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Crossbred steers were grazed in the spring and early summer on endophyte-infected (Neotyphodium coenophialum), Kentucky-31 tall fescue (Lolium arundinaceum) pastures to evaluate effects and interactions of feeding pelleted soybean hulls (PSBH) and steroid hormone implants (SHI) on steer performance, serum prolactin, and hair coat ratings (HCR). Steers were stratified by BW for assignment to six 3.0-ha toxic tall fescue pastures. With or without daily PSBH feeding, treatments were assigned randomly to pastures as the main plot treatment in a split-plot design. Pelleted soybean hulls were group-fed to provide 2.3 kg(steer·d-1) (as fed). With or without SHI (200 mg of progesterone and 20 mg of estradiol) treatments were randomly assigned as the subplot treatment to 2 steer subgroups within each pasture. Sixty-four steers were grazed for 77 d in 2007, and 60 steers were grazed for 86 d in 2008. Pasture forage mass declined linearly over time, but the rate of decline was greater (P = 0.001) in 2007 than in 2008. Pasture forage mass was never below 2,300 kg of DM/ha in either year. Average daily gain for steers on the combined PSBH and SHI treatments was greater (P < 0.01) than for those on the PSBH-only, SHI-only, and control (no SHI, no PSBH) treatments. Average daily gain for the PSBH-only steers was greater (P < 0.01) than for SHI-only and control steers and tended (P = 0.063) to be greater for SHI-only than for control steers. Steroid implants did not affect (P = 0.826) serum prolactin concentrations; how- ever, prolactin concentrations in PSBH steers, with or without SHI, were increased (P = 0.01) 2-fold over SHI-only and control steers. Feeding PSBH and SHI treatments both reduced (P < 0.05) the percentage of steers with rough HCR, and a greater percentage of steers fed PSBH tended (P < 0.076) to have sleek hair coats. An economic analysis was conducted, which determined that costs of additional ADG with PSBH feeding were below breakeven costs over a wide range of PSBH costs and cattle prices. Breakeven costs for PSBH-only treatment for a range of cattle prices of $1.80 to $2.40/kg of BW were less than $120/t, whereas with PSBH feeding combined with SHI the breakeven cost was less than $240/t. Results indicate that steers grazing endophyte-infected tall fescue can be fed PSBH and implanted with steroid hormones to cost effectively increase ADG and that feeding PSBH can increase serum prolactin concentrations and induce some shedding of rough hair coats. [ABSTRACT FROM AUTHOR]

First and second harvests of lucerne ( Medicago sativa L.), perennial ryegrass ( Lolium perenne L.) and a lucerne–perennial ryegrass mixture [80 or 144 g kg−1 dry matter (DM) of ryegrass] at the first and second harvests were cut and conditioned, wilted to 500 or 700 g DM kg−1 then baled and stretch-wrapped for silage on the same dates. Lucerne bales were denser (411 kg m−3) than bales of perennial ryegrass (331 kg m−3) ( P < 0·05). After an 8-month storage period, silage made from high DM-content forage had a higher concentration of neutral-detergent fibre (NDF) and was less digestible than that made from low DM-content forage. Daily DM intakes by beef steers, when the silages of the second harvest were fed ad libitum, were 31·2, 31·2 and 22·3 g kg−1 live weight for lucerne, lucerne–perennial ryegrass mixture and perennial ryegrass silages, respectively ( P < 0·01), when the herbage had been wilted to 500 g kg−1. In vivo digestibility of NDF in the lucerne–perennial ryegrass mixture silage (0·587) was significantly lower than that of perennial ryegrass silage (0·763) but higher than lucerne silage (0·518). Higher intakes of baled lucerne silage tended to offset its lower digestibility values. Lucerne–perennial ryegrass mixture silage had a higher DM and NDF digestibility than lucerne silage, indicating perhaps the presence of associative effects. [ABSTRACT FROM AUTHOR]

Pearl millet [Pennisetum americanum (L.) Leeke] is an annual warm season (C4) grass that has a high yield potential during summers when cool season species are heat-stressed and unproductive. In two field trials, 650 kg round bales were made from long (>100 cm) or short (chopped) (≈5 cm) forage and at bale chamber pressures of 421 or 842 × 103 Pa. After 24 h of wilting, forage moisture concentrations at Trial 1 and Trial 2 were 771 and 583 g kg-1, respectively. The higher baling pressure increased both mass and density of bales (P < 0.05). Length of cut had no effect on bale weight or density. Core temperatures were lower in higher density bales when the concentration of forage moisture was lower. Water-soluble carbohydrate concentrations were lower in silages made from the shorter forages (P = 0.013). Nutritive value of silage decreased during 8 mo of storage regardless of treatment. Baling chamber pressure and forage chopping treatments did not affect neutral detergent fiber (NDF) or in vitro dry matter digestibility (IVDMD) of post-storage silage. Acidity of silage ranged from pH 4.13 to 5.31. Lactic acid concentrations were lowest in silage in Trial 1 made from the wetter forage (771 g kg-1) when chopped to 100 cm. Listeria was present in bales made from the wetter forage. Clostridium botulinum was detected in silage made from chopped forage when baled at low chamber pressure. [ABSTRACT FROM AUTHOR]

Ensuring the genetic purity of parental lines and hybrids is a prerequisite to realize their full potential. The cytoplasmic male sterile (CMS) lines that are utilized for developing the popular ’three-line’ hybrids, often get contaminated with their isonuclear maintainer lines during CMS line multiplication. Use of such CMS lines in hybrid seed production results in the production of genetically impure hybrid seed. We report the identification of a DNA sequence that is homologous to rice mitochondrial DNA but unique to the Wild Abortive (WA) cytoplasmic male sterile lines of rice (Oryza sativa L.). In a polymerase chain reaction (PCR) using total genomic DNA as a template, oligonucleotide primers based on this unique DNA sequence could amplify a fragment from CMS lines of rice and their hybrids but not from their cognate maintainer lines. In tests on mixed samples of plants containing both CMS and Maintainer lines, this PCR assay was used to correctly predict the genotypes of these plants indicating that it can be used to detect the mixture of maintainer lines in the seed stocks of the CMS line. [ABSTRACT FROM AUTHOR]