Effects of Forage Availability on Voluntary Intake and Feeding Behavior of Grazing Heifers

Forage intake by animals is an important factor in determining production of livestock products from rangelands. However, relatively little is known of effects of such forage variables as availability and distribution in space upon intake. Even less is known about how the grazing animal modifies its feeding tactics when confronted with diminishing or limited supplies of available forage and how such altered behavior may affect the animal\u27s energetic cost for existence. Forage intake, body weight gain, grazing time and biting rate of Angus heifers was related to forage availability and plant height on semiarid crested wheatgrass rangeland during the late summer. Forage availability was estimated within 10 percent of the 2 mean (P2plots. Forage intake was estimated from data on fecal production and in vitro digestibility of forage. Fecal production was determined by total collection, using fecal collection bags, and by a single-dose marker technique, used to estimate fecal production indirectly. Digestibility was determined by an in vitro procedure. Additionally crude protein and cell contents of forage were determined. Grazing time was measured by mechanical grazing clocks (Vibracorders) mounted on animals\u27 necks. Biting rate was determined visually using a stop watch to time specific grazing intervals during which all bites were counted. There were a total of four 4-day trials during 1977 and five 4-day trials during 1978. Crude protein content within years was significantly higher during the third period in 1977 and during the fifth period in 1978 when regrowth occurred. Within years, in vitro digestibility was significantly higher only for the fifth trial during 1978. Cell contents decreased as grazing progressed only during 1978. Crude protein content, cell contents and in vitro digestibility were higher during 1977 than 1978. Forage intake of heifers did not vary significantly among successive grazing trials as forage availability declined from 919 to 143 kg DM/ha. Heifers apparently compensated for the diminishing forage availability by increasing grazing time from 380 to 656 min/day and biting rate from 37 to 50 bites/min. Grazing time was inversely related to forage availability and was expressed by the relationship y = 676.8 - 0.3x; r2 = 0.93. Biting rate was less correlated with forage availability and was described as y = 50.4 - 0.02x; r2 = 0.86. However, biting rate was more closely correlated with plant height as described by the relationship y = 53.0 - 0.48x; r2 = 0.95. Heifers maintained or gained 0.1 to 0.7 kg/head/day weight during all trials except the last trial in 1978 when they lost approximately 1.1 kg/head/day. The weight loss for this trial was apparently not a result of restricted forage intake or limited forage quality but partly due to extra maintenance energy expenditures attributable to increased grazing time and biting rate. Correlation between estimates of fecal output by the single dose marker technique with total fecal collection were not significant (

Teaching precision farming and entrepreneurship for European students: Sparkle online course

Within the framework of the European project named ‘SPARKLE’, an online course was created after studying educational needs on precision agriculture (PA), state of the art of technologies and a prospective study of the commercial sector. Five educational and research institutions, high-tech farms and enterprises specializing in technology transfer created the syllabus of the course and the platform contents. The course was designed to provide 30 h of student dedication, via online presentations, documents and videos for each topic. A free pilot course started in April 2020 and 385 students from Italy, Portugal, Greece & Spain enrolled. To trace performance and acquisition of competences, questionnaires were completed by students for each topic and a final overall test. Students’ opinions about the course were also registered using anonymous polls, and results evaluated, to be able to enhance the Sparkle course for subsequent editions. Students also took part in a business model competition, to solve real challenges proposed by farms, related to the use of these technologies

Diets of goats grazing oak shrubland of varying cover in northern Greece

The effects of 3 brush cover proportions (Low Brush pasture: 52% brush/32% herbage, Medium Brush pasture: 62% brush/20% herbage, and High Brush pasture: 66% brush/12% herbage) on dietary selection of goats in northern Greece were investigated. Diet samples were collected from esophageally fistulated goats during 14 grazing periods at monthly intervals from June 1987 to July 1988. Kermes oak foliage (Quercus coccifera L.) was the main component of the available forage in all pastures during all grazing periods. The herbaceous component contributed more than 50% for the goats' diet during spring for Low Brush pasture, 46% for Medium Brush pasture, and 40% for High Brush pasture. In the remaining grazing periods, goats selected larger quantities of browse. For Low Brush pasture browse contribution ranged from 48% to 66%, for Medium Brush from 54% to 77%, and for High Brush from 66% to 80%. Leaves of all forage species contributed more than 56% during all test periods. The quantities of twigs from shrubs and stems from herbaceous species were low but constant during all test periods. Fruits and flowers, despite representing low percentages of the overall production, were important for the animals' nutrition, since they provided a high percentage of nutrients. Our results indicated that goats adapted diets to forage class availability.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

A modified faecal harness for grazing goats on Mediterranean shrublands

A modified faecal harness for goats was specially designed for grazing conditions in dense mediterranean shrublands and subsequently tested successfully for total faecal collection. The details of design and collection are presented.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Estimating digestibility of oak browse diets for goats by in vitro techniques

Predicting digestibility of shrubs is important to evaluating many of the world's rangelands. We examined laboratory procedures for predicting in vivo digestion of browse-alfalfa (Medicago sativa) mixed diets and how drying temperature and inoculum source affect digestibility. In addition, we considered the effect of oak tannin on pepsin activity and dry matter digestion. The commonly used Tilley and Terry (1963) two-stage in vitro digestion technique was a precise (r2=0.97) but inaccurate predictor of in vivo apparent digestibility of mixed oak (Quercus gambelii) and alfalfa diets for goats. The Van Soest et al. (1966) neutral detergent method for predicting true digestibility was less precise (r2=0.76). Estimates from the Goering and Van Soest (1970) summative equation were not correlated (P is lesser than or equal to 0.05) with in vivo digestion. Separate regression equations are necessary if in vitro methods are to predict accurately in vivo digestibility of browse diets. In vitro digestibility was inversely related to percentage of oak in the diets and the amount of oak in the inoculum donors' diets. High drying temperatures depressed digestibility of oak browse and this effect was greater for immature than for mature forage.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

The Voluntary Forage Intake of Heifers Grazing a Diminishing Supply of Crested Wheatgrass

Intake estimates for Angus heifers grazing a declining quantity of available crested wheatgrass forage were obtained during the summer grazing seasons of 1978 and 1979. The study was conducted on rangelands in Central Utah that are characteristic of the Eastern Great Basin. Organic matter intake (OMI) was measured by total collection procedures during five periods each year following forage maturation. Available forage was reduced prior to each succeeding intake measurement within each year by grazing animals. In the first year, OMI averaged 1.2% of body weight as available forage decreased from 920 to 140 kg/ha. In the second year, OMI averaged 1.3% of body weight as available forage decreased form 880 to 280 kg/ha. Intake differences between periods within years were not significant. In vitro organic matter digestibility ranged from 33 to 40% in the first year and 34 to 43% in the second year

Effects of Forage Availability on Grazing Behavior of Heifers

Effects of decreasing availability of crested wheatgrass (Agropyron desertorum and Agropyron cristatum) on grazing time and biting rate of Angus heifers were investigated. In the first year of the study, as standing crop decreased from 474 to 170 kg dry matter/ha, grazing time increased from 517 to 203 min/day, while biting rate increased from 56 to 64 bites/min. In the second year, as standing crop decreased from 919 to 144 kg dry matter/ha, grazing time increased from 380 to 656 min/day while biting rate increased from 37 to 50 bites/min. Grazing times were similar to those reported in the literature for pastures having much higher levels of available forage. Although grazing times may be correlated with available forage, comparison of grazing times under different pasture conditions are not meaningful unless considered along with other forage and animal factors. On crested wheatgrass pastures, maximum biting rates occurred at lower levels of available forage than reported on tropical pastures.This material was digitized as part of a cooperative project between the Society for Range Management and the University of Arizona Libraries.The Journal of Range Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 202

Food resources and quality for the introduced cretan wild goat or agrimi Capra aegagrus cretica on Atalandi Island, Greece, and implications for ecosystem management

A study of seasonal food availability and quality for Cretan wild goat or agrimi Capra aegagrus cretica introduced on Atalandi Island, Greece, was conducted during 1988-89. The major portion of available forage consisted of Olea europaea var. sylvestris, Pistacia lentiscus and Cistus ssp. The first two species are the main food resources in late summer and early autumn, the critical period for agrimi nutrition, and the only species with crude protein (CP) content exceeding maintenance requirements of agrimi. Grasses contained the highest level of neutral detergent fibre (NDF) among all plant categories in all seasons. Herbaceous species had the lowest level of lignin and shrubs the highest. In vitro organic matter digestibility (IVOMD) of herbaceous species was > 50% only in spring. During summer only Olea europaea produced sufficient forage with digestibility c. 50%. Future management must be directed toward maintaining a balance between vegetation productivity and grazing pressure. Maintaining the agrimi population at grazing capacity would allow an increase of productivity of palatable species. The seeding of palatable native herbs would provide nutritious feed for the agrimi and reduce the grazing impact. Continuous monitoring of the agrimi population, vegetation and soil trends is considered indispensable

Facets of value emerging through the operation of short food supply chains

Short food supply chains (SFSCs) are market schemes that allow different types of value to emerge. In this work, we aimed to uncover these facets of value. To do so, we built upon two conceptual models: a Triple Layered Business Model Canvas and an eight-dimensional blueprint developed for our purposes. Then, we conducted two studies using these models as theoretical templates. In Study I, we followed a business model canvas perspective, aiming to portray the components that contribute to the generation of economic, functional, and social value produced in SFSCs. By drawing on a sample of farmers who participate in SFSCs, we developed regression models to uncover the antecedents of value. Our analysis revealed that the effectiveness of performed activities catalyses the economic value of SFSCs. In addition, the social value depends on the capacity of SFSCs to enhance local communities’ well-being and provide significant outreach. Finally, environmental value is associated with the distribution of products. In Study II, using data from a pool of experts, we assessed the importance of eight facets of value. Participants appraised economic, social, cultural, and environmental value as more important than the remaining dimensions. Our studies shed light on the dimensions of value created in SFSCs, also confirming the usefulness of business model canvases for understanding value creation processes. However, our work also offers a new framework for conceptualising supply chains’ value, distinguishing value into primary (which is produced and remains within SFSCs) and secondary (which extends beyond supply chain limits)