Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 10 of 10
Full-Text Articles in Physical Sciences and Mathematics
Temperate Pasture And Sheep Performance Under Radiata Pine And In Open Pasture, K M. Pollock, R J. Lucas, D B. Pownall, S E. Thomson
Temperate Pasture And Sheep Performance Under Radiata Pine And In Open Pasture, K M. Pollock, R J. Lucas, D B. Pownall, S E. Thomson
IGC Proceedings (1997-2023)
Forage production from years 4 to 6 of an agroforestry system at 400-600 trees per ha and pasture alone were compared for a temperate sub-humid environment. Forage production was best for lucerne pasture followed by phalaris/clover and cocksfoot/clover, and least for ryegrass/clover and the ryegrass only pastures. Total pasture production in the agroforest relative to the open pasture was from 10% more for phalaris to 20% less for lucerne. Sheep carrying capacity over all pastures was 14.6 sheep/ha in the open and 11.8 sheep/ha in the agroforest and varied by ±15% according to the pasture types.
Species Preference Influences On Cattle Grazing Behaviour, G P. Cosgrove, C B. Anderson, R H. Fletcher
Species Preference Influences On Cattle Grazing Behaviour, G P. Cosgrove, C B. Anderson, R H. Fletcher
IGC Proceedings (1997-2023)
Lotus corniculatus offers specific nutritional benefits to animals, but exploiting these advantages in grazing systems depends on the proportion of lotus in the feed offered and the animals' preference, hence desire to select for it. To determine preference for lotus, heifers were offered free-choice in contrasting, spatially separated but adjacent monocultures of ryegrass-lotus or red clover-lotus. Following a one-week period to adjust to the species offered and their arrangement, 10 young heifers were observed at 10-minute intervals during daylight hours, and the species they were on and whether or not they were grazing was recorded. This procedure was conducted in …
Use Of Flow Cytometer In Breeding Festuca X Lolium Hybrids, M C. Kerlan, M Ghesquiere
Use Of Flow Cytometer In Breeding Festuca X Lolium Hybrids, M C. Kerlan, M Ghesquiere
IGC Proceedings (1997-2023)
Ploidy in various generic Lolium - Festuca progenies were assessed by flow cytometry and compared to conventional chromosome counting. In non-segregating triploid and tetraploid progenies, the cytometer estimated so accurately the level of plant ploidy that chromosomes counting would be no use. In segregant progenies, all the tetraploid plants according to the cytometer had effectively 28 chromosomes. Among the triploid and pentaploid plants detected by the cytometer, 40% of the plants were tetraploid. They represented only 29% of the progeny which must be counted. The flow cytometry can be used in routine interspecific breeding programmes. Conventional chromosome counting should be …
Persistency In Lolium X Festuca Hybrid Derivatives And Its Relationships With Flowering Traits, M Ghesquiere, C Mousset
Persistency In Lolium X Festuca Hybrid Derivatives And Its Relationships With Flowering Traits, M Ghesquiere, C Mousset
IGC Proceedings (1997-2023)
Using amphiploid and backcrossed derivatives of Italian ryegrass x tall fescue hybrids, the paper emphasizes the interest of introgression vs amphiploidization in breeding for specific traits such as persistency or seed production from tall fescue or ryegrass resp. Persistency in amphiploid and Lolium-introgressed progenies were assessed in nursery together with variation of flowering traits. Persistency was found lower, on average, in introgressed progenies than in hybrid progenies but with enlarged variability within progeny suggesting possible advantageous rearrangements of fescue chromosomes. Although significantly associated, persistency in both populations was only very little affected by the variations in flowering traits such …
Field Evaluation Of Crown Rust In Annual Ryegrass Populations, G M. Prine
Field Evaluation Of Crown Rust In Annual Ryegrass Populations, G M. Prine
IGC Proceedings (1997-2023)
Crown rust (Puccinia coronata [Pers.] Cda.) is the most prevalent disease found on annual ryegrass (Lolium multiflorum L.) of the southeastern USA. Determination of crown rust resistance is difficult because of the erratic nature of infections at most locations. As crown rust is present at Gainesville, FL each year, a rust nursery was designed to evaluate rust resistance and susceptibility of annual ryegrass. Evaluation consists of periodic rust ratings of the seed crop and regrowth of part of each plot after cutting. Nursery results indicate the buildup of rust, including at the date of 90% heading (start of …
Selection For Field Survival Increases Freezing Tolerance In Festulolium, M D. Casler, P G. Pitts, P C. Bilkey, C A. Rose-Fricker
Selection For Field Survival Increases Freezing Tolerance In Festulolium, M D. Casler, P G. Pitts, P C. Bilkey, C A. Rose-Fricker
IGC Proceedings (1997-2023)
Festulolium (Festulolium braunii K.A.) is marginally adapted to the north central and northeastern USA and southern Canada. The purpose of this study was to evaluate four festulolium populations selected for field survival under harsh winter conditions for their freezing tolerance in controlled environments. Progenies of all four populations showed some improvement in freezing tolerance compared to their parents. Improvements were dependent on the temperature at which measurements were made and varied among germplasms. Improvements were manifested in both decreased plant mortality and decreased injury to surviving plants. Genetic variation for freezing tolerance appears to be a viable mechanism …
Selection For Nitrogen Use Efficiency In Perennial Ryegrass Using Hydroponics, E N. Van Loo, A.J. P. Van Wijk, O Dolstra, H.J. P. Marvin, C.H. A. Snijders
Selection For Nitrogen Use Efficiency In Perennial Ryegrass Using Hydroponics, E N. Van Loo, A.J. P. Van Wijk, O Dolstra, H.J. P. Marvin, C.H. A. Snijders
IGC Proceedings (1997-2023)
A selection method was tested for improving nitrogen use efficiency of perennial ryegrass (Lolium perenne L.) using a hydroponics system that controls the plant nitrogen concentration. Divergent selection for plant production, leaf area increase and dry matter distribution in six segregating populations under limiting nitrogen supply resulted in differences between offspring of upward and downward selections larger than 20 % in most characteristics. Moderately high realized heritabilities were found for some characteristics (up to 0.88). It is concluded that early selection for nitrogen use efficiency is feasible using this hydroponics system.
How Do Cattle And Sheep Alter Ingestive Behaviour In Response To Changes In Sward State?, P D. Penning, R J. Orr, A J. Parsons, A Harvey
How Do Cattle And Sheep Alter Ingestive Behaviour In Response To Changes In Sward State?, P D. Penning, R J. Orr, A J. Parsons, A Harvey
IGC Proceedings (1997-2023)
Ingestive behaviour of yearling Friesian heifers continuously stocked on monocultures of Lolium perenne (G) or Trifolium repens (C) maintained at sward heights of 7-8 cm, was recorded. Bite masses, prehension biting and mastication rates were similar between treatments (211 vs. 230 mg DM prehension bite-1, 61 vs. 55 prehension bites and 11 vs. 13 mastications, min-1 for G and C, respectively). DM intake rates were 12.9 g min-1 for both treatments. Animals grazed longer (536 vs.436 min) and ruminated longer (526 vs. 267 min-1) on G compared with C. Daily intakes were 6.9 vs.5.6 kg DM for G and C. …
Effects Of Fasting On Ingestive Behaviour Of Sheep Grazing Grass Or White Clover Monocultures, P D. Penning, M Boval
Effects Of Fasting On Ingestive Behaviour Of Sheep Grazing Grass Or White Clover Monocultures, P D. Penning, M Boval
IGC Proceedings (1997-2023)
Effects of fasting sheep for 24 h (F), compared with controls (NF), on their ingestive behaviour and particle size in extrusa was investigated using oesophageally fistulated animals, grazing monocultures of Lolium perenne (G) or Trifolium repens (C). Bite masses tended to be lower on G than C and tended to increase with fasting (40, 64, 61 and 70 mg DM bite-1) for treatments GNF, GF, CNF and CF, respectively. Prehension rate was lower (52 vs. 69 bites min-1) and masticating rate was higher (106 vs.86 mastications min- 1) for G and C treatments, respectively. Over 24 h following fasting, NF …
Quality Evaluation Of Feed Resources At The Newly Reclaimed Area In Egypt, M K. Hathout, F Z. Swidan, M F. El-Sayes, H A. Eid
Quality Evaluation Of Feed Resources At The Newly Reclaimed Area In Egypt, M K. Hathout, F Z. Swidan, M F. El-Sayes, H A. Eid
IGC Proceedings (1997-2023)
The objective of this study was to examine the productivity of Egyptian clover (Trifolium alexandrinum L.) interseeded with ryegrass (Lolium multiflorum) and alfalfa (Medicaga sativa L.). These species were planted in newly reclaimed land in Ismailia, Egypt under two fertilization systems; organic (OF) or chemical (CF) during winter season of (1994-1995) using a split plot design. Feeding quality of forages was evaluated by conducting digestibility trials with rams and feeding trials with growing lambs where forage was offered ad. libitum with 1% of LBW concentrate. Productivity data indicated that organic fertilization yielded significantly more DM. Chemical …