Agronomy and Crop Sciences Commons^™

Trees And Shrubs As Secondary Components Of Pasture, A N. Atta-Krah

IGC Proceedings (1977-2023)

Traditionally, the concept of pasture has precluded tree crops in any meaningful and productive way. Grasses and herbaceous legumes have been the major components of pasture. The place of trees in pasture is often limited to live fencing, and a few other trees interspersed within the pasture, to provide shade for livestock. In tropical and subtropical areas, where trees are a significant part of the natural vegetation, the non-inclusion· of trees in pasture and agricultural production systems and their increasing rate of disappearance from the zone are giving rise to serious environmental and agricultural concerns. There is an increasing realisation …

Pastures As The Secondary Components In Tree-Pasture Systems, Chin Peng Chen

IGC Proceedings (1977-2023)

The multi-stata canopy structure of rain forest allows only I% sunlight penetration, too little for the survival of forage beneath it. However, man-made forest plantation (rubber, oil palm and coconut) allows more light for forage species. Initially, 60-70 forage species were recorded under these modified forest canopies but only one third of them survived heavy shading. Forage dry matter yields declined from 2.8-4.8 I/ha DM at immature phase of plantations, to 0.1-1.0 I/Im at mautre phase. Nutrients. available to grazing animals from forages under plantations were guile high (18.4 kg Nit DM and 5609 MJ MEit DM) from native forages, …

Grazing Potential Of Desiccation-Tolerant Tropical And Subtropical Grasses, Y A. Sutaryono, D F. Gaff

IGC Proceedings (1977-2023)

Some desiccation-tolerant grasses possess the potential for use as a grazing source for animals. Some species compared favourably in nutrient content and digestibility with other tropical animal fodder grasses. The Sporobolus species, S. aff, fimbriatus, S. lampranthus, S. pellucidus, together with Eragrostis invalida and Eragrostiella nardoides showed the most promising combination of desirable characteristics. Resurrection grasses contained potentially toxic substances, but, it appears, in amounts harmless to animals, Animal feed trials are needed to test their real feed value, palatability and non-toxicity to animals.

Beef Cow Adaptation To Hot Dry Climates, T.D A. Forbes, J W. Holloway, B G. Warrington

IGC Proceedings (1977-2023)

Behavioural adaptation of Bos taurus (Angus) and B. indicus B: taurus cross (Brangus) females to high ambient temperatures was studied in 2 trials (maximum ambient temperatures of 37 .8 and 32.5°C respectively) in a semi-arid area of south Texas. Brangus females grazed for longer (297 v. 239 min/day, P<0.0001) spent less time in shade (288 v. 395 min/day, P<0.0001), and spent less time watering (95 v. 115 min/day, P<0.0001) than Angus females. Trial by breed interactions were detected (P<0.001) for resting in shade, resting in sun and watering time. Both breeds were apparently restricted in grazing time by high ambient temperatures during both trials, but the Angus were restricted to a greater extent. Although ambient temperatures were lower in the second trial, the threshold for allowing grazing unrestricted by heat stress was apparently not reached for either breed,

Mixed-Species Grazing In The Highland Sourveld Of South Africa: An Evaluation Of Animal Production Potential, M B. Hardy, N M. Tainton

IGC Proceedings (1977-2023)

The effects of mixed-species grazing, at 5 cattle to sheep ratios all at the same stocking rale, on individual animal mass change/ ha mass change/ Ila were monitored for 2 grazing seasons, The ratios were balanced in terms of animal units which equate the expected intake of cattle and sheep. The study was conducted on a humid grasslands in which the herbage characteristically loses quality as Jt mature1. Mass gains of individual cattle were higher when the cattle grazed 10ge1her with the sheep than when they grazed alone. This was ascribed to increasing herbage availability as the ratio of cattle …

Prediction Of Live-Weight Gain Of Cattle Grazing Pastures On Brigalow Soil, M Hirata, C K. Mcdonald, R M. Jones

IGC Proceedings (1977-2023)

A model for predicting the live-weight gain-(LWD) of cattle from climatic conditions and pasture and cattle attributes was developed. The model was calibrated and validated against the data from a long-term grazing experiment on brigalow soil, sown with green panic pastures. When validated, the model tended to overestimate LWG as the proportion of green panic (Panicum maximum var. trichoglume) in the pasture decreased, because the model was calibrated, without considering species composition, to data from years when green panic was dominant. This study emphasises the limitations of empirical models of grazing systems. The study also implies that there …

Beef Production From Commercial Leucaena Leucocephala Pastures In A Dry Subtropical Environment, R L. Clem, C R. Esdale, M J. Conway, D Macintyre

IGC Proceedings (1977-2023)

Leucaena leucocephala is a legume widely adapted to the tropics and subtropics and is currently recommended for sowing on fertile clay soils in the subconstal (100-1000 mm) rainfall areas of Queensland. It produces high quality forage that can be used as browse with native or sown grass pastures to improve live-weight gain of grazing beef cattle. At Banana in central Queensland a commercial grazing enterprise has been developed on 1450 ha of land cleared of brigalow scrub and cropped for 20-30 years before sowing to leucaena. Leucaena has been established on about 80% of the property. Stocking rates are varied …

Improving Livestock Production Using The Heavy-Duty Blade Plough On Pastures Infested With Brigalow Suckers, P Filet, J Agnew, R Barnett, J Clewett

IGC Proceedings (1977-2023)

Reducing brigalow {Acacia harpophylla) sucker numbers is necessary to maintain the productivity of grass pastures on brigalow soils in' Australia. Blade ploughing brigalow sucker regrowth is an effective control oplion. A 97% mortality was achieved when brigalow suckers were treated with a blade plough in central Queensland. Pasture yield was 3 times higher in a blade-ploughed paddock than in an adjacent sucker paddock 6 months after treatment and after 2 more summers. During 3 years of grazing, stocking rates were 7 .5 ha/steer in the sucker paddock and 2.3-3.2 ha/steer in the blade0ploughed paddock, Annual· live-weight gains/head were …

Animal Feed Research In Eastern And Southern Africa: Historical And Actual Priorities, Samuel C. Jutzi, J C. Tothhill

IGC Proceedings (1977-2023)

A review of animal feed research reports from 7 countries of eastern and southern Africa is used to assess historical and actual research emphases. Priority was on feed supply and evaluation for cattle production with strong rangelands improvement programmes. Most research focused on ecologically favoured regions and larger-scale livestock commodity production. Strong efforts for the exploitation of grasses for improved feed supply were supported by legume work for feed quality improvement. There was a strong emphasis on feed agronomy work, one third of all that work involving animals. Component research results were reported with little discussion of target systems implications, …

Tropical Pasture Establishment In Thailand By Direct-Drilling, C Lekchom, S Sukpituksakul, N Wongsuwan, B R. Watkin

IGC Proceedings (1977-2023)

The establishment, early production and quality of 4 tropical grasses was compared when established by direct-drilling into uncultivated, herbicide-kllled pasture or when sown into a fully cultivated, well­prepared seedbed. Direct-drilling resulted in significantly better establishment and early production than drilling into a prepared seedbed at the first cut, but not at subsequent cuts. Forage quality in terms of both crude protein and dry matter digestibility was high in all treatments, with no difference between sowing techniques and only small differences between species. Results are discussed in relation to farming practice.

Legumes In African Star Grass- Herbaceous Legume Pastures As A Partial Substitute For Concentrate Feed For Dairy Production, Francis Asiedu, B Ahmed, R Paterson, R Simpson, R Motta

IGC Proceedings (1977-2023)

Two groups of 10 equally matched Jamaica Hope cows from a commercial dairy farm in Jamaica were grazed (stocking rate 3.5 cows/ha) for 2 years on pure African star grass (Cynodon nlemfuensis) and African star grass in mixture with herbaceous legumes in a cross­over design. Dairy ration was fed at the rate of 0.26 and 0.18 kg/day/ kg milk for the grass and mixed pastures respectively. The proportion of legumes in the mixed pasture averaged 0.35 in 1990/91 and 0.20 in 1991/92. Available herbage dry matter was higher for the grass pasture ( 4.43 v. 4.11 t/ha) but …

Animal Production And Dynamics Of Pangola Grass, Ryegrass, And White Clover As Influenced By Grazing Pressure, A De Moraes, G E. Maraschin

IGC Proceedings (1977-2023)

A grazing experiment was conducted at the Estacao Experimental Agronomica - UFRGS, Eldorado do Sul, RS, from June 1989 to March 1990, to evaluate a mixed pasture of pangola grass (Digitaria eriantha), ryegrass (Lolium multiflorum) and white clover (Trifolium repens) under 4 levels of grazing pressure (GP), namely: 3.S, 7 ,0, 10.5 and 14.0 kg DM of forage on offer /100 kg live weight (LW), with 2 field replications. Average live-weight gain (LWG) decreased as grazing pressure increased. Maximum LWG was obtained at grazing pressures of approximately 12%, which was associated with DM residues …

Cultivated Pasture, Forage On Offer And Animal Responseg, G E. Maraschin, A De Moraes, L.F. A. Da Silva, J Riboldi

IGC Proceedings (1977-2023)

Animal gains on pasture are influenced by the forage dry mailer on offer (DMO). To ascertain this relationship a pangola grass (Digitaria eriantha) pasture was evaluated under forage DMO levels of 3.5%, 7.0%, 10.5% and 14.0% of live weight (LW)/head/day. Two steers were assigned to each treatment as tester animals plus a number of put-and­take steers to maintain the desired levels of forage DMO, at the Estacao Experimental Agronomica • UFRGS • 30°S, from November 1989 to March 1990 (period I) and from October 1990 to May 1991 (period II). Pasture DM production and crude protein were not …

Effect Of Supplementation On Pasture Selection By Grazing Steers. I. Quality Of Ingested Forage, O R. Rosso, P O. Gomez, F Overjero

IGC Proceedings (1977-2023)

Three oesophageal fistulated Hereford steers (average live weight 304 kg) were supplemented throughout a trial at 0, 0.7 or 1.4% of live weight, with a mixture of 90% ground maize and 10% sunflower expeller. Adaptation and sampling periods were 7 and 4 days respectively. Steers were allocated randomly to 4 Agropyron•dominated pastures of 1800, 2000, 8200 and 8900 kg OM/ha and leaf percentage of 5.8, 28.9, 23.2 and 14.0, respectively. Fistula samples were taken once daily, air dried at 60°C and analysed. Supplementation significantly (P<0.05) affected DM digestibility, which was 51.3, 54.7 and 57.2 for 0, 0.7 and 1.4% levels, respectively. Nitrogen and cell wall content differences were not detected. It appears that supplemented steers preferred pasture components with the highest digestibility.

Seasonal Changes In The Dry Matter Digestibility Of Individual Tillers Of Napiergrass At Two Sites Of At Different Altitudes, Y Ishii, K Ito, H Numaguchi

IGC Proceedings (1977-2023)

An investigation was made into the seasonal changes in the in vitro dry matter digestibility (IVDMD) of leaf blade (LB) and stem (ST) of individual tillers of napiergrass (Pennisetum purpuretum) grown at the high-altitude site (HA) and low-altitude site (LA) in Miyazaki prefecture, south-western Japan. Within a single sampling date, the variation in the IVDMD with tillers was small both for LB and ST. Negative logarithmic relationships held between the LB percentage and tiller dry weight and between the IVDMD and dry weight of LB and ST. The HA plants produced less dry matter as well as digestible …

Tropical Pastures For Dairy Heifers In The South-Eastern Region Of Brazil, S Aronovich, S R. De Carvalho, Mm Aronovich

IGC Proceedings (1977-2023)

A number of experiments using improved tropical pastures (mostly Digltaria decumbems cv. Transvala) for heifers were made in the south-eastern region of Brazil from 1970. The results are presented as: (A) experiments with heifers during· the nursing period, (B) experiments with heifers after. weaning and (C) experiments with heifers older than 6 months. The results and the economical analyses lead to the following conclusions: ( 1) the use of well managed, improved tropical pastures enables adequate growth and development of dairy heifers, (2) the heifers reach sexual maturity before 20 months of age, and (3) the cost of replacement heifers …

Mineral Supplementation And Phosphorus Fertilizer Application On Native Pastures In North-East Argentina, R M. Pizzio, O Royo Pallares

IGC Proceedings (1977-2023)

Extensive cattle production systems in north-east Argentina are based on the use of native pastures. One of the most important limiting factors to improve production is the acute phosphorus deficiency of soils and pastures. A large experiment was set up to study the effect of phosphorus fertiliser and mineral supplementation on the live­weight gain of steers of 2 ages grazing native pastures. Supplementation with a mixture of bone meal and salt, residual effect of P fertilisation, and both treatments applied together increased the annual animal live-weight gain by 60, 66 and 106%, respectively. The response of younger steers to fertiliser …

Nebraska Crop Budgets Updated For 2025, Glennis Mcclure

Cornhusker Economics

For the 2025 production season, 83 crop budgets were developed for Nebraska. These budgets show slightly lower per-unit costs compared to 2023 and 2024. The primary factor behind the reduction in input costs is the lower estimated costs of fuel and fertilizer. In most cases, machinery depreciation and opportunity costs remained relatively stable, while land values and rental rates increased slightly. Additionally, seed and interest costs also rose in the 2025 budgets. Budget scenarios for individual producers may vary depending on the timing of their input purchases and fluctuations in prices.

The Nebraska crop budgets are updated annually to serve …

Insect Frass Fertilizer As Soil Amendment For Improved Forage And Soil Health In Circular Systems, Amanda J. Ashworth, Helen Carla S. Amorim, Gerson L. Drescher, Philip A. Moore, Maria Guadalupe Rojas, Juan Morales-Ramos, Ann M. Donoghue

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Insect farming is expected to increase in coming years, thus generating high quantities of frass (insect excreta). Frass valorization hinges on basic agronomic research prior to industry upscaling. Here, we investigated soil physiochemical properties, SMAF (Soil Management Assessment Framework) soil health, CO2 efflux, and bermudagrass [Cynodon dactylon (L.) Pers.] yield and quality as affected by yellow mealworm (Tenebrio molitor L.) frass [3400 and 6800 kg ha-1, low (LF) and high (HF) rates], poultry litter (PL; 3400 kg ha-1), and ammonium nitrate (AN; 67 kg N ha-1). HF increased soil C, N, P, K, and Mg by 10, 12, 44, 58, …

Milk Yield Of Cows With Different Genetic Potential On Grass And Grass-Legume Tropical Pastures, C E. Lascano, P Avila

IGC Proceedings (1977-2023)

A grazing experiment was carried out at CIAT's Quilichao research station to assess the effect of legumes selected for acid soils on milk production of cows with different genetic potential. Pastures of Brahiaria dictyoneura cv. Llanero and Andropogen gayanus cv. Carimagua l, alone and in association with Centrosema acutifolium (CIAT 5568) and C. macrocarpum (CJAT 5713), were grazed by Holstein and Zebu crossbred cows using a Latin square crossover design. Fat corrected milk (FCM) yield of Holstein cows was 17 and 19% higher in the associations of B. dictyoneura and A. gayanus, respectively, than in the grass-only pastures. With the …

Fattening Heifers On Nitrogen Fertilized And Irrigated Pastures: A Productive And Sustainable System For The Tropics?, F Champanhet, M Mahieu

IGC Proceedings (1977-2023)

Beef production from nitrogen-fertilised and irrigated pastures was studied for 4,S years on vertisols, South Martinique (rainfall 1400 mm). Digitaria decumbens (pangola) pastures received 230��7S-ISO kg/ha/year N-P·K and were rotationally grazed (S days grazed, 30 days rested) all year round with a fixed stocking rate (6.6 heifers/ha). Mean live-weight gains were: 1121 kg/ha/year and 170 kg/head/ year. Pangola showed good persistence and cover at the end of the experiment exceeded 9S%, It is concluded that heifers fattening on nitrogen-fertilised pastures is a productive and stable system.

Comparative Use Of Digitaria Decumbens And Cynodon Nlemfuensis By Local Suckling Ewes In Martinque (Fwi), Maryline Boval, Gisele Alexandre, M Mahieu, P Cruz, M Meuret

IGC Proceedings (1977-2023)

Pastures of Digitaria decumbens (Dd) and Cynodon nlemfuensis (Cn) were each grazed by 64 native suckling ewes ( 40 ewes/ha) in Martinique. Forage characteristics, ewe feeding behaviour and lamb growth were studied. The available herbage mass (kg DMJLW0-75/day) was lower for the Dd pastures than for the Cn pastures: 295 v. 355 for the leaves (P<0.05) and 820 v, 1360 for the stems (P<0.01), respectively. There was no difference in the diurnal activities (grazing, ruminating) between the ewes in the 2 groups. Number of bites/min was higher on Dd pasture than that for Cn: 31 v. 26 (P<0.001), Pre­weaning daily weight gain (g/day) was higher for the Dd lambs group than for Cn: 170 v. 140 (P<0.01). The lamb mortality rate(%) was respectively: 15 v. 27 (P<0.05). Pasture management problems are discussed.

Stockpiling Of Brachiaria Decumbens For Steer Maintenance During The Dry Season, Esther G. Cardoso, V.P B. Euclides, J.M Da Silva

IGC Proceedings (1977-2023)

A Brachiaria decumbens pasture was evaluated in a factorial experiment (2 stocking rates and 2 pasture managements). Eight steers averaging 370 kg live weight (LW) were allocated to the paddocks at the beginning of the wet season ( 1 December). For the deferred management treatment, half of the area was closed off at the end of the rainy season ( 15 March to 15 June) for utilisation as stockpiled feed during the dry season (15 June to 30 October). B. decumbems was capable of fattening Nellore steers during the rainy ·season, but maintained steer live weight (LW) only in the …

Seasonal Changes In The Chemical Composition Of Cultivated Tropical Grasses In The Savannas Of Brazil, M.C M. Macedo, V.P B. Euclides, M.P De Oliveira

IGC Proceedings (1977-2023)

Five tropical grasses; Brachiaria brizantha cv. Marandu, B, decumbens cv. Basilisk, Panicum maximum cv. Coloniilo, P. maximum cv, Tobiatil, P. maximum cv. Tanzania-I, were planted on a dark red latosol (Oxisol) and grazed for 3 rainy and 3 dry seasons . The original savanna vegetation was removed, the soil cultivated and fertilised with 1000 kg/ha of dolomitic limestone, 350 kg/ha of single superphosphate, 100 kg/ha of KCI and 40 kg/ha of fritted traced elements. Treatments were arranged in a RCB design with 3 replicates. Paddocks were 1.5 ha. Grazing pressure was adjusted to approximately 8 or 15 kg of …

Evaluation Of Panicum Maximum Cultivars Under Grazing, V.P B. Euclides, M.C M. Macedo, A Vieira, M P. Oliveira

IGC Proceedings (1977-2023)

A grazing trial was conducted in Brazil, for a 3-year period, to study animal production from Panicum maximum cultivars (Coloniao, Tobiatii and Tanz5nia-1). Three 1.5-hn paddocks of each cultivar were stocked continuously with 3 steers, and additional grazers were added or removed as required to ensure similar grazing pressure in each treatment. Steers on Tanzania-I had a superior average daily gain (ADG) to those on Tobiatii and Coloniffo. However, the lack of difference in carrying capacity between Tanzdnin and Tobiatil pastures resulted in similar live-weight gain (LWG)/ha. The ADG and LWG/ ha of Coloniilo were significantly lower than the other …

Evaluation Of Brachiaria Decumbens And Brachiaria Brizantha Under Grazing, V.P B. Euclides, A H. Zimmer, M P. Oliveria

IGC Proceedings (1977-2023)

A 3-year grazing trial was conducted in Brazil, to relate changes in sward characteristics of B. decumbens and B. brizantha to animal live-weight gain (LWG). Three 1.5-ha paddocks of each grass species were stocked continuously with 3 steers, and additional grazers were added or removed as required to ensure similar grazing pressure in each treatment. Despite similar (P>0.85) annual average daily gains (ADO) of steers grazing both species, the ADO of steers grazing B. brizantha pasture was significantly (P<0.05) higher during the wet season, and significantly (P<0.05) lower in the dry period, when compared with those on B. decumbens. Annual LWG per area of both species were also similar (P>0.85). The best predictor of ADO was …

Effects Of Grain Supplement For Steers Grazing Stargrass Pastures On Subsequent Feedlot Gains And Carcass Characteristics, G.M.J Horton, W D. Pitman, E M. Hodges

IGC Proceedings (1977-2023)

Performance of steers (181 kg) grazing slargrass pastures was evaluated al 2 levels of grain supplementation in comparison with unsupplemenled cattle and with steers in drylot fed a high-roughage diet. Supplements during the 140-day winter period were fed at 1.0 (moderate) and 1.5% body weight (BW)lday (high), followed by 0.40 kg (moderate) and 0.5% BW/day (high) during the 98-day spring grazing period. Gains during a subsequent 100-dny, high-energy feeding period and resulting carcass characteristics were also compared. Gains during !he grazing period did not differ between !he 2 levels of supplement. Daily rate of gain of unsupplemented cattle (0.44 kg) …

Large-Scale Property Demonstrations Of The Effect Of Sexa Stylo And Phosphorus On Beef Cattle Growth In Central Queensland, Australia, C H. Middleton, K J. Murphy, G W. Blight, Vicki-Lee Hansen

IGC Proceedings (1977-2023)

Seca style (Stylosanthes scabra) was oversown into black speargrass (Heteropogon comortus)•dominant pasture after a burn at 2 sites in central Queensland, and the pasture was continuously grazed. At one site with <5 ppm bicarbonate-extractable soil P, Seca growth was poor and gave only a small animal growth response (18 kg/steer/year) over native pasture. With the addition of superphosphate (27 kg P/ha) the Seca-native grass produced an additional live-weight gain of 70 kg/ steer/year over the native pasture control. At a second site with 6-8 ppm available soil P, Seca grew well, and with a P supplement given to steers, live-weight gains were 40 kg/steer/year more than for P­supplemented animals grazing native pasture. Oversowing Seca into native pasture with P as fertiliser or a supplement can dramatically improve animal performance. The project was conducted on private properties and was aimed to focus producer attention on this technology, which is suited to large areas of northern Australia.

Improving Hill Agriculture Systems In Nepal: A Case Study, B N. Tiwari, J B. Abington

IGC Proceedings (1977-2023)

The Kingdom of Nepal is characterised by complex, diverse smallholder farming systems in which crops, livestock and forest resources are all interlinked. Traditional feeding practices throughout the hills are coming under severe pressure due to the high density of livestock. Consequently, acute shortages of forage are e, experienced, especially during the dry winter season. A case study is presented In which the integration of forage management into the whole farming system is practised, User groups are improving community grazing lands by the introduction of more productive herbage and fodder tree species. Fodder is sold to livestock farmers, animal management is …

Development Of Forage Systems For Dairying In Subtropical Australia, R J. Moss, K F. Lowe

IGC Proceedings (1977-2023)

The development of productive dairy farm systems integrating irrigated temperate pastures with rain-grown tropical pastures in subtropical Australia is described, Milk production increased from 2976-34211/cow (P<0,01) with increased temperate pasture allowance from 0. I to 0.2 ha/cow, and this increase was similar for nitrogen­fertilised ryegrass or clover-ryegrass mixtures, Temperate pastures provided cows with a high protein diet (20-30% crude protein}, enabling energy-rich grain and molasses concentrates to be efficiently used, Increasing supplementation to S kg grain/cow day increased milk yields to S109 I/lactation. Nitrogen fertilisation of perennial tropical grasses enabled higher stocking rates to be used and, together with the increases in production/cow, increased farm output from 464S I/ha to 7300 I/ha.