Host Animal—rumen Relationships

Egan, A. R.

doi:10.1079/pns19800011

Cited by 49 publications

(15 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, steers ruminated regularly between meals when fed alfalfa, whereas rumination was brief, sporadic or nonexistent when they were fed the high concentrate diet. As predicted by NAS-NRC (1976) use of ME differed between diets, as exemplified by decreased net hepatic uptake of AAN and greater splanchnic release of AAN (Table 3) (Huntington and Reynolds 1986) or radioisotope dilution techniques (Norton et al 1978;Nolan and Stachiw 1979;Egan 1980;Kennedy 1980;Kennedy and Milligan 1980;Norton et al 1982a,b (Fig. 1).…”

Section: Discussionmentioning

confidence: 99%

“…1). Thus, with alfalfa endogenous urea in saliva would be associated with ingested feed and ammonia from ureolysis would be predominantly in the "deep digesta" (Egan 1980). With the high concentrate diet, ureolysis would be predominantly at the rumen wall.…”

Section: Discussionmentioning

confidence: 99%

“…With the high concentrate diet, ureolysis would be predominantly at the rumen wall. Javorsky et al (1987) (Cheng and Wallace 1979;Egan 1980;Kennedy et al 1981;Javorsky et al 1987). The ability of rumen bacteria to fix NH3N when energy is readily available (Kennedy 1980;NAS-NRC 1985) …”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Hepatic Urea Synthesis and Site and Rate of Urea Removal From Blood of Beef Steers Fed Alfalfa Hay or a High Concentrate Diet

Huntington¹

1989

Can. J. Anim. Sci.

132

100

View full text Add to dashboard Cite

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Hepatic Urea Synthesis and Site and Rate of Urea Removal From Blood of Beef Steers Fed Alfalfa Hay or a High Concentrate Diet

Huntington¹

1989

Can. J. Anim. Sci.

132

100

View full text Add to dashboard Cite

show abstract

“…Given pre-loads of energy or nitrogen, lambs prefer flavours previously paired with nitrogen or energy, respectively, during the ensuing meals (Villalba and Provenza, 1999). Thus, animals maintain a balance of energy to protein that meets their nutritional needs, and in the process, they associate different internal states with the ingestion, or lack thereof, of different nutrients (Egan, 1980;Kyriazakis and Oldham, 1993). Likewise, lambs deficient in phosphorus and calcium increase preferences for flavours and supplements that provide those minerals (Villalba et al, 2006a;J.…”

Section: Self-medication In Herbivoresmentioning

confidence: 99%

Self-medication and homeostatic behaviour in herbivores: learning about the benefits of nature’s pharmacy

Villalba

Provenza

2007

Animal

View full text Add to dashboard Cite

Traditional production systems have viewed animals as homogeneous 'machines' whose nutritional and medicinal needs must be provided in a prescribed manner. This view arose from the lack of belief in the wisdom of the body to meet its physiological needs. Is it possible for herbivores to select diets that meet their needs for nutrients and to write their own prescriptions? Our research suggests it is. Herbivores adapt to the variability of the external environment and to their changing internal needs not only by generating homeostatic physiological responses, but also by operating in the external environment. Under this view, food selection is interpreted as the quest for substances in the external environment that provide homeostatic utility to the internal environment. Most natural landscapes are diverse mixes of plant species that are literally nutrition centres and pharmacies with vast arrays of primary (nutrient) and secondary (pharmaceutical) compounds vital in the nutrition and health of plants and herbivores. Plant-derived alkaloids, terpenes, sesquiterpene lactones and phenolics can benefit herbivores by, for instance, combating internal parasites, controlling populations of fungi and bacteria, and enhancing nutrition. Regrettably, the simplification of agricultural systems to accommodate inexpensive, rapid livestock production, coupled with a view of secondary compounds as toxins, has resulted in selecting for a biochemical balance in forages favouring primary (mainly energy) and nearly eliminating secondary compounds. There is a global need to create a more sustainable agriculture, with less dependence on external finite resources, such as fossil fuels and their environmentally detrimental derivatives. Self-medication has the potential to facilitate the design of sustainable grazing systems to improve the quality of land as well as the health and welfare of animals. Understanding foraging as the dynamic quest to achieve homeostasis will lead to implementing management programs where herbivores have access not only to diverse and nutritious foods but also to arrays of medicinal plants.

show abstract

“…Preference for food high in energy (protein) increases after a meal high in protein (energy) (Perez et al; Berteaux et al 1998;Villalba & Provenza, 1998a,c). Lambs maintain a relatively constant ratio of energy to protein in their diets, when they can select from foods varying in macronutrients (Egan, 1980;Provenza et al 1996;Wang & Provenza, 1996a), by discriminating between feedback signals from energy and protein (Villalba & Provenza, 1998a). The synchrony of energy and protein fermentation also influences preference (Kyriazakis & Oldham, 1997;Early & Provenza, 1998).…”

Section: Preference Depends On Nutritional Statementioning

confidence: 99%

Self-organization of foraging behaviour: From simplicity to complexity without goals

et al. 1998

View full text Add to dashboard Cite

A herbivore faces challenges while foraging-angoing changes in its physiological condition along with variation in the nutrient and toxin concentrations of foods, spatially and temporally-that make selecting a nutritious diet a vital affair. Foraging behaviours arise from simple rules that operate across levels of resolution from cells and organs to individuals and their interactions with social and physical environments. At all these levels, behaviour is a function of its consequences: a behaviour operating on the environment to induce changes is itself changed by those events. Thus, behaviour emerges from its own functioning-behaviour selforganizes-not from that of its surroundings. This ostensible autonomy notwithstanding, no self-organizing system (cell, organ, or individual) is independent of its environs because existence consists of an ongoing exchange of energy and matter. According to this view, the notion of cause and effect is replaced with functional relationships between behaviours and environmental consequences. Changes in physical environments alter the distribution, abundance, nutritional, and toxicological characteristics of plants, which affect food preference. Social interactions early in life influence behaviour in various ways: animals prefer familiar foods and environments, and they prefer to be with companions. Animals in unfamiliar environments often walk farther, ingest less food, and suffer more from malnutrition and toxicity than animals in familiar environments. An individual's food preferences-and its ability to discriminate familiar from novel foods-arise from the functional integration of sensory (smell, taste, texture) and postingestive (effects of nutrients and toxins on chemo-, osmo-, and mechano-receptors) effects. The ability to discriminate among foods is critical for survival: all problems with poisonous plants are due to an inability to discriminate or a lack of alternatives. Animals eat a variety of foods as a result of nearing or exceeding tolerance limits for sensory and postingestive effects unique to each food. After eating any food too frequently or excessively, the likelihood increases that animals will eat alternative foods owing to exceeding sensory-, nutrient-, and toxin-specific tolerance limits. Cyclic patterns of intake of a variety of foods reflect seemingly chaotic interactions among flavours, nutrients, and toxins interacting along continua.

show abstract

Host Animal—rumen Relationships

Cited by 49 publications

References 21 publications

Hepatic Urea Synthesis and Site and Rate of Urea Removal From Blood of Beef Steers Fed Alfalfa Hay or a High Concentrate Diet

Hepatic Urea Synthesis and Site and Rate of Urea Removal From Blood of Beef Steers Fed Alfalfa Hay or a High Concentrate Diet

Self-medication and homeostatic behaviour in herbivores: learning about the benefits of nature’s pharmacy

Self-organization of foraging behaviour: From simplicity to complexity without goals

Contact Info

Product

Resources

About