Duodenal Cannulas Research Articles

FLEXIBLE DUODENAL MONOCANNULA OF THE NATIONAL AGRICULTURAL AND FOOD CENTRE DESIGN FOR THE DETERMINATION OF INTESTINAL NUTRIENT DIGESTIBILITY IN CATTLE

Research in physiology of ruminant nutrition using the in sacco and mobile bag methods and developing and testing of a duodenal cannula of our own construction including our own surgical application in cattle, led to the intellectual property protection. The duodenal monocannula for determination of nutrient intestinal digestibility in cattle, designed by the National Agricultural and Food Centre (NPPC, Slovak Republic), has been registered by European Union intellectual property office, as a Registered Community Design. The innovativeness of the technical design of the "NPPC cannula" lies in the fact that the cannula is made of one piece of a straight tube with an inner diameter of 22 mm. The tube is smooth, with no additional extensions and glued parts. The operation does not require ligation of the bowel with an arterial prosthesis or a polyurethane felt. The dimensions of the cannula allow the use of the mobile bag method without any problems. The vinyl chloride emulsion was designed to polymerize at the lower temperature, than has been currently used in this procedure (130 °C), and the end used for fixation in the intestine could be shaped after immersion in warm water. During the growth of the animals, the tube length can be prolonged to adapt to the duodenal size. As a result, the life of cannulated animals can be extended without age limitation.

In situ ruminal degradability and intestinal digestibility of dry matter and crude protein of low-protein fraction from sunflower meal

The objective of this study was to evaluate rumen degradation kinetics and intestinal digestibility of low-protein fraction from sunflower meal (LPSFM). Three non-lactating Jersey cows with an average body weight of 436 ± 18 kg fitted with a rumen and T-type duodenal cannulas were used in the experiment. Five samples of LPSFM from different batches produced in 20-d intervals were collected and incubated in the rumen of the cows for 0, 2, 4, 8, 16, 24 and 48 h in 6 replicates. The average CP content of LPSFM was 175 (SD = 6.98) g/kg. Data were fitted to nonlinear regression model and analyzed statistically using SPSS. The soluble or rapidly degradable fraction а of LPSFM dry matter (DM) ranged from 105 to 137 (SD = 11.3) g/kg. The effective degradability of DM at assumed rumen outflow rate of 0.06/h ranged from 293 to 338 (SD= 16.3) g/kg. Fraction a of CP ranged from 124 to 189 (SD = 23.9) g/kg. Effective degradability of LPSFM CP at rumen outflow rate of 0.06/h ranged from 515 to 560 g/kg (SD = 16.2). Intestinal digestibility of LPSFM (after 16-h rumen incubation) DM and CP measured by the mobile bag technique varied from 318 to 349 g/kg (SD = 10.5) and from 766 to 820 g/kg (SD = 17.7), respectively. The average estimated Protein Digestible in the small Intestine (PDI) and Rumen Protein Balance (RPB) of the LPSFM samples analyzed in the current study, following equations in the Bulgarian feed evaluation system (at 0.06/h outflow rate), were 113 (SD = 1.67) g/kg and 125 (SD = 14.9) g/kg, respectively. The protein degradability and digestibility values obtained in this experiment can be effectively used in formulating rations for ruminant animals.

Intestinal Synthesis and Lymphatic Secretion of Apolipoprotein A–IV Vary with Chain Length of Intestinally Infused Fatty Acids in Rats

To evaluate the hypothesis that stimulation of intestinal apolipoprotein (apo) A–IV by dietary fat depends upon assembly and transport of chylomicrons, we examined the effect of duodenal infusion of fatty acids of graded chain length on mucosal synthesis and lymphatic output of lipid and apo A–IV. Rats with duodenal cannulas and mesenteric lymph fistulas were given 8-h duodenal infusions of lipid emulsions containing either butyric (4:0), caprylic (8:0), lauric (12:0), myristic (14:0), stearic (18:0), oleic (18:1), linoleic (18:2) or arachidonic (20:4) acids, or tributyrin, tricaprylin or triolein. Lymph outputs of triglyceride, phospholipid and apo A–IV were measured at 0, 2, 4, 5, 6, 7 and 8 h after the start of lipid infusion. Significant increases in lymph lipid (triglyceride, phospholipid) and apo A–IV output were observed in response to long-chain fatty acids (14:0, 18:0, 18:1, 18:2, 20:4) or triolein; short- or medium-chain fatty acids (4:0, 8:0, 12:0) or tributyrin or tricaprylin produced no significant increase in lymph lipid output above basal levels. Similarly, increased jejunal mucosal synthesis of apo A–IV was observed in response to duodenal infusion of oleic acid but not butyric or caprylic acid. These results provide direct support for the hypothesis that stimulation of apo A–IV by dietary fat depends upon transport of absorbed lipid via chylomicrons in lymph.

The Effect of Horn Fly (Diptera: Muscidae) Infestation on Behavior, Water, and Feed Intake, and Digestion Characteristics of Beef Cattle.

Seven mature Angus × Hereford crossbreed cows (544 ± 23.2 kg of body weight) fitted with duodenal and ruminal cannulas were used in a crossover design to evaluate the effects of horn fly (Haematobia irritans) (L.) infestation on horn fly-induced defensive behaviors, feed and water intake, as well as digestion characteristics of beef cows. Cows were randomly assigned to one of two treatment groups: 1) a horn fly infested (1,000 flies per cow) or 2) a noninfested control group. All cows were housed in individual screened pens. Fly counts and infestations were performed daily to maintain consistent populations throughout the study. Sudan hay (11.4 % crude protein, dry matter basis) was selected to mimic forage quality that range cattle frequently graze in the southwest region. Horn fly-induced host defensive behaviors were greater (P ≤ 0.0002) for horn fly infested cattle. Intake of water, dry matter, organic matter, crude protein, and neutral detergent fiber were similar (P ≥ 0.4765) among infested and noninfested cows. However, total volatile fatty acid concentration tended to increase (P = 0.0967) when horn flies were present. Dry matter fecal excretion and total tract digestion were not affected (P ≥ 0.2602) by horn fly infestation. These data indicate that horn fly infestations do not affect forage intake or digestion characteristics of beef cattle (Bos taurus) in confinement settings.

A multiparametric approach to assessing residual pain experienced by dairy cows undergoing digestive tract surgery under multimodal analgesia

This study assessed residual pain responses of dairy cows undergoing fistulation surgery under multimodal analgesia using a multiparametric method combining behavioural and physiological indicators. A longitudinal study was conducted on five dairy cows, each acting as her own control. The surgery consisted of implanting a ruminal and a duodenal cannula in each cow. The multimodal drug protocol consisted of a combination of N-Methyl-D aspartic Acid antagonists, α2-agonists, and local anaesthetic during surgery, and non-steroidal anti-inflammatory drugs (NSAIDs) and opioid treatment postsurgery. Cow responses to surgery were monitored by direct behavioural observation, physiological assay indicators, and milk production from day (D) −6 days before surgery (D-6) to D13 postsurgery. From the data recorded, the variables that contributed most to the discrimination of days pre- and postsurgery were identified using factorial discriminant analysis. Components 1 and 2 of the factorial discriminant analysis explained 68.2% and 17.9%, respectively, of the total variance. Component 1 was mainly explained by haptoglobin (contribution to axis: 0.885), oxidative stress (ratio of oxidized gluthatione to reduced glutathione (GSH/GSSG), −0.746; vitamin E, −0.683; vitamin A, −0.597; malondialdehyde (MDA), 0.416), and behavioural indicators (general attitude, 0.594). On this axis, the higher the score, the higher were the apathy and haptoglobin and MDA concentrations, and the lower were the GSH/GSSG ratio and concentrations of vitamins A and E. This axis opposed cows on D-6 to cows on D3 and D5; cows on D1 and D13 were intermediate. Component 2 was mainly explained by the Hypothalamic-pituitary-adrenal axis (non-esterified fatty acid (NEFA), 0.686; cortisol, 0.669), milk yield (−0.725), oxidative stress (MDA, −0.584; nitric oxide (NO), 0.454), and behavioural indicators of pain (ear position, 0.467; leg postures, 0.431). On this axis, the higher the score, the higher the NEFA, cortisol, and nitric oxide concentrations; the more the ear and leg pain postures; and the lower the milk production and MDA concentrations. This axis opposed cows on D13 to cows on D1. These results suggest that cows may experience some pain only on D1, whereas on subsequent days, the inflammatory response and oxidative stress did not seem to be associated with pain. Our results should be considered for different surgeries to improve analgesia immediately after surgery, and to provide antioxidants along with NSAIDs to promote recovery.

Effects of dietary tallow containing trace amounts of ractopamine on beef cattle performance and tissue residue levels and the effect of withdrawal time on ractopamine residues in the gastrointestinal-tract digesta

The objectives of these experiments were to evaluate (1) if inclusion of inedible tallow containing ractopamine (RAC) in the cattle diet influences feedlot performance, carcass characteristics, and results in detectable RAC in tissues and (2) the effect of withdrawal time on RAC residues in the gastrointestinal-tract digesta of cattle. In Exp. 1, beef steers (n = 28) were assigned to dietary treatments formulated with feed tallow ranging from 100% inedible tallow to 100% technical tallow. After 91 d, steers were transported to a commercial abattoir and slaughtered, and tissues were collected for RAC analysis. In Exp. 2, steers fitted with ruminal and duodenal cannulas were assigned to the control group (no RAC) or a group in which RAC was supplemented at 400 mg of RAC∙animal −1 ∙d −1 for 28 d. On d 29, RAC supplementation was withdrawn. Daily ruminal, duodenal, and fecal samples were obtained for RAC analysis beginning 3 d before RAC withdrawal and continuing to d 13 after withdrawal. No treatment effects of dietary inedible tallow inclusion was observed for final BW ( P < 0.67), ADG ( P < 0.70), DMI ( P < 0.26), feed efficiency (G:F; P < 0.48), hot carcass weight ( P < 0.26), DP ( P < 0.24), or YG ( P < 0.32). However, RAC was detected in abomasum and fat tissues. By the end of the 10-d withdrawal period, RAC concentrations in all samples from treated steers were numerically similar to controls, and RAC was detectable in all samples, including controls, at all time points measured. The results indicate that RAC residue in feed tallow does not affect animal performance or carcass characteristics. Detectable RAC in sampled tissues and gastrointestinal digesta suggests a need for further investigation of RAC residues to maintain compliance for exported beef products.

Effect of Rye Grain Derived from Different Cultivars or Maize Grain Use in the Diet on Ruminal Fermentation Parameters and Nutrient Digestibility in Sheep

Abstract Six wether sheep with ruminal and duodenal cannulas were used in a replicated 3 × 3 Latin square to determine the effect of rye grain (from an open-pollinated or a hybrid cultivar) and maize grain from hybrid cultivar inclusion in the diet on ruminal fermentation parameters and nutrient digestion in different gastrointestinal tract compartments. The experimental diets consisted of meadow hay (800 g/day) and a concentrate mixture (300 g/day) that contained rye grain from an openpollinated cultivar (OPRG), rye grain from a hybrid cultivar (HRG), or maize grain from a hybrid cultivar (MG) as a main energy source. Each experimental period lasted 17 days and consisted of 10 days for diet adaptation and 7 days for data and sample collection. Ruminal fermentation (pH, short-chain fatty acids, and ammonia concentration) and nutrient digestion up to the duodenum (in reticulorumen, omasum, and abomasum), in the intestine, as well as in the total digestive tract was investigated. Mean ruminal pH was higher for MG compared to HRG and OPRG (P&lt;0.01) but did not differ between HRG and OPRG (6.45, 6.35, and 6.29 for MG, HRG, and OPRG, respectively). Treatment did not affect short-chain fatty acid concentration in the rumen, except for the molar proportions of valeric acid and of isovaleric acid of the total short-chain fatty acids, which was or tended to be higher (P≤0.06) for MG compared to HRG and OPRG. Less starch was digested in the gastrointestinal tract up to the duodenum and more in the intestine for MG compared to HRG and OPRG (P=0.01); however, total tract nutrient digestibility did not differ between treatments. In conclusion, usage of rye grain in sheep diets resulted in a lower ruminal pH compared to maize grain usage. No differences for ruminal fermentation, nutrient digestion up to the duodenum, in the intestine, as well as in the total digestive tract between rye grain from open-pollinated and hybrid cultivar usage in sheep diets were found.

The effects of 2-hydroxy-4-methylthio-butanoic acid supplementation on the rumen microbial population and duodenal flow of microbial nitrogen

Four multiparous, lactating Holstein cows (average DIM 169.5 ± 20.5 d), fitted with ruminal and duodenal cannulas, were used in a 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments to investigate the effects of 2-hydroxy-4-methylthio-butanoic acid (HMTBA) when fed with diets differing in metabolizable protein (MP) supply and equal levels of crude protein on milk production and composition, rumen microbial activity, duodenal protein flow, and rumen bacterial community composition in vivo and in vitro. Experimental periods were 28 d in length. Cows were housed in individual tie stalls and were randomly assigned to 4 dietary treatments: low MP or high MP, supplemented with or without 25 g of HMTBA, which was top-dressed once daily at 0930 h. No interactions were observed between HMTBA and level of dietary MP, with the exception of ruminal acetate-to-propionate ratio. Milk yield was not affected by treatment and averaged 23.8 ± 2.06 kg/d. There was a tendency for increased milk protein percent in cows receiving low MP diets, averaging 3.30 ± 0.09% and 3.21 ± 0.09% for low MP and high MP, respectively. The total-tract apparent digestibility of organic matter, neutral detergent fiber, and nitrogen were greater in cows consuming the low MP diet. Rumen pH was lower in cows consuming high MP diets as well as in those consuming HMTBA. Rumen ammonia concentrations tended to be greater in cows consuming HMTBA, and volatile fatty acid concentrations were greater in cows consuming HMTBA. Duodenal dry matter flow, nitrogen flow, and microbial nitrogen flow did not differ between treatments. The bacterial community structure of cows receiving HMTBA was not affected at the phylum level. The relative abundance of bacterial phyla in vivo differed when compared with in vitro conditions for Firmicutes, Bacteroidetes, Proteobacteria, TM7, Tenericutes, Spirochaetes, SR1, and Verrucomicrobia.

Effect of Hybrid Rye and Maize Grain Processing on Ruminal and Postruminal Digestibility Parameters

Abstract The aim of the study was to determine the effect of the method of fragmentation of hybrid rye and maize grain on digestibility parameters for ruminants. Varying degrees of fragmentation – none (whole grains; WG), crushed (CG) or ground to pass through a 4.0 (GG4.0) or 1.5 mm (GG1.5) screen – were estimated by the in sacco nylon bag technique, in vitro true digestibility (IVTD), and the in vitro gas production (GP) technique. WG, CG, GG4.0 and GG1.5 were categorized as none, slight, moderate and extensive fragmentation of the grain kernel, respectively. Three non-lactating cows fitted with ruminal and duodenal cannulas were used to determine the effective rumen degradability (ERD) and intestinal and total tract digestibility (ID and TTD, respectively) of dry matter (DM), crude protein (CP) and starch. IVTD was determined with an ANKOM DaisyII Incubator, and GP and in vitro organic matter digestibility were determined with an ANKOMRF Gas Production System. Dry matter, CP and starch of hybrid rye grain were rapidly degraded in the rumen, and this degradability as well as ID and TTD was only marginally affected by the method of kernel fragmentation; however, among the methods used, the ERD of GG4.0 rye was the lowest. On the other hand, the greater the degree of kernel fragmentation, the higher ERD, ID and TTD were obtained for the DM, CP and starch of maize grain. In summary, rye grain is more susceptible to fermentation in the rumen than maize grain, but the means of grain processing may alter the rate, extent and site of their digestion, particularly for maize grain.

Feeding diets varying in forage proportion and particle length to lactating dairy cows: II. Effects on duodenal flows and intestinal digestibility of amino acids

A study was conducted to evaluate the effects of forage-to-concentrate (F:C) ratio and forage particle length (FPL) on intake, duodenal flow, and digestibility of individual AA in the intestine of lactating dairy cows. The experiment was designed as a 4 × 4 Latin square with a 2 × 2 factorial arrangement of treatments using 4 lactating dairy cows (parity 2) with ruminal and duodenal cannulas. Low (35:65) and high (60:40) F:C ratios (dry matter basis) were combined with 2 FPL of alfalfa silage (short vs. long; 7.9 vs. 19.1 mm). Few interactions between F:C and FPL for duodenal flow and intestinal digestibility of AA occurred, but interactions were detected for intakes of several AA. Intake of essential AA and nonessential AA decreased with increasing F:C, and the intake of several individual AA increased or decreased with increasing FPL. Increasing F:C decreased duodenal flows of essential AA, nonessential AA, and microbial AA due to consistent decreased flows of most individual AA (except Glu). Degradability of most individual AA in the rumen was not affected by F:C ratio or FPL except that the degradability of His was greater with high than low F:C diets, and the degradability of Ser was greater with long versus short FPL diets. However, the degradability of individual AA within diet varied considerably. Overall, F:C ratio and FPL did not affect intestinal digestibility of AA and rumen undegradable protein AA, whereas the digestibility of individual AA in the intestine varied considerably regardless of dietary treatment. These results indicate that increasing F:C ratio decreased AA supply due to decreased flow of AA to the duodenum but altering FPL did not affect AA supply. The results also revealed the necessity to consider both the flows and digestibility of individual AA when optimizing ration formulation to meet AA requirements of dairy cows.

A Novel Approach in Spinal Cord Stimulation for Enhancing Gastric Motility: A Preliminary Study on Canines.

Background/AimsGastroparesis is commonly seen in patients with diabetes and functional dyspepsia with no satisfactory therapies. Dysautonomia is one of the main reasons for the imbalanced motility. We hypothesized that spinal cord stimulation (SCS) is a viable therapy for gastroparesis via the autonomic modulation to improve gastric motility. The aim is to find an optimal method of SCS for treating gastroparesis.MethodsEight healthy-female dogs were implanted with a gastric cannula, a duodenal cannula, 2 multi-electrode spinal leads, and an implantable pulse generator. Gastric motility index (MI) was used to determine the best stimulation location/parameters of SCS. Optimized SCS was used to improve glucagon-induced gastroparesis.ResultsWith fixed parameters, SCS at Thoracic 10 (T10) was found most effective for increasing gastric MI (37.8%, P = 0.013). SCS was optimized with different parameters (pulse width: 0.05–0.6 msec, frequency: 5–500 Hz, motor threshold: 30–90%) on T10. Our findings revealed that 0.5 msec, 20 Hz with 90% motor threshold at T10 were the best parameters in increasing MI. Glucagon significantly delayed gastric emptying, and this inhibitory effect was partially blocked by SCS. Gastric emptying at 120 minutes was 25.6% in the control session and 15.7% in glucagon session (P = 0.007 vs control), while it was 22.9% with SCS session (P = 0.041 vs glucagon). SCS with the optimal parameters was found to maximally enhance vagal activity and inhibit sympathetic activity assessed by the spectral analysis of heart rate variability.ConclusionsSCS with optimized stimulation location and parameters improves gastric motility in healthy-dogs and accelerates gastric emptying impaired by glucagon via enhancing vagal activity.

Administration of encapsulated L-tryptophan improves duodenal starch digestion and increases gastrointestinal hormones secretions in beef cattle.

ObjectiveThis study investigated the effects of oral administration of rumen-protected L-tryptophan (RPL-T) on duodenal starch digestion and gastrointestinal hormones (GIH) secretions using Hanwoo beef steers as the animal models.MethodsFour steers (423±24 kg) fitted with ruminal and duodenal cannulas were employed in a crossover design replicated twice. Treatments were control (basal diet) and RPL-T (basal diet+191.1 mg/kg body weight [BW]) group. Blood and duodenal samples were collected to measure serum GIH levels and pancreatic α-amylase activity at day 0, 1, 3, and 5 (−30, 30, 90, 150, and 210 min) of the study. Samples from each segment of the gastrointestinal tract were collected via ruminal and duodenal cannulas and were used to determine soluble protein and the starch digestion rate at days 6 (−30, 180, 360, and 540 min) and 8 (−30, 90, 270, and 450 min) of the experiment.ResultsNo significant difference in ruminal pH, NH3-N, and total volatile fatty acid including the levels of acetate, propionate, butyrate, isobutyrate, valerate, isovalerate, and the acetate-to-propionate ratio was observed between groups (p>0.05). Crude protein uptake was higher and feces starch content was lower in RPL-T group than the control group (p<0.05). The D-glucose contents of feces in RPL-T group decreased at day 5 compared to those in the control group (p<0.05), however, no change was found at day 0, 1, or 3 compared to the control group (p>0.05). Serum cholecystokinin (CCK), melatonin, duodenal pancreatic α-amylase activity, and starch digestion were significantly higher in RPL-T group than the control group (p<0.05).ConclusionTaken together, oral administration of RPL-T at the rate of 191.1 mg/kg BW consistently increased CCK concentration, pancreatic α-amylase activity in duodenal fluids, and starch digestion rate in the small intestine and thus found to be beneficial.

Soybean hulls as feed substitute of ground corn can increase the fiber digestibility and bacterial fibrolytic profile of grazing Nellore steers during the rainy season

This study aimed to evaluate the effect of replacement of ground corn by soybean hulls associated or not to whole soybean grain in the feed supplement on intake, nutrient digestibility, rumen microbial population, and fermentation parameters of growing Nellore steers grazing Brachiaria brizantha cv. Xaraés during rainy season. Were used eight castrated Nellore steers (425 ± 36 kg of body weight (BW)) fitted with ruminal and duodenal cannulas in a replicated 4 × 4 Latin square with a 2 × 2 factorial arrangement, allocated into 4 paddocks of 0.25 ha each, consisting of Brachiaria brizantha cv. Xaraés and supplemented with: (1) ground corn combined with whole soybean grain (SG); (2) ground corn without SG; (3) soybean hulls (SH) combined with SG; and (4) SH without SG. Supplement intake was no affected by SG or SH (mean 2.12 kg-1 d, P &gt; 0.05). There were no interactions between SH and SG on DM and nutrients intake (P &gt; 0.05). The addition of SG reduced the dry matter (DM) intake expressed as % of BW and Kg-1 d, as well forage DM, organic matter (OM), crude protein (CP), neutral detergent fiber (aNDF), and gross energy (GE) intake (P ? 0.01). Animals supplemented with SH without SG had greater digestibility of DM (74.52), OM (77.62), CP (77.51), NDF (71.93) and GE (72.90) than animals supplemented with SH with SG (DM =69.01, OM = 71.92, CP = 72.81, NDF = 66.01, GE =68.01) expressed as % (P ? 0.01). The addition of SG in the supplements declined the ruminal pH and NH3-N (P=0.02). Animals supplemented without SH without SG showed greater Entodinium counts (6.01 n x 104 ml-1, P=0.04), and SG supplementation decreased the numbers of Dasytricha, Isotricha, and ruminal total protozoa (P &lt; 0.01). The abundance of Ruminococcus albus, R. flavefaciens, and Archaeas were higher for SH without SG supplement. Additionally, animals supplemented with SG had lower numbers of Fibrobacter succinogenes. The use of soybean hulls without whole soybean grain in the supplement may be effective to increase fiber digestibility, N retained, R. albus and R. flavefaciens in the rumen of Nellore steers grazing Brachiaria brizantha cv. Xaraés during the rainy season.

Fatty acid profile of duodenal digesta and of meat of feedlot beef cattle fed diets containing different levels of concentrate

The objective of this study was to evaluate the fatty acid profile of duodenal digesta (experiment I) and of meat of beef cattle (experiment II) fed diets containing different levels of concentrate (220, 400, 590 and 790 g of concentrate/kg of dry matter of the diets). The experiment I was conducted with four Charolais-Nellore steers (460 ± 18.2 kg of BW), with a T-shaped duodenal cannula, using a double 4 × 4 Latin square as an experimental design. In experiment II, 16 crossbred Charolais-Nellore young bulls (192.44 ± 18.2 kg of BW) were randomly distributed in the experimental treatments (220, 400, 590 and 790 g of concentrate/kg of dry matter of the diets). The diets were isonitrogenous (120 g of crude protein/kg of dry matter). The intramuscular fat content was used as a covariant for the statistical analysis of the meat fatty acid profile. The duodenal content of fatty acid C17:0 decreased with increase of concentrate levels, while its content in the meat presented a quadratic variation with the increase of the concentrate levels of the diets, being the lowest values observed for the diet with 400 g of concentrate. The duodenal content of fatty acid C18:1 trans-11 decreased, whereas the content of this fatty acid in the meat increased with the increase of the dietary concentrate levels. The increase in the level of concentrate reduced the content of polyunsaturated fatty acids C18:3 n-3, C20:3 n-6, C20:4 n-6, and C20:5 n-3 EPA in both the duodenal digesta and meat. No difference was observed in the n-6/n-3 fatty acids ratio (mean of 13.96) of the meat between diets. The elevation of the level of concentrate in confinement diets reduces the nutraceutical quality of the meat of Charolais-Nellore young bulls slaughtered at 14-16 months of age due to the reduction of the polyunsaturated fatty acids content important for human health.

Evaluation of Hair Characteristics and Animal Age on the Impact of Hair Cortisol Concentration in Feedlot Steers.

Hair cortisol is a novel biomarker of chronic stress. The objective of this study was to determine the effect of hair color and length, as well as, animal age on hair cortisol concentration in beef feedlot steers. Nineteen beef crossbred steers used for nutrition research and housed in a small feedlot setting were used for this study. Seven of the steers (680 ± 4.5 kg; ~9 years of age) were fitted with ruminal fistulas and duodenal cannulas. The other 12 steers (473 ± 3.1 kg; ~2.5 years of age) were fitted with only ruminal fistulas. Hair samples from each steer were collected throughout a period of 6 weeks from six different areas and analyzed for cortisol concentrations. One pre-determined area was shaved each week for 5 weeks (Weeks 1–5). During week 6, all five, previously shaved areas and an additional area was shaved to collect hair samples of various lengths. Hair length was recorded prior to the collection of each hair sample. Only data from the last week (Week 6) of collection were included in the analyses. Steers were categorized into one of three groups: old with black hair (OB, n = 3); old with white hair (OW, n = 3); young with black hair (YB, n = 12). Older steers exhibited greater hair cortisol concentrations than younger steers (P < 0.001). Hair cortisol concentration was not impacted by duration of growth (P = 0.33). Cortisol concentrations exhibited a weak, positive correlation with hair length (r = 0.33, P-value = 0.01). The average hair growth per week of beef steers in the winter months was calculated to be 0.90 mm. Further research should be performed to improve our understanding of the effect of hair characteristics, sampling methodologies and analysis techniques on hair cortisol concentrations.

PSII-1 Evaluation of RUP content and digestibility of feeds from organic and conventional sources

Abstract The purpose of this study was to evaluate and compare 17 different feeds for in situ rumen undegradable protein content (RUPc) and digestibility (RUPd) with the main objective being a comparison of organic and conventional sources of feeds. Two steers fitted with rumen cannulas and two heifers with duodenal cannulas were utilized for this study. Feeds used were procured from both conventional and USDA certified organic sources. Conventional feeds included field peas (FP), fish meal (FM), soybean meal (SBM), and dehydrated alfalfa (DA). Organic feeds included field peas (FPO), fish meal (FMO), soybean meal (SBMO), and dehydrated alfalfa (DAO). Each sample was weighed into both 5×10 cm and 10×20 cm dacron bags. Bags were evenly distributed between steers and ruminally incubated for 16 hours, replicated over two days. The 5×10 cm bags were treated with pepsin/HCl solution, inserted into the duodenum of the heifers, and retrieved from the feces to measure RUPd. Bags were washed, oven dried overnight, and residues composited to determine RUPc and RUPd. No digestibility data were gathered from FM or FMO due to lack of residue from digestion. Statistical analysis was performed using the Glimmix procedure of SAS, with sample as the experimental unit. The RUPc of DAO was not different (P = 1.0) from DA; SBMO was 32.7% greater (P &lt; 0.01) than SBM; FMO was 30.2% greater (P &lt; 0.01) than FM; FPO were not different (P = 0.46) than FP. The RUPd of DAO was 26.3% greater (P &lt; 0.01) than DA; no differences were observed between SBMO and SBM or FPO and FP (P &gt; 0.98). These data indicate that there may be some differences in rumen undegradable protein content and digestibility between conventional and certified organic feeds when measured in situ.

Effect of conventional and extrusion pelleting on postprandial patterns of ruminal and duodenal starch appearance in dairy cows

Intra-ruminal mixing of separately fed pelleted compound concentrates differing in physical functional properties of pellets was investigated by measuring postprandial starch concentration in rumen medial contents and duodenal starch and protein appearance in dairy cows fed a basal diet low in starch. Four compound concentrate meals were produced containing either 100% wheat, 50% wheat + 50% soybean meal (SBM; as is basis), 100% maize, or 50% maize + 50% SBM. Compound concentrate meals were pelleted by either conventional pelleting, or by cooking extrusion using two distinct settings giving pellets with either high density (HD) or low density (LD). For each compound concentrate, a 3 × 3 Latin square digestibility test was conducted using three lactating Danish Holstein cows fitted with ruminal and duodenal cannulas, and the three pelletizing methods as treatments. Seven sample sets of rumen medial digesta and fluid, rumen ventral fluid, and duodenal digesta taken at -0.5, 0.5, 1.5, 2.5, 4.0, 5.5, and 7.0 h relative to separate allocation of experimental concentrates at 8.00 h were investigated. Low palatability was observed especially for LD pellets from cooking extrusion of the 100% grains as the pellets became sticky in contact with saliva and water. The rumen medial starch concentrations and fermentation variables did not differ among pelletizing methods in a clear manner across the four concentrate mixes investigated, as neither did fermentation variables in the rumen ventral contents. Except for 100% maize, the postprandial duodenal starch appearance was greater for conventional pellets as compared with other pellet types tested. The rumen outflow of crude protein did not differ among pelletizing techniques used for the four concentrates investigated. In conclusion, the current study indicated that concentrate pellets with differing physical functional properties had limited effects on the intra-ruminal mixing into the particulate mat. Yet, rumen escape of conventional pellets might be of a substantial magnitude if pellets with both high density and stability in liquid can be produced. Indeed, further investigations are needed.

Impacts of whey protein on starch digestion in rumen and small intestine of steers.

Four Korean native steers (511 ± 17.2 kg; 2 × 2 replicated crossover design) fitted with duodenal cannulas were used to investigate the influence of oral administration of soluble whey protein (WP; 82.29% crude protein) on ruminal fermentation, gastrointestinal (GI) hormone secretion in the blood, pancreatic α-amylase activity in the duodenum, and disappearance rate in each segment of the GI tract. Steers were orally fed the basal diet (control; TMR [total mixed ration] 9 kg/d) or the basal diet with enriched WP (400 g/d) for 14 days. The apparent crude protein disappearance rate in the rumen of the WP was higher than in control (p < 0.05). However, no difference between groups was observed in the apparent crude protein disappearance rate in the intestine and the apparent starch disappearance rates in the rumen, GI tract. The level of cholecystokinin, secretin, and ghrelin in serum and pancreatic α-amylase activity in the duodenum of the WP also did not change. The changes in the level of blood urea nitrogen related to protein metabolism were higher in the WP than in the control (p < 0.05). However, the levels of total protein, lipid, carbohydrate and mineral metabolites did not change. Consequently, we suggest that the oral administration of WP in steers assisted in ruminal fermentation due to the population increase of microbes in the rumen but did not improve the starch digestion rate in the small intestine because GI hormone secretion in the blood and pancreatic α-amylase activity did not change.

Trace mineral source influences ruminal distribution of copper and zinc and their binding strength to ruminal digesta1,2,3.

Eight crossbred steers (BW 719.0 ± 65.0 kg) with ruminal and duodenal cannulae were used to examine the effect of trace mineral (TM) source on digestibility; ruminal and duodenal solubility of Cu, Zn, and Mn; and in vitro release of Cu, Zn, and Mn from the solid fraction of ruminal digesta. Experiment 1 determined the effect of TM source on DM and NDF digestibility in steers fed a corn silage and steam-flaked corn-based diet. Treatments consisted of 10 mg Cu, 20 mg Mn, and 30 mg Zn/kg DM from either sulfate TM (STM) or hydroxy TM (HTM) sources. Following a 14-d adaptation period, total fecal output was collected for 5 d. Dry matter digestibility was not affected by treatment, but NDF digestibility tended (P < 0.09) to be greater in HTM vs. STM supplemented steers. In Exp. 2, steers were fed a diet without supplemental Cu, Zn, or Mn for 19 d. Steers were then administrated a pulse dose of STM or HTM (2× the National Research Council requirements for Cu, Mn, and Zn) via the rumen fistula. Ruminal and duodenal samples were obtained at 2-h intervals starting at -4 and ending at 24 h relative to dosing. Ruminal soluble Cu and Zn concentrations were affected by treatment, time, and treatment × time. Soluble concentrations and percent soluble Cu and Zn in ruminal digesta increased (P < 0.05) above 0-h values for 10 h following dosing with STM, but not HTM. Concentrations of Cu and Zn in ruminal solid digesta were also affected by treatment, time, and treatment × time. Steers dosed with STM had greater (P < 0.05) solid digesta Cu concentrations at 2 and 4 h but lesser (P < 0.05) concentrations from 6 to 20 h post-dosing than those receiving HTM. Ruminal solid digesta Zn concentrations were greater (P < 0.05) in HTM vs. STM-dosed steers from 6 through 24 h post-dosing. Distribution of Mn in ruminal digesta was affected by TM source, but to a lesser extent than Zn and Cu. Duodenal soluble TM concentrations were variable and not affected by treatment. Binding strength of TM to ruminal solid digesta was estimated at 0, 6, and 12 h post-dosing using dialysis against chelating agents. The percentage of Cu and Zn released from ruminal solid digesta by dialysis against Tris-EDTA was greater (P < 0.05) at 12 h post-dosing from steers receiving HTM vs. STM. Results indicate that Cu and Zn from HTM have low solubility in the rumen and appear to be less tightly bound to ruminal solid digesta than Cu and Zn from STM.

Technical cashew nut shell liquid associated with non-protein nitrogen sources in high-grain diets for ruminants: intake and digestibility of nutrients, ruminal fermentation, and microbial protein synthesis

This study aimed to evaluate the association of technical cashew nut shell liquid (tCNSL) and two sources of non-protein nitrogen (NPN), dry matter intake (DMI), the partial and total apparent digestibility coefficient of nutrients, ruminal fermentation, microbial synthesis, and blood characteristics. Four Holstein steers (438 kg ± 17.14 kg) fitted with ruminal and duodenal cannula were used. Diets had (in DM basis) 135 g kg?1 of crude protein and 746 g kg?1 of total digestive nutrients. The roughage to concentrate ratio was 30:70. The experimental design was a 4 x 4 Latin square with 14-day experimental periods. The non-protein nitrogen sources used were livestock urea (U) and slow-release urea (SRU) (Optigen® II). The treatments consisted of diets containing U or SRU associated or not with tCNSL. The tCNSL was added to the diet in a proportion of 300 mg kg?1 of concentrate. DMI and ruminal, intestinal and total apparent digestibility coefficients of nutrients were not affected by experimental diets. The association of sources of NPN and tCNSL did not affect pH, ammoniacal nitrogen (NH3-N), plasma urea nitrogen (PUN), and microbial synthesis of animals consuming high-grain diets.