos para novilhos no período de transição seca-águas: características nutricionais

Avaliaram-se fontes proteicas em suplementos para novilhos em pastagens de Brachiaria decumbens Stapf., durante a transição seca-águas, sobre as características nutricionais. Utilizaram-se quatro animais Holandês x Zebu, não castrados, com média de peso de 300kg, fistulados no esôfago, rúmen e abomaso, distribuídos em delineamento em quadrado latino 4x4. Avaliaram-se suplementos isoproteicos, balanceados para 38% de proteína bruta (PB), sendo um tratamento controle mistura mineral (MM); e três suplementos à base de grãos de milho moído + ureia (MU); grãos de milho moído + farelo de soja (MFS) e farelo de algodão 38% PB (FA), fornecidos na quantidade de 0,17% do peso vivo (PV). O consumo de fibra em detergente neutro pelos animais do tratamento MU, de 12,1g/kg PV, foi maior em 19,9% do que o observado para os dos tratamentos MM e MFS, 10,2g/kg PV, e semelhante ao observado para os do tratamento FA, 11,0g/kg PV. Foram observados valores mais altos de digestibilidade aparente total da matéria seca (MS) para os tratamentos MU e MFS em relação aos demais. Os valores de pH ruminal, produção de nitrogênio microbiano e eficiência de síntese microbiana não foram influenciados pelos tratamentos. A suplementação com MU proporciona maior consumo e digestibilidade aparente total da MS em relação ao tratamento MM.

The Effect of Energy Supplementation on Intake and Utilisation Efficiency of Urea-treated Low-quality Roughage in Sheep II. Rumen Kinetics and Acetate Clearance Rate

Inadequate supply of glucose or glucogenic substrates to the body tissues can affect metabolism of absorbed acetogenic metabolites from the gut and therefore, influence feed intake in ruminants. This study investigated the effect of energy supplementation on rumen kinetics in the gut, and the acetate clearance rate in the body tissues of sheep fed low quality basal roughage. A basal diet consisting of urea-treated mixture of wheaten chaff and barley straw (3:1 DM) containing 22.2 g N/kg DM was used. Four Merino cross wethers weighing fitted with permanent rumen and abomasal cannulae were allocated to four treatments in a LSD. The treatments were basal diet (), or basal diet supplemented with sucrose (112.5 g/d) administered intraruminally (), abomasally (), or via both routes (50:50) (). There was no difference (p>0.05) in the rumen liquid kinetics parameters between the four dietary treatments. However, there was a trend of animals supplemented with sucrose wholly or partly through the abomasum having lower faecal DM and therefore poor pellet formation, and low pH. Although the glucogenic potential of the fermentation products absorbed from the rumen was increased (p and ), there was no significant difference (p