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Full-Text Articles in Physical Sciences and Mathematics
Using Cuticular Wax Alkanes And Computer Simulation To Estimate Diet Selection, Herbage Intake And Nutrient Cycling In Grazing Sheep, H Dove, R J. Simpson
Using Cuticular Wax Alkanes And Computer Simulation To Estimate Diet Selection, Herbage Intake And Nutrient Cycling In Grazing Sheep, H Dove, R J. Simpson
IGC Proceedings (1997-2023)
In grazing ewes, plant cuticular wax alkanes were used as markers to estimate diet selection, herbage intake, N intake and N excretion in faeces. Pasture and animal data were then used as inputs to the decision-support system GrazFeed, which simulates grazing and digestion to predict herbage intake, N intake and N excretion. Estimated and predicted intakes agreed closely, especially for N intake, and it is concluded that, subject to further investigation of the possibility that GrazFeed slightly under-estimated faecal N excretion, the close agreement between estimated and predicted OM and N intakes suggests that this combined use of alkane methods …
Foraging Behavior Of Zebu Cattle Grazing Deciduous Forest, L Ortega, J Castillo, F Rivas
Foraging Behavior Of Zebu Cattle Grazing Deciduous Forest, L Ortega, J Castillo, F Rivas
IGC Proceedings (1997-2023)
The objective of this study was to determine whether the foraging behavior of Zebu cattle in deciduous forest was affected by time of the year. Data were recorded during the wet, nortes and dry seasons. Ten Zebu cows were used to record biting rate. Intake and bite size was estimated using three esophageally fistulated animals. Cattle browsed shrubs and trees in the wet season and ingested litter leaves in the dry season which resulted in differences of ingestive behavior. In general, bite size and intake were higher in the wet season and decreased during the nortes and dry seasons.
Intake And Diet Selection By Sheep Grazing Grass/Clover Patches, I J. Gordon, A W. Illius
Intake And Diet Selection By Sheep Grazing Grass/Clover Patches, I J. Gordon, A W. Illius
IGC Proceedings (1997-2023)
The effects of the spatial dispersion of ryegrass (Lolium perenne L) and clover (Trifolium repens L), at the feeding station scale, on diet composition and feeding behaviour were studied for sheep. There were no significant changes in diet composition with changes in the spatial dispersion of sward components. Bite size, bite rate and intake rate did increase as the species became more aggregated.
Modeling Intake Of Grazing Cows Fed Complementary Feeds, D R. Buckmaster, L A. Holden, L D. Muller, R H. Mohtar
Modeling Intake Of Grazing Cows Fed Complementary Feeds, D R. Buckmaster, L A. Holden, L D. Muller, R H. Mohtar
IGC Proceedings (1997-2023)
A model suitable for predicting intake for grazing or non-grazing dairy cows is presented. The model integrates the potentially intake limiting factors of physical fill, physiological energy demand, wet mass, herbage availability, herbage cover, and grazing time. Integration of these factors with a simple set of linear ration balancing constraints yields a model suitable for predicting supplemental feed requirements as well as potential animal production from a grazed land. The model is semi-theoretical, being descriptive in structure, but containing empirical relationships.
Intake And Quality Of Panicum Maximum (Cv. Gatton) Receiving Different Levels Of Nitrogen During Autumn, W.A. Van Niekerk, N F.G. Rethman
Intake And Quality Of Panicum Maximum (Cv. Gatton) Receiving Different Levels Of Nitrogen During Autumn, W.A. Van Niekerk, N F.G. Rethman
IGC Proceedings (1997-2023)
The objective of this study was to investigate the influence of N fertilization on the quality of Panicum maximum cv. Gatton (Panicum) and the subsequent intake thereof. Hand cut samples increased in N (1.8 - 2.7%) and NO3-N content (0.75 - 1.54%) and decreased in WSC (14.6 - 13.9 g/kg) content, but with no changes in IVDOM as N fertilization levels raised from 0 to 150 kg N/ha respectively. No changes occurred in the NDF and ADL values. The animal selected N, and IVDOM values were higher and NDF value lower than the hand cut samples, which was expected due …
Intake And Partial Digestibility Of Panicum Maximum (Cv. Gatton) At Three Stages Of Maturity During Summer, W.A. Van Niekerk, N F.G. Rethman
Intake And Partial Digestibility Of Panicum Maximum (Cv. Gatton) At Three Stages Of Maturity During Summer, W.A. Van Niekerk, N F.G. Rethman
IGC Proceedings (1997-2023)
The objective of this study was to determine the influence of stage of maturity on the intake and digestibility of P. maximum (cv. Gatton) during the active growing season. Low DM content at the young and medium growth stages (24.9 and 25.2%) did not hamper DOMI (48.8 and 44.1 g/kg W0.75/d) respectively. The N concentration of the three stages were well within the limit required for optimal rumen microbial production (1.8 - 2.0%). The high NDF value of the adult stage (59.5%) resulted in a significantly lower IVDOM value (62.3%) but the IVDOM values of all stages were on the …
Effects On Intake Of Supplementing Low-Quality Roughage With Protein-Rich Feeds, J.J. M.H. Ketelaars, G A. Kaasschieter, M Kane
Effects On Intake Of Supplementing Low-Quality Roughage With Protein-Rich Feeds, J.J. M.H. Ketelaars, G A. Kaasschieter, M Kane
IGC Proceedings (1997-2023)
Intake responses of ruminants to supplementation with protein-rich concentrates or legume hays have been related to the ratio of nitrogen (N) content and organic matter digestibility (OMD) of the basal feed. Marginal intake effect of supplements, i.e. change of organic matter intake (OMI) from the basal feed per unit OMI from supplement, decreased on average from 1.7 to 0 and -0.8 g. g-1 at N/OMD of 0.010, 0.016 and > 0.030 g. g-1, respectively. Marginal effect of supplements defined as change of total digestible organic matter intake (DOMI) per g DOMI from supplement was 2.5, 1 and 0.3 g. g-1 for …
The Effect Of Sward Height And Bulk Density On Herbage Intake And Grazing Behaviour Of Dairy Cows, C S. Mayne, D Mcgilloway, A Cushnahan, A S. Laidlaw
The Effect Of Sward Height And Bulk Density On Herbage Intake And Grazing Behaviour Of Dairy Cows, C S. Mayne, D Mcgilloway, A Cushnahan, A S. Laidlaw
IGC Proceedings (1997-2023)
The effects of sward height and bulk density on herbage intake and grazing behaviour of dairy cows during 1 hour grazing periods was investigated. Sward factors had a marked effect on dry matter (DM) intake/bite, which ranged from 0.4 to 1.1 g, and this was reflected in hourly intake rates. Intake/bite was largely influenced by sward height, reflecting increased bite depth in taller swards, with inherent differences between swards at low sward heights largely attributable to differences in bulk density (BD). The results indicate that DM intake rates up to 4.0 kg DM/hour can be achieved in short term grazing …
Intake, Relative Palatability Indices And Blood Parameters Of Vetch Varieties As A Component Of Goat Diet, N. H. Msiza, K. E. Ravhuhali, H. K. Mokoboki, Sydney Mavengahama, G. M. Chelopo
Intake, Relative Palatability Indices And Blood Parameters Of Vetch Varieties As A Component Of Goat Diet, N. H. Msiza, K. E. Ravhuhali, H. K. Mokoboki, Sydney Mavengahama, G. M. Chelopo
IGC Proceedings (1997-2023)
Therefore, the objective of this study was to assess the feed intake, relative palatability indices and blood parameters of vetch varieties as a component of goat diet. The field and palatability study was carried out at the North West University, Molelwane Farm, North West province, South Africa. Ten weaner goats (16 ±2 kg) were used in this experiment. Four feeds (Vicia sativa – common & volga vetch ), Vicia villosa Roth (haymaker plus vetch) and buffalo hay grass were used in this experiment and each goat was exposed to these treatment diets. A cafeteria feeding method was used, allowing …
Methane Of Animal Origin In Cattle Fed High Or Low Tannin Sorghum Silage, T. T. Berchielli, S. G. Oliveira, M. P. Pedreira, O. Primavesi, M. A. Lima, R. Frighetto
Methane Of Animal Origin In Cattle Fed High Or Low Tannin Sorghum Silage, T. T. Berchielli, S. G. Oliveira, M. P. Pedreira, O. Primavesi, M. A. Lima, R. Frighetto
IGC Proceedings (1997-2023)
The harmful or beneficial effects associated with the presence of tannin in plants depends on its concentration and form. One of these beneficial effects is the reduction of the production of methane in the rumen (Woodward et al., 2001). This study financed by FAPESP aimed to evaluat the effect of diets containing low or high tannin sorghum silage supplements on dry matter intake (DMI) and methane production in cattle.
Intake By Lactating Goats Browsing On Mediterranean Shrubland, M. Decandia, G. Pinna, A. Cabiddu, G. Molle
Intake By Lactating Goats Browsing On Mediterranean Shrubland, M. Decandia, G. Pinna, A. Cabiddu, G. Molle
IGC Proceedings (1997-2023)
In Mediterranean regions goat feeding systems are mainly based on shrubland that contain a wide variety of species. There are only a few equations for predicting feed intake of stall-fed goats (Luo et al., 2004). The objective of this study was to develop a model for predicting the intake of lactating goats browsing on Mediterranean shrubland.
Intake, Digestibility And Rate Of Passage Of Grass In Grazing By Light Breed Horses On Different Pastures, Masahito Kawai, N. Yabu, T. Asa, K. Deguchi, S. Matsuoka
Intake, Digestibility And Rate Of Passage Of Grass In Grazing By Light Breed Horses On Different Pastures, Masahito Kawai, N. Yabu, T. Asa, K. Deguchi, S. Matsuoka
IGC Proceedings (1997-2023)
In a previous study, grazing light breed horses could ingest CP and DE requirements for maintenance without supplements. However, their grazing behaviour, such as biting and chewing efficiency, which related to the passage rate of forage in the digestive tract and fibre digestibility, was affected by the pasture conditions (Kawai et al., 2004). In this study, the DM intake, digestibility and mean retention time (MRT) of grass in light breed horses were determined and compared in spring, summer and autumn on an improved pasture.
Elasticity Of Ingestive Behaviour And Intake In Sheep Associated With Food Diversity On Plurispecific Swards, C. Cortes, J. C. Damasceno, G. Bechet, J. Jamot, S. Prache
Elasticity Of Ingestive Behaviour And Intake In Sheep Associated With Food Diversity On Plurispecific Swards, C. Cortes, J. C. Damasceno, G. Bechet, J. Jamot, S. Prache
IGC Proceedings (1997-2023)
Animals on heterogeneous swards generally opt for a varied diet. This may stimulate their intake, unless searching constraints limit intake rate (Champion et al., 1998). However the management of plurispecific swards presents a risk of overgrazing the preferred species and undergrazing the less-preferred species. This study aimed to test the effect of type of diversity and type of management on the elasticity of ingestive behaviour and intake in sheep.
Estimating Pasture Intake By Dairy Cows, Dennis R. Cosgrove, D. P. Cooper
Estimating Pasture Intake By Dairy Cows, Dennis R. Cosgrove, D. P. Cooper
IGC Proceedings (1997-2023)
Proper nutrient management planning minimizes the environmental impact of manure from dairy farms. Manure output from dairy cows can be predicted from feed intake (Wilkerson et al., 1997). Weighing feed and refusals each day can determine accurately the feed intake of dairy cows in confinement. Intake determination is more difficult for dairy cows on pasture (Vasquez & Smith, 2000). As part of a larger study aimed at estimating manure production of dairy cows on pasture, this study compares 3 methods for estimating pasture yield and feed intake.
Estimating Pasture Intake By Cattle Using Alkanes And A Known Amount Of Supplement, E. Charmley, J. L. Duynisveld, H. Dove
Estimating Pasture Intake By Cattle Using Alkanes And A Known Amount Of Supplement, E. Charmley, J. L. Duynisveld, H. Dove
IGC Proceedings (1997-2023)
The alkane ratio method for estimating pasture intake involves calculating the fecal ratio of plant (endogenous) and exogenous alkanes. This method is effective for sheep, although the delivery mechanism for the exogenous alkanes has presented challenges in cattle (Charmley et al. 2003). Dove et al. (2003) have shown that the relative concentration of components in a mixed diet can be estimated from fecal alkane concentrations using least squares methods. Further, if the amount of one dietary component is known, then the amount of all components, and hence intake, can be determined. In this trial beeswax was added to …
Using The N-Alkane Technique To Estimate The Herbage Intake And Diet Composition Of Cattle Grazing A Miscanthus Sinensis Grassland, Y. J. Zhang, Y. Togamura, K. Otsuki
Using The N-Alkane Technique To Estimate The Herbage Intake And Diet Composition Of Cattle Grazing A Miscanthus Sinensis Grassland, Y. J. Zhang, Y. Togamura, K. Otsuki
IGC Proceedings (1997-2023)
Plant wax alkanes are now widely used as marker substances (Dove & Mayes 1991) for the estimation of forage intake and diet composition of grazing herbivores. The objective of this study was to evaluate this method with cattle grazing a M. sinensis grassland in Japan.
Rich Information In The Acoustic Signals From Feeding And Grazing In Ruminants, Montague W. Demment, J. R. Galli, Carlos A. Cangiano, Emilio A. Laca
Rich Information In The Acoustic Signals From Feeding And Grazing In Ruminants, Montague W. Demment, J. R. Galli, Carlos A. Cangiano, Emilio A. Laca
IGC Proceedings (1997-2023)
Because of their impact on productivity and the environment, feeding behaviour, ingestion and rumination are critical to understand intake in grazing ruminants. Many systems, mainly mechanical, have been developed to measure ingestive behaviour. However, these systems have problems, including mechanical failure and the inability to distinguish between the complex jaw movements of prehension and ingestion (Laca et al., 1994). The sounds generated by these behaviours are rich in information that holds potential not only to distinguish and count behaviours, but also identify aspects of the nature of the foods ingested.
The Sound Of Chewing, J. R. Galli, Carlos A. Cangiano, Emilio A. Laca, M. W. Demment
The Sound Of Chewing, J. R. Galli, Carlos A. Cangiano, Emilio A. Laca, M. W. Demment
IGC Proceedings (1997-2023)
Acoustic biotelemetry has been proposed as a way to count ingestive bites and chews of grazing animals. Recent work has indicated the possibility that detailed analysis of 'sounds of chewing' contains information about other characteristics of the ingestive process that can be used to study grazing behaviour of free ranging animals (Laca & Wallis DeVries, 2000), or to monitor stall-fed animals in more detail.
Ensiling Characteristics And Nutritive Value Of Browse/Maize Forage Mixtures, F. B. Bareeba, H. Kato, Elly N. Sabiiti
Ensiling Characteristics And Nutritive Value Of Browse/Maize Forage Mixtures, F. B. Bareeba, H. Kato, Elly N. Sabiiti
IGC Proceedings (1997-2023)
The practice of growing fodder tree and shrubs is being advocated for and adopted in smallholder dairy production systems. In Uganda, Calliandra calothyrsus, Gliricidia sepium, and Leucaena leucocephala have been identified and recommended as the most suitable species (Sabiiti, 2001). However tree foliage contains toxic compounds (Lowry, 1990), which may be alleviated by ensiling. The objective of the experiment was to study the ensiling characteristics of browse/ maize forage mixtures and their nutritive value when fed to lactating dairy cows.
The Feeding Value Of Silage Made From Peas Grown Alone Or In Mixture With Cereals, A. Kirilov
The Feeding Value Of Silage Made From Peas Grown Alone Or In Mixture With Cereals, A. Kirilov
IGC Proceedings (1997-2023)
The interest in pea as a forage crop rich in protein does not decrease. In areas frequent summer drought pea (Pisum sativum) as a whole plant for forage gives assured yield and may be used for zero grazing, hay or silage. The winter varieties use winter-spring soil moisture better and give higher yield than the spring varieties, but they lodge, so it is necessary to sow them with supporting cereal crops to increase lodging resistance. The objective of the study was to compare the intake, digestibility, energy value and quality index of two wilted silage made from winter …
Predicting Intake From Indigestible Fibre, Kenneth J. Moore, J. R. Russell
Predicting Intake From Indigestible Fibre, Kenneth J. Moore, J. R. Russell
IGC Proceedings (1997-2023)
Dry matter intake (DMI) of forages is often estimated as a reciprocal function of fibre concentration: DMI = fibre intake capacity / dietary fibre concentration (Mertens, 1987). This theoretical relationship is based on the concept that consumption of forage diets is limited by fill and that fibre represents the bulk of forage diets. This model, however, does not account for differences in DMI which should occur among forages with similar fibre concentrations but differing fibre digestibility. To account for these differences, we proposed an intake model where DMI is a reciprocal function of indigestible fibre concentration: DMI = c / …
Whole Crop Cereal Silage In Dairy Production, J. Wallsten, L. Ericson, K. Martinsson
Whole Crop Cereal Silage In Dairy Production, J. Wallsten, L. Ericson, K. Martinsson
IGC Proceedings (1997-2023)
Whole-crop cereal silages (WCCS) are used to some extent in Sweden, but knowledge about the use of this feed for high yielding dairy cows is scarce. The crop is often harvested at different stages of maturity, from heading to yellow ripeness, which gives forages that differ in chemical composition. The purpose of this trial was to compare intake and milk production of dairy cows fed a WCCS based on barley harvested at three different stages of maturity.
Using The N-Alkane Technique To Estimate The Herbage Intake And Diet Composition Of Cattle Grazing A Miscanthus Sinensis Grassland, Y. Zhang, Y. Togamura, K. Otsuki
Using The N-Alkane Technique To Estimate The Herbage Intake And Diet Composition Of Cattle Grazing A Miscanthus Sinensis Grassland, Y. Zhang, Y. Togamura, K. Otsuki
IGC Proceedings (1997-2023)
Plant wax alkanes are now widely used as marker substances (Dove & Mayes 1991) for the estimation of forage intake and diet composition of grazing herbivores. The objective of this study was to evaluate this method with cattle grazing a M. sinensis grassland in Japan.
Intake And Milk Production Of Lactating Dairy Cows Grazing Diverse Forage Mixtures Over Two Grazing Seasons, K. Soder, M. A. Sanderson, J. L. Stack, L. Muller
Intake And Milk Production Of Lactating Dairy Cows Grazing Diverse Forage Mixtures Over Two Grazing Seasons, K. Soder, M. A. Sanderson, J. L. Stack, L. Muller
IGC Proceedings (1997-2023)
Voluntary intake and stocking rate are key determinants of animal performance on pasture. Greater plant diversity in grassland plant communities has been linked to increased primary production, greater stability in response to disturbance, and reduced weed pressure. Thus, increasing plant diversity may be one approach to improving animal productivity. An experiment was conducted to determine the effects of forage diversity on intake and milk production of lactating dairy cows over two grazing seasons.
Intake By Lactating Goats Browsing On Mediterranean Shrubland, M. Decandia, G. Pinna, A. Cabiddu, G. Molle
Intake By Lactating Goats Browsing On Mediterranean Shrubland, M. Decandia, G. Pinna, A. Cabiddu, G. Molle
IGC Proceedings (1997-2023)
In Mediterranean regions goat feeding systems are mainly based on shrubland that contain a wide variety of species. There are only a few equations for predicting feed intake of stall-fed goats (Luo et al., 2004). The objective of this study was to develop a model for predicting the intake of lactating goats browsing on Mediterranean shrubland.
Use Of Alkanes To Estimate Dry Matter Intake Of Beef Steers Grazing High Quality Pastures, G. Scaglia, H. T. Boland, I. Lopez-Guerrero, R. K. Shanklin, J. P. Fontenot
Use Of Alkanes To Estimate Dry Matter Intake Of Beef Steers Grazing High Quality Pastures, G. Scaglia, H. T. Boland, I. Lopez-Guerrero, R. K. Shanklin, J. P. Fontenot
IGC Proceedings (1997-2023)
Pastures remain the most important source of nutrients for ruminant livestock and nutrition is critical to optimize animal production. The daily quantity of dry matter that is consumed by an animal is a critical measurement to make nutritional inferences about feed and subsequent animal response. Researchers are facing the dilemma that, while estimates of individual animal performance are readily obtained, it is still difficult to estimate the herbage intake of individual animals. The objectives of this experiment were to estimate forage intake in beef steers grazing tall fescue (Festuca arundinacea Schreb.) and alfalfa (Medicago sativa)/tall fescue pastures …
Effects Of Rumen Fill On Intake And Milk Production In Dairy Cows Fed Perennial Ryegrass, A. V. Chaves, A. Boudon
Effects Of Rumen Fill On Intake And Milk Production In Dairy Cows Fed Perennial Ryegrass, A. V. Chaves, A. Boudon
IGC Proceedings (1997-2023)
Physical limitation often limits dry matter intake (DMI) of high producing cows or cows fed high forage diets. The extent to which DMI is regulated by distention in the rumen depends upon the cow’s energy requirement and filling effects of the diet offered (Allen, 2000). The objective here was to challenge middle lactation dairy cows with rumen fill (rumen inert bulk – RIB) feeding ryegrass fresh cut (indoors) or grazed to determine whether RIB affects intake and milk production.
The Effect Of Chop Length And Additive On Silage Intake And Milk Production In Cows, V. Toivonen, T. Heikkilä
The Effect Of Chop Length And Additive On Silage Intake And Milk Production In Cows, V. Toivonen, T. Heikkilä
IGC Proceedings (1997-2023)
Effects of reduced silage chop length on silage intake and milk production by dairy cows have been variable. Chopping of grass at harvest generally improves silage fermentation quality and consequently intake. The objective of this study was to assess the effect of chopping flail harvested silage ensiled with acid or biological additive prior to feeding on intake, milk yield and milk composition in dairy cows.
The Influence Of Crop Maturity And Type Of Baler On Whole Crop Barley Silage Production, P. Lingvall, M. Knicky, B. Frank, B. Rustas, J. Wallsten
The Influence Of Crop Maturity And Type Of Baler On Whole Crop Barley Silage Production, P. Lingvall, M. Knicky, B. Frank, B. Rustas, J. Wallsten
IGC Proceedings (1997-2023)
Bale ensiling is based on long cut forages. Earlier studies (Honig, 1984; 1987) have shown the importance of laceration and high density in preventing fungi growth and storage instability. On the other hand use of an efficient baling technology reduces the time between moving and wrapping of bale to less than 10 minutes with a combi-baler compared to two hours with a separate wrapper. Even during feeding late fermentation is restricted as the bale is fed within some hours after opening. Ensiling of whole crop cereals needs the addition of silage additives to avoid clostridial fermentation (Weissbach et al., …
The Importance Of Patch Size In Estimating Steady-State Bite Rate In Grazing Cattle, E. D. Ungar, N. Ravid, T. Zada, E. Ben-Moshe, R. Yonatan, S. Brenner, H. Baram, A. Genizi
The Importance Of Patch Size In Estimating Steady-State Bite Rate In Grazing Cattle, E. D. Ungar, N. Ravid, T. Zada, E. Ben-Moshe, R. Yonatan, S. Brenner, H. Baram, A. Genizi
IGC Proceedings (1997-2023)
Since the pioneering work of Black and Kenney (1984), various intake studies have been conducted at the spatial scale of a single feeding station ("patch") to elucidate the processes that determine instantaneous intake rate (e.g. Laca et al., 1994). While these are well-suited for patch depletion studies, it is less clear how well they represent non-patchy and relatively homogeneous environments (Ungar & Griffiths, 2002). Clearly, grazing should be restricted to the upper grazing horizon (i.e. layer of bites), but sample duration may be insufficient to characterize steady-state behaviour, especially when grazing commences on an empty mouth. We examined the …