Redberry juniper as a roughage source in lamb feedlot rations: Performance and serum nonesterified fatty acids, urea nitrogen, and insulin-like growth factor-1 concentrations1

2010 ◽  
Vol 88 (4) ◽  
pp. 1492-1502 ◽  
Author(s):  
T. R. Whitney ◽  
J. P. Muir
1994 ◽  
Vol 45 (6) ◽  
pp. 1125 ◽  
Author(s):  
RD Sainz ◽  
BJ Hosking ◽  
FJ Hart ◽  
GSG Spencer

This study was part of an experiment on the effects of cottonseed meal (CSM) and growth hormone-releasing factor (GRF) on growth in lambs fed lucerne chaff. Forty-eight crossbred lambs were fed lucerne chaff ad libitum, alone or with a cottonseed meal supplement (CSM; 300 g/day). Eight lambs from each group were injected twice daily with recombinant or synthetic GRF (rGRF and sGRF respectively; 30 8g per kg body weight/day) or excipient only for 28 or 30 days. Jugular blood samples were obtained on days 0, 7, 14, 21 and 28. On day 29, blood samples were taken from selected lambs (n = 2/group) at 0, 20, 40, 60, 80, 100, 120, 160 and 240 min after injection. Supplementation of lucerne chaff with CSM generally increased glucose and urea concentrations in plasma, reflecting improved energy and protein status. However, concentrations of growth hormone, insulin-like growth factor-1 and insulin were unaffected by CSM, as were plasma proteins, triacylglycerols and non-esterified fatty acids. Injection of rGRF and sGRF stimulated secretion of growth hormone (GH), insulin-like growth factor-1 (IGF-1) and insulin. Peak GH concentrations (20 min) following injection of GRF appeared to be higher in lambs fed CSM than in those receiving lucerne chaff alone. In contrast, maximal concentrations of IGF-1 were seen after 14 days of treatment. These changes were accompanied by increased plasma glucose, with no changes in triacylglycerols, non-esterified fatty acids and protein. Plasma urea was reduced by GRF, indicating that amino acids were diverted away from catabolism towards protein synthesis. These two sources of GRF were very similar in their endocrine and metabolic effects. This confirms similar observations regarding their effects on growth performance and carcass composition.


1998 ◽  
Vol 67 (2) ◽  
pp. 339-347 ◽  
Author(s):  
W. D. Kraetz ◽  
C. Zimmer ◽  
D. Schneider ◽  
D. Schams

AbstractThe aim of the study was to investigate the influence of different energy levels during a 4-week lactation on the regulation of the metabolic hormones somatotropin (GH), prolactin, insulin and insulin-like growth factor-1 (IGF-1). A total of 21 crossbred sows (German Landrace × Duroc) were cannulated for daily blood collection from 3 weeks before parturition until 2 weeks after weaning and for weekly window sampling (every 20 min for 10 h). Nineteen sows were given 2·8 kg food during late gestation, 5·0 kg food during lactation and 2·8 kg food per day after weaning and two sows were given food at a restricted level (3·0 kg) during lactation. In the 19 sows, the different energy balance was induced by allocation of different numbers of sucking piglets to the respective sows. One group of sows suckled seven piglets and served as a control (C; no. = 7) and another group suckled 10 to 12 piglets and was energy deficient (D). After the study, the sows of the deficient group were, based on their litter weight gain from parturition until weaning, divided into low (D-L; no. = 6) or high (D-H; no. = 6) litter weight gain. The D-H sows lost more body weight during lactation than C and had lower glucose and higher nonesterified fatty acids levels before morning feeding. GH and prolactin increased around parturition and their secretory profiles during lactation were altered by the frequent sucking stimulus, whereby the access of the piglets to their dams was not controlled. During lactation, GH and prolactin were highest in D-H sows. The results suggest a possible role of not only GH but also of prolactin in nutrient partitioning to the mammary gland just before the start of lactation and for minimizing the adverse effects of a negative energy balance. Furthermore, insulin and IGF-1 increased around parturition in all sows. Insulin was higher before and after feeding and the highest levels were found in C and D-L sows. The regulation patterns of insulin and IGF-1 indicate that the lactating sow is able to mobilize enough energy from body reserves to prevent metabolic disorders, even during a period with deficient energy supply. This is contrary to the regulation in the dairy cow, where the negative energy balance is coupled with a severe glucose deficit during phases of high milk yield, which causes decreased levels of insulin and IGF-1. In the sow, the glucose intake with the food meets the glucose requirement for metabolic pathways also during a deficient lactational energy intake. Therefore, in sows IGF-1 can be stimulated by increased GH levels via the GH receptor in the liver during a state of nutritional energy deficiency and the fact that sows can compensate a deficient metabolic state much better than cows is also reflected in the respective endocrinology.


1989 ◽  
Vol 120 (6) ◽  
pp. 735-744 ◽  
Author(s):  
H. Ronge ◽  
J. Blum

Abstract. Insulin-like growth factor I, other hormones and blood metabolites were measured in growing heifers before, during and after a 3-day period of normal feed intake and a corresponding period of reduced feed intake. In addition, 0.1 or 0.5 mg recombinant bovine GH/kg was injected daily for 5 days during normal or during and following reduced feed intake. During reduced feed intake blood concentrations of insulin-like growth factor I, insulin, T4, T3, glucose and urea-nitrogen decreased, whereas those of non-esterified fatty acids, albumin and protein increased (P< 0.05). GH, insulin-like growth factor I and insulin increased, whereas urea-nitrogen decreased in response to exogenous GH when heifers were adequately fed (P< 0.05). In contrast, insulin-like growth factor I did not change during GH injections while heifers received reduced amounts of feed. Therefore, during insufficient energy and (or) protein intake, characterized by low glucose, insulin and thyroid hormone levels and increased non-esterified fatty acid concentrations, insulin-like growth factor I concentrations and responses to GH administration were markedly reduced.


2003 ◽  
Vol 28 (1) ◽  
pp. 64-78 ◽  
Author(s):  
Debra L. Waters ◽  
Richard I. Dorin ◽  
Clifford R. Qualls ◽  
Brent C. Ruby ◽  
Richard N. Baumgartner ◽  
...  

Disruption of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis has been reported and studied in menopause, hypothalamic amenorrhea, and anorexia nervosa, but not in weight-stable amenorrheic athletes. We investigated the effects of short-term transdermal estradiol on basal and exercise-stimulated serum GH, IGF-1, and associated binding proteins (IGFBP-1 and IGFBP-3) in seven weight-stable female amenorrheic athletes with percentage body fats greater that 12%. Each subject received a 72 h placebo patch followed by 144 h of transdermal estradiol. Serum samples for GH, IGF-1, IGFBP-1, and IGFBP-3 were obtained at baseline (t1), 72 hr (t2), 144 hr (t3), and during three 90-minute trials of aerobic exercise. Basal, and exercise GH, IGF-1, and IGFBP-1 were not different between trials. Baseline IGFBP-3 decreased from t1 to t2 (p = 0.04) and serum free fatty acids increased from t1 to t2, and t1 to t3 (p = 0.04, and 0.02 respectively). These findings differ from postmenopausal women, and women having weightloss-associated amenorrhea, suggesting that estrogen, exercise, and nutritional deficiencies may have independent effects on the GH/IGF-1 axis. Key words: transdermal estradiol, insulin-like growth factor binding protein-3, insulin-like growth factor binding protein-1, free fatty acids


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