Bahiagrass Hay Research Articles

Tropical plant supplementation effects on the performance and parasite burden of goats.

ObjectiveExamine the effects of supplementing bahiagrass hay (BG) with potentially anthelmintic quantities of hays of perennial peanut (PEA) or sericea lespedeza (LES) or seeds of velvet bean (Mucuna pruriens L.; MUC) or papaya (PAP) on the intake and nutritive value (Experiment 1), and the performance and parasite burden (Experiment 2) of goats.MethodsIn Experiment 1, 38 male goats (27.4±5.7 kg body weight) were randomly assigned to each of 5 treatments: i) BG alone and BG plus; ii) PEA; iii) LES; iv) MUC; and v) PAP. Goats were fed for ad libitum consumption and adapted to the diets for 14 d followed by 7 d of measurement. The PEA, LES, MUC (50%, 50%, and 10% of the diet dry matter [DM], respectively), and PAP (forced-fed at 10 g/d) were fed at rates that would elicit anthelmintic effects. In Experiment 2, goats remained in the same treatments but were allocated to 15 pens (3 pens per treatment) from d 22 to 63. All goats were infected with parasites by grazing an infected bahiagrass pasture from 0800 to 1500 h daily and then returned to the pens.ResultsDry matter intake tended to be greater in goats fed PEA and LES than those fed BG (757 and 745 vs 612 g/d, respectively). Digestibility of DM (59.5% vs 54.9%) and organic matter (60.8% vs 56.0%) were greater in goats fed MUC vs BG, respectively. In Experiment 2, feeding PAP, LES, and PEA to goats reduced nematode fecal egg counts by 72%, 52%, and 32%, reduced abomasal adult worm counts by 78%, 52%, and 42%, and decreased plasma haptoglobin concentrations by 42%, 40%, and 45% relative to feeding BG alone, respectively.ConclusionSupplementation with PEA, LES, and PAP decreased the parasite burden of goats but did not increase their performance. PAP was the most effective anthelmintic supplement.

Influence of cow breed type, age and previous lactation status on cow height, calf growth, and patterns of body weight, condition, and blood metabolites for cows grazing bahiagrass pastures1,2,3,4

This study was initiated to evaluate performance and patterns of cow traits and blood metabolites of 3 breeds of cows grazing bahiagrass (Paspalum notatum Flügge) pastures in central Florida. Purebred cows (n = 411) of either Angus (Bos taurus), Brahman (Bos indicus), or Romosinuano (Bos taurus) breeding, rotationally grazed (moved twice weekly) bahiagrass pastures year-round, and received bahiagrass hay supplemented with molasses and soyhulls or legume hay supplemented with unfortified molasses from October to June each production year. At monthly intervals, all cows were weighed, measured at the hip (HH), scored for BCS, and blood samples collected by jugular puncture from 10 cows per cow breed/block group for plasma urea N (PUN), glucose and non-esterified fatty acids (NEFA). Data were analyzed on cows that calved with a statistical model that included fixed effects of year, cowage, cow breed, month, block, supplement group (n = 2, but not presented), and whether the cow weaned a calf the previous year. Cow was a repeated observation over mo. Three-way interactions involving monthly patterns for cowage x year, year x lactation status the previous year, cowage × cow breed, year × cow breed, and cow breed × lactation status the previous year were significant (P < 0.001) for BW and BCS. The interaction for cowage × month was also significant (P < 0.05) for glucose, and cow breed × month was important (P < 0.01) for PUN, glucose, and NEFA. Important differences included: 1) greater BW and BCS for older cows compared to 3-yr old cows; 2) greater BW and BCS before calving for cows that did not lactate the previous year; 3) PUN levels were above 11 mg/dl except for February, August and September, and was generally greater in tropically adapted breeds; 4) GLU was greatest in Brahman, lowest in Angus, and intermediate in Romosinuano cows; and 5) plasma levels of NEFA escalated at calving and then declined, but Brahman cows maintained greater (P < 0.05) levels from calving until weaning than the other breeds. Cows that lactated the previous year had less NEFA than those that did not lactate. Brahman cows were less fertile than Bos taurus breeds, and weaned heavier calves.

1530 Effects of calcium–ammonium nitrate on in vitro fermentation of bahiagrass hay with supplemental molasses

1530 Effects of calcium–ammonium nitrate on in vitro fermentation of bahiagrass hay with supplemental molasses

1370 Effects of bismuth subsalicylate and calcium-ammonium nitrate on in vitro fermentation of bahiagrass hay with supplemental molasses

1370 Effects of bismuth subsalicylate and calcium-ammonium nitrate on in vitro fermentation of bahiagrass hay with supplemental molasses

Intake, digestibility, and nitrogen retention by sheep supplemented with warm-season legume hays or soybean meal

The increasing cost of feed supplements necessitates evaluation of alternatives for ruminant livestock grazing poor quality warm-season grasses. This study determined how supplementing bahiagrass hay (Paspalum notatum Flügge cv. Pensacola) with soybean [Glycine max (L.) Merr.] meal or warm-season legume hays affected intake, digestibility, and N utilization by lambs. Dorper x Katadhin crossbred lambs (30.6 +/- 5.5 kg; n = 42) were fed bahiagrass hay (73.8% NDF, 8.1% CP) for ad libitum intake and supplemented with nothing (control), soybean meal, or hays of annual peanut [Arachis hypogaea (L.) cv. Florida MDR98; 46.2% NDF, 14.7% CP], cowpea [Vigna unguiculata (L.) Walp. cv. Iron clay; 62.2% NDF, 11.7% CP], perennial peanut (Arachis glabrata Benth. cv. Florigraze; 43.3% NDF, 15.2% CP), pigeonpea [Cajanus cajan (L.) Millsp. cv. GA-2; 78.6% NDF, 12.2% CP], or soybean (cv. Pioneer 97B52; 59.0% NDF, 13.5% CP). Legume hays were supplemented at 50% of total diet DM, and soybean meal was supplemented at a level (4.25% of diet DM) that matched the average dietary CP content (10.8%) of the legume hay-supplemented diets. The cowpea, pigeonpea, and soybean were harvested at respective maturities that maximized DM yield and nutritive value, and the peanuts were first cuttings. Diets were fed to 6 lambs per treatment for 2 consecutive 21-d periods. Supplementation with hays of annual and perennial peanut, cowpea, and soybean increased (P < 0.01) DMI vs. control, but apparent DM digestibility was only increased (P = 0.03) by supplementation with annual or perennial peanut hay. Compared with the control, N intake, digestibility, and retention were increased (P < 0.01) by supplementation with legume hay or soybean meal. Responses were greatest when annual or perennial peanut hays were fed. Ruminal ammonia concentration was increased (P < 0.01) by all legume hay supplements vs. the control. Microbial N synthesis and ruminally degraded OM were increased (P = 0.03) by perennial and annual peanut hay supplementation, but efficiency of microbial synthesis was not different (P = 0.52) among diets. Unlike other supplements, annual and perennial peanut hays increased DM and N intake and digestibility and improved microbial N synthesis; therefore, they were the best supplements for the bahiagrass hay under the conditions of this study.

Effects of different mixtures of fibrolytic enzymes on digestion and fermentation of bahiagrass hay

This study was designed to determine the best combination of ferulic acid esterase (FAE), cellulose (CEL), and xylanase (XYL) for hydrolyzing mature bahiagrass in the absence of rumen fluid, and to evaluate effects of the best multienzyme cocktails on digestibility and fermentation of bahiagrass in the presence of rumen fluid. In Experiment 1, 42 enzyme mixtures of pure CEL, XYL, and FAE were dissolved in a citrate phosphate buffer (pH 6.0) and added to 0.5 g of a 12-week regrowth of bahiagrass ( Paspalum notatum) hay. In each mixture, each enzyme was applied at 0, 0.5, 1, or 2 g/100 g of dry matter (DM) except that FAE was not applied at 2 g/100 g DM. Dry matter (DM) disappearance was measured after the solutions were incubated at 39 °C for 24 h. Each enzyme was applied in triplicate and the experiment was repeated thrice. The highest DM disappearance was with enzyme cocktails containing 2, 2, and 0 (2–2–0) or 2, 2, and 1 (2–2–1) g of XYL, CEL, and FAE, respectively/100 g of forage DM. In Experiment 2, the hay was treated with nothing (Control), a commercial enzyme preparation (Depol 740, D740L) containing all three enzymes, or the 2–2–0 and 2–2–1 enzyme cocktails from Experiment 1. The enzyme mixtures were dissolved in 1 ml of citrate–phosphate buffer (pH 6.0) and sprayed on 0.5 g of bahiagrass hay in triplicate in each of two runs. Samples were fermented in buffered-rumen fluid using a wireless automated gas production system for either 24 or 96 h in duplicate runs, and residues were analyzed for DM and volatile fatty acid concentrations. The kinetics of 96 h fermentation were determined by fitting a non-linear model to the data. For the 24 h fermentations, enzyme application did not increase DM or NDF digestibility but all enzyme mixtures decreased acetate concentration (P<0.001) and increased (P<0.04) propionate and butyrate concentrations. Consequently, all enzyme mixtures decreased (P<0.001) the acetate to propionate ratio. For the 96 h fermentations, all enzyme mixtures decreased the lag phase (P<0.05) but did not impact DM or NDF digestibility, gas pool size or fermentation rate. This study identified certain mixtures of XYL, CEL, and FAE that increased 24-h DM disappearance of bahiagrass in the absence of rumen fluid. Application of these multienzyme cocktails reduced the lag phase and improved efficiency of fermentation of mature bermudagrass in rumen fluid but did not improve extent of DM digestion.

Effects of treatment with ammonia or fibrolytic enzymes on chemical composition and ruminal degradability of hays produced from tropical grasses

In the first of two experiments, effects of applying NH 3 or a fibrolytic enzyme (Promote ®, Pr) on the fiber concentration, and dry matter (DM) and fiber digestibility of two tropical grass hays was measured. In Experiment 2, effects of applying NH 3 or 3 fibrolytic enzymes, Biocellulase X-20 ® (X-20), CA ® (CA), and Biocellulase A-20 ® (A-20) on the same variables as in the previous experiment were measured. In situ rumen degradability responses were also measured in Experiment 2. The forages were 12-week regrowths of Coastal bermudagrass hay ( Cynodon dactylon; BE) and Pensacola bahiagrass hay ( Paspalum notatum; BA). The NH 3 was applied at 40 g/kg DM and the enzymes were applied at 0 (Control) 0.5, 1, and 2 times the rates recommended by the respective manufacturers. In vitro DM (IVDMD), neutral detergent fiber (NDF, IVNDFD) and acid detergent fiber (ADF, IVADFD) digestibilities were calculated after digesting the hays in buffered-rumen fluid for 6 or 48 h in 2 ANKOM II Daisy Incubators. In Experiment 1, Pr and NH 3 application to BA resulted in hydrolysis of NDF into water-soluble carbohydrates (WSC). Whereas, application of both additives to BE resulted in less ADF and higher 6 h IVDMD. Ammoniated hays consistently had more CP than Pr-treated or Control hays, and only NH 3 treatment increased 6 and 48 h IVNDFD and IVADFD of both hays. In Experiment 2, all additive treatments decreased the NDF concentration and increased 6 h IVDMD of BE. Enzyme X-20 increased the 48 h IVDMD of both hays and CA and A-20 had similar tendencies. Ammonia treatment increased the 6 h IVDMD of BA, the CP concentration of both hays, the 6 and 48 h IVNDFD of BE, and the 48 h IVNDFD of BA. The 6 h IVADFD of BE hay was improved by X-20, A-20, and NH 3 treatment. Treatment with X-20 and NH 3 increased the washing loss (‘ a’) fraction of BE, but only NH 3 treatment increased that of BA. Only ammoniation increased the insoluble, but potentially degradable (‘ b’) fraction, the total degradable fraction ( a + b) and potential degradability ( P) of both forages. Therefore, these fibrolytic enzymes had negligible effects on the extent of fiber digestion and in situ DM degradation of the hays, but X-20 and A-20 treatment increased the initial and later phases of DM digestion. Ammoniation was more effective than any enzyme treatment at improving DM and fiber digestibility, and in situ degradability.

Intake and Digestibility of Bahiagrass Hay by Cattle that are Supplemented with Molasses or Molasses-Urea with or without Soybean Hulls

ABSTRACT Two experiments were conducted to evaluate the effect of molasses or molasses-urea supplementation with or without soybean hulls on digestibility, intake, and animal performance in cattle fed bahiagrass (Paspalum notatum Flugge) hay. In Experiment 1, 6 Holstein steers (average BW 256 ± 15 kg) were fed 1 of 6 treatment diets: 1) bahiagrass hay only; 2) hay plus molasses; 3) hay plus molasses-urea; 4) hay plus soybean hulls; 5) hay plus soybean hulls and molasses; and 6) hay plus soybean hulls and molasses-urea. Molasses were fed at 0.59% ofBW (DM basis), soybean hulls at 0.75%, and urea at 4.5% of the weight of the molasses. Dry matter intake and apparent digestibility were measured in an incomplete Latin square design with a 28-d recovery period between each period. Digestibility of dietary DM, OM, and ADF was increased with soybean hulls (P 0.10) by soybean hulls. Urea added to molasses increased nonesterified fatty acids (P 0.10) by treatments. Blood glucose was increased (P

Optimizing nitrogen utilization in growing steers fed forage diets supplemented with dried citrus pulp

Our objectives were to compare the effects of sources of supplemental N on ruminal fermentation of dried citrus pulp (DCP) and performance of growing steers fed DCP and bahiagrass (Paspalum notatum) hay. In Exp. 1, fermentation of DCP alone was compared with that of isonitrogenous mixtures of DCP and solvent soybean meal (SBM), expeller soybean meal (SoyPLUS; SP), or urea (UR). Ground (1 mm) substrates were incubated in buffered rumen fluid for 24 h, and IVDMD and fermentation gas production kinetics and products were measured. Nitrogen supplementation increased (P < 0.10) ruminally fermentable fractions, IVDMD, pH, and concentrations of NH3 and total VFA, but reduced the rate of gas production (P < 0.10) and the lag phase (P < 0.01). Supplementation with UR vs. the soy-based supplements increased ruminally fermentable fractions (P < 0.05) and concentrations of total VFA (P < 0.10) and NH3 (P < 0.01), but these measures were similar (P > 0.10) between SBM and SP. In Exp. 2, 4 steers (254 kg) were fed bahiagrass hay plus DCP, or hay plus DCP supplemented with CP predominantly from UR, SBM, or SP in a 4 x 4 Latin square design, with four 21-d periods, each with 7 d for DMI and fecal output measurement. Nitrogen-supplemented diets were formulated to be isonitrogenous (11.9% CP), and all diets were formulated to be isocaloric (66% TDN). Intake and digestibility of DM, N, and ADF were improved (P < 0.05) by N supplementation. Compared with UR, the soy-based supplements led to greater (P < 0.05) DM and N intakes and apparent N and ADF digestibilities. Plasma glucose and urea concentrations increased (P < 0.10) with N supplementation and were greater (P < 0.01) for the soy-based supplements than for UR. Intake, digestibility, and plasma metabolite concentrations were similar (P > 0.1) for SBM and SP. In Exp. 3, 24 steers (261 kg) were individually fed bahiagrass hay plus DCP (control), or hay plus DCP supplemented with CP predominantly from UR or SBM. Over 56 d, DMI and ADG were greatest (P < 0.05) in steers fed SBM. Nitrogen supplementation increased (P < 0.05) DMI, ADG, and G:F. However, SBM supplementation produced greater (P < 0.05) DMI and ADG and similar (P > 0.05) G:F compared with UR supplementation. We conclude that supplemental N is important to optimize ruminal function and performance of growing steers fed forage diets supplemented with DCP. Diets with supplemental N mainly from SBM improved diet digestibility and animal performance beyond that achieved by UR.

A novel, wireless, automated system for measuring fermentation gas production kinetics of feeds and its application to feed characterization

This study describes a novel automated method of measuring fermentation gas production kinetics of feeds using sensors that intermittently measure the pressure arising from fermentation of feeds within culture bottles, and relays them to a server using a wireless radio frequency (RF) signal. Measurements can be downloaded from the server at any location that has internet access and saved in ASCII or Excel format. Consequently, once the measurement frequency is set, and the incubation commences, there is no need for attention to the system until the end of the fermentation. In order to validate the system, fermentation parameters of three 1 mm ground feeds (i.e., corn grain, dehydrated citrus pulp (DCP), Pensacola bahiagrass hay ( Paspalum notatum) were determined using the RF sensors and compared to those determined with a digital manometer. A second experiment used both pressure measuring devices to determine fermentation parameters of 1 mm ground bermudagrass hay ( Cynodon dactylon) treated with an esterase enzyme at 0, 1 and 2 g/100 g DM. Feed samples were incubated in buffered rumen fluid in quadruplicate (Experiment 1) or triplicate (Experiment 2) in 250 ml gas tight culture bottles at 39 °C. Each culture bottle was connected to a pressure sensor with a three-way Luer lock that was secured into a hole in the culture bottle cap. Pressure sensors made hourly pressure measurements to 96 h. A digital manometer was used to take pressure readings from the culture bottles after 0, 2, 4, 6, 8, 12, 24, 48, 60, 72 and 96 h of incubation, and an exponential model was fitted to fermentation gas production data from the sensors and the digital manometer. Fermentation parameters were compared using a factorial (Experiment 1) or completely randomized design (Experiment 2). In both experiments, method of gas pressure measurement did not affect fermentation parameters, and there was no method×feed interaction. In Experiment 1, corn grain and DCP had bigger ( P<0.001) gas pool sizes, faster fermentation rates and a longer lag phases than hay. Compared to DCP, corn had a longer ( P<0.05) lag phase, similar fermentation rate and a bigger ( P<0.01) gas pool size. In Experiment 2, increasing esterase enzyme levels did not affect fermentation rate, but increased ( P<0.05) the lag phase and tended ( P=0.063) to increase gas pool size. There was a good relationship between RF sensor and manometer-based estimates of gas pool size ( r 2 = 92), fermentation rate ( r 2 = 83), and lag phase ( r 2 = 60). Total measured gas volume correlated to in vitro digestibility ( r 2 = 0.60) and to stoichiometrically predicted total gas volumes ( r 2 = 0.74). This study demonstrates the potential of this RF sensor technique to differentiate fermentation kinetics among feeds.

Methane Emissions of Beef Cattle on Forages

Fermentation in the rumen of cattle produces methane (CH4). Methane may play a role in global warming scenarios. The linking of grazing management strategies to more efficient beef production while reducing the CH4 emitted by beef cattle is important. The sulfur hexafluoride (SF6) tracer technique was used to determine the effects of best management practices (BMP) grazing compared with continuous grazing on CH4 production in several Louisiana forages during 1996–1998. Cows and heifers (Bos taurus) grazed common bermudagrass [Cynodon dactylon (L.) Pers.], bahiagrass (Paspalum notatum Flugge), and ryegrass (Lolium multiflorum Lam.) pastures and were wintered on bahiagrass hay with supplements of protein molasses blocks (PMB), cottonseed meal and corn (CSMC), urea and corn (URC), or limited ryegrass grazing (LRG). Daily CH4 emissions were between 89 and 180 g d−1 for young growing heifers and 165 to 294 g d−1 for mature Simbrah cows. Heifers on “ad lib” ryegrass in March and April produced only one-tenth the CH4 per kg of gain as heifers on LRG of 1 h. Using BMP significantly reduced the emission of CH4 per unit of animal weight gain. Management-intensive grazing (MIG) is a BMP that offers the potential for more efficient utilization of grazed forage crops via controlled rotational grazing and more efficient conversion of forage into meat and milk. Projected CH4 annual emissions in cows reflect a 22% reduction from BMP when compared with continuous grazing in this study. With the BMP application of MIG, less methane was produced per kilogram of beef gain.

Methane emissions of beef cattle on forages: efficiency of grazing management systems.

Fermentation in the rumen of cattle produces methane (CH4). Methane may play a role in global warming scenarios. The linking of grazing management strategies to more efficient beef production while reducing the CH4 emitted by beef cattle is important. The sulfur hexafluoride (SF6) tracer technique was used to determine the effects of best management practices (BMP) grazing compared with continuous grazing on CH4 production in several Louisiana forages during 1996-1998. Cows and heifers (Bos taurus) grazed common bermudagrass [Cynodon dactylon (L.) Pers.], bahiagrass (Paspalum notatum Flugge), and ryegrass (Lolium multiflorum Lam.) pastures and were wintered on bahiagrass hay with supplements of protein molasses blocks (PMB), cottonseed meal and corn (CSMC), urea and corn (URC), or limited ryegrass grazing (LRG). Daily CH4 emissions were between 89 and 180 g d(-1) for young growing heifers and 165 to 294 g d(-1) for mature Simbrah cows. Heifers on "ad lib" ryegrass in March and April produced only one-tenth the CH4 per kg of gain as heifers on LRG of 1 h. Using BMP significantly reduced the emission of CH4 per unit of animal weight gain. Management-intensive grazing (MIG) is a BMP that offers the potential for more efficient utilization of grazed forage crops via controlled rotational grazing and more efficient conversion of forage into meat and milk. Projected CH4 annual emissions in cows reflect a 22% reduction from BMP when compared with continuous grazing in this study. With the BMP application of MIG, less methane was produced per kilogram of beef gain.

Effects of Tuli, Senepol, Brahman, Angus, and Polled Hereford Sire Breeds on Birth and Weaning Traits of Offspring

Progeny (n = 861) of tropically adapted breeds [Tuli (TU), Senepol (SE), and Brahman (BR)] and temperate breeds [Angus (AN) and Polled Hereford (HP)] were evaluated for birth and weaning traits in each of 5yr. Multiparous crossbred cows representing three genetic types [British (Bt), ½BR½Bt, and ¾Bt¼BR] were mated to AN, HP, TU, SE, and BR sires, with the exception that BR sires were not mated to ½BR½Bt cows. Calving season was January through early March. Following calving, cows were provided bermudagrass hay and bahiagrass hay and had limited access to rye and ryegrass pastures. Cow and calf pairs grazed bermudagrass and bahiagrass pastures as available until weaning without access to creep feed. Male calves were castrated at birth and were not implanted. Data included birth weight, cannon bone length at birth, weaning weight, weaning hip height, ADG from birth to weaning (ADGBW), ADG from birth to April (ADGBA), ADG from April to weaning (ADGAW), and weight per day of age (WDA). Data were analyzed by PROC Mixed using a model that included calf genetic type, calf sex, calf birth day of year, and calf genetic type × calf sex interaction. Random effects were cow age, birth year, and sire and dam of calf. Calf genetic type and calf sex were significant sources of variation for all characteristics. Linear contrasts revealed that BR-sired calves were heavier at birth, had longer cannon bones at birth, and were taller at weaning (P<0.01). Tuli- and SE-sired calves were similar to AN- and HP-sired calves for birth weight, cannon bone length at birth, and weaning hip height. Angus-, HP-, and BR-sired calves were heavier at weaning compared with TU-sired calves, and SE-sired calves were intermediate for weaning weight (P<0.01). In conclusion, the TU-sired calves were smaller at birth and at weaning when compared with BR-sired calves. The TU- and SE-sired calves appear to offer more moderate size and growth rate through weaning than do the BR-sired calves.

NUTRIENT REQUIREMENTS OF SEVEN PLANT SPECIES WITH POTENTIAL USE IN SHORELINE EROSION CONTROL

Many factors contribute to shoreline erosion including a lack of vegetation that can survive under periods of flooding, drying, and wave action. Biotechnical methods of shoreline erosion control seem to be a low cost alternative to conventional methods. This study was an attempt, first, to evaluate the feasibility of several breakwater materials for controlling wave action; and secondly, to study the growth response of seven wetland and terrestrial plant species for potential use in biotechnical methods of shoreline erosion control. The site for the field experiment was Water F. George Reservoir located on the Chattahoochee River between Alabama and Georgia. In a greenhouse experiment, plants were evaluated at different fertility levels. Results of the field experiments indicated that wire-wrapped square straw bales, coconut fiber logs, and pine logs were effective in controlling wave action and trapping sand. Round hay bales were less effective breakwater materials. Greenhouse data indicated that cattail, soft rush, soft stem bulrush, and maidencane responded significantly to nitrogen fertilizer up to 50 kg ha−1. This rate was also optimum for bahiagrass, switchgrass, and marsh hay cordgrass. No significant increase in dry matter yield or stem count was observed by the addition of N up to 100 kg ha−1. Most of these plant species did not significantly respond to the addition of micronutrients.

Average daily gain, blood metabolites, and body composition at first conception in Hereford, Senepol, and reciprocal crossbred heifers on two levels of winter nutrition and two summer grazing treatments.

Hereford (n = 48), Senepol (n = 42), and reciprocal crossbred (n = 34) heifers from two consecutive calf crops were stratified by breed, age, and BW to receive bahiagrass (Paspalum notatum) hay offered free choice and 150 mg monensin x heifer(-1) x d(-1) in addition to either 2.27 kg x heifer(-1) x d(-1) of a 75% cracked corn and 25% soybean meal mixture (CS) or .91 kg x heifer(-1) x d(-1) of soybean meal (SBM). Heifers in each treatment were divided into two winter pasture replicates and exposed to fertile bulls. In spring of each year, one-half of the heifers from each winter treatment were allotted to either a continuous (CONT) or rotational (ROTA) grazing system on bahiagrass pastures for the summer phase of the study. Heifers supplemented with CS had higher ADG from the beginning of the study to first conception than heifers fed SBM (.39 vs .31 +/- .02 kg/d; P < .01). Heifers fed CS were younger at first conception than SBM heifers (500 vs 563 +/- 32 d of age; P < .05) but had similar BW (312 vs 317 +/- 7 kg; P > .10). During the 2-yr study, a subset of Hereford (n = 12), Senepol (n = 15), and reciprocal crossbred (n = 14) heifers were subjected to urea space measurements to determine body composition at first conception. Change in body composition over time was analyzed by regression and body composition at first conception was predicted from these regressions. At first conception, percentage of empty body fat was not affected by treatment or year; however, percentage of empty body fat tended to be higher in crossbred than in Hereford and Senepol heifers (16.6 vs 14.3 and 14.4 +/- .94%; P < .10). Stepwise regression of BW, body condition score (BCS), fat thickness (determined by ultrasound), and body composition at first conception on age at first conception revealed that BCS and BW accounted for 55% of the variation in age at first conception (P < .01).

Relative Feeding Value of Rhizoma Perennial Peanut Hay as a Supplement to Bahiagrass Hay for Wintering Cows and Heifers

Rhizoma perennial peanut (Arachis glabrata Benth.) hay was evaluated as a replacement for purchased concentrate supplement given to cows and heifers being wintered on residual bahiagrass (Paspalumnotatum Fiugge) pasture and bahiagrass hay in central Florida. Data were collected over 2yr from 237 Hereford and 177 Senepol cows and first-calf heifers. Treatments were .9kg·head-1·d-1 of a commercially available 20% CP supplement (CUBE) or 2.3kg·head-1·d-1 of perennial peanut hay (PNUT). Supplements were fed for 16 wk from January through April each year. Response variables evaluated were cow and heifer body weight (BW) change, body condition score (CS) change, pregnancy rate, plasma urea nitrogen concentration (PUN), calf birth weight (CBW), and adjusted 205-d calf weaning weight (AWW). Both years, AWW was higher (P<.01) for calves with Senepol dams than for calves with Hereford dams (year 1: 209 vs. 184kg; year 2: 226 vs. 172kg), but AWW was not affected by treatment. Treatment did not affect pregnancy rate in either year; however, more (P<.05) Hereford (74%) compared to Senepol cows and heifers (62%) were palpated pregnant in year 2. Also in year 2, CBW was heavier (P<.01) for Senepol dams compared with Hereford dams (35.1 vs. 30.3kg), and BW and CS changes were greater (P<.01) in Senepol cows and heifers compared with Hereford (-90 vs. -67kg; -2.6 vs. -1.9). There were a few differences in PUN between treatments and breeds, but the greatest changes in PUN were observed over time through the wintering period. No other treatment or breed effects were observed either year. These data indicate that 2.3kg of the perennial peanut hay used in this study had a replacement value about equal to .9kg of a 20% CP concentrate cube supplement.

Nutritive Value of Pensacola Bahiagrass Stolons1

AbstractForage shortage and low forage quality during the winter season are critical in Florida during some years. Pensacola bahiagrass (Paspalum notatum Flugge) produces massive stolon‐root systems with relatively high crude protein concentrations if adequate nutrients are supplied. Preliminary in vitro digestion studies with these stolons indicated high digestibility. An experiment was initiated to study the feed value of this material and to determine the feasibility of using it during critical winter periods. Stolon evaluation was made by chemical analyses and by feeding trials with sheep to determine voluntary intake and nutrient digestibilities. Chopped stolons were mixed with chopped bahiagrass hay to give variable hay:stolon ratios. Each ration was supplemented with 10% molasses and 10% soybean meal. Dry matter and crude protein contents for all rations were approximately 86 and 12.5%, respectively. No difference was found in intake of organic matter or digestible organic matter among treatments. Cellulose digestibility decreased as the proportion of stolons in the rations was increased, but crude protein digestibility increased. Animals on all treatments averaged gains in excess of 5 kg during the 21‐day period. The chopped stolons were not readily accepted by sheep, but the addition of molasses and soybean meal markedly improved palatability. Cattle withheld from feed for 2 days consumed the stolons satisfactorily.