Publications (5)8.04 Total impact
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Article: Levels of hormones and metabolites, insulin responses to glucose infusions, glucose tolerances and growth rates in different breeds of steers: Studies during and after an alpine sojourn
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ABSTRACT: Levels of Hormones and Metabolites, Insulin Responses to Glucose Infusions, Glucose Tolerances and Growth Rates in different Breeds of Steers: Studies during and after an Alpine SojournInsulin (IRI) responses to iv infusions of glucose (1.83 mmol/kg0.75 for 5 min) and glucose tolerances were determined in Simmental (SI) and Holstein-Friesian (HF) steers (I) during reduced growth, 84 days after the animals had been on an alpine pasture at 2000m above sea level, and (II) during compensatory growth, 70 days after the animals had returned from alpine sojourn (group A). Glucose infusions were at the same time performed in normally growing steers, held continuously in a loose housing system at 400m above sea level, fed corn silage ad libitum and 1 kg of concentrates/animal/day (group C). Immediately before glucose infusion I, body weights (253 ± 19 kg), growth rates (185 ± 11 g/day) and blood levels of IRI (−0.54 μg/l), thyroxine (T4; − 27.2 nmol/l), 3,5,3′-triiodothyronine (T3; −0.55 nmol/l) and glucose (−0.92 mmol/l) were lower (P < 0.01), whereas those of growth hormone (+ 3.17 μg/l), non esterified fatty acids (NEFA; + 0.12 mmol/l) and urea (+ 1.27 mmol/l) were higher (P < 0.05) in group A than in group C (body weight: 380 ± 22 kg; growth rate: 1065 ± 151 g/day). Concentrations of acetoacetate (AAC), albumin, α-aminoaced nitrogen (AAN) and 3-methyl-histidine were similar in both groups. IRI responses to glucose infusion I were smaller in group A than in group C (P < 0.05), although glucose increased to higher levels (P < 0.01) and fractional glucose turnover rates (K-values) were identical. Immediately before glucose infusion II, growth rates were higher in group A (1719 ± 124 g/day) than in group C, whereas blood levels of IRI, T4, T3, glucose, NEFA, AAC, urea, albumin and AAN were comparable in both groups. In response to glucose infusion II, glucose levels reached were lower (P < 0.05) in group A than in group C, but IRI responses and fractional glucose turnover rates were similar in both groups. IRI responses and K-values were higher (P < 0.05) in HF than in SI steers, although glucose levels were similar, and 3-methyl-histidine levels were lower. Metabolic alterations, including reduced IRI responses in the presence of enhanced increments of glucose levels to glucose infusions, during reduced growth on alpine pasture are expressions of shifts in energy metabolism to insufficient energy intake. Because IRI responses were markedly different between breeds suggests genetic influences on insulin secretion.ZusammenfassungKonzentration von Hormonen und Metaboliten, Insulinfreisetzung bei Glucoseinfusionen, Glucosetoleranzen und Wachstumsraten bei Ochsen verschiedener Rassen: Untersuchungen während und nach der AlpungBei Simmentaler-(SI) und Holstein-Friesian (HF)-Ochsen wurde die Reaktion der Blutplasmakonzentration von Insulin (IRI) auf intravenöse Glucoseinfusionen (1,83 mmol/kg0,75 während 5 min) untersucht und zwar (I) während reduziertem Wachstum (nach 84 Tagen dauernder Alphaltung auf 2000m ü. M.) und (II) während kompensatorischen Wachstums (70 Tage nach Rückkehr der Tiere von der Alpweide und entsprechend langer Stallhaltung auf 400m ü. M.) (Gruppe A). Gleichzeitig wurden Glucoseinfusionen durchgeführt bei normal wachsenden Ochsen, welche stets in einem Laufstall bei 400m ü. M. gehalten wurden (Gruppe C). Diese Tiere erhielten Silage und 1 kg Kraftfutter/Tag. Unmittelbar vor der Glucoseinfusion (I) hatten die Tiere der Gruppe A ein tieferes Körpergewicht (253 ± 19 kg), eine geringere Wachstumsrate (185 ± 111 g/Tag), tiefere Blutplasmakonzentrationen von Insulin (−0,54 μg/l), Thyroxin (T4; −27,2 nMol/l), 3,5,3′-Trijodthyronin (T3; −0,55 nMol/l) und Glucose (−0,92 mMol/l) und höhere Konzentrationen nicht-veresterter Fettsäuren (NEFA; +0,12 mMol/l) und Harnstoff (+1,27 mMol/l) als die Tiere der Gruppe C, deren Körpergewicht 380 ± 22 kg und deren Wachstumsrate 1065 ± 151 g/Tag betrug (P < 0,05). Dagegen wurden bei den beiden Versuchsgruppen ähnliche Acetoacetat (AAC)-, Albumin-, α-Aminosäurestickstoff (AAN)- und 3-Methylhistidinkonzentrationen gemessen. Die IRI-Konzentrationen stiegen während und nach der Glucoseinfusion (I) bei der Gruppe A weniger stark an als bei der Gruppe C (P < 0,05), trotz stärkerer Hyperglycaemie (P < 0,01). Die Glucoseclearanceraten (K-Werte) waren allerdings identisch. Unmittelbar vor der Glucoseinfusion (II) waren die Wachstumsraten bei der Gruppe A (1719 ± 124 g/Tag) höher als bei der Gruppe C, während die Blutplasmakonzentrationen von IRI, T4, T3, Glucose, NEFA, AAC, Harnstoff, Albumin und AAN vergleichbar waren. Die Glucosekonzentrationen stiegen während der Glucoseinfusion (II) bei der Gruppe A weniger stark an als bei der Gruppe C, während die K-Werte und der Anstieg der Insulinkonzentrationen bei den beiden Gruppen ähnlich war. Die HF-Ochsen reagierten auf die Glucoseinfusionen mit einem stärkeren Anstieg der Insulinkonzentrationen und die K-Werte waren höher als bei den SI-Ochsen (P < 0.05), obschon die Glucosekonzentrationen ähnlich waren. Zusätzlich wurden bei HF-Ochsen tiefere Methylhistidinkonzentrationen gemessen als bei den Simmentalern (P < 0.01). Die Stoffwechselveränderungen, der verminderte Anstieg des Insulins während und nach den Glucoseinfusionen trotz stärkerer Hyperglycaemie, während der Phase verminderten Wachstums bei Alphaltung, können als Ausdruck veränderter Energiesubstratverteilung zwecks Anpassung an Energiedefizite gewertet werden. Der stark unterschiedliche Anstieg der Insulinkonzentrationen bei den untersuchten Rassen dürfte auf genetische Beeinflussung der Insulinsekretion zurückzuführen sein.RésuméConcentrations en hormone et métabolites, liberation d'insuline après une infusion de glucose, tolérance au glucose, gain de poids vif: mesurés avant et après une période en alpage chez des boeufs de différentes racesLa libération d'insuline après une infusion iv de glucose (1.83 mmol/kg0.75 pendant 5 minutes) et la tolérance au glucose ont été déterminées chez des boeufs de race Simmentaler (SI) et Holstein-Frisonne (HF) pendant une période de croissance réduite (I) (après 84 jours passés sur un alpage à 2000 m d'altitude), et pendant la croissance compensatrice (II) (70 jours après le retour en plaine), (groupe A). En même temps du glucose a été infusé à des boeufs gardés en stabulation libre à 400 m d'altitude et ayant une croissance normale (groupe C). Ces animaux recevaient de l'ensillage de mais à volonté et 1 kg/d'aliment concentré/animal/jour. Juste avant l'infusion de glucose I les animaux de groupe A avaient: un poids vif moins élevé (253 ± 19 kg), un gain journalier plus petit (253 ± 111 g), de plus petites concentrations dans le plasma sanguin en insuline (−0.54 μg/l), en thyroxine (T4; −27.2 nmol/l), en 3,5,3′-triiodothyronine (T3; −0.55 nmol/l), et en glucose (−0.92 mmol/l) (P < 0.01); des concentrations plus élevés en hormone de croissance (+ 3.17 μg/l), en acides gras non estérifiés (NEFA; +0.12 mmol/l) et en urée (+ 1.27 mmol/l) (P < 0.05) que ceux du groupe C (poids vif: 380 ± 22 kg; gain journalier: 1065 ± 151 g). Les concentrations en acétoacétate (AAC), albumine, acides animés (AAN) et 3-méthyl-histidine étaient identiques dans les deux groupes. Pendant et après l'infusion de glucose I, la concentration en insuline a augmenté moins fortement chez les animaux du groupe A que chez ceux du groupe C (P < 0.05), et ce malgrès une plus forte hyperglycémie (P < 0.01). Les valeurs K étaient semblables. Juste avant l'infusion de glucose II, les animaux du groupe A avaient un gain journalier (1719 ± 124 g) plus élevé que ceux du groupe C. Cependant les concentrations en insuline, T4, T3, glucose, NEFA, AAC, urée, albumine et AAN étaient semblables dans les deux groupes. Les concentrations en glucose attaintes après l'infusion de glucose II étaient plus basses (P < 0.05) dans le groupe A que dans le groupe C, les concentrations en insuline ont augmenté de façons identiques dans les deux groupes, et les valeurs K étaient semblables. La libération d'insuline et les valeurs K étaient plus élevées chez les boeufs HF queles SI (P < 0.05), bien que les niveaux en glucose fussent semblables, et ceux en 3-méthyl-histidine inférieurs. Pendant la phase de croissance réduite (alpage), des changements métaboliques, comme la moins grande libération d'insuline pendant et après l'infusion de glucose, malgrès une hyperglycémie, sont l'expression des changements dans le métabolisme énergétique causés par le déficit en énergie. Les augmentations des concentrations en insuline tiès différentes entre les races témoignent très influences génétiques lors de la sécretion de l'insuline.ResumenConcentraciones de hormona y metabolitos; secretiones de insulina como consecuencia de inyecciones de glucosa; toleranza de glucosa y aumento de peso vivo. Investigaciones realizadas en toros de diferentes razas, antes y después del periodo de alpageLa reacción a inyecciones intravenosas de glucosa (1.03 mmol/kg durante 5 minutos) de la concentración de insulina (IRI) en el plasma, ha sido estudiada en toros de la raza Simental (SI) y Holstein-Friesona (HF). Los datos fueron recolectados, (I) durante un periodo de crecimiento reducido (Después de 84 dias de alpage a 2000 m.s.n.m.), y (II) durante el crecimiento compensatorio (70 dias después del retorno del ganado al plano) (grupo A). Al mismo tiempo fueron inyectados con glucosa, toros de crecimiento normal en estabulación libre criados a 400 m.s.n.m. (Grupo C). Estos animales recibieron ensilage de mais y 1 kg de concentrado por dia.Inmediatamente antes de la inyección de glucosa (I) los animales del Grupo A presentaron: un bajo peso vivo (253 ± 111 g/dia), en el plasma sanguineo concentraciones menores en insulina (−0.54 μg/l), en thyroxina (T4; −27.2 nmol/l), en 3,5,3′-triyodo-thyronina (T3; −0.55 nmol/l), y en glucosa (−0.92 mmol/l); concentraciones mas elevadas de ácidos grasos no esterificados (NEFA; +0.12 mmol/l) y de urea (+ 1.27 mmol/l) que los animales del grupo C, cuyo peso vivo correspondian a 380 ± 22 kg y cuyo crecimiento era de 1065 ± 151 g/dia (P < 0.05). Por el contrario en el segundo grupo se registraron valores similares, concerniente a la concentration de aceto-acetato (ACC), de albumina, de α-aminoacidos (AAN) y 3-metilhistidina estos eran idénticos en los dos grupos. Las concentraciones de insulina (IRI) aumentaron durante y después de inyecciones de glucosa, (I) en el grupo A en menor cuantia que en el grupo C (P < 0.05), no obstante una mayor hiperglicemia (P < 0.01). Los valores k'fueron idénticos. Immediatamente antes de la inyeccion de glucosa (II) el crecimiento de los animales del grupo A (1719 ± 124 g/dia) era mayor que en el grupo C. Mientras las concentraciones en el plasma sanguineo de IRI, T4, T3, glucosa, NEFA, AAC, urea, albumina y ANN eran parangobables en los dos grupos. Los concentraciones de glucosa aumentaron durante las inyecciones (II) de glucosa en el grupo A en menor grando que en el grupo C, mientras el valor de K' y el aumento de la concentraciones en insulina era similar en los dos grupos. Los toros HF reaccionaron a la inyección de glucosa con un incremento mayor de la concentración de insulina a los valores de K' eran mas altos que en los toros SI (P < 0.05), no obstante las concentraciones de glucosa eran iguales.Además fueron mesuradas, concentraciones mas bajas de 3-metilhistidina en toros HF que en toros SI (P < 0.01). Los cambios en el metabolismo y el menor aumento durante y después de los aplicaciones de glucosa, no obstante una mayor hyperglicemia durante la fase de crecimiento reducido del alpage; pueden ser considerados, como la expresión de los modificaciones en la distribucion del substrato energético causado por el déficit de energia. La notable diferencia en el aumento de la concentración de insulina en las razas controladas, deberia ser relacionada a la influenca genética en la secrecion de insulina.Journal of Animal Breeding and Genetics 03/2011; 102(1‐5):23 - 33. · 1.46 Impact Factor -
Article: Influence of high altitude grazing on productive and physiological traits of dairy cows
Journal of Animal Breeding and Genetics 04/2010; 106(1‐6):278 - 288. · 1.46 Impact Factor -
Article: Concentrate feeding strategy in lactating dairy cows: metabolic and endocrine changes with emphasis on leptin.
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ABSTRACT: This study aimed to evaluate metabolic and endocrine adaptations to energy intake in multiparous Holstein cows (n = 90; mean 9434 kg energy-corrected milk yield/305 d) over the first 20 wk postpartum and to assess the association of leptin with metabolic, endocrine, and zootechnical traits. Concentrates were fed automatically for 24 h at 30% (C30) or 50% (C50) of total dry matter intake (DMI) from wk 1 to 10 postpartum and at linearly reduced amounts thereafter. Roughage was fed for ad libitum intake. The DMI was measured over 24 h; milk yield and body weight (BW), twice/d; milk composition, 4 times/wk; and milk acetone, weekly. Blood samples for determination of metabolite, hormone, and electrolyte concentrations and enzyme activities were obtained at wk 2 prepartum, and at wk 1 to 16 and at wk 20 postpartum from 0730 to 0900. Body condition scores (BCS) and backfat thickness were measured postpartum and during wk 1, 4, 8, 12, 16, and 20. Energy balance (EB) was considerably lower, but milk yield only slightly lower, in C30 than C50. Metabolic stress was more marked in C30 than C50, expressed by lower, glucose, insulin, insulin-like growth factor-1 (IGF-1), triiodothyronine, milk protein, and lactose concentrations, higher nonesterified fatty acid, beta-hydroxybutyrate, growth hormone, and milk acetone concentrations, and an accelerated decrease in BCS and backfat thickness. Nevertheless, C30 adapted successfully and thus maintained high milk yields despite negative EB. Leptin concentrations were lower in C30 than in C50 over the first 20 wk postpartum and were positively associated with BCS, EB, BW, cholesterol, albumin, insulin, and IGF-1; negatively associated with DMI and triiodothyronine; and were higher in cows calving in spring than in fall. Leptin is one among several factors involved in the regulation of energy metabolism and may be important for overall homeostatic and homeorhetic control of metabolism and thus for maintenance of performance.Journal of Dairy Science 06/2003; 86(5):1690-706. · 2.56 Impact Factor -
Article: Estimation of energy balance at the individual and herd level using blood and milk traits in high-yielding dairy cows.
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ABSTRACT: This study aimed to estimate individual and herd-level energy balance (EB) using blood and milk traits in 90 multiparous high-yielding Holstein cows, held on a research farm, from wk 1 to 10 postpartum (p.p.) and to investigate the precision of prediction with successively decreased data sets simulating smaller herd sizes and with pooled samples. Dry matter intake, milk yield, and BW were measured daily from parturition through wk 10 p.p. Milk composition was determined 4 times per week, and milk acetone was measured weekly. Blood samples for the determination of metabolites, hormones, electrolytes, and enzyme activities were taken weekly from wk 1 to 10 p.p. between 0730 and 0900. Body condition scores and ultrasonic measurements of backfat thickness and fat depth in the pelvic area were evaluated in wk 1, 4, and 8 p.p. Concentrations of glucose, cholesterol, urea, insulin, insulin-like growth factor-1, triiodothyronine, and thyroxine (T4) in blood plasma and of lactose and urea in milk were positively correlated with EB, whereas concentrations of nonesterified fatty acids (NEFA), creatinine, albumin, beta-hydroxybutyrate, and growth hormone and enzyme activities in blood, and concentrations of fat, protein, fat:lactose ratio, and acetone in milk were negatively correlated with EB. Leptin concentration was not correlated to EB over the first 10 wk p.p. To estimate EB linear mixed-effects, models were developed by backward selection procedures. The most informative traits for estimation of EB were the fat:lactose ratio in milk and NEFA and T4 concentrations in blood. The precision of estimation of EB in individual cows was low. Using blood in addition to milk traits did not result in higher precision of estimation of herd-level EB, and decreasing sample sizes considerably lowered the precision of EB prediction. Estimation of overall mean herd-level EB over the first 10 wk p.p. using pooled samples was precise even with small sample sizes, but does not consider the level of EB in particular weeks. In conclusion, estimation of herd-level EB at individual weeks using milk traits only has practical implication with herd sizes of > or = 100 cows if calving is highly seasonal and of or = 400 cows if calving is uniformly distributed. Using blood in addition to milk traits does not improve precision of estimation of herd-level EB, regardless of sample size.Journal of Dairy Science 12/2002; 85(12):3314-27. · 2.56 Impact Factor -
Article: Thyroid hormones, blood plasma metabolites and haematological parameters in relationship to milk yield in dairy cows
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ABSTRACT: To study their relationship to milk yield, the concentrations, in jugular venous blood, of thyroxine iodine (T4I), thyroxine (T4), 3,5,3'-tri-iodothyronine (T3), glucose, non-esterified fatty acids (NEFA), triglycerides, phospholipids, cholesterol, total protein, albumin, urea, haemoglobin and packed cell volume (PCV) have been measured in 36 cows (Simmental, Swiss Brown, Holstein and Simmental × Holstein) of different ages during a full lactation, pregnancy, dry period, parturition and 150 days of the ensuing lactation. Thyroid hormones and triglycerides were negatively, and total protein, globulin, cholesterol and phospholipids were positively, correlated with uncorrected or corrected milk yield during several periods of lactation, whereas glucose, NEFA, albumin, urea, haemoglobin and packed cell volume were not correlated with milk yield. The 10 animals with the highest milk yield (18·9 to 23·5 kg/day) exhibited significantly lower values of T4I, T4, T3 and glucose, significantly higher levels of total protein and globulin and tended to have higher levels of NEFA than the 10 cows with the lowest milk yield (10·9 to 14·3 kg/day) throughout or during certain periods of lactation, whereas concentrations of triglycerides, phospholipids, cholesterol, albumin, haemoglobin and PCV did not differ. Changes in T4I, T4, T3, glucose and total protein during lactation were also influenced by age, presumably associated with an increase in milk production with age. T3 was consistently lowest and cholesterol and phospholipids, during later stages of lactation, were highest in Holsteins, which had the highest milk yields of all breeds. Changes of blood parameters were mainly caused by shifts in energy and protein metabolism in association with level of milk productionAnimal Science. 01/1983; 36(01):93 - 104.
