Coastal Bermudagrass Pastures Research Articles

Relationships between restricted residual feed intake of Brahman bulls measured in confinement and under different stocking intensities on Coastal bermudagrass pastures

ABSTRACT Efficiency of animal production is an important component of the beef industry. The research objectives of this 2-yr study were to (1) estimate residual feed intake (RFI) of yearling Brahman (Bos indicus) bulls grazing Coastal bermudagrass [Cynodon dactylon (L.) Pers.] using DMI measured with n-alkanes; (2) compare RFI under grazing (RFIg) with RFI determined in confinement under restricted feed intake at 2.8% of BW (RRFIc); and (3) assess the relationships of carcass traits and gastrointestinal tract anatomy to RFIg. Bulls RRFIc-phenotyped as efficient (n-RFI) and inefficient (p-RFI) in both 2009 and 2010 were assigned to 2 replicate pastures at either low or high stocking intensity (STK) for 60 d. In 2009 there was no difference (P > 0.3) between n-RRFIc and p-RRFIc for initial or final BW, ADG, DMI, or feed-to-gain ratio. There was an interaction of RFIg × STK (P = 0.043) for ADG in which p-RFIg bulls on low STK had the greatest gain. The p-RFIg bulls had the greatest DMI regardless of STK (P

Persistence of Alfalfa Sod‐Seeded into Bermudagrass Pastures on Coastal Plain Soils

Alfalfa (Medicago sativa L.) production and persistence in the Lower South of the USA are dependent on climate, soil, and competition from warm‐season perennial grasses such as bermudagrass [Cynodon dactylon (L.) Pers.]. A 3‐year study was conducted at Texas A&M AgriLife Research, Overton, to evaluate ‘Alfagraze’ alfalfa persistence on a Darco loamy fine sand (loamy, siliceous thermic Grossarenic Paleudult) when sod‐seeded at three row spacings (10, 20, and 30 inches) into a well‐established ‘Coastal’ bermudagrass pasture. Alfagraze was rotationally stocked with animal residence time from 5 to 13 d and deferment periods ranging from 18 to 27 d. In Year 1, during the first three grazing periods (1 April to 31 May), alfalfa was the dominant species (P < 0.05). Thereafter, from 30 June to 3 October, bermudagrass was dominant (P < 0.05). At the initiation of harvest in Year 2 (1 April), alfalfa dry matter (DM) was 1353, 783, and 690 lb/acre, respectively, at 10‐, 20‐, and 30‐inch drill‐row spacing prior to bermudagrass growth. At the end of Year 2 (3 October), alfalfa DM was 33, 10, and 0.90 lb/acre, respectively, at 10‐, 20‐, and 30‐inch spacings while bermudagrass DM was 1424, 1557, and 1080 lb/acre. At the beginning of Year 3, the percent stands of alfalfa were 14, 11, and 5%, respectively, for 10‐, 20‐, and 30‐inch spaced alfalfa plantings, while the respective percent stands of bermudagrass were 86, 89, and 95%. Under the climatic and sandy Coastal Plains soils of this vegetation region, Alfagraze was not persistent under grazing at any row spacing for more than 3 years when sod‐seeded into a well‐established Coastal bermudagrass pasture.

Impacts of Thirty‐Seven Years of Stocking on Soil Phosphorus Distribution in Bermudagrass Pastures

Pasture management affects soil properties, but information concerning the effects of long‐term stocking and fertility regimens on soil P in pastures is limited. This study investigated changes in extractable soil P concentrations from Coastal and common bermudagrass [Cynodon dactylon (L) Pers.] pastures stocked for 37 yr at different intensities on an Ultisol. From 1969 through 2004, pastures were continuously stocked during February to September to achieve high, medium, and low herbage mass. Annual fall‐applied P averaged 44 kg ha–1 from 1969 to1984 and 51 kg ha–1 from 1998 to 2004. Extractable soil P concentrations in the 0‐ to 15‐cm depth increased (P ≤ 0.0001) from 5 mg kg–1 (very low) in 1975 to 43 mg kg–1 in 2004 (high), and deeper depths showed 14 to 36% increased P levels. Elimination of P fertilizer for 13 yr, 1985 to 1997, decreased (P ≤ 0.0001) extractable soil P in the 0‐ to 15‐cm depth by 30 and 47% in common and Coastal bermudagrass pastures, respectively. An interaction between year and stocking rate was evident as extractable P levels increased after 20 yr at high stocking rates. After 37 yr, extractable P levels at the 0‐ to 120‐cm soil depth followed the order high > medium ≥ low stocking rate. Despite the effect of stocking rate on soil P, 37 yr of continuous stocking showed no evidence of excessive P accumulation at levels that may pose an environmental threat. Phosphorus recycled through the soil–forage–animal system sustained adequate forage and animal productivity.

Bermudagrass management in the Southern Piedmont USAV: Gastrointestinal parasite control in cattle

Parasite-free pastures would improve cattle health and performance, resulting in possible economic return to producers. Our objective was to determine the effect of a single series of anthelmintic treatment of steers prior to stocking on Coastal bermudagrass pastures, during five consecutive summers, on the parasite burden in cattle. The site for this experiment had been conventionally cropped for several decades, with no exposure to cattle, and would be expected to be relatively free of nematode larvae. The experimental design was a randomized complete block (landscape features) with a split plot arrangement of treatments where main plots were pasture fertilization treatments (mineral, clover plus mineral, and broiler litter) and split plots were low and high forage mass. Anthelmintic treatment included pour-on ivermectin on day −21, albendazole on day −7, and injectable ivermectin 48 h prior to stocking of pastures, with the cattle remaining in drylot during the 48-h period prior to being placed on the experimental paddocks. All steers received only one series of treatments during any given year. Yearling Angus steers (Bos taurus) were managed in a put-and-take grazing system with three “tester” steers assigned to each paddock and “grazer” steers added or removed at 28-day intervals. From 1994 to 1998, steers grazed the paddocks for a 140-day period from mid May until early October each year. Fecal samples for worm egg counts were obtained on day 0 and at 28-day intervals, thereafter. On all sampling days after day 0, samples were obtained only from tester animals. Over the 5-year period, the mean eggs per gram of feces (epg) gradually increased from 0 (following treatment) to a mean of 2.2 (range from 0.7 to 3.0) by the end of the grazing season (the last sampling date) in October. Although the epg were not zero, they were below threshold levels that would allow development of a parasite burden in cattle. In traditional management systems, cattle graze parasite-contaminated pastures; therefore, parasites negatively impact growth and productivity throughout the entire grazing period. Periodic anthelmintic treatments simply give a temporary reprieve from those parasitic infections. Conceptually, using the current grazing system, it should be possible to maintain these pastures in a parasite-free status indefinitely; however, from a drug resistance perspective, it would be most applicable in sod-based rotation systems where cattle graze from two to five years before land is returned to row-crops. By removing the effect of parasites, cattle can grow without the physiological constraints that gastrointestinal parasites place on appetite, digestion, nutrient utilization, and general well being.

Bermudagrass management in the Southern Piedmont USA: V: Gastrointestinal parasite control in cattle

Parasite-free pastures would improve cattle health and performance, resulting in possible economic return to producers. Our objective was to determine the effect of a single series of anthelmintic treatment of steers prior to stocking on Coastal bermudagrass pastures, during five consecutive summers, on the parasite burden in cattle. The site for this experiment had been conventionally cropped for several decades, with no exposure to cattle, and would be expected to be relatively free of nematode larvae. The experimental design was a randomized complete block (landscape features) with a split plot arrangement of treatments where main plots were pasture fertilization treatments (mineral, clover plus mineral, and broiler litter) and split plots were low and high forage mass. Anthelmintic treatment included pour-on ivermectin on day −21, albendazole on day −7, and injectable ivermectin 48 h prior to stocking of pastures, with the cattle remaining in drylot during the 48-h period prior to being placed on the experimental paddocks. All steers received only one series of treatments during any given year. Yearling Angus steers ( Bos taurus) were managed in a put-and-take grazing system with three “tester” steers assigned to each paddock and “grazer” steers added or removed at 28-day intervals. From 1994 to 1998, steers grazed the paddocks for a 140-day period from mid May until early October each year. Fecal samples for worm egg counts were obtained on day 0 and at 28-day intervals, thereafter. On all sampling days after day 0, samples were obtained only from tester animals. Over the 5-year period, the mean eggs per gram of feces (epg) gradually increased from 0 (following treatment) to a mean of 2.2 (range from 0.7 to 3.0) by the end of the grazing season (the last sampling date) in October. Although the epg were not zero, they were below threshold levels that would allow development of a parasite burden in cattle. In traditional management systems, cattle graze parasite-contaminated pastures; therefore, parasites negatively impact growth and productivity throughout the entire grazing period. Periodic anthelmintic treatments simply give a temporary reprieve from those parasitic infections. Conceptually, using the current grazing system, it should be possible to maintain these pastures in a parasite-free status indefinitely; however, from a drug resistance perspective, it would be most applicable in sod-based rotation systems where cattle graze from two to five years before land is returned to row-crops. By removing the effect of parasites, cattle can grow without the physiological constraints that gastrointestinal parasites place on appetite, digestion, nutrient utilization, and general well being.

Exogenous PGF 2α enhanced GnRH-induced LH release in postpartum cows

This study evaluated the effect of exogenous PGF 2α on circulating LH concentrations in postpartum multiparous (n = 32) and primiparous (n = 46) Brahman cows. The cows were randomly allotted within parity and calving date to receive 0, 1, 2 or 3 mg im PGF 2α (alfaprostol)/100 kg body weight (BW), with or without GnRH on Day 30 after calving. Blood samples were collected at weekly intervals from calving through treatment. Serum progesterone concentrations were determined using RIA procedures to assure that only anestrous cows were treated. Sterile marker bulls were maintained with cows on Coastal bermudagrass pastures until the first estrus was detected. Multiparous cows had a shorter (P < 0.05) interval from calving to estrus than did primiparous cows. Serum LH was affected by time (P < 0.0001), PGF 2α dose (P < 0.0002), GnRH (P < 0.0001), parity by PGF 2α dose (P < 0.0003), PGF 2α dose by GnRH (P < 0.0009), parity by GnRH (P < 0.0008), and by parity by PGF 2α dose by GnRH (P < 0.0005). Multiparous cows not receiving GnRH had higher mean serum LH (P < 0.02), LH peak pulse height (P < 0.03), and area under the LH release curve (P < 0.03) compared with primiparous cows. The number of LH pulses/6 h was greater (P < 0.06) in multiparous than primiparous cows, and was greater (P < 0.02) in multiparous cows receiving 3 mg/100 kg BW than in cows receiving 2 mg/100 kg BW, but not in the controls or in cows receiving 1 mg/100 kg BW. Exogenous GnRH resulted in increased (P < 0.0001) serum LH concentrations in all cows, and LH was enhanced (P < 0.0009) by simultaneous treatment with PGF 2α. Primiparous cows had a greater response (P < 0.0005) to PGF 2α and GnRH compared with multiparous cows. Pituitary release of LH in response to GnRH was enhanced by simultaneous exposure to PGF 2α in Day 30 postpartum cows.

Influence of undegraded intake protein supplementation on milk production, weight gain, and reproductive performance in postpartum Brahman cows

Eighty first-calf Brahman heifers and 51 mature Brahman cows were allotted to one of three diets based on parity, sex of calf, and breed of calf sire (Angus, Brahman, or Tuli) to evaluate rumen undegraded intake protein's (UIP) influence on production characteristics and reproductive performance. Supplements contained either 38.1% (low), 56.3% (medium), or 75.6% (high) UIP. Supplements were given from d 7 to 119 after calving to dams grazing rye-ryegrass overseeded Coastal bermudagrass pastures and with access to Coastal bermudagrass hay. Dam and calf BW and dam body condition score were recorded on d 7, 35, 63, 91, and 119 after calving. Four-hour milk production was recorded on the above days for low (n = 18), medium (n = 19), and high (n = 18) UIP animals and on d 7 and 35 for the entire group. Blood for progesterone RIA was drawn weekly and on d 6, 8, 10, and 12 after an observed estrus. Medium UIP heifers produced more (P < .02) milk (1.18 +/- .07 kg/4 h) than high UIP heifers (.94 +/- .07 kg/4 h), but milk production in mature cows was not influenced by diet. Low UIP dams had lower (P < .04) first-service conception rates (29.2%) than medium (57.6%) and tended (P < .10) to have lower rates than high UIP dams (54.6%). Overall pregnancy rates tended (P < .10) to be higher in medium (61.5%) and high (56.4%) UIP groups than in the low (43.2%) UIP group. Supplementing UIP at the medium rate improved first-service conception rates and tended to improve pregnancy rates.

Crabgrass Control In Coastal Bermudagrass

AbstractMany hectares of ‘Coastal’ bennudagrass [Cynodon dactylon (L.) Pers.] stands are lost during the second growing season after planting because of competition from large crabgrass [Digitaria sanquinalis (L.) Scop]. Experiments were conducted in southern Georgia on a Cecil (thermic, Typic Hapludults) sandy clay loam and central Georgia on a Greenville (clayey, thermic, Rhodic Kandiudults) sandy loam soil to evaluate chemical treatments for managing large crabgrass in Coastal bermudagrass. Herbicide treatments were applied to Coastal bermudagrass stands during the second growing season after planting to evaluate crabgrass control and to fully established stands to determine treatment damage to the Coastal bermudagrass. Norflurazon {4‐chloro‐5 ‐ (methylamino)‐2‐[3 ‐ (trifluoromethyl)phenyl] ‐3(2H)‐pyridazinone} applied during March at rates of 1.12 and 2.24 kg ai ha−1 resulted in &gt;80% control of large crabgrass up to 90 and 50 d after treatment, respectively. Treatments with norflurazon at rates as high as 2.24 kg ha−1 did not damage the Coastal bemudagrass stand or decrease yield compared to the untreated control. These data indicate that norflurazon would be an excellent candidate herbicide for use in the control of large crabgrass in Coastal bermudagrass pastures and hayfields.

Coastal Bermudagrass-Legume Mixtures vs. Nitrogen Fertilizer for Grazing in a Semiarid Environment

‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.] is the most commonly planted warm-season perennial grass in the southern USA. To be productive, it requires liberal inputs of N fertilizer and warm temperatures. Cool-season annual clover plants have a potential to supply N and also provide much needed quality forage during the winter-spring season when bermudagrass is dormant. A major concern with overseeding of winter legumes in the semiarid area of the southern USA is that the additional forage production in the spring may result in reduced bermudagrass production in the summer season. ‘Yuchi’ arrowleaf clover (Trifolium vesiculosum Savi) and ‘Woogeneliup’ subterranean clover (T. subterraneum L.) were established separately in replicated Coastal bermudagrass pastures at Beeville, TX. These clover-bermudagrass pastures were compared to similar bermudagrass pastures that received two 50-lb N/acre applications of fertilizer each year. All pastures received 50 lb P2O5/acre each autumn. All pastures contained varying amounts of burr medic (Medicago polymorpha L.) and rescuegrass [Bromus unioloides (Willd.) H.B.K.], which were only a minor component in Year 1, but the medic was dominant in the N-fertilized pastures by Year 4. The predominant soil types were Parrita (fine, mixed, hyperthermic, shallow Petrocalcic Paleustolls) and Weestache (fine-loamy, mixed, hyperthermic Typic Argiustolls) sandy clay loams. Pastures were grazed continuously with crossbred [(Bos taunts (L.) × B. indicus (L.)] yearling heifers in each of 4 yr. When rainfall was plentiful (year 2 and 4), variable stocking was used in the winter-spring (up to mid-June) to provide similar amounts of available forage per animal. In the limited rainfall years (Year 1 and 3) and during each summer season (mid-June to mid-September), fixed stocking was used. During the winter-spring season of the first 3 yr, heifers grazing arrowleaf clover pastures gained about 0.4 lb/d more than (P < 0.05) heifers grazing subterranean clover or N-fertilized pastures (averaged 1.94,1.57, and 1.54 lb/d, respectively). In Year 4, there were no differences among pasture treatments for average daily gains (ADG) (P > 0.05) as burr medic dominated the N-fertilized pastures. Grain per acre was always largest for arrowleaf clover (192 to 242 lb/acre) and smallest for N-fertilized pastures (111 to 206 lb/acre) during the winter-spring season. The summer season resulted in generally lower ADGs than the winter-spring season, with subclover pastures generally providing the best summer gains. These data suggest that winter annual clover can be used in the semiarid region of southern Texas. Stocking density and ADGs for clover pastures were never inferior to N-fertilized Coastal bermudagrass pastures, and in years with plentiful rainfall, stocking density and ADGs were superior on arrowleaf clover based pastures in the winter-spring season.

A Comparison of Herbicide Sprays and Pellets for Control of Broadleaf Weeds in Pastures

Picloram was applied broadcast on kleingrass pastures in the spring either as sprays or as pellets containing 2, 5, or 10% ae. The carrier in 5 and 10% pellets was inert clay, but 2% pellets were formulated with sufficient ammonium sulfate to contain 14.4% N. Dry formulations of picloram (10% ae), dicamba (5% ae), and tebuthiuron (20% ai) were compared to sprays at equal rates in a coastal bermudagrass pasture. Picloram was more effective as a spray than as pellets in two of five experiments. Few differences in weed control were observed with 2, 5, and 10% picloram pellets. Picloram applied up to 3 kg ae/ha as 2% pellets did not reduce kleingrass standing crop and up to 29 kg/ha of N as ammonium sulfate applied with or without picloram did not increase kleingrass production. None of the herbicides controlled weeds during the year following application.

Sulfometuron for Eliminating Bahiagrass (Paspalum notatum) From Centipedegrass (Eremochloa ophiuroides) and Bermudagrass (Cynodon dactylon)

This study was conducted to determine if ‘Pensacola’ bahiagrass, a major weed in turf and pastures in the southeastern United States, could be eliminated selectively from centipedegrass and ‘Tifway’ bermudagrass turf and a ‘Coastal’ bermudagrass pasture by treating with sulfometuron. Established Pensacola bahiagrass usually was controlled satisfactorily in Tifway bermudagrass and centipedegrass turf and in a Coastal bermudagrass pasture with sulfometuron at 210, 160, 105 g ai/ha applied twice, respectively. Bahiagrass seedlings were eliminated from both newly planted centipedegrass and Tifway bermudagrass turf with 105 g/ha sulfometuron applied once.

Luteal competency during the resumption of ovarian cyclicity in postpartum Brahman cows

Twenty pluriparous, spring-calving Brahman cows were used to determine luteal competency, as measured by serum progesterone concentrations, during the first and the second postpartum estrous cycles. Prior to and after calving, all cows were maintained in good body condition on Coastal bermudagrass pasture (IFN 1-00-703). The calves were allowed to suckle ad libitum, and sterile marker bulls were maintained with the cow herd as an aid in estrus detection throughout the trial. Cow weight and body condition score were recorded within 24 hours after calving and again at the first behavioral estrus observed. From day 1 through day 14 (day 0 = estrus) of both the first and the second postpartum estrous cycles, blood samples were collected from each cow, processed to yield serum and analyzed by radioimmunoassay for progesterone concentrations. There was a higher incidence of abnormal estrous cycles following the first postpartum estrus (35%) than following the second (5%) postpartum estrus (P<0.05). The abnormal first estrous cycles were characterized by either a short luteal phase (four cows) or by standing estrus behavior without luteal tissue formation (three cows). When serum progesterone concentrations were compared for all cows during the first estrous cycle with those during the second estrous cycle, there was less progesterone released during the cycle (P<0.05) and lower peak progesterone concentrations (P<0.10) during the first estrous cycle. However, if the abnormal cows were excluded from the analyses, there was no difference (P>0.10) in either progesterone concentrations through the 14 days measured or in peak progesterone concentrations between the first and the second postpartum estrous cycles. It can be concluded from this study that the higher incidence of abnormal luteal function following the first postpartum estrus may contribute to the decreased conception rates observed when cows are bred at their first postpartum estrus.

Simulated effect of calving season and winter hay feeding level on cow herd productivity.

The Texas A & M Cattle Production Systems Model was used to study herd productivity under several management plans open to cow-calf producers in the southeastern United States. An east Texas farm herd was simulated as a self-contained unit where all hay fed in the winter months was harvested from hay pastures or as surplus forage from grazed pastures. Management options examined involved (1) variation in the amount of forage fed as hay, and (2) spring vs fall calving. All forage was produced on well fertilized, intensively managed Coastal bermudagrass pastures. The winter feed options consisted of hay fed (1) ad libitum, and at (2) 80, (3) 60 and (4) 40% of the ad libitum level. The hay feeding period was November 15 through April 15. Overall herd productivity decreased as level of winter feeding decreased. Higher levels of hay feeding resulted in fewer cattle/unit land area but higher production/breeding cow. Herd size increased by 2.9, 11.9 and 32.5% as winter hay levels were reduced from ad libitum to 80, 60 and 40% of ad libitum, respectively, under spring calving management, whereas herd productivity measured as total live weight sold/herd (fixed land area) declined by 2.2, 9.4 and 10.3% with the respective feed levels. Spring-calving herds were approximately 3.2% larger in number than corresponding fall-calving herds on the same land area, but fall-calving herds produced an average of 3.6% more live weight sales.

Winter Stocking-Summer Finishing Systems Using Rye, Kentucky-31 Tall Fescue and Coastal Bermudagrass Pastures

Studies were conducted to compare wintering of steers on Kentucky-31 tall fescue with (1) wintering on rye seeded in tall fescue sod or in Coastal bermudagrass sod and (2) wintering on rye in a double cropping sequence after soybeans. The subsequent effects of the winter treatments on performance and carcass characteristics when these steers were finished with limited grain on either tall fescue or Coastal bermudagrass pasture were also determined. In each of three 140-day wintering trials, 56 steers were stocked at a rate of .24 ha/steer from early January through late May on (1) tall fescue (F), (2) rye seeded in dormant Coastal bermudagrass sod (BR), (3) rye conventionally seeded after soybeans for 105 days followed by 35 days on tall fescue (R) or (4) rye seeded in tall fescue sod (FR). Steers grazing BR gained more (P<.05) than those grazing R, and both the BR and R treatments resulted in greater (P<.05) steer gains than did either the F or FR treatment. Average winter gains per steer with BR, R, F and FR were 95.9, 70.6, 53.1 and 58.5 kg, respectively. After each wintering trial, seven steers from each winter treatment were limit-fed the same quantity of grain on either tall fescue (SF) or Coastal bermudagrass (B) pastures for 140 days. There were no winter × summer treatment interactions (P>.05). Steers grazing B consistently gained more (P<.05) than those grazing SF, with average summer gains of 68.6 and 45.5 kg/head, or 565 and 374 kg/ha, respectively. Total winter/summer gains of 155.4 kg by steers grazing BR/B exceeded (P<.05) gains on all other winter/summer treatment combinations except R/B. The lowest (P<.05) winter/summer treatment gains were obtained by steers grazing the FR/SF and F/SF (104.5 and 103.0 kg, respectively). Except for carcass weight, there were no differences (P>.05) in carcass characteristics associated with either winter or summer treatments. Steers that had grazed Coastal bermudagrass in the summer tended to have higher (P<.13) carcass grades than those that had grazed tall fescue.

Effect of herbage allowance on the efficiency of defoliation by the grazing animal

AbstractAn experiment examining the relationship of daily herbage disappearance (DHD) and daily herbage allowance (DHA) is described. Cows with calves were grazed at three stocking rates on Kleingrass and Coastal Bermudagrass pastures. DHD and DHA were monitored at 14‐d intervals. A significant positive linear relationship was noted between DHD and DHA (P0·25). Equations derived for Coastal Bermudagrass and Kleingrass were not significantly different and resulted in a combined equation Ŷ= 0·275X + 0·209 with an r2 vaiue of 0·27. As DHA exceeded 6–9 kg DM per 100 kg live weight, efficiency of defoliation by the cows and calves declined.

Effect of Monensin on Gains of Steers Grazed on Coastal Bermudagrass

A 140-day grazing trial was conducted to determine the effects of various levels of monensin on gains made by steer calves and yearlings while grazing Coastal bermudagrass pasture. Cattle on all treatments were grazed on Coastal bermudagrass forage at a stocking rate of 2.5 head per acre (6.2 steers per hectare). Corn, yellow, grnd., pelleted, 4 02 992 (ground, pelleted corn) was fed at a rate of 2 lb (908g) per head daily as a carrier for the appropriate monensin levels. The treatments were no corn, corn only, and corn plus 25, 50, 100, or 200 mg monensin per head daily. Each treatment was replicated twice. Ten cattle, with equal numbers of steer calves and yearling steers, were grazed in each replicate. The cattle were rotated among pastures within each set of replicates at 7-day intervals. Cattle on all levels of monensin produced larger (P<.05) weight gains than the control cattle. Animals fed corn with no monensin performed better than those on forage only. Growth rates of the steers receiving monensin increased as the drug level increased through 100 mg per head daily. Cattle fed the 200 mg level of monensin gained only slightly, but significantly, more than those on the 25 mg level.

Coastcross-1 Bermudagrass, Coastal Bermudagrass and Pensacola Bahiagrass as Summer Pasture for Steers

Three 2-acre (.81 ha) pastures of Pensacola bahiagrass, Coastal bermudagrass and Coastcross-1 bermudagrass were grazed during a 4-year period by yearling beef steers. During all 4 years, the average daily gains of steers grazing Coastcross-1 bermudagrass were superior (P<.05) to gains made by steers grazing Pensacola bahiagrass or Coastal bermudagrass. The mean average daily gains were 0.95, 1.08 and 1.50 lb. (0.43, 0.49 and 0.68 kg) per day for Pensacola bahiagrass, Coastal bermudagrass and Coastcross-1 bermudagrass and resulted in calculated average beef production per acre (hectare) values of 222, 331 and 469 lb. (249, 372 and 527 kg) per year for the three grasses. The average dry matter yield from Coastal bermudagrass pastures was about 35% greater than dry matter yields from either Pensacola bahiagrass or Coastcross-1 bermudagrass pastures. Periodic average daily gain and in vitro dry matter digestibility time trends were related (P<.05).

Species and Seasonal Occurrence of Leafhoppers and Planthoppers in a Coastal Bermudagrass Pasture in the Macon Ridge Area of Louisiana12

Species and Seasonal Occurrence of Leafhoppers and Planthoppers in a Coastal Bermudagrass Pasture in the Macon Ridge Area of Louisiana12

Diet supplementation of growing pigs raised in Coastal Bermuda grass (Cynodon dactylon) pasture lots

SUMMARYSeventy Duroc × Landrace weanling pigs (initial weight 20 kg) were used in a 91-day experiment in a semi-tropical environment, to determine the effects of deletion of the vitamin-antibiotic or mineral supplement to a corn-sucrose-soya bean meal diet on performance of pigs in Coastal Bermuda grass pasture lots. Pigs fed the complete diet in confinement in concrete-floor pens had significantly faster body-weight gain than pigs fed the same diet on pasture. Pigs fed the complete diet on pasture gained weight significantly faster than those given the same diet but without a vitamin-antibiotic premix. Those fed the complete diet without a Ca-P-trace mineral supplement on pasture gained weight significantly more slowly than all other groups, and showed lameness and femur and rib fractures (2 animals) indicative of Ca deficiency rickets.

Dursban® Insecticide Persistence in Grass and Corn Forage12

Persistence of Dursban® ( O,O -diethyl O -3,5,6-trichloro-2-pyridyl phosphorothioate), and its oxygen analog ( O,O -diethyl O -3,5,6-trichloro-2-pyridyl phosphate) was examined on Coastal bermudagrass and corn forage in the field and in jar silos. Residues, determined from field applications of Dursban insecticide sprays at 1 lb/acre, decreased rapidly in Coastal bermudagrass pasture and corn; low levels of the oxygen analog were also detected. Residues remained relatively stable in grass and corn silage.