The Effect of Lactation on Ouabain-Sensitive Respiration of the Duodenal Mucosa of Cows

McBride, B.W.; Milligan, L. P.

doi:10.4141/cjas84-095

Cited by 19 publications

(8 citation statements)

References 24 publications

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“…Despite the fact that this increase is associated with a greater energetic demand [38], increasing the maintenance requirements [51]; the cost-benefit of this more functional small intestine results in more animal growth (productivity) per unit of feed intake. Expenditures with tissue plasticity [52] and cellular biochemical processes in small intestine are known to be largely influenced by the animal’s different physiological states [39] and also by changes according to the level of intake and diet composition via changes in the visceral organ mass [53]. The present study indicates that there is also variation in these expenditures due to individual variation and that such variation is associated with feed efficiency.…”

Section: Discussionmentioning

confidence: 52%

“…The intense metabolic rate of the small intestine is mostly due to the energy expenditure for biochemical processes by the intestinal cells [34] and is also due to constant and continuous epithelium renewal [35-37] to maintain or to cope with variations in workload [38,39]. The later factor is associated with changes in tissue structure [40,41].…”

Section: Discussionmentioning

confidence: 99%

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Small intestine histomorphometry of beef cattle with divergent feed efficiency

et al. 2013

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BackgroundThe provision of feed is a major cost in beef production. Therefore, the improvement of feed efficiency is warranted. The direct assessment of feed efficiency has limitations and alternatives are needed. Small intestine micro-architecture is associated with function and may be related to feed efficiency. The objective was to verify the potential histomorphological differences in the small intestine of animals with divergent feed efficiency.MethodsFrom a population of 45 feedlot steers, 12 were selected with low-RFI (superior feed efficiency) and 12 with high-RFI (inferior feed efficiency) at the end of the finishing period. The animals were processed at 13.79 ± 1.21 months of age. Within 1.5 h of slaughter the gastrointestinal tract was collected and segments from duodenum and ileum were harvested. Tissue fragments were processed, sectioned and stained with hematoxylin and eosin. Photomicroscopy images were taken under 1000x magnification. For each animal 100 intestinal crypts were imaged, in a cross section view, from each of the two intestinal segments. Images were analyzed using the software ImageJ®. The measurements taken were: crypt area, crypt perimeter, crypt lumen area, nuclei number and the cell size was indirectly calculated. Data were analyzed using general linear model and correlation procedures of SAS®.ResultsEfficient beef steers (low-RFI) have a greater cellularity (indicated by nuclei number) in the small intestinal crypts, both in duodenum and ileum, than less efficient beef steers (high-RFI) (P < 0.05). The mean values for the nuclei number of the low-RFI and high-RFI groups were 33.16 and 30.30 in the duodenum and 37.21 and 33.65 in the ileum, respectively. The average size of the cells did not differ between feed efficiency groups in both segments (P ≥ 0.10). A trend was observed (P ≤ 0.10) for greater crypt area and crypt perimeter in the ileum for cattle with improved feed efficiency.ConclusionImproved feed efficiency is associated with greater cellularity and no differences on average cell size in the crypts of the small intestine in the bovine. These observations are likely to lead to an increase in the energy demand by the small intestine regardless of the more desirable feed efficiency.

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Section: Discussionmentioning

confidence: 52%

Section: Discussionmentioning

confidence: 99%

Small intestine histomorphometry of beef cattle with divergent feed efficiency

et al. 2013

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“…Although no published data demonstrate the comparative metabolic activity of all seven major GIT components, previous studies have reported on the in vitro metabolic activity of bovine (Harmon et al 1991;Kelly et al 1991Kelly et al , 1993aKelly et al , 1995 and ovine (Burrin et al 1990) rumen mucosa, bovine (McBride & Milligan, 1984) and ovine (McBride & Milligan, 1985;Kelly et al 1993b) duodenal mucosa, and bovine (McBride et al 1989) and ovine (Burrin et al 1990) jejunum (combined mucosa and muscularis). These studies have demonstrated consistent values for DM weight-specific O 2 uptake by mucosa of 6-9 ml/g DM per h, across species and ages, with the single reported value for muscularis (bovine rumen, 2 : 8 ml/g DM per h; Kelly et al 1991) being only 36 % of the corresponding mucosal value.…”

Section: Discussionmentioning

confidence: 99%

The role of gut tissue in the energy metabolism of growing lambs fed forage or concentrate diets

2001

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The role of the gastrointestinal tract (GIT) in explaining the less efficient utilization of metabolizable energy (ME) in growing lambs fed forage rather than concentrate-based diets was investigated by feeding forage (legume-grass silage) and concentrate (whole shelled maize) diets, at isoenergetic intakes (ME basis), using five groups of lambs. One group of seven lambs was an initial slaughter group and of the two groups (eight lambs per group) fed each diet, one group was fed for 8 weeks, whereas the other group was fed for 16 weeks. All lambs were slaughtered between 18 : 5 and 20 h following their last meal. Retained energy (as a percentage of ME intake) was higher (concentrate-fed 28, forage-fed 17; P,0 : 001) for the concentrate-fed animals. Weight-specific mucosal O 2 uptake (ml/g DM per h), measured in vitro, was 37 % higher for the forestomach (reticulum, rumen and omasum) and small intestine (jejunum) than for the abomasum and large intestine (caecum and colon), but there was no evidence for a diet effect (except colon; forage-fed 5 : 3, concentrate-fed 4 : 2; P¼0 : 036). Total GIT heat loss was estimated as 14 (forage-fed) and 18 (concentrate-fed) % of the whole-body heat loss. Although the GIT did not contribute to increased thermogenesis in the forage-fed lambs in the present study, greater relative contribution of GIT tissue to whole-body mass, i.e. GIT as a percentage of empty-body weight(forage 7 : 6, concentrate 6 : 6; P,0 : 001) in the forage-fed animals supports a role for the GIT in contributing to higher thermogenesis observed in ruminants fed forage as opposed to concentrate diets.Gut energy metabolism: Forage: Concentrate

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“…There may be variation between individuals as well as between breeds in the efficiency with which nutrients (food energy) are used for maintenance processes (Taylor et al 1986b). Ion transport is a major contributor to maintenance energy costs (Milligan & Summers, 1986) and has been found, in duodenal mucosa, to be enhanced in lactation in cows, although this may be as much the result of altered food consumption as a direct reflection of changed physiological state (McBride & Milligan, 1984). Genetic variations in ion transport costs have been identified as a result of selection for growth in sheep, but analogous differences in lactation have yet to be sought or identified.…”

Section: Animal Variationmentioning

confidence: 99%

Sources of variability in lactational performance

Oldham

Friggens

1989

Proc. Nutr. Soc.

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Variation in lactational performance comes about as a result of variation in the nature of the animal, its environment, or with time. Table 1 lists a variety of sources of variability, classified under broad headings of variation with the animal (species, breed and individual), with time and with various aspects of the environment. The list is probably not comprehensive, but even so, it contains more issues than can be dealt with in depth here. So we have chosen to select for comment a few issues in which we have a particular interest and which are likely to interest members of this Society.An important feature in any consideration of lactational performance must be to note that 'lactational performance' has many dimensions. There are elements of milk secretion, change in maternal state, the growth and well-being of offspring and, in species which display lactational oestrus, the initiation of a subsequent cycle of reproduction. Each of these elements of lactational performance varies depending on species, environment and time, but not usually independently of each other. So, for example, animals which are thin at parturition might adjust both the amount of food they choose to eat and their rate of milk secretion in relation to the extent and state of their body tissue reserves. There may also be metabolic adjustments which alter the likelihood of renewed conception. It is the concerted set of events which represents lactational performance. The orchestration of the various elements of overall performance is subject to a variety of controls which deal both with tactical (homeostasis) and strategic (homeorhetic) aspects of metabolism (Bauman & Cume, 1980).A thorough appraisal of variability in lactational performance requires knowledge of each of the different contributing elements. Unfortunately, many reports of lactation concentrate only on the milk secretory process and tend to ignore other, associated, changes. We have tried here to recognize and emphasize the multi-dimensional aspect of lactational performance, and to emphasize the important interactions between the nature of the animal and its environment in determining temporal changes in overall lactational performance.A number of important issues are dealt with superficially or not at all. In addition to papers in this symposium, the following are useful reference sources which deal with variability in lactational performance in relation to evolutionary strategies, the thermal Table 1. Sources of variability in lactational performance classifid according to animal, environment and time

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The Effect of Lactation on Ouabain-Sensitive Respiration of the Duodenal Mucosa of Cows

Cited by 19 publications

References 24 publications

Small intestine histomorphometry of beef cattle with divergent feed efficiency

Small intestine histomorphometry of beef cattle with divergent feed efficiency

The role of gut tissue in the energy metabolism of growing lambs fed forage or concentrate diets

Sources of variability in lactational performance

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