scholarly journals Exogenous bovine somatotropin and mist-fan cooling synergistically promote the intramammary glucose transport for lactose synthesis in crossbred Holstein cows in the tropics

2021 ◽  
pp. 1247-1257
Author(s):  
Narongsak Chaiyabutr ◽  
Siravit Sitprija ◽  
Somchai Chanpongsang ◽  
Sumpun Thammacharoen

Background and Aim: Milk synthesis by the mammary gland is negatively influenced in part by high ambient temperature (AT). This study aimed to clarify the pathway of intramammary glucose utilization involved in mediating lactose synthesis during treatment with somatotropin under housing with misters and fans. Materials and Methods: A single subcutaneous injection of 500 mg of recombinant bovine somatotropin (rbST) was administered 3 times once every 14 days to 87.5% crossbred Holstein cattle in early-/mid-/late lactation, under housing in a normal shaded barn and in a shaded barn with a mist-fan cooling system. Results: The milk yields of the cooled cows tended to increase compared with those of uncooled cows and exhibited more potentiated effects in response to rbST treatment, coinciding with increases in mammary plasma flow and glucose uptake, but not in the mammary extraction of glucose. Treatment with rbST in the cooled cows resulted in a greater increase in the milk glucose concentration and a greater decrease in the milk glucose-6-phosphate concentration at all stages of lactation. Conclusion: rbST treatment exerted its galactopoietic action more by local intramammary factors than by other extramammary factors at a low AT and the synergistic effect between rbST treatment and low AT increased the availability of intramammary glucose transport in activating the process of lactose synthesis.

1995 ◽  
Vol 73 (10) ◽  
pp. 3051 ◽  
Author(s):  
J D Armstrong ◽  
R W Harvey ◽  
M A Poore ◽  
R B Simpson ◽  
D C Miller ◽  
...  

2014 ◽  
Vol 722 ◽  
pp. 182-189
Author(s):  
Li Gang Ma ◽  
Chang Le Xiang ◽  
Tian Gang Zou ◽  
Fei Hong Mao

The paper proposes a cascade control strategy of speed feedback in inner loop and temperature feedback in outer ring for hydro-viscous driven fan cooling system, and compares the simulation of PID and fuzzy PID. The simulation result shows that the double-loop control system while the response time longer, but much smaller overshoot, can achieve a good feedback to adjust the fan speed and temperature and realize stepless speed regulation of hydro-viscous driven fan cooling system under the premise of stability for fan speed and system temperature.


1999 ◽  
Vol 52 (3) ◽  
pp. 481-496 ◽  
Author(s):  
L.J. Judge ◽  
P.C. Bartlett ◽  
J.W. Lloyd ◽  
R.J. Erskine

1995 ◽  
Vol 269 (5) ◽  
pp. E897-E902
Author(s):  
H. Ishihara ◽  
T. Asano ◽  
K. Tsukuda ◽  
H. Katagiri ◽  
K. Inukai ◽  
...  

Accumulated evidence suggests that GLUT-2, in addition to its role in glucose transport, may also have other functions in glucose-stimulated insulin secretion. As a first step in addressing this possibility, we have engineered MIN6 cells overexpressing human GLUT-2 by transfection with human GLUT-2 cDNA. Stable transformants harboring human GLUT-2 cDNA exhibited an approximately twofold increase in 3-O-methyl-D-glucose uptake at 0.5 and 15 mM. Glucokinase activity or glucose utilization measured by conversion of [5-3H]glucose to [3H]H2O was not, however, altered in the MIN6 cells overexpressing human GLUT-2. Furthermore, glucose-stimulated insulin secretion was not affected by over-expression of human GLUT-2. An abundance of GLUT-2, therefore, does not correlate with the glucose responsiveness of cells in which glycolysis is regulated at the glucose phosphorylating step. These data suggest that GLUT-2 by itself does not have significant functions other than its role in glucose transport in glucose sensing by MIN6 cells.


2018 ◽  
Vol 3 (1) ◽  
pp. 443-455 ◽  
Author(s):  
Philipe Moriel ◽  
Bruno Ieda Cappellozza ◽  
Matheus B Piccolo ◽  
Reinaldo F Cooke ◽  
Miguel F Miranda ◽  
...  

Abstract The present study evaluated the growth and puberty attainment of Bos indicus heifers administered recombinant bovine somatotropin (bST) or saline injections during preweaning and/or postweaning. On day 0, 177 suckling Nellore heifers were stratified by initial age and body weight (BW) (80 ± 10 d; 97 ± 16 kg), and randomly assigned, in a 2 × 2 factorial design (n = 44 to 45 heifers/treatment), to receive s.c. injections of saline (5 mL 0.9% NaCl) or sometribove zinc (Posilac; Elanco, Greenfield, IN; 6.14 mg/kg of BW0.75) on days 0 and 10 (PRE) and/or days 167 and 177 (POS). All heifers were managed as a single group in Brachiaria decumbens pastures from day 0 until 24 d postweaning (day 191), and then provided a corn silage–based TMR from days 191 to 380 to achieve 65% to 70% of mature BW at the end of the study (day 380). Heifer full BW was collected on days 0, 10, 167, 177, and monthly from days 191 to 380. Transrectal ultrasonography of ovaries was performed on days 1 and 10 of each month from days 229 to 380 to assess the percentage of pubertal heifers. Liver biopsies and blood samples from jugular vein were collected on days 0, 10, 167, 177, and 380. Additional blood samples were collected monthly from days 259 to 380 (n = 10 to 15 heifers/treatment). No interactions among day of the study, PRE, and POS injections of saline or bST were detected (P ≥ 0.11). Preweaning bST injections increased heifer average daily gain (ADG) from days 0 to 10 and plasma IGF-1 on day 10 (P ≤ 0.03), did not affect ADG from days 0 to 177, plasma IGF-1 from days 259 to 380, and any liver gene mRNA expression (P ≥ 0.19), but tended to decrease ADG from days 191 to 380 (P = 0.07) and percentage of pubertal heifers on days 349 (P = 0.07), 359 (P = 0.002), and 380 (P = 0.0001) compared with saline injections. Postweaning bST injections increased plasma IGF-1 on day 177 and overall liver mRNA expression of GHR-1A (P ≤ 0.05), decreased plasma IGF-1 from days 259 to 380 (P = 0.03), tended to decrease liver mRNA expression of GHR-1B on day 177 (P = 0.08), but did not affect ADG from days 167 to 177 and 191 to 380, and puberty attainment from days 229 to 380 (P ≥ 0.12) compared with saline injections. Thus, preweaning and postweaning injections of bST successfully increased heifer plasma IGF-1 concentrations 10 d after first injection. Postweaning injections of bST had no impact on puberty attainment, whereas preweaning bST injections of bST impaired puberty attainment of Nellore beef heifers.


2019 ◽  
Vol 125 ◽  
pp. 331-334
Author(s):  
Ana Paula Kaminski ◽  
Maria Luisa Andrade Carvalho ◽  
Marcio Saporski Segui ◽  
Luiz Ernandes Kozicki ◽  
Victor Breno Pedrosa ◽  
...  

Author(s):  
Dong-Il Kim ◽  
Ki-So Bok ◽  
Han-Bae Lee

To seek the fan operating point on a cooling system with fans, it is very important to determine the system impedance curve and it has been usually examined with the fan tester based on ASHRAE standard and AMCA standard. This leads to a large investment in time and cost, because it could not be executed until the system is made actually. Therefore it is necessary to predict the system impedance curve through numerical analysis so that we could reduce the measurement time and effort. This paper presents how the system impedance curve (pressure drop curve) is computed by CFD in substitute for experiment. In reverse order to the experimental principle of the fan tester, pressure difference was adopted first as inlet and outlet boundary conditions of the system and then flow rate was calculated. After determining the system impedance curve, it was compared with experimental results. Also the computational domain of the system was investigated to minimize computational time.


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