VTechWorks Repository :: Browsing by Author "Fontenot, Joseph P."

Browsing by Author "Fontenot, Joseph P."

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Adding Urea to Corn Silage
Murley, W. Ray; Mast, C. C.; Fontenot, Joseph P.; Polan, Carl E. (Virginia Cooperative Extension Service, 1967-09)
Considerable interest in adding urea to corn silage at ensiling time has been shown in recent years because of the low protein content of corn silage. Also, when fed in proper amounts, urea is a low-cost source of protein. Research results at Virginia Tech and the Forage Research Station, Middleburg, as well as other state research stations, indicate that urea can be added to corn silage at ensiling time and good response obtained in beef and dairy animals. Adding urea to corn silage raises the level of protein in the silage, thus, a lower percent protein supplement can be fed, or in feeding dry cows or beef cows, no protein supplement is needed.
Canopy, microenvironment, and nitrogen effects on summer recovery of tall fescue
Stringer, William C. (Virginia Tech, 1977-07-05)
Stand losses in temperate grasses after summer defoliation of tall canopies inspired an investigation of microenvironmental and plant responses in tall fescue. Microenvironment and regrowth of tall fescue in response to mowing managements and nitrogen rates in spring that created different canopy structures was studied. In early spring, 50 and 160 kg/ha of N were applied. Mowing managements were: clipping at 4 or 8 cm biweekly, monthly, and in late June. In late June all 6 treatments were mowed to prescribed stubble heights with a seventh unmowed check. Canopy light regimes, leaf area index, and regrowth of tillers were monitored along with soil, fair, and shoot temperatures in stubbles after the June harvest. Mowing more frequently in spring decreased canopy yields of the June harvest, but increased leaf area (LAI) of stubbles as compared to spring-accumulated canopies. High nitrogen decreased specific leaf weights (SLW) in stubble leaves and increased LAI except in spring-accumulated canopies. Increased LAI decreased light penetration and canopy temperatures. Temperatures were highest in harvested spring-accumulated stubbles with a shift of 4-10 C between unharvested and harvested stands while radiation penetration into the stubble increased from 5 to 75% of total. Some large stand losses occurred in lodged portions of harvested Spring-accumulated plots. Generally, regrowth yields were not affected by prior clipping managements. Concentration of TNC was uniformly high with all treatments.
Chemical and physical changes associated with maturity of different plants and enhancement of nutritional value by chemical treatment of crop residues
Naseer, Zarga (Virginia Tech, 1990)
Experiments were conducted to study the chemical changes and microanatomical characteristics associated with maturity, rate and extent of DM digestion, behavior and extent of tissue digestion and mode of microbial attack during simulated ruminal digestion. Barley and millet plants were collected at four different stages of development: vegetative, boot, heading and mature. Berseem was harvested at three different stages of development: vegetative, bud and full bloom. For the first three stages of grasses and legumes, the plants were separated into three botanical fractions: leaf blades (leaflets), leaf sheaths (petioles) and stems. Grasses were harvested at mature stage and barley seeds were separated by thresher and millet seed by hand cutting the head. Straws were chopped in a hammer mill through a 2.5 cm screen and treated: 1) no added water (control), 40% added water, 2) alone or with 3) urea, 4) NH₄OH and 5) H₂O₂ at pH 11.5. Grasses showed higher (P<.05) cell wall constituents, xylose, p-coumaric and ferulic acid and lower (P<.05) IVDMD values for stems and leaf sheaths than leaf blades. Legume showed higher (P<.05) values for cell wall constituents and xylose for stems, compared to petioles and leaflets. At advanced maturity, scanning electron microscopy (SEM) showed increased lignification and decreased tissue digestion for leaf sheaths and stems, compared to leaf blades. Lignification was higher in millet leaf sheaths than barley leaf sheaths. Within berseem plant parts, petioles showed better digestion than leaflets and stems. The contents of ADF, cellulose and lignin were increased (P<.05) and hemicellulose was decreased (P<.05) in alkaline H₂O₂-treated straws, compared to untreated, NH₃- and urea-treated straw. Total phenolic acids were decreased (P<.05) in treated, compared to untreated straw. In vitro DM digestibility was increased (P<.05) for all chemical treatments, with larger (P<.05) increase for NH₃ treatment than alkaline H₂O₂ treatment.
Community Decision Making Aids for Improved Pasture Resources in the Madiama Commune of Mali
El Hadj, Meriem (Virginia Tech, 2004-11-29)
The lack of forage resources in the Sahelian region of Mali is a major constraint to food production and food sufficiency. Madiama commune is located in northern Mali, in the Niger Delta region. Three separate experiments were conducted to investigate ways to improve pasture resources and productivity. The first experiment (2003) was designed to investigate the influence of sheep grazing tethered at two different residual heights on botanical composition, forage biomass and animal performance. Young sheep weighing approximately 18-24 kg were tethered for a certain period of time depending on residual canopy height. Two treatments 3 or 6 cm residual height were each replicated 4 times. Animals were rotated based on canopy height and each tethered animal followed an 8 paddock rotation. Measurements included forage biomass, plant diversity, animal performance, and botanical composition. The forage species found on these pastures were primarily Schoenfeldia gracilis, Panicum laetum, Setaria palludefusca, Eragrostis turgida, Eragrostis tremula, Zornia glauchidiata, Tephrosia pedicellata, and Cynodon spp. Accumulated seasonal forage biomass increased while forage quality declined as the growing season progressed. Treatment had only a slight effect on animal weight gains (1 to 3kg season-1). These results suggest that residual height may not affect livestock gain. The second experiment was designed to investigate the potential of Cassia tora (C. tora) which is an invasive weed in the region as a supplemental feed for livestock. Cassia tora was harvested within the Madiama commune and ensiled with or without additives (water and or honey/sugar) for 60 or 90 days. Harvest occurred at the vegetative stage in year 1 and mature growth stage in year 2. Prior to placing the chopped material in the bags for ensiling, sub-samples of fresh C. tora were obtained for dry matter (DM) and chemical analysis (NDF, ADF, CP, IVDMD and TDN). In year 1, the ensiled material/fresh material across treatments and locations had NDF varying from 48 to 56 %/ 56 to 57%, ADF from 34 to 41 %/40 to 42%, CP from 9 to 10 %/9 to 23%, and IVDMD from 53 to 64 %/52 to 54%. In year 2, CP averaged twice as much as year 1 with significantly less fiber probably due to the fact that harvest occurred at the vegetative stage. Addition of water or sugar/honey improved the nutritive values of the ensiled material. These results suggest that C. tora can be a reliable feed source during the dry season. A greenhouse experiment was conducted using various P sources (Tilemsi phosphate rock (TPR), North Carolina phosphate rock (NCPR), Aluminum phosphate (AlP), Iron phosphate (FeP), and Triple superphosphate (TSP) and rates (0, 20, 40, 60, and 80 mg P kg-1 soil). Plants were grown for 10 wks, harvested and separated into above and below ground plant parts. The root and plant material were dried, ground and analyzed for elemental P. The result showed variable P solubility and uptake by the plant. Overall, addition of P resulted in an increase in above ground biomass as well as root mass compared with the untreated control. Field and greenhouse experiments showed that in the Sahel region of Africa where feed resources are scarce 8 out of 12 months a year, anything we can do to increase pasture resources and animal productivity while maintaining a healthy ecosystem, could improve the quality of life in the community.
Comparison of techniques for estimating pasture herbage mass and productive ground cover for Lakota prairie grass, Kentucky 31 endophyte free tall fescue, Kentucky 31 endophyte infected tall fescue and Quantum 542 tall fescue grazed by stocker steers
Rotz, Jonathan Daniel (Virginia Tech, 2006-04-10)
In terms of acreage, forage is the number one crop in Virginia. The backbone of these forages has long been tall fescue (Lolium arundinaceum (Schreb.) S.J. Darbyshire). Knowledge of the plant species that make up a pasture and the relative amounts of each species present is important for interpreting potential animal performance. It is also important to know the relative amounts and types of weeds present and to monitor for the presence of poisonous plants or noxious weeds. An experiment was conducted in 2003 through 2005 to investigate botanical composition and yield of "Lakota" prairie grass (Bromus catharticus Vahl.), "Kentucky 31" endophyte-infected (KY31 E+), endophyte-free (KY31 E-), and "Quantum" tall fescue (non toxic endophyte infected) under grazing by stocker steers. Forage botanical composition and yield were determined by clipping three 0.25-m2 areas per treatment replicate. Prior to harvesting, the canopy height within each quadrate was measured with a disc meter. In 2005, productive ground cover was assessed using visual evaluation techniques, point quadrat method, and digital imagery quantified with terrestrial remote sensing. Forages were established September 2002 and grazing was initiated in July of 2003. Experimental design was a randomized complete block with four replications. Averaged over the three years the yield of KY31E+ was higher (p<0.05) than all other treatments. Lakota prairie grass had lower (p<0.05) yields than both KY31 E+ and Quantum tall fescue, however no yields did not differ between Lakota prairie grass and KY31 E-. Our results showed a typical forage distribution curve for all the treatments. Early spring, summer, and fall productivity of Lakota prairie grass was less than all the fescues, thus did not extend the grazing season. Forage persistence was greatest for KY31 E+ and Quantum and lowest for Lakota when averaged over all years. Among sampling methods for ground cover, terrestrial remote sensing was the most accurate, compared with visual evaluation and point quadrat methods. For estimates of all yield indirect methods of assessment had high errors; however the plate meter calibrated by sward density seemed the least variable of the methods tested.
Compatibility, Yield, and Quality of Matua Prairie Grass, Bromus willdenowii (Kunth), with Legumes
Guay, Jennifer Fincham (Virginia Tech, 2003-12-08)
Matua prairie grass has a potential to extend the grazing season in Virginia due to its higher early spring and fall production. However, little is known about the compatibility of Matua prairie grass with legumes or the effects of legumes on the yield and quality of Matua prairie grass/legume mixtures. An experiment was conducted in 1998 and 1999 to investigate the botanical composition, yield, and chemical composition of Matua prairie grass grown with legumes. Legume treatments consisting of ladino clover (Trifolium repens), red clover (Trifolium pratense), alfalfa (Medicago sativa), and annual lespedeza (Lespedeza stipulacea) were drilled into a Matua prairie grass stand. Nitrogen was applied once each fall at two treatment levels of 0 or 84 kg/ha. The experiment was arranged in a randomized split block design with four replications. Legume treatments had no effect on percentage Matua prairie grass or total dry matter yield in 1998. However, in 1999 the ladino clover and red clover treatments increased (P<0.05) total dry matter yield, but also resulted in a substantial decrease (P<0.05) in percentage Matua prairie grass. Nitrogen application in the fall of 1998 had a residual effect (P<0.05) on the percentage Matua prairie grass and yield in 1999. The highest response to nitrogen fertilization occurred in the harvest immediately after fertilization, in October of 1999, which resulted in the largest increase (P<0.05) in percentage Matua prairie grass and yield, and the greatest decrease (P<0.05) in percentage legumes. The legume and nitrogen treatments similarly influenced the chemical composition of the Matua prairie grass/legume mixed forage. Ladino clover, red clover, and alfalfa treatments generally improved forage quality as indicated by a decrease (P<0.05) in NDF, ADF, hemicellulose, and cellulose, and an increase (P<0.05) in CP and IVDMD. Nitrogen fertilization did not influence the chemical composition of the forages to the same extent as the legume treatments, as a decrease in fiber components and an increase in CP and IVDMD were observed due to nitrogen. Overall, alfalfa appeared to be most compatible with Matua prairie grass, and the incorporation of alfalfa into a Matua prairie grass stand resulted in some improvements in total dry matter yield and nutritive value of the forage, without the detrimental suppression of Matua prairie grass.
Composition and in vivo and in vitro digestibility of cattle fecal waste
Lucas, Donald Montgomery (Virginia Tech, 1974-04-05)
Three digestion trials were conducted with six yearling steers to study apparent digestibility of fecal waste from steers fed a ground, high roughage finishing ration. In the first trial steers were fed a basal ration containing approximately 50% roughage. The ration contained 14.3% crude protein and 22.8% crude fiber, dry basis. Apparent digestibility was 65% for dry matter and 66% for crude protein. The feces collected during this trial were dried in a forced air oven at 120 C and ground. The chemical composition of the feces was 13.2% crude protein, 31.4% crude fiber, 2.8% ether extract, 5.4% ash, 38.8% NFE, 70.9% cell walls and 44.8% ADF, dry basis. For trials 2 and 3 a switch-back design was used. In each trial one-half of the steers were fed the basal and the remainder were fed a ration in which dried cattle feces collected during trial 1 were substituted for 20% of the basal ration.
Determining the Nutritional Status of Mature Beef Cows
Horsley, Donald Shane (Virginia Tech, 2002-01-09)
Improved prediction of forage quality and cow performance may enhance the nutritional management of beef cows. In two 12 mo trials, mature beef cows (n=136) grazing tall fescue pastures were used to compare estimates of forage quality and animal performance. Forage quality was estimated by proximate analysis of forage samples (FOR) or by near infrared reflectance spectroscopy of fecal samples (FNIR). Nutritional Balance Analyzer (NutBal), NutBalPro and 1996 NRC Nutrient Requirements of Beef Cattle (NRC) programs were used to predict animal performance. The objectives were to compare FOR and FNIR estimates of CP and TDN and to evaluate the accuracy of cow performance predicted by FNIR-NutBal, FNIR-NutBalPro and FOR-NRC systems. Initial BW, body condition score (BCS), hip height and breed were used to establish cow biotypes for prediction programs. Every 28 d, cow BW and BCS were measured and forage and fecal samples collected. Weather data, cow status and FOR or FNIR results were entered into NutBal, NutBalPro and NRC programs. Forage CP estimated by FNIR (CPFNIR) or FOR (CPFOR) were similar. In trials 1 and 2, correlation coefficients between CPFNIR and CPFOR were r = .24 and r = .43, respectively. Forage TDN estimated by FNIR was greater (P <.05) and lowly or moderately correlated to FOR estimates. Actual BW change between weigh periods (BWCHG) and ADG were similar to NRC predictions, but less (P<.0001) than predicted by NutBal or NutBalPro. The NutBal or NutBalPro mean BCS change between weigh periods (BCSCHG) were greater (P<.001) than NRC or Actual BCSCHG. Actual and NRC BCSCHG were similar (P>.2, trial 1) or tended (P<.1, trial 2) to be similar. Cow performance estimated by NRC was highly correlated to Actual. Absolute differences in animal performance were also investigated for each prediction program. In trials 1 and 2, NutBal and NutBalPro over-predicted BWCHG, ADG and BCSCHG by 40 kg, 1.25 kg/d and .75 BCS, respectively, compared to actual cow performance. It appears that FNIR is a promising predictor of forage CP but not TDN. Also, the FOR-NRC is a satisfactory predictor of cow performance.
Development of cassava (Manihot esculenta Crantz) leaf meal as an animal feed
Ravindran, Velmurugu (Virginia Polytechnic Institute and State University, 1985)
Research was conducted in Sri Lanka to evaluate the feasibility of developing cassava (Manihot esculenta Crantz) leaf meal as an animal feed. In feeding trials with broilers, improvements in performance were observed at 10% inclusion of cassava leaf meal (CLM). High levels (20 and 30%) of CLM depressed gain, feed intake and feed per gain. Weights of spleen and liver (% of body weight) linearly increased with increasing levels of CLM. Carcass pigmentation values favored the CLM-based diets. Dietary additives (methionine, sodium thiosulfate or soybean oil plus methionine) improved the growth of broilers fed 20% CLM diet without, however, having any beneficial effect when added to the basal diet. Gain of broilers tended to decrease with increasing dietary levels of cyanide. Feeding trials with growing pigs showed that CLM can be included up to 26.7% level without any effect on performance. Gain and feed per gain were improved at 13.3% CLM level, whereas marked depressions were noted at 40% CLM level. Results of the balance trials indicated that cassava leaf protein is utilized more efficiently by the pigs, although the nutrients in CLM are not as digestible as those in coconut oil meal. The overall results suggest that bulkiness, low energy content, methionine deficiency and presence of anti-nutritional factors, are the major factors limiting the high level use of CLM in non-ruminant diets. Studies on the processing of CLM revealed that simple drying is sufficient to eliminate almost 90% of the initial cyanide level in the fresh cassava leaves. A combination of chopping and 3-day wilting prior to drying proved most effective in lowering the cyanide level of CLM. Field trials conducted with a short-age cassava variety, MU 22, demonstrated that it is possible to increase cassava leaf dry matter yields by defoliating once during the growing season and to produce within 86% of the normal yield of roots. Two defoliations during the growing season depressed the root crop by more than half.
Digestibility and apparent mineral utilization by Arabian geldings fed alfalfa, tall fescue, and Caucasian bluestem
Crozier, Jennifer Anderson (Virginia Tech, 1994-08-05)
Three palatability and digestion trials were conducted with six Arabian geldings fed alfalfa (Medicago sativa L.), endophyte-free tall fescue (Festuca arundinacea Schreb.), and Caucasian bluestem (Bothriochloa caucasica (Trin.) C.E. Hubbard) as hay to determine nutritional value of the hays for horses at maintenance in a Latin Square designed experiment. Alfalfa had higher (P < .01) dry matter digestibility, and voluntary intake, compared to grasses. Tall fescue and Caucasian bluestem did not differ in dry matter digestibility and voluntary intake. Feeding alfalfa resulted in higher (P < .05) intake and digestibility of CP and higher (P < .05) apparent absorption of Ca, P, K, and S, compared to the grass hays. Tall fescue was higher (P < .01) in CP concentration and digestibility, total nonstructural carbohydrate concentration, and apparent absorption of Mg and S, compared to Caucasian bluestem. Caucasian bluestem was higher (P < .05) in Zn compared to tall fescue. At the end of the palatability trials, horses fed alfalfa had higher serum concentrations of blood urea nitrogen, vitamin A, and serum P, S, and Cu, compared to horses fed grasses. Serum Zn was higher (P < .05) and Se tended to be higher (P < .06) in horses fed Caucasian bluestem, compared to tall fescue. All forages were below the recommended dietary Cu and P concentration but only Caucasian bluestem resulted in negative apparent P absorption. Caucasian bluestem would meet most nutrient requirements for horses at maintenance. Alfalfa supplied more crude protein, Ca, Mg, and K than was required by horses at maintenance.
Digestion and nitrogen utilization by sheep fed diets supplemented with processed broiler litter
Kwak, W. S.; Fontenot, Joseph P.; Herbein, J. H. (2003-11)
In vivo digestion and metabolism trials were conducted with 10 wethers equipped with ruminal, abomasal, and ileal cannulae to evaluate digestion of ensiled broiler litter (EBL), deepstacked broiler litter (DBL), and composted broiler litter (CBL). Wethers were fed a low protein (6.3% CP) basal diet alone or supplemented to 10.3% CP with EBL, DBL, CBL or soybean meal (SBM). All diets were formulated to be isoenergetic (56% TDN, DM basis). Apparent digestibilities of DM, OM, and ADF were not affected (p<0.05) by diet, but digestibility of CP was improved (p<0.05) by N supplementation. Apparent digestibility of CP was lower (p<0.05) for diets supplemented with CBL and DBL than for diets supplemented with SBM and EBL. Ruminal NH(3) concentration was 20 to 24 mg/dl at 2 h after feeding litter-supplemented diets compared with 13 mg/dl for SBM. Abomasal N, NH3 N, and nonammonia N flows were increased (p<0.05) by N supplementation, whereas microbial N flow was not influenced (p<0.05) by diet. Compared with SBM and EBL, undegraded dietary CP flow to the abomasum tended to be greater (p<0.1) when wethers were fed DBL and CBL-supplemented diets. Retention of N (g/d) also was greater (p<0.05) due to greater (p<0.05) N intake and lower (p<0.05) urinary N excretion when wethers were fed diets supplemented with litter (especially EBL) vs. SBM. Overall, characteristics of ruminal fermentation and digestion indicated that broiler litter N was utilized efficiently by wethers, but ensiling may be preferable to deepstacking or composting.
Effect of application of fluidized bed combustion residue to reclaimed mine pastures on forage yield, composition, animal performance and mineral status
Smedley, Kristi Olson (Virginia Polytechnic Institute and State University, 1985)
Reclaimed surface mined soils in Appalachia are typically infertile and must be amended for optimum vegetative growth. Fluidized bed combustion residue (FBCR), a by-product of coal-fired power plants, has high levels of Ca, S, Zn, Fe, and Al, and 50% of the neutralizing capacity of limestone. Three treatments were applied to three replicated .81 ha reclaimed mine pastures: control (no amendment), 6760 kg FBCR/ha, and 3380 kg limestone/ha. Based on forage availability, six steers were rotationally grazed on pastures receiving each treatment. Steers were weighed and blood samples collected at 14-d intervals and all animals were sacrificed for tissue sampling at the end of the 114-d trial. Amendment with FBCR or limestone increased soil pH (P < .05) above control levels. Forage yield and steer gain were not significantly affected by treatment. Forage samples collected during the trial indicated that FBCR and limestone amendments elevated forage ash, Ca, Mg, S, Cu and Ca:P ratio (P < .05). Cellulose and NDF were depressed in forage grab samples collected from FBCR- and limestone-amended pastures. The forage sampled the following spring was lower in hemicellulose, Zn, un and Ni; and higher in ash, Ca, S, the Ca: P ratio in the FBCR- and limestone-amended pastures. Mean serum mineral levels of steers were not affected by pasture treatment. The blood packed cell volume was higher in cattle grazing FBCR-amended pastures. Liver levels of Fe, H, Hi and Na were lower in cattle on pastures amended with FBCR or limestone. Bile levels of Mn were depressed in cattle grazing FBCR~ and limestone-amended pastures. The level of Cu in the liver and serum was at deficiency levels and was not detectable in bile, regardless of treatment. Higher kidney levels of Ca, Hg and P were recorded for steers grazing FBCR- and limestone-amended pastures. Hair Zn was higher in cattle grazing the FBCR- and limestone- treated pastures. Rib Cr and long bone Cd levels were lower in animals grazing the limestone- and FBCR-treated pastures. This study suggests that FBCR amendment enhances nutrient quality of forage and mineral status of animals at least as well as limestone application to acidic reclaimed mine pastures.
Effect of Feeding Different Protein and Energy Supplements on Performance and Health of Beef Calves During the Backgrounding Period
Austin, Robert Jesse (Virginia Tech, 2001-08-15)
Newly received or weaned calves are highly susceptible to the incidence of bovine respiratory disease. In addition to high levels of stress, decreased feed intake and exposure to foreign antigens result in increased morbidity and possibly death losses. Four backgrounding trials were conducted to examine the effects of protein and energy supplements to stressed calves consuming different forages. Body weights, rectal temperatures and blood samples were taken on d 0, 7, 14, 28 and 42. Supplements consisted of corn or mixtures of corn and soybean meal. In trial 1, 48 heifers (average BW = 219 kg) fed fescue hay in drylot, were allotted to four treatments: no supplement, 15% CP supplement (0.5% BW), 15% CP supplement (1.0% BW) and 30% CP supplement (0.5% BW). Supplemented heifers had higher (P<0.05) ADG than unsupplemented heifers by 42 d. Heifers fed the 30% CP supplement had higher (P<0.05) plasma urea-N by d 42. In trial 2 (pasture study 1), 36 steers (average BW = 217 kg) grazed stockpiled tall fescue and were allotted to three treatments: no supplement, a 15% CP supplement (0.5% BW), and a 15% CP supplement (1.0% BW). After wk 1, ADG was lower (P<0.05) for supplemented calves. At the end of the trial, steers supplemented at 0.5% BW had higher (P<0.05) ADG than steers supplemented at 1.0% BW. Glutathione peroxidase levels were lower (P<0.05) for supplemented steers on d 28. For trial 3 (pasture study 2), 48 steers (average BW = 202 kg) grazed stockpiled tall fescue and were allotted to three treatments: no supplement, corn (1% BW), and 15% CP supplement (1% BW). After wk 1, ADG was higher (P<0.05) for steers supplemented with corn. Steers supplemented with 15% CP supplement had the lowest (P<0.05) ADG after 7 d. At d 42, supplemented steers gained faster (P<0.05) than unsupplemented steers. For trial 4 (pasture study 3), 48 steers (average BW = 202 kg) grazed stockpiled tall fescue or fescue-alfalfa and were allotted to two treatments: no supplement and a 15% CP supplement (0.5% BW). During wk 1, steers grazing fescue had higher (P<0.05) ADG than steers grazing fescue-alfalfa. During wk 1, supplemented steers had a higher (P<0.05) morbidity scores. At d 42, ADG was higher (P<0.05) for supplemented steers. No consistent differences were detected in forage and blood serum mineral concentrations in all trials. Glutathione peroxidase activity increased (P<0.05) for all trials on d 14, regardless of supplementation. Supplementation improved ADG by d 42 but did not affect overall health status of calves in all trials.
Effect of feeding high levels of broiler litter on mineral metabolism and health of beef cows
Wright, Martha A. (Virginia Tech, 1996)
Some cattle producers have reported metabolic disturbances in beef cows fed high levels of broiler litter. Therefore, an experiment was conducted to evaluate mineral metabolism of beef cows fed different levels of broiler litter. Sixty Angus-Hereford crossbred cows ranging in age from 3 to 12 yr were blocked by age, BW, and stage of gestation, and randomly allotted within blocks to three diets: 1) mixed hay, full-fed; 2) 4.1 kg of a mixture of 80% broiler litter and 20% cornmeal plus mixed hay (low-litter diet); and 3) 8.2 kg of the 80% litter and 20% cornmeal mixture plus mixed hay (high-litter diet). Cows fed the litter diets were fed 57 g of magnesium oxide per head per day in the litter-corn mixture. Cows fed the three diets had access to a high-Mg mineral mixture. Experimental diets were fed from January 4, 1995 to April 19, 1995, and calving began on March 15. There were no physical signs of metabolic disturbances in any of the cattle. Blood serum Ca decreased and P levels increased in the cows fed both levels of broiler litter after the first 28 d on experiment. On d 28, average serum Ca values were 8.5 mg / dL for the cows fed hay, compared to 7.9 and 7.6 mg / dL for those fed the low and high levels of litter, respectively (P < .01). The average serum P values were 5.7, 8.2, and 9.1 mg/dL, respectively (P < .01). Generally, serum Ca remained lower and serum P remained higher for the cows fed broiler litter until the end of the winter feeding period (105 d). By mid-summer, serum Ca and P were similar (P > .05) for cows that had been fed the three diets. Serum Mg, Cu, and Zn were not affected by feeding litter. Urinary Ca and Mg, expressed as units per unit of creatinine, did not differ (P > .05) among treatments. Serum parathyroid hormone (PTH) was higher (P < .05) in cows fed the lower level of litter than those fed the higher level in April (105 d). Serum PTH values for cows fed hay were intermediate. Birth weights, rate of gain, and weaning weights of calves did not differ among the three diets. Feeding high levels of broiler litter to beef cows appears to affect serum Ca and P.
Effect of Form and Amount of Phosphorus and Phytase Supplementation on Phosphorus Utilization by Ruminants
Shanklin, Rachel Kristina (Virginia Tech, 2001-07-11)
The use of animal manures to replace commercial fertilizer has increased the economic and environmental sustainability of agriculture. However, this practice has resulted in excess P being applied to the soil in some areas. Excess P may run-off into surface water and leach in the ground, causing eutrophication. Decreasing the amount of P fed and improving the utilization of P are two possible nutritional solutions to this problem. Two experiments were conducted to investigate the effects of levels of dietary P, chemical form of P, and phytase supplementation in ruminants. For Exp. 1, 24 steers (average BW = 229 kg) were allotted to two diets containing 0.12 and 0.19% dietary P for a 112-d growth trial. The steers were individually full-fed, weighed every 14 d, and blood samples were collected every 28 d. The steers fed the 0.12% P diet had increased (P<0.02) ADG during the first 28 d, after which there were no differences. They also had higher (P<0.05) feed intake. By d 56 serum P for the 0.12% P group was lower (P<0.01), and this difference continued for the remainder of the trial. For Exp. 2, 18 wether lambs (average BW = 23 kg) were allotted to the following six diets for each of two metabolism trials: 1) a negative control diet deficient in P, 2) control diet supplemented with inorganic P, 3) control diet supplemented with phytic acid, 4) control diet supplemented with phytic acid and phytase, 5) control diet supplemented with cottonseed meal, and 6) control diet supplemented with cottonseed meal and phytase. Each metabolism trial was preceded by a 5 wk depletion phase in which the lambs were fed a low-P diet. The metabolism trials consisted of a 10 d preliminary period followed by a 10-d collection of feces and urine. On the final day ruminal fluid, blood, and saliva were collected. At the end of the second metabolism trial 10th rib bones were collected from each lamb. Absorption of P was lowest (P<0.0001) for the low-P treatment, compared to the other treatments. There was no treatment effect on saliva P. Ruminal fluid P was higher (P<0.05) for lambs receiving P supplementation. Within supplementation treatments, ruminal fluid P was higher (P<0.05) for lambs fed organic P than for those fed inorganic P. Feeding CSM resulted in higher (P<0.001) ruminal fluid P than phytic acid. The addition of phytase to the diets with organic P resulted in more (P<0.04) P in the ruminal fluid. There was a decrease (P<0.003) in serum P associated with the low-P treatment. There was no difference in bone ash or breaking strength.
Effect of land application of fluidized-bed combustion residue on soil and plant characteristics of reclaimed surface-mined pastures, performance and mineral status of grazing steers and nutrient balance by sheep fed the forage
Cochran, Michele A. (Virginia Tech, 1988-02-15)
Fluidized-bed combustion residue (FBCR) results from mixing coal with limestone during the combustion process. This by-product may be used as a liming agent. A grazing trial was conducted on an acidic mine soil to compare FBCR to dolomitic limestone and no amendment (control). Six steers per treatment were grazed rotationally on three replications (rep) of three .8 ha pastures. Both materials increased soil pH similarly, and reduced plant uptake of Fe, Zn, Mn, and Ni similarly. Calcium concentration increased in forages by both amendments, Mg increased with limestone and S with FBCR application. Cell wall components decreased, while ash and lignin increased with both amendments. Serum mineral levels of cattle were normal except Cu was low. Animal tissues reflected differences in mineral concentration observed in forages. Hay harvested from one rep was used in a mineral balance trial with 18 wethers. Apparent digestibility of dry matter, crude protein and fiber components, and N retention were not affected by treatment. Control animals were in negative Ca balance. Apparent absorption of Mg was higher (P < .01) for limestone treatment animals; S absorption was higher for the FBCR group; and, Zn absorption was higher for controls. Serum mineral levels of sheep were normal except Cu was low. No appreciable accumulation of heavy metals occurred in forage or animal tissues. Low Cu levels observed for all treatment groups indicate a problem inherent of the study site. FBCR appears to be a safe and efficient soil pH amendment.
The effect of stage of maturity on the biological availability of magnesuim from wheat and orchardgrass fed to sheep
Stager, Cynthia Lee (Virginia Tech, 1976-12-05)
Wheat, a tetany prone forage, and orchardgrass, a non-tetany prone forage, were cut at three stages of maturity to determine the magnesium availability in these forages for lambs. The forages were dried in forced air ovens and ground through a 2.5 cm screen. The nitrogen contents of the forages were not significantly different between forages but decreased quadratically with maturity in wheat (P < .Ol) and linearly in orchardgrass (P < .Ol). Nonprotein nitrogen was significantly higher in wheat than in orchardgrass. The magnesium content of the wheat was lower (P < .O1) than orchardgrass (.14 vs .21%). Magnesium content in wheat was similar at all maturities but decreased with maturity in orchardgrass. Potassium, calcium and phosphorous levels in the forages were similar between wheat and orchardgrass but decreased with advancing maturity in both forages. In two metabolism trials with 18 wether lambs, the biological availability of magnesium was determined for the two forages cut at three stages of maturity. The biological availability of magnesium for lambs fed wheat was slightly lower than for those fed orchardgrass. It increased linearly with increasing maturity in wheat (P < .O1) and tended to decrease with maturity in orchardgrass. In the first two maturities of wheat, the biological availability of magnesium was approximately 22% and for the third maturity it approached 39%. In orchardgrass, it was 36, 34 and 28% for maturities l, 2 and 3, respectively.
Effect of sulphur fertilization on growth and chemical composition of sorghum (Sorghum Bicolor L.) and on utilization of sorghum silage fed to wethers
Ahmad, Muhammad Rashid (Virginia Tech, 1991-05-24)
Sulphur (S) is an essential element for plant and animal nutrition, but widespread deficiencies of S occur world wide. Current recommendations for nitrogen (N):S ratios are 15 to 18:1 and 10 to 12:1 for plant and animal nutrition, respectively; but recent information suggests these may not predict animal response. Sorghum is an important crop, particularly in drier climatic regions but little is known concerning S-nutrition for sorghum growth or utilization of S-fertilized forages. Sorghum "Pioneer 947" was grown on a Lucy loamy sand (loamy, siliceous, thermic Arenic Kandiudult) in King William County, VA, with and without S fertilization (0 vs. 138 kg S ha⁻¹ as ammonium sulphate) in a randomized block design with four replications. Sulphur fertilization decreased (P < 0.05) soil pH and increased soil S in the 0 to 25 cm (P < 0.08) and 25 to 50 cm (P < 0.05) soil layers. An increase in Mehlich-I extractable soil P, Mn (P < 0.05) and soil N0₃-N (P < 0.06) at surface 25 cm layer occurred with S-fertilization. At harvest, S-fertilization increased (P < 0.05) S and water soluble carbohydrates and decreased (P < 0.05) N:S ratio and P concentration in whole plants. Sorghum leaves were higher (P < 0.05) in N, S, Ca, Mn and Cu in S fertilized compared to non-S fertilized sorghum. Sulphur fertilization decreased (P < 0.05) concentration of hydrocyanic acid (HCN) in the upper three leaves. A greenhouse experiment was conducted with the Lucy soil and 'Pioneer 947' sorghum to further investigate effects of fertilization (0, 70, and 140 kg S ha ⁻¹) as ammonium sulphate in a completely randomized design with five replications. Sulphur application decreased soil pH, and extractable soil K linearly (P < 0.01), and increased extractable soil S linearly (P < 0.01).
The effect of supplementation strategy, stress level, and tall fescue type on performance of fall-weaned beef calves
Pickworth, Carrie Lynn (Virginia Tech, 2005-06-20)
The beef cattle marketing structure imposes stress on calves due to weaning, transport, commingling, and adaptation to new diets, resulting in a weakened immune systems at the height of disease risk, frequently causing bovine respiratory disease. Backgrounding programs facilitate opportunities for calves to overcome stressors by building immunity, and adapting the rumen to high concentrate diets for improved feedlot performance. Four experiments were conducted to compare backgrounding strategies and effects of supplementation frequency performance and the effects of the ruminal environment. In Exp. 1, 48 weaned steers were used to investigate the effects of transportation and supplementation frequency, while in Exp. 2, 36 heifers were used to investigate only supplementation frequency. No differences in gains were observed due to transportation stress or supplementation frequency. Weaning stress resulted in elevated (P < 0.05) creatine kinase and neutrophil:lymphocyte ratios during the first week. In Exp. 3, 48 calves were used to compare the effect of tall fescue type on performance and health. Calves on novel endophyte fescue had higher ADG (P = 0.07) than on endophyte-infected fescue. Experiment 4 investigated the changes in ruminal environment due to supplementation frequency. No differences were observed between supplementation frequencies for ruminal pH, ammonia, or VFA concentration, and DM, or CP digestibility. Therefore, the rumen maintained a hospitable environment to promote bacterial protein synthesis and fiber digestion with every 48 h supplementation. Backgrounding calves with high fiber co-product supplements or on novel endophyte fescue can enhance calf performance.
The Effect of Three Fescue Types and Lakota Prairie Grass on Copper Status, Dry Matter Intake, and Alkaloid Appearance of Beef Steers
Stewart, Robert Lawton Jr. (Virginia Tech, 2006-10-27)
Tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] is an important forage crop in the United States and covers over 14 million ha. The presence of Neotyphodium coenophialum, an endophytic fungus in tall fescue, is associated with several disorders in grazing livestock, but also increased persistence of tall fescue. These disorders, commonly called fescue toxicosis, are responsible for large economic losses in the beef cattle industry each year. This research examined the effect of three fescue types [endophyte-infected Kentucky 31 tall fescue (E+), endophyte-free Kentucky 31 tall fescue (E-), non-ergot alkaloid-producing endophyte Q4508-AR542 tall fescue (Q)], and Lakota prairie grass (L; Bromus catharticus Vahl.) on animal response, alkaloid appearance, DMI, and copper status. Ergovaline (EV) is the most abundant ergot alkaloid in tall fescue and has previously been considered the causative toxin in fescue toxicosis. More recently it is simpler ergot alkaloids, such as lysergic acid amide (LSA) have been implicated. The objective of the first project was to evaluate animal performance and alkaloid (EV and LSA) appearance in forage and ruminal fluid of steers grazing E-, Q, E+, and L. Average daily gains were greater (P < 0.05) on E-, Q and L compared to E+, and there was a trend (P = 0.11) for gains on E- to be higher than with Q. The seasonal appearance of LSA in ruminal fluid was similar to the seasonal pattern of alkaloids in E+ forage. Ergovaline was not detectable in ruminal fluid of steers grazing E+. Alkaloids were not detectable in forage or ruminal fluid of steers grazing E-, Q, or L. The appearance of LSA in ruminal fluid of steers grazing E+ suggests that this alkaloid may contribute to fescue toxicosis. Low DMI of animals grazing E+ tall fescue is considered a key factor in decreased animal performance compared to other fescue types. The objective of the second project was to evaluate DMI of steers grazing E-, E+, Q, and L pastures using the alkane technique. Dry matter intake of steers grazing E- was greater (P < 0.001) than Q, E+, and L and DMI of steers grazing Q and E+ were similar (P > 0.10) in 2004. In 2005, DMI did not differ (P = 0.23) among fescue types. These results suggest that decreased DMI effects ADG of steers grazing E+ compared to those grazing E-, and lower DMI of Q suggests that the fescue variety Q4508 may not be the optimal variety for the incorporation on non-ergot alkaloid-producing endophytes. Reactive oxygen metabolites such as superoxide (O₂⁻) are produced by both endogenous and exogenous sources and an accumulation of these compounds can result in oxidative stress. Copper/zinc superoxide dismutase (SOD) is a Cu-based antioxidant metalloprotein that acts as a defense against oxidative stress by the scavenging of O₂⁻. Neotyphodium-infected tall fescue is typically lower in Cu which could potentially increase oxidative stress of animals grazing this forage. Therefore the objective of the third project was to investigate the Cu and SOD status of steers grazing E-, E+, Q, and L forages. Copper levels of all forages were below the dietary requirement (10μg Cu/g DM) of growing cattle. In 2004, steers grazing E+ exhibited lower (P <0.05) liver Cu compared to E- and Cu intake was lower (P < 0.001). Cu/Zn SOD enzymatic activity and mRNA relative expression did not differ (P > 0.10) among treatments. Copper intake of steers grazing E+ tall fescue was sufficient to maintain, but not replenish liver Cu, and SOD status did not appear compromised by grazing E+ at these Cu levels.

Browsing by Author "Fontenot, Joseph P."

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