Wool production and blood supply to skin and other tissues in sheep

Hales, J. R. S.; Fawcett, A. A.

doi:10.2527/1993.712492x

Cited by 17 publications

(14 citation statements)

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“… § Wool production is calculated using a daily wool growth value of 0.7 mg/cm2/day (18) and the relationship between body surface area (S, m 2 ) and body weight (BW, kg), S = 0.11BW 0 . 67 ,17 …”

Section: Resultsmentioning

confidence: 99%

Bodily variability of zinc natural isotope abundances in sheep

Balter

Zazzo

Moloney³

et al. 2010

Rapid Comm Mass Spectrometry

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Evidence is growing that the range of zinc stable isotope compositions, represented by the deviation of 66 Zn in permil units relative to a standard and expressed as d 66 Zn, is larger in organic matter than in inorganic material. This study reports the variations of d 66 Zn in various organs of sheep raised on a controlled diet. Zinc was purified by anion-exchange chromatography. The Zn concentrations and Zn stable isotope compositions were determined by quadrupole inductively coupled plasma mass spectrometry and multi-collector inductively coupled plasma mass spectrometry, respectively. The data show that d 66 Zn variability exceeds 1%, with bone, muscle, serum and urine enriched in the heavy isotopes, and feces, red blood cells, kidney and liver enriched in light isotopes, all relative to the diet value. The 66 Zn enrichment of the circulating serum reservoir is likely to take place in the digestive tract, probably through the preferential binding of lighter isotopes with phytic acid, which is known to control the uptake of metallic elements. Mass balance calculations suggest that the 66 Zn depletion between diet and feces, which is not balanced by any other outward flux, leads to a secular isotopic drift in serum. A simple time-dependent two-box model, involving the gastrointestinal tract on the one hand and the muscle and bone on the other, predicts that the maximum 66 Zn enrichment, which equals the difference in d 66 Zn between diet and bulk ($0.25%), is reached after about ten years. Therefore, a better understanding of the variations of natural abundance of Zn isotopes in animals and humans will probably bring new perspectives for the assessment of their Zn status. Copyright # 2010 John Wiley & Sons, Ltd.Zinc is an essential element for living organisms as it is required for the activity of >300 enzymes. 1 It has five stable isotopes, 64 Zn, 66 Zn, 67 Zn, 68 Zn and 70 Zn, with average natural abundances of 48.6, 27.9, 4.1, 18.8 and 0.6%, respectively. Although still at a very early stage, studies of the variations of Zn stable isotope ratios a in vegetal tissues show d 66 Zn values ranging from À0.6% to 1.4% in plants, [2][3][4] exceeding the variability known for geological terrestrial materials ($ À0.2% to 0.6%; for reviews, see 5,6 ). Such a large variation in d 66 Zn values is thought to be the result of massdependent fractionation during diffusion processes, first from growth media to plant, and then among plant physiological components (seed, stem and leaf). There is little data available for d 66 Zn values in animal tissues.Maréchal et al. 7 report values for standard bulk plankton (CRM 414), lobster liver (CRM TORT-2) and mussel tissue (CRM 278) that are 66 Zn-enriched by 0.07%, 0.16% and 0.47%, respectively, relative to English Channel seawater (0.35 AE 0.08% 8 ). Values of 0.50 AE 0.03% for standard bovine muscle (SRM 8414) and bovine liver (SRM 1577a) were reported by Ohno et al. 9 An average d 66 Zn value of 0.40 AE 0.15% (n ¼ 9) can be calculated for human blood using data published by ...

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Section: Resultsmentioning

confidence: 99%

Bodily variability of zinc natural isotope abundances in sheep

Balter

Zazzo

Moloney³

et al. 2010

Rapid Comm Mass Spectrometry

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“…By comparison, blood flow through individual tissues of the limbs ranged from 1.9 to 65.6 ml/min/100 g wet tissue in skeletal muscle, from 2.2 to 47.2 ml/min/100 g in adipose tissues, from 0.3 to 22.2 ml/min/100 g in skin, and averaged 3 and 5 ml/min/100 g in connective tissues and bones, respectively (Hales, 1973;Bell etal, 1976;Rhodes et al, 1991;Hales and Fawcett, 1993 (table V). However, with forage-rich diets, feeding increased blood flow mainly through the reticulorumen with little changes from the abomasum down to the large intestine (Barnes et al, 1983).…”

Section: Blood Flow Per Unit Tissue Weightmentioning

confidence: 99%

Responses of the splanchnic tissues of ruminants to changes in intake: absorption of digestion end products, tissue mass, metabolic activity and implications to whole animal energy metabolism

Ortigues¹,

Doreau²

1995

Ann. Zootech.

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“…It has been suggested that the increased capillary-bed blood flow would enhance nutrient delivery to the wool follicle and, hence, wool growth (Sokolowski et al 1969;Hales and Fawcett 1993). In theory, the cardiovascular effects of nitric oxide (NO) formed from the reduction of absorbed NO 2 (Sakai et al 2000;Pinder et al 2009) would increase capillary-bed blood flow and nutrient supply to the wool follicle, which should stimulate wool growth.…”

Section: Introductionmentioning

confidence: 99%

Effect of added dietary nitrate and elemental sulfur on wool growth and methane emission of Merino lambs

Silveira

Nolan

et al. 2013

Anim. Prod. Sci.

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The effects of dietary nitrate (NO3) and elemental sulfur (S) on nutrient utilisation, productivity, and methane emission of Merino lambs were investigated. Forty-four lambs were randomly allocated to four groups (n = 11) fed isonitrogenous and isoenergetic diets. The basal feed was supplemented with 1% urea + 0.18% S (T1), 1.88% NO3 + 0% S (T2), 1.88% NO3 + 0.18% S (T3), or 1.88% NO3 + 0.40% S (T4). Retention of S was improved by increasing the content of elemental S in the NO3-containing diet (P < 0.001), yet the N retention (g/day) by the animal, and the N and S content of wool (%), were not altered by S supplementation (P > 0.05). Dry matter intake, liveweight gain, and feed conversion ratio did not differ (P > 0.05) between treatments. Replacing urea with NO3 improved the rate of clean wool growth by 37% (P < 0.001, T1 vs T3). Clean wool growth increased by 26% (P < 0.001) when the S content of the NO3-containing diet was increased from 0 to 0.18% (T2 vs T3). Methane production (g/day) and methane yield (g/kg DM intake) were reduced (P < 0.05) by 24% when urea was replaced by NO3 (T1 vs T3). The addition of 0.4% S to a diet containing 1.88% NO3 also reduced methane production (P = 0.021) and methane yield (P = 0.028). In conclusion, the addition of 1.88% NO3 and 0.18% elemental S to a total mixed diet increased clean wool production and reduced methane production. However, there was no evidence of inter-relationships between NO3 and S.

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Wool production and blood supply to skin and other tissues in sheep

Cited by 17 publications

References 14 publications

Bodily variability of zinc natural isotope abundances in sheep

Bodily variability of zinc natural isotope abundances in sheep

Responses of the splanchnic tissues of ruminants to changes in intake: absorption of digestion end products, tissue mass, metabolic activity and implications to whole animal energy metabolism

Effect of added dietary nitrate and elemental sulfur on wool growth and methane emission of Merino lambs

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