Serum Growth Hormone Concentration in Hereford and Angus Calves: Effects of Breed, Sire, Sex, Age, Age of Dam, and Diet

Keller, D. G.; Coulter, G.H.; Smith, V. G.; King, G. J.

doi:10.4141/cjas79-045

Cited by 36 publications

(22 citation statements)

References 14 publications

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“…This is similar to the findings in cattle (4,10 -12). Younger animals secrete more GH per unit body weight than older animals (13,26), which supports the result of the present study.…”

Section: Discussionsupporting

confidence: 94%

“…This result supports the suggestion by Joakimsen and Blom (4) and Keller et al (26) that GH concentration appears to increase as the animals are reaching advanced stages of pubertal development, thereby, suggesting that our experimental buffaloes may be reaching the peripubertal period. The decreasing trend of plasma GH in the present study up to week 29 of the experiment may be due to gradual dilution of GH with increasing age and size of the animals, as also suggested in bovines (14,26,27). On the basis of the result in this study, the overall trends are for GH and ratios of GH to body weight (GH per 100 kg body weight) to be higher in younger calves, with a tendency for blood levels to decline during a few months of life, followed by a general leveling off thereafter (4,6,7,10,13,28,29).…”

Section: Discussionmentioning

confidence: 71%

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Changes in Plasma Growth Hormone (GH) and Secretion Patterns of GH and Luteinizing Hormone in Buffaloes (Bubalus bubalis) During Growth

Mondal

Prakash

2004

Endocrine Research

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To assess the changes of plasma growth hormone (GH) and secretion patterns of GH and luteinizing hormone (LH) during growth in buffaloes, six growing female Murrah buffalo calves (mean age 6+/-0.9 months and body weight 66+/-6 kg) were selected. Plasma samples were collected twice a week for 52 weeks for GH and LH assay. To examine for pulsatile secretion samples were collected at 15 minutes interval for 9 hr at weeks 6 and 42 for GH and LH measurements. Plasma progesterone was also estimated in twice-a-week samples to assess whether any of the buffalo had begun ovarian cyclicity. The body weight of all animals was recorded at weekly interval. Plasma GH concentration decreased (P < 0.01) only up to week 29 and showed an increasing trend (P < 0.01) thereafter. The ratio of plasma GH to body weight declined (P < 0.01) throughout the entire experimental period. Plasma GH showed a declining trend only up to when the animals attained 155 kg body weight and thereafter showed an increasing trend (P < 0.01). Plasma GH revealed distinct pulsatile patterns of release, with a mean of 6 and 5 pulses in the 6-week and 42-week samples, respectively. The plasma LH concentrations around the 42-week time period were significantly higher (P < 0.01) than at the 6-week time period, and they exhibited pulsatility. No animal reached puberty until the end of the experiment. In summary, plasma GH levels have a definite pattern of change during growth and patterns of secretion of plasma GH and LH also have a relation with body weight in this species of animal.

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“…This is similar to the findings in cattle (4,10 -12). Younger animals secrete more GH per unit body weight than older animals (13,26), which supports the result of the present study.…”

Section: Discussionsupporting

confidence: 94%

Section: Discussionmentioning

confidence: 71%

Changes in Plasma Growth Hormone (GH) and Secretion Patterns of GH and Luteinizing Hormone in Buffaloes (Bubalus bubalis) During Growth

Mondal

Prakash

2004

Endocrine Research

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“…Besides, recombinant bovine somatothropin has been proven to modulate the activity of liver P450 enzymes in the rat [60]. By considering, as in the rat, a possible regulation of CYP3A expression by GH, it has been previously demonstrated that Hereford and Aberdeen-Angus bulls had significantly higher serum GH levels than heifers of the same age [22]; by contrast, it has also been reported that GH plasma concentrations did not differ significantly among Holstein, Simmental, Normandy and Blue White Belgian cows [44]. Based on our results and bibliographic evidence, no clear-cut conclusions can therefore be made.…”

Section: Discussionmentioning

confidence: 99%

Effect of breed and gender on bovine liver cytochrome P450 3A (CYP3A) expression and inter-species comparison with other domestic ruminants

et al. 2005

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-The cytochrome P450 (P450) superfamily represents a group of relevant enzymes in the field of drug metabolism and several exogenous or constitutional factors contribute to regulate its expression. Cattle represent an important source of animal-derived food-products and studies concerning the P450 expression are needed for the extrapolation of pharmacotoxicological data from one species to another and for the evaluation of the consumer's risk associated with the consumption of harmful residues found in foodstuffs. In the present study, possible breed-, genderand species-differences in P4503A (the P450 subfamily more expressed in the human liver) expression were studied in vitro in Piedmontese (PDM) and Limousin (LIM) meat cattle breeds of both sexes and in domestic Ruminants (cattle, sheep and goats). Cytochrome P450 and P4503A contents as well as CYP3A-dependent drug metabolising enzymes (DME) were measured in liver microsomes. Significant lower levels of P450 (P < 0.001) and P4503A (P < 0.05) contents were observed in PDM vs. LIM of both sexes; the P4503A-dependent DME activities were significantly (P values ranging from 0.05 up to 0.001) higher in PDM cattle, particularly in males. A gendereffect in DME activities was noticed (P < 0.05) only in PDM male cattle. With regards to the species, the expression of both P4503A apoprotein and some of the related DME activities were more pronounced in sheep (P < 0.01 vs. cattle) and in goats (P < 0.05 vs. sheep; P < 0.01 vs. cattle) than in cattle. The significant differences in P4503A expression observed in LIM and PDM cattle are consistent with previously published data on strain-and breed-differences pointed out in rats and men. As far as a possible sex-effect is concerned, no clear-cut evidence is likely to be drawn. Finally, P4503A expression was more relevant in small ruminants. ruminants / liver drug metabolism / CYP3A / gender / breed

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“…Heifers had lower mean and smooth mean GH values than bulls (PO.01). Keeler et al (1979) Time, min males at 5 months of age. Our results could indicate that the GH secretory profile may be affected earlier by sex hormones and behavioural states in faster growing Piemontese than in slower growing BW cattle.…”

Section: Resultsmentioning

confidence: 99%

Comparison of blood plasma growth hormone levels in young dairy and beef cattle

Grochowska¹,

Snochowski²,

Woliñska-Witort³

et al. 1999

J. Anim. Feed Sci.

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The characteristics of the growth hormone (GH) secretion pattern in the peripheral blood plasma of young dairy and beef cattle were described. Ten Black and White (BW) and nine Piemontese cattle of both sexes, aged 11 months, were tested. The blood was sampled through catheters at 15-min intervals over a period of 4 h. The GH concentration was determined by double antibody radioimmunoassay. Pulse characteristics of GH were calculated using the PULSAR program. The results obtained confirmed the pulsatile nature of GH release in the analyzed breeds. Moreover, significant differences (P<0.01) of mean GH values between BW and Piemontese heifers (17.8 vs 2.8 ng/mL) and of smooth mean (9.5 vs 1.3 ng/mL), as well as the peak amplitude between BW and Piemontese bulls (20.8 and 6.7 ng/ml, respectively) were found. A high GH concentration appears to be characteristic of young dairy cattle when compared with beef cattle, and to reflect a genetic potential for high milk production.

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Serum Growth Hormone Concentration in Hereford and Angus Calves: Effects of Breed, Sire, Sex, Age, Age of Dam, and Diet

Cited by 36 publications

References 14 publications

Changes in Plasma Growth Hormone (GH) and Secretion Patterns of GH and Luteinizing Hormone in Buffaloes (Bubalus bubalis) During Growth

Changes in Plasma Growth Hormone (GH) and Secretion Patterns of GH and Luteinizing Hormone in Buffaloes (Bubalus bubalis) During Growth

Effect of breed and gender on bovine liver cytochrome P450 3A (CYP3A) expression and inter-species comparison with other domestic ruminants

Comparison of blood plasma growth hormone levels in young dairy and beef cattle

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