Reviews of the progress of dairy science: long term effects of plane of nutrition on the performance of the dairy cow.
About: This article is published in Journal of Dairy Research.The article was published on 1984-02-01. It has received 86 citations till now.
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01 Jan 2000
TL;DR: In this paper, the authors identified and discussed important metabolic factors involved in the regulation of dry matter intake in dairy cattle and their integration with metabolism, and discussed the adaptations of intake and metabolism and discussed mechanisms of intake regulation.
Abstract: There has been great interest in dry matter intake regulation in lactating dairy cattle to enhance performance and improve animal health and welfare. Predicting voluntary dry matter intake (VDMI) is complex and influenced by numerous factors relating to the diet, management, housing, environment and the animal. The objective of this review is to identify and discuss important metabolic factors involved in the regulation of VDMI and their integration with metabolism. We have described the adaptations of intake and metabolism and discussed mechanisms of intake regulation. Furthermore we have reviewed selected metabolic signals involved in intake regulation. A substantial dip in VDMI is initiated in late pregnancy and continues into early lactation. This dip has traditionally been interpreted as caused by physical constraints, but this role is most likely overemphasized. The dip in intake coincides with changes in reproductive status, fat mass, and metabolic changes in support of lactation, and we have described metabolic signals that may play an equally important role in intake regulation. These signals include nutrients, metabolites, reproductive hormones, stress hormones, leptin, insulin, gut peptides, cytokines, and neuropeptides such as neuropeptide Y, galanin, and corticotrophin-releasing factor. The involvement of these signals in the periparturient dip in intake is discussed, and evidence supporting the integration of the regulation of intake and metabolism is presented. Still, much research is needed to clarify the complex regulation of VDMI in lactating
558 citations
TL;DR: Much research is needed to clarify the complex regulation of VDMI in lactating dairy cows, particularly in the periparturient animal, and evidence supporting the integration of the regulation of intake and metabolism is presented.
493 citations
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31 Dec 1999TL;DR: In this article, the authors provide an overview of their research program which for the past 25 years has involved the use and coordination of both experimental and modeling research approaches, and their overall goal has been to advance our understanding of animal digestion (particularly in ruminants) and metabolism, and devise objective and quantitative means to bridge the gap between our knowledge of basic animal functions and animal performance.
Abstract: Our general objective in this chapter is to provide an overview of our research program which for the past 25 years has involved the use and coordination of both experimental and modeling research approaches. Our overall goal has been to advance our understanding of animal digestion (particularly in ruminants) and metabolism, and devise objective and quantitative means to bridge the gap between our knowledge of basic animal functions and animal performance. Early on we came to the view that systems analysis may be the only approach available which enables rigorous quantitative evaluations of our knowledge of animal functions and full utilization of this knowledge in the solution of problems in animal production. This approach is compatible with the view of science depicted in schematic form (Fig. 1) by Thornley and France (1984) and discussed in greater detail by Forbes and France (1993) and Baldwin (1995).
316 citations
TL;DR: The purpose of this review was to determine with accuracy the effect of the lactation stage, length of under/over-feeding, age and production potential of the animals on the milk output and milk protein content response to variations in the energy supply.
176 citations
TL;DR: Two models of lactating dairy cows were constructed by combining mechanistic models of digestion and metabolism reported previously and by adding elements to allow simulation of changes in tissue metabolic capacities over time to illustrate the potential usefulness of mechanistic, as compared to empirical, models in analyses of energy balance in lactating Dairy cows.
Abstract: Two models of lactating dairy cows were constructed by combining mechanistic models of digestion and metabolism reported previously and by adding elements to allow simulation of changes in tissue metabolic capacities over time. One model (day version) had an integration interval of 0.005 d and was suitable for simulation of within-day dynamics of nutrient supply and partition. The other (lactation version) had an integration interval of 1 d and was suitable for simulation of full lactation cycles. A number of simulation analyses were conducted to characterize and evaluate the models, to examine quantitative and dynamic properties of mechanisms which influence partition of nutrients, to identify aspects requiring further study, and to illustrate the potential usefulness of mechanistic, as compared to empirical, models in analyses of energy balance in lactating dairy cows.
128 citations
References
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01 Jan 1993
TL;DR: In this article, the authors investigated the effect of nutrition on stress and immunity in dairy cows and discussed the potential applications of GM technology on pig performance and piglet starter feeding in a changing business environment, with special emphasis on tryptophan and valine.
Abstract: Preface * Fatty acids and fertility in dairy cows * Environmental and genetic influences on successful heifer rearing * Reducing dietary phosphorus inputs within dairy systems * Practical aspects of feeding grass to dairy cows * Practical considerations of feed evaluation systems for dairy cows * Adapting livestock production systems to climate change * Legislation affecting animal production systems * Mycotoxin issues in farm animals and strategies to reduce mycotoxins in animal feeds * The effect of nutrition on stress and immunity * Potential applications of GM technology * Influence of feed processing technology on pig performance * Piglet starter feeding in a changing business environment * Organic acids in pig diets * Amino acid requirements in piglets with special emphasis on tryptophan and valine * Factors affecting pork quality * List of participants * Index
1,592 citations
Journal Article•
TL;DR: This research examines the effect of nutrition on stress and immunity, legislation affecting animal production systems, and potential applications of GM technology on pig performance in a changing business environment.
Abstract: Preface * Fatty acids and fertility in dairy cows * Environmental and genetic influences on successful heifer rearing * Reducing dietary phosphorus inputs within dairy systems * Practical aspects of feeding grass to dairy cows * Practical considerations of feed evaluation systems for dairy cows * Adapting livestock production systems to climate change * Legislation affecting animal production systems * Mycotoxin issues in farm animals and strategies to reduce mycotoxins in animal feeds * The effect of nutrition on stress and immunity * Potential applications of GM technology * Influence of feed processing technology on pig performance * Piglet starter feeding in a changing business environment * Organic acids in pig diets * Amino acid requirements in piglets with special emphasis on tryptophan and valine * Factors affecting pork quality * List of participants * Index
1,440 citations
TL;DR: In this article, the general shape of the curve, defined by the locus of weekly yield of a single lactation, remains substantially unchanged, and it is shown that the animal which produces milk at a moderate level steadily throughout her lactation is preferred to one which produces a great deal of milk at her peak but little thereafter.
Abstract: MANY factors may influence the total milk yield of a single lactation, but the general shape of the curve, defined by the locus of weekly yield, remains substantially unchanged. Economically, the configuration of the curve is important, for the animal which produces milk at a moderate level steadily throughout her lactation is to be preferred to one which produces a great deal of milk at her peak but little thereafter (see Cersovsky1 for a review of the literature).
1,018 citations