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by
J. A. Carroll |
Total Records (
5 ) for
J. A. Carroll |
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A. M. Gaines
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J. A. Carroll
and
G. L. Allee
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A 21 d growth experiment was conducted to investigate effects of flucocorticoid injection on pig performance postweaning. At weaning, 30 pigs were weighed and allotted to one of three treatments: saline (Control), Dex (2mg/kg BW i. injection of dexamethasone) or Predef? (2mg/kg BW i. m. injection of Predef? 2x). Initial weights at weaning (5.57?0.02kg) did not differ among treatments (P<0.75). During the first 7 days postweaning, threre was a Time x Treatment effect for ADFI (P<0.02) with predef? pig having higher feed intakes compared to control and Dex pigs. At d7, Predef? pigs were heavier (P<0.002), gaining faster (P<0.001) and consuming more feed (P<0.04) comapred to control and Dex pigs. By d14, predef? pigs tended to be heavier (P<0.08) compared to control and Dex pigs. There were no differences in ADG (P<0.97), ADFI (P<0.84), or Gain:Feed (P<0.30) during the 2nd week postweaning. At d21 there were no differences in BW (p<0.17), ADG (P<0.77), or ADFI (P<0.51). For the overall period, there were no differences in ADG (P<0.16) or Gain: Feed (P<0.12). There was a trend for ADFI to be higher in Predef? pigs (P<0.10) compared to control and Dex pis. Results indicate that dexamethasone injection immediately postweaning doest no improve performance; however, Predef? injection does improve growth performance of pigs during the first 7 days postweaning.
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S. T. Willard
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J. A. Carroll
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M. A. Lammoglia
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C. N. Kemper-Green
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H. Welsh, Jr.
and
R. D. Randel
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An investigation was conducted to determine whether plasma concentrations of growth hormone (GH) and GH secretory profiles (pulse frequency and amplitude) were associated with ovarian follicular growth during the estrous cycle in the Brahman cow. To investigate these relationships, blood plasma was collected and transrectal ultrasonography of the ovaries performed on Brahman cows (n = 9) from d 1 following estrus (d 0) through the mid-luteal phase. Intensive blood sampling (10-min intervals for 6 h) was conducted on d 3 of the estrous cycle, d of the first observed 8 mm follicle and at 48 h after PGF2a injection. PGF2 a was administered at the appearance of the second 8 mm follicle post-estrus. Daily plasma samples were analyzed for progesterone (P4) and estradiol (E2), while samples collected daily and during intensive sampling were analyzed for GH by RIA. Plasma GH did not differ (P > 0.10) during the first 12 d of the estrous cycle, while plasma P4 increased (P < 0.01) and E2 decreased (P < 0.01). Overall GH mean, baseline GH, number of GH peaks and peak height also did not differ (P > 0.10) among intensive sampling periods. However, the amplitude of GH peaks tended (P < 0.08) to be greater at 48 h after PGF2a administration compared to d 3 of the estrous cycle or on the day of the first 8 mm follicle. Moreover, plasma GH on d 4 through d 8 were positively correlated (r-value > 0.73 depending on day; P < 0.02) with numbers of large follicles on d 7 and 8. In summary, while mean daily plasma GH did not differ during the estrous cycle, correlations among GH, ovarian steroids and numbers of large follicles may support a role for GH in mediating ovarian follicular population dynamics, directly or indirectly, in the bovine. |
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T. A. Strauch
and
J. A. Carroll
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Daidzein is a phytoestrogen isoflavone found in soybeans and other legumes, and has been implicated as an immune enhancer. Objectives of this study were to determine the effects of daidzein supplementation to weaned pigs on pig growth and response to a lipopolysaccharide (LPS) challenge. Forty crossbred barrows were removed from their sows and allowed a period of 5 d to acclimate to new housing and dry feed. After that time, pigs were weighed, individually penned, and assigned to either daidzein (D; n=20) or control (C; n=20) treatment. The D pigs received 50 mg d-1 daidzein (LC Laboratories, Woburn, MA) hand-fed in dough balls, and C pigs received dough balls without D. After supplementation with D for 14 d, all pigs were weighed, non-surgically cannulated in the jugular vein, and assigned to rectal temperature (RT) measurement (n=10 D, 10 C) or blood collection groups (n=10 D, 10 C). The following day, blood samples and rectal temperatures were collected at 30 min intervals from -1 to 4 hr post-LPS. At time 0, all pigs received a 50 g kg-1 dose of LPS through the jugular cannulae. Serum was collected from all blood samples and stored at -80 C until assayed for cortisol concentrations by radioimmunoassay. Data for BW, ADG, serum concentrations of cortisol, and rectal temperature were analyzed using ANOVA in StatView. There was no difference (P > 0.72) in initial BW, with average BW of 8.36 ? 1.13 and 8.24 ? 0.93 kg for D and C pigs, respectively. There was no difference (P > 0.50) in final BW, with average BW of 15.30 ? 2.30 and 15.73 ? 1.65 kg for D and C pigs, respectively. Accordingly, there was no difference (P = 0.18) in ADG (0.46 ? 0.10 kg d-1 D; 0.50 ? 0.07 kg d-1 C). There was no treatment by time interaction (P > 0.66) for serum concentrations of cortisol; however, there was an effect of time (P < 0.0001), with cortisol concentrations increasing over time. Similar to cortisol, RT increased (P < 0.0001) over time in both D and C pigs. There was a trend (P < 0.12) for decreased RT in D as compared to C pigs, with RT decreasing in D pigs by 4 hrs post-LPS as compared to C pigs that demonstrated no decrease in RT by 4 hrs post-LPS. This study suggests that daidzein might provide some beneficial protection against an immune challenge. |
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Strauch T. A
,
J. A. Carroll
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E. L. Berg
and
B. E. Salfen
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Objectives were to determine the effects of the estrogenic compound zeranol on maternal and piglet performanceand components of the somatotrophic axis. Treated sows (R) were administered a Ralgro? implant, which contains 36 mg zeranol, subcutaneously in the ear on d 60 of gestationand control (C) sows were administered a sham implant. There was no difference (P>0.38) in serum growth hormone (GH) between C and R sows, but there was a trend for increased (P<0.12) insulin-like growth factor-I (IGF-I) in R sows. There was no difference (P<0.14) in litter size, number born alive, or piglet survival to weaning; however, there was a trend (P<0.11) for greater total litter weight at birth in C sows. There was no difference (P>0.47) in piglet body weight at birth, but there was a treatment effect (P<0.002) on average daily gain (ADG) to 7 d of age, with increased ADG in R pigsand the increased ADG continued until weaning (P<0.02). Treatment did not affect piglet serum concentrations of GH at birth (P>0.18) or weaning (P>0.64); however, it increased (P < 0.0006) serum concentrations of IGF-I in R pigs at birth, but not weaning (P>0.31). Hypothalamic mRNA expression of growth hormone-releasing hormone tended (P<0.07) to be greater in R pigs. These data indicate that zeranol administration to gestating sows increases circulating concentrations of IGF-Iand improves pre-weaning ADG of pigs exposed to zeranol in utero. |
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K.R. Maddock
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J. A. Carroll
and
E. P. Berg
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The objectives of this study were to: 1) determine the affect of supplemental lipoic acid (LA) on feed conversion and rate of gain on weanling pigs and 2) to evaluate the potential immunological benefits of supplementing piglet starter diets with lipoic acid. Twenty-one weaned gilts (d 21, 7 kg) were randomly allotted to three treatment groups: 1) Control, no supplemental LA (n=7); 2) LA-8, orally supplemented with 8 mg/kg body weight of LA per day (n=7); and 3) LA-15, orally supplemented with 15 mg/kg body weight of LA per day (n=7). Pigs were individually penned and treatments were administered orally for 12 days. Feed intake and body weights were recorded from d 0 to d 12. On d 11, pigs were nonsurgically fitted with jugular cannulae. On d 12, all pigs received a dose of 150 ug/kg of lipopolysaccharide (LPS). Blood samples were collected at 15 min intervals for 30 min prior to the LPS challenge and for 180 min after LPS challenge to monitor serum cortisol, tumor necrosis factor-alpha (TNF- ), glucoseand insulin. Additional whole blood samples were collected to determine total neutrophils and lymphocytes, as well as percentages. After the last blood sample was collected, all pigs were sacrificed for the collection of muscle and liver samples. Orally supplemented LA had no effect (P > 0.05) on average daily gain, average daily feed intake, or gain to feed ratios. No effect of LA was seen throughout the LPS challenge period (P>0.05) on serum cortisol or tumor necrosis factor- (TNF- ) concentrations. For serum glucose concentrations, differences among treatments were observed at –30 min pre-LPS such that serum glucose was lower (P<0.05) in the LA-8 and LA-15 groups as compared to the LA-0 group. A LA treatment effect (P<0.05) was observed between 45 and 165 min post-LPS, as LA-8 had higher serum glucose as compared to the LA-0 and LA-15 groups. From 120 until 165 min post-LPS, both LA-8 and LA-15 had higher serum glucose as compared to the LA-0 group (P<0.05). Serum insulin concentrations did not differ (P>0.05) among groups due to LA supplementation. There was a trend (P<0.15) for the LA-15 group to have lower glycogen content in the muscle samples as compared to the LA-0 and LA-8 groups. Glycogen content in the liver was lower in the LA-0 group as compared to the LA-8 group. On d 12, prior to the LPS challenge, the percentage of neutrophils was greater and the percentage of lymphocytes was lower (P<0.05) in the LA-15 group as compared to the LA-0 and LA-8 groups. Further research is needed to determine if supplemental LA may indeed be utilized as a beneficial immunomodulator in swine. |
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