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R B Muntifering

Publications and source records attributed to R B Muntifering.

17 recordsLinked to original sources
PubMed1995

Growth and subsequent feedlot performance of estradiol-implanted vs nonimplanted steers grazing fall-accumulated endophyte-infested or low-endophyte tall fescue.

A growing-finishing study using Angus steer calves was conducted in three phases: 1) grazing stockpiled 'Kentucky-31' tall fescue (Festuca arundinacea Schreb.) with high (65%; HE KY-31) and low (0%; LE KY-31) infestation rates of Acremonium coenophialum Morgan-Jones and Gams and 'Kenhy' and 'Johnstone' tall fescue with low (< 1%) infestation rate of Acremonium coenophialum from October 24 to December 19; 2) drylot feeding of Johnstone and HE KY-31 haylage (December 19 to April 10); and 3) feedlot finishing on a common high-concentrate diet (April 11 to August 1). In Phase 1, ADG was greatest (P < .05) for Kenhy, intermediate for Johnstone and LE KY-31, and lowest (P < .05) for HE KY-31. Implantation with estradiol 17-beta increased ADG (P < .01) by 23, 27, 7, and 2% for steers grazing Johnstone, HE KY-31, LE KY-31, and Kenhy, respectively. Dry matter digestibility and DMI of stockpiled Johnstone and HE KY-31 were not different (P > .10). During Phase 2, steers consuming Johnstone haylage had greater (P < .01) DMI, ADG, and gain:feed ratio (G:F) than steers consuming HE KY-31 haylage. During Phase 3, steers previously consuming Johnstone had greater DMI (P < .10); however, steers previously fed HE KY-31 had greater ADG (P < .05) and G:F (P < .01). By the end of the study, steer body weights were not different (P > .10) between treatments. These data indicate that growth-decreasing effects of endophyte-infested fescue were evident at hypothermal-ambient temperatures.(ABSTRACT TRUNCATED AT 250 WORDS)

Acremonium↗
PubMed1993

Feed aversion learning in cattle with delayed negative consequences.

Two experiments were conducted to study the ingestive behavior of cattle when given a delayed dose of the aversive agent lithium chloride (LiCl) after eating a novel feed. In the first experiment, 20 calves were randomly divided into four groups (n = 5). The control group (G1) received 80 mg/kg BW of sodium chloride (NaCl) 4 h after eating a novel feed. Groups 2 (G2), 3 (G3), and 4 (G4) received 80 mg/kg of LiCl at 4, 8, and 12 h, respectively, after eating the novel feed. When calves were offered the novel feed on subsequent days, G2 and G3 ate less (P < .05) than G1. There was no difference (P > .05) in intakes between G1 and G4. In the second experiment, 15 calves were randomly divided into three groups (n = 5). The control group (G1) received 80 mg/kg BW of NaCl 12 h after eating a novel feed, whereas G2 and G3 received 80 and 160 mg/kg BW, respectively, of LiCl 12 h after eating the novel feed. When calves were offered the novel feed on subsequent days, G1 and G2 ate similar (P > .05) amounts, whereas G3 ate much less (P < .05) of it than the other groups. Cattle learned to avoid novel feeds even when they experienced negative postingestive consequences up to 12 h after they ate the feeds. The capacity for long-delay learning seems to be related to the severity of negative consequences experienced.

Animal Feed↗
PubMed1992

Voluntary intake and ingestive behavior of steers grazing Johnstone or endophyte-infected Kentucky-31 tall fescue.

Effects of grazing low-endophyte (Acremonium coenophialum Morgan-Jones and Gams, less than 1% infection) Johnstone (J) or high-endophyte (60% infection) Kentucky-31 (K) tall fescue (Festuca arundinacea Schreb.) on grazing behavior and voluntary intake were studied. Six Angus steers (average initial BW = 326 kg) grazed 1.21-ha plots of each forage cultivar (three steers per cultivar) in four 28-d periods beginning May 27. Daytime observations (0630 until 2130) revealed that J steers spent more (P less than .10) time grazing and lying down and took more (P less than .05) prehensile bites than K steers did; conversely, steers grazing K spent more (P less than .10) time standing and idling than J steers did. Idling time showed a forage x period interaction (P less than .10). Mean OM bite size (grams per bite) was not affected (P greater than .10) by forage but differed (P less than .10) among periods. Limited nighttime observations (2130 until 0630) revealed no effects (P greater than .10) of forage on grazing time or number of prehensile bites taken. Voluntary intakes of OM and NDF did not differ (P greater than .10) between steers grazing J and K; however, a forage x period interaction (P less than .10) existed such that, during Period 1, steers grazing J had greater (P less than .01) OM and NDF intakes than did steers grazing K. These data suggest that cattle grazing endophyte-infected tall fescue display altered daytime grazing behavior and that reduction of voluntary intake attributable to endophyte infection may be less severe under free-grazing than has been reported for controlled environmental conditions.

Acremonium↗
PubMed1990

Forage composition and intake by steers grazing vegetative regrowth in low endophyte tall fescue pasture.

A grazing trial was conducted with six half-sib yearling Angus steers (average initial weight 281 kg) to quantitate nutrient composition and voluntary intake of vegetative regrowth forage in low-endophyte (Acremonium coenophialum Morgan-Jones and Gams) Kentucky-31 tall fescue (Festuca arundinacea Schreb.) pasture. A new .6-ha section in each of two 3.0-ha pastures (three steers/pasture) was clipped to a 5-cm height on five consecutive days to establish a series of plots that could be grazed continuously during 5-d test periods at uniform stages of vegetative regrowth; each period represented a specific regrowth stage (7, 14, 21, 28 and 35 d). Steers were conditioned by training them to graze to satiety while tethered with an adjustable-length rope to a 1-m galvanized steel post. Grazing time was limited to two sessions daily beginning at 0800 and 1400, and satiety was achieved after no more than 2.5 h of continuous grazing in each session. Forage DM availability was controlled by adjusting tether length and was set each day at 4% of steer BW. Fecal DM output was measured by chromic oxide dilution. A quadratic (P less than .05) effect of regrowth stage was observed for forage contents of NDF and ADF due to abrupt increases in both fractions at wk 5; values for ADL were unaffected by stage of forage regrowth. Forage contents of CP and ash showed a cubic (P less than .05) response to advancing stage of regrowth, with highest (23.6 and 11.0%, respectively) and lowest (14.7 and 9.1%, respectively) values for both fractions occurring at wk 1 and 5, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1989

Metabolism of decoquinate in chickens and Japanese quail.

Thirty mature chicken hens and 40 mature Japanese quail hens were used in an experiment to compare pathways of decoquinate (DQ) excretion. Labelled DQ was injected into chickens (.5 microCi via wing vein puncture) and quail (.25 microCi via cardiac puncture) on Day 0. Blood was sampled at 0, 1.5, 3, 6, 9, 12, 24, and 48 h postinjection. Eggs and excreta of chickens and quail were collected for 28 and 14 days, respectively, and analyzed for 14C. Six chickens and eight quail were sacrificed prior to 14C-DQ injection and also on Days 1, 7, 14, and 34 or 32 postinjection. Samples of liver, heart, kidney, bile, skin, fat, and muscle were analyzed for 14C. Blood rapidly cleared 14C in both species, and the half-time of 14C excretion via excreta was more rapid in quail (.37 day) than in chickens (.92 day). Little 14C was found in the eggs of quail (.32% of dose) and chickens (.17% of dose). Quail appeared to excrete peak amounts of detectable 14C 1 day earlier (Day 4) than chickens (Day 5). Liver contained the greatest concentration of 14C on Day 1 in both species. By the end of the experiment, less than 1% of the dose remained in liver or other organs. Results indicate that chickens and quail metabolize 14C-DQ at comparable rates and by similar pathways.

Animal Feed↗
PubMed1988

Comparative drug depletion in domestic animals and birds.

Decoquinate (Rhone-Poulenc Inc) and Narasin (Eli Lilly and Co) were selected as model drugs for a comparison of metabolism between major (cattle and chickens) and minor (sheep and quail) species. Decoquinate has been studied in all four species. Narasin studies are in progress in chickens and quail. More than 96% of injected 14C-decoquinate (DQ) was eliminated from blood of all species within 1 hr. Disappearance of the remaining 1 to 4% from blood was rapid for all species. Half-times for DQ appearance in excreta were all less than one day. Cumulative excretion of DQ in eggs of chickens and quail was about 1% for both species. Disappearance of DQ from tissues was essentially complete in 14 days. More than 80% of injected 14C-narasin was eliminated from blood within 1/2 hr. Disappearance of the remainder was rapid for both chickens and quail.

Animals↗
PubMed1987

Effect of dietary protein level on nitrogen metabolism in lambs: studies using 15N-nitrogen.

Six wether lambs (31 kg) were randomly assigned to two treatments (three lambs/treatment): a high protein intake (HP; 21 g N/d) or a low protein intake (LP; 12 g N/d). Each lamb received 860 g/d dry matter (DM) of a pelleted diet (75% corn-soybean meal, 25% cottonseed hulls) offered hourly in 24 equal portions. Single injections of 15N-labelled compounds were made into the ruminal NH3-N and blood urea-N pools to measure the rate of flux through, and transfer of N between, these and the bacterial N pool. Total tract digestibilities of DM and N were lower (P less than .05) for the LP than the HP treatment. Abomasal flows of total, feed or bacterial N tended to be greater (P greater than .05) in lambs fed HP than LP. Lambs fed HP excreted more (P less than .01) urinary N, yet retained a greater (P less than .01) amount of N than lambs fed LP (6.2 vs 1.8 and 9.7 vs 4.1 g N/d, respectively). Pool size and production rate for both ruminal NH3-N and blood urea-N were greater (P less than .05) for the HP than LP treatment. Lambs consuming HP degraded more (P less than .05) blood urea-N in the gastro-intestinal tract (13.4 vs 6.9 g N/d); however, lambs fed LP degraded a greater (P less than .05) percentage of synthesized body urea-N (88.7 vs 71.8%). Ruminal NH3-N absorption was greater (P less than .01) for the HP than LP treatment (3.1 vs .5 g N/d). Although the percentage of bacterial N derived from ruminal NH3-N was similar (P greater than .05) between diets (51.1 vs 63.9), a greater (P less than .05) percentage of bacterial N was derived from blood urea-N in lambs fed LP than HP (77.1 vs 30.2%). Lambs fed LP incorporated a greater (P less than .10) amount of blood urea-N into bacterial N than lambs fed HP (5.5 vs 2.6 g N/d). These data are interpreted to suggest that blood urea-N may provide a substantial quantity of N for bacterial protein synthesis and, thus, may be an important source of protein in the deficient animal. In addition, urea recycling may play an important role in the recovery of ruminal NH3-N lost through absorption in animals fed a high level of protein.

Animals↗
PubMed1987

Effect of feeding frequency on forage fiber and nitrogen utilization in sheep.

Four crossbred wether lambs (38 kg) with permanent ruminal and abomasal cannulae were used in a 4 X 4 Latin square arrangement of treatments to determine the effect of feeding frequency (FF) on forage fiber and N utilization. Lambs were offered 900 g of good quality (vegetative) Kentucky-31 tall fescue hay in equal portions either 2, 4, 8 or 16 times daily. Water consumption increased (P less than .05; linear) with increased FF. Apparent total tract digestibilities of dry matter, organic matter and cell wall constituents were not affected (P greater than .05) by FF, but apparent total tract digestibility of crude protein decreased (P less than .05; linear) with increased FF. Ruminal and post-ruminal digestion of acid detergent fiber (percent of total tract digestion) differed (P less than .05; cubic) among FF treatments. Although N retention was not affected (P greater than .05) by FF, increased FF decreased (P less than .05; linear) mean ruminal ammonia-N concentrations. Both the quantity of total N reaching the abomasum and the efficiency of microbial crude protein synthesis tended to increase (P greater than .05) with increased FF. In addition, the daily quantity of microbial N reaching the abomasum was affected (P less than .05; cubic) by FF. Ruminal pH was not affected (P greater than .05) by FF, whereas total volatile fatty acid concentrations (VFA) decreased (P less than .05; linear) with increased FF. Responses in molar proportions of individual VFA to FF were variable, and suggest that increasing FF elicits significant changes in the distribution of fermentation end-products.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Nutritional Physiological Phenomena↗
PubMed1987

Growth and metabolism of growing beef calves fed tall fescue haylage supplemented with protein and(or) energy.

Endophyte (Acremonium coenophialum)-infected Kentucky 31 tall fescue was fertilized in mid-August, stockpiled, harvested November 4 to 6 and stored in a concrete stave silo. Ninety-six growing calves (189 kg) were assigned to the following treatments (24 calves/treatment): 1) corn silage (CS) plus .4 kg/d of soybean meal (SBM; 2) fescue haylage plus .4 kg/d of SBM; 3) fescue haylage plus 1.6 kg/d of corn and 4) fescue haylage plus 1.6 kg/d of corn and .4 kg/d of SBM. Daily gains and dry matter (DM) intakes during the 91-d trial were .52, 4.58; .51, 5.22; .59, 6.06; and .63, 6.18 kg for treatments 1 through 4, respectively. Daily gains of calves fed corn silage plus SBM and fescue haylage plus SBM were not different (P greater than .05). However, a difference (P less than .05) existed between treatments 1 and 2 vs 3 and 4. Feed conversion was improved (P less than .05) in calves fed corn silage. Calves in a metabolism trial were fed either 1) 6.2 kg November-ensiled fescue haylage or 2) 6.2 kg November-ensiled fescue haylage plus 1.6 kg/d of corn. Digestibility of DM, N-free extract (NFE) and TDN did not differ (P greater than .05) between treatments. Ether extract digestibility was greater (P less than .05) for the added corn diet, while that of CP was greater (P less than .05) for the fescue haylage diet. Nitrogen retained was higher (P less than .05) for calves fed added corn. A follow-up trial with 96 growing calves (190 kg) compared September- and November-harvested fescue haylages supplemented with either 1.3 or 2.6 kg corn/d.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1986

Effects of diet concentrate level and sodium bicarbonate on site and extent of forage fiber digestion in the gastrointestinal tract of wethers.

Four adult wethers (45 kg) with permanent ruminal and abomasal cannulae were used in a repeated measures Latin-square arrangement of treatments to quantitate the effects of diet concentrate level and sodium bicarbonate (NaHCO3) on site and extent of forage fiber digestion in the gastrointestinal tract. Experimental diets consisted of Kentucky-31 tall fescue hay, soybean meal and a semi-purified concentrate mixture in ratios of 95:5:0, 76:4:20, 57:3:40 and 38:2:60; NaHCO3 represented 0 or 7.5% of the concentrate mixture. Ruminal digestion (% of intake) of neutral detergent fiber (NDF) and hemicellulose decreased linearly (P less than .05), whereas acid detergent fiber (ADF) digestion responded in a cubic (P less than .05) fashion to increasing concentrate level; NaHCO3 improved ruminal digestion of NDF (P less than .10) and ADF (P less than .05), but not hemicellulose. Post-ruminal digestion (% of rumen non-degraded) of NDF and ADF tended to increase, whereas hemicellulose digestion responded in a cubic (P less than .05) fashion to increasing concentrate level; NaHCO3 decreased (P less than .05) post-ruminal digestion of all fiber fractions. Total tract digestion of NDF and ADF showed a cubic (P less than .05) response, whereas hemicellulose digestion responded in a quadratic (P less than .05) fashion to increasing concentrate level; NaHCO3 had no effect on total tract digestion of any fiber fraction. Correlations of ruminal hemicellulose digestion with mean pH (r = .33; P = .07) and minimum pH (r = .30; P = .09) were attained in a 24-h feeding cycle.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1986

Pancreatic amylase, plasma glucose, and insulin responses to propionate or monensin in sheep.

Yearling wethers fitted with reentrant bile-pancreatic duct cannulae were in a two-part study of effects of duodenal propionate infusions or increased ruminal propionate caused by dietary monensin on pancreatic alpha-amylase secretion and glucose and insulin in blood plasma. Continuous duodenal infusion of propionate increased concentrations of glucose and insulin in blood plasma of wethers fed alfalfa. Results supported a direct response of insulin secretion to propionate. Amylase secretion was not affected. Addition of monensin (22 ppm) to an 80% corn diet reduced the ratio of acetate:propionate in rumen, but bile-pancreatic flow and amylase activity were unaffected. Monensin supplementation had little influence on glucose and insulin in blood plasma. Pancreatic alpha-amylase secretion of ruminants seems to be a complex phenomenon that is not regulated strictly by fluctuations of glucose or insulin.

Amylases↗
PubMed1986

Comparative metabolism of 14C-decoquinate in chickens, quail and sheep.

Removal of pulse doses of 14C-decoquinate from blood was studied in chicken hens, quail hens, and ewe lambs. Estimated clearance before the first post-injection sample at 1 1/2 hr was 96% for sheep, 99% for chickens and over 99% for quail. Half-times for removal of the remaining radioactivity from the blood were 26.8 hr for sheep, 144.7 hr for chickens and 27.2 hr for quail. Treating the chicken data as biphasic yielded a 3.4 hr half-time for an initial fast phase and 210 hr for a later slow phase. Radioactivity disappeared from sheep blood between 2 and 7 d, from chicken blood between 7 and 14 d, and from quail blood between 1 and 2 d. Urine accounted for 35% of the radioactivity administered to sheep. It did not contain detectable activity after the third day.

Animals↗
PubMed1985

Effect of forage: concentrate on kinetics of forage fiber digestion in vivo.

With five rumen-fistulated Holstein steers in a Latin square design, we determined the effect of dietary concentrate (0, 20, 40, 60, or 80% cracked corn) on kinetic characteristics influencing forage fiber digestion in vivo. Rate and potential extent of neutral detergent fiber degradation were determined for fescue hay in situ by nylon bag technique. Rate of fiber passage from the rumen was measured by fecal excretion of chromium-mordanted fescue cell walls. Apparent extent of forage fiber digestion was predicted by a model in which fiber disappearance from the rumen is conceptualized as the sum of two competing first-order processes, digestion and passage, modified further by a discrete lag time during which fiber passes from the rumen before digestion commences. Stepwise multiple regression analysis revealed that potential extent of fiber degradation in situ was the primary determinant of depression of fiber digestibility as dietary concentrate increased. Rate of digestion, rate of passage, and lag effects collectively accounted for a small portion of the depression of fiber digestibility.

Animals↗
PubMed1982

Plasma magnesium levels as influenced by cold exposure in fed or fasted sheep.

Eight ewes weighing about 52 kg were used in a 2 X 2 factorial arrangement of treatments replicated with temperature reversal to determine the effect of cold exposure on plasma Mg, Ca, free fatty acids (FFA), glucose and insulin concentrations and on renal clearance of Mg and Ca. Closely sheared ewes were fed a complete mixed diet at either 1.5% of body weight with no pretreatment fast or fed ad libitum followed by fasting 3 days before initiation of temperature treatments. Fasting superimposed on cold exposure reduced (P less than 0.01) plasma Mg at 1 hour after exposure to cold, and this effect continued during the cold treatment period, whereas Mg concentration was not significantly affected in fed sheep. Plasma FFA measured across temperature treatments was increased (P less than 0.01) by fasting. FFA measured across dietary treatments was only slightly increased by cold exposure. Plasma glucose levels of fasting sheep were lower (P less than 0.05) than those of fed sheep; however, levels rose (P less than 0.05) after exposure to cold. A tendency for plasma insulin to increase after cold stress was observed. Renal clearances of Mg and Ca were markedly reduced (P less than 0.01) by fasting, but clearance was not changed by cold stress. These results suggest that exposure to cold (2-5 degrees) and a deficient dietary intake synergistically reduce plasma Mg in sheep.

Animals↗
PubMed1981

Effects of monensin on site and extent of whole corn digestion and bacterial protein synthesis in beef steers.

Monensin was fed at 0 and 33 ppm in a crossover trial designed to determine the effect of this compound on ruminal and postruminal utilization of a corn-based diet and bacterial protein synthesis in abomasally fistulated steers. Monensin decreased (P greater than .10) ruminal true digestion of organic matter (OMc, corrected for bacterial cell synthesis) and apparent ruminal digestion of starch by 19%, but had not effect on apparent total tract digestion of OM or starch. Apparent ruminal and total tract digestibilities of crude protein (CP) were unchanged. Monensin decreased (P greater than .07) the contribution of bacterial N to total abomasal N (52 vs 58%), and increased (P greater than .06) the contribution of ruminally undegraded feed N (46 vs 40%), but had not effect on total N or amino acids recovered from the abomasum. Efficiency of bacterial protein synthesis (grams bacterial CP/100 g ruminally digested OMc) was unchanged. Monensin decreased (P greater than .05) the fraction of bacterial N to total N digested postruminally (42 vs 50%) and increased (P greater than .05) the contribution of ruminally undegraded feed N digested postruminally (58 vs 50%). Monensin caused a greater proportion of feed N and starch to be digested in the intestines than in the rumen (with possibly greater resultant metabolic efficiency), and this may account for some of the benefits obtained from feeding this compound with high grain diets.

Abomasum↗
PubMed1980

Effect of monensin on nitrogen utilization and digestibility of concentrate diets by steers.

Monensin was fed at levels of 0 and 33 ppm in a series of digestion and metabolism trials to determine its effect on utilization of high grain diets and on ruminal parameters in yearling steers. Monensin had no effect (P greater than .05) on apparent digestibility of dry matter, gross energy or starch when fed with a 90% corn diet (10.5% crude protein, dry matter basis). Monensin in this corn-based diet tended to increase crude protein digestibility (63.4 vs 61.3%) and decrease ruminal ammonia concentration (2.5 vs 6.5 mg/100 ml) measured 3 hr postprandially (P greater than .05). In metabolism trials with a 76% sorghum grain diet (11.7% crude protein, dry matter basis), monensin improved apparent digestibility of crude protein (P less than .05) but not dry matter or gross energy (P greater than .05). Retention of nitrogen, expressed as a percentage of nitrogen intake, tended to improve (24 vs 20%) in response to monensin addition to the sorghum grain-based diet (P greater than .05); a similar trend was observed (P greater than .05) for nitrogen retention expressed as a percentage of nitrogen absorbed (41 vs 36%). Total ruminal volatile fatty acid (VFA) concentrations measured 3 hr postprandially were not altered by monensin fed with either diet. The proportion of acetic acid d-creased (P less than .05) and that of propionic acid increased (P less than .05) in response to monensin fed with the corn-based diet. Monensin did not appreciably alter proporations of VFA when fed with the sorghum grain-based diet. Results suggest that a possible improvement in N utilization may account for some of the benefits of feeding monensin with high grain diets.

Animals↗