Effect of creatine phosphate supplementation on anaerobic working capacity and body weight after two and six days of loading in men and women

The purpose of this study was to determine the effects of 2 and 6 days of creatine phosphate loading on anaerobic working capacity (AWC) and body weight (BW) in men and women. Sixty-one men (n = 31) and women (n = 30) randomly received 1 of 3 treatments (4 x 5 g.d(-1) x 6 days) using a double blind design: (a) 18 g dextrose as placebo (PL); (b) 5.0 g Cr + 20 g dextrose (Cr); or (c) 5.0 g Cr + 18 g dextrose + 4 g of sodium and potassium phosphates (CrP). AWC was determined at baseline and following 2 and 6 days of supplementation using the Critical Power Test. BW increased significantly over time, and the mean value for the men was significantly greater compared to that for women, but there were no interactions (p > 0.05). There were gender-specific responses for AWC expressed in both absolute values (kJ) and relative to BW (kJ. kg(-1)), with the women demonstrating no significant interactions. For the men, CrP loading significantly increased AWC following 2 days (23.8%) and 6 days (49.8%) of supplementation vs. PL (kJ and kJ.kg(-1)). Cr supplementation increased AWC 13-15% in both genders compared to PL (1.1%- 3.0% decline); although this result was not statistically significant, it may have some practical significance.     

Effect of two and five days of creatine loading on anaerobic working capacity in women

The purpose of this study was to determine the effects of 2 and 5 days of Cr loading on anaerobic working capacity (AWC) using the critical power (CP) test in women. Ten physically active women randomly received 2 treatments separated by a 5 week washout period: (A) 18 g dextrose as placebo (PL) or (B) 5.0 g Cr + 18 g dextrose taken 4 times per day for 5 days. Following a familiarization trial, each subject completed the CP test at baseline and following 2 and 5 days of supplementation. The PL resulted in no significant changes in AWC following supplementation; however, Cr increased AWC by 22.1% after 5 days of loading (p < 0.05). There was a significant main effect for body weight (BW), however, there was no significant increase in BW due to Cr supplementation. These results suggest that Cr supplementation is effective for increasing AWC in women following 5 days of loading without an associated increase in BW.     

The effects of creatine monohydrate loading on anaerobic performance and one-repetition maximum strength

The purpose of this study was to examine the effects of 7 days of supplementation with 20 g·d?1 of creatine monohydrate (CM) on mean power (MP) and peak power (PP) from the Wingate anaerobic test (WAnT), body weight (BW), 1-repetition maximum (1RM) bilateral leg extension (LE) strength, and 1RM bench press (BP) strength. This study used a randomized, double-blind, placebo-controlled design. Twenty-two men (mean ± SD: age = 22.1 ± 2.0 years; height = 178.0 ± 5.8 cm; body weight [BW] = 77.6 ± 7.6 kg) were randomly assigned to either a supplement (SUPP; n = 10) or placebo (PLAC; n = 12) group. The SUPP group ingested 20 g·d?1 of CM powder for 7 days, whereas the PLAC ingested 20 g·d?1 of maltodextrin powder. Measurements for the PLAC and SUPP groups included BW, PP, and MP from two 30-second WAnTs (separated by 7 minutes), and 1RM strength for LE and BP. Testing was conducted before (PRE) and after (POST) 7 days of ingesting either the supplement or placebo. The results of this study indicated that there was a significant (p ≤ 0.05) increase from PRE to POST testing in MP for the SUPP group (5.4%) but not for the PLAC group (-0.3%). There were no between-group differences, however, for 1RM LE and 1RM BP strength. Furthermore, there were no changes in PP or BW for either group. The findings of this study indicated that loading with 20 g·d?1 of CM for 7 days increased MP (5.4% increase) from the WAnT, but it had no effect on strength (1RM LE and 1RM BP), PP, or BW.     

Clinical evaluation of different applications of misoprostol and aglepristone for induction of abortion in bitches

The aim of the present study was to compare the clinical and endocrinological effects of different applications of misoprostol (MIS) and aglepristone (AGL) for the induction of abortion in bitches. For this purpose, 28 healthy pregnant bitches from different breeds, ages, body weights (Body weigt, BWs, 10–40 kg), and between Days 25 to 35 of gestation were used. Bitches were randomly assigned to four groups. In group 1 (GI, n = 7), AGL (10 mg/kg BW, s.c. on 2 consecutive days); in group 2 (GII, n = 7), AGL (as in GI), intravaginal MIS (IVag, 200 μg for bitches with ≤20 kg BW, 400 μg for bitches with >20 kg BW, daily intravaginally until completion of abortion); in group 3 (GIII, n = 7), AGL (as in GI), ICVag (as in GII), per os MIS (400 μg for bitches with ≤20 kg BW, 800 μg for bitches with >20 kg BW, daily orally, until completion of abortion); in group 4 (GIV, n = 7), AGL (as in GI), per os MIS (as GIII) were used. Clinical, vaginal, and ultrasonographic examinations were performed daily until abortion was completed. For measurement of serum progesterone, blood samples were collected in all groups immediately after the first AGL administration and every other day until completion of abortion. No statistical differences were found between groups concerning the duration until completion of abortion after treatment (nonsignificant); however, in GII, one bitch completed abortion 2 days after the start of treatment.     

Effect of creatine supplementation on cycle ergometer exercise in a hyperthermic environment

In order to examine thermoregulatory response to creatine (CR) supplementation, competitive male cyclists and triathletes (n = 7, VO2max = 50.6 +/- 0.8 ml x kg(-1) x min(-1)) completed three 1-hour hyperthermic (ambient temperature = 38.7 +/- 1.0 degrees C, relative humidity = 33 +/- 4%) exercise sessions at 181 +/- 12 W (50% of Wmax, approximately 66% of VO2max). Subjects completed a baseline (BL) session, then 2 sessions following 5 days of CR (20 g x d(-1)) and placebo (PL, 20 g x d(-1)) administered in a double-blind counterbalanced crossover manner with > or = 28-day washout. Pre-exercise BL, CR, and PL body mass were unchanged, with similar decreases in postexercise mass among the three conditions. Tympanic temperature, heart rate, systolic blood pressure, perceived exertion, and lactate, cortisol, and aldosterone concentrations increased similarly during BL, CR, and PL exercise. A greater (p = 0.013) estimated decrease in plasma volume occurred following BL (-16.5 +/- 2.0%) and PL (-17.6 +/- 1.7%) exercise compared to CR (-13.5 +/- 2.1%). Creatine supplementation reduces plasma volume loss during 1 hour of hyperthermic exercise but does not appear to otherwise change thermoregulatory response to hyperthermic exercise.     

Genistein and daidzein modulate in vitro rat uterine contractile activity

The present study investigated the effect of genistein, daidzein and estradiol on in vitro rat uterine responsiveness to oxytocin (OT) and PGF(2)alpha or luprostiol (L). In a first experiment, animals were either sham-operated (SH; n=5), or ovariectomized (OVX; n=20) and orally treated for three months with either genistein (G; n=5; 10 microg/g BW/d) or daidzein (D; n=5; 10 microg/g BW/d) or 17 alpha-ethinylestradiol (E; n=5; 23 microg/kg BW/d) or untreated (OVX; n=5). At necropsy, the basal uterine tension was lower in OVX, G and D than in SH, the highest value being measured in E. Oxytocin (10(-12); 10(-11) M) or PGF(2)alpha (10(-12); 10(-9) M) induced an increase in SH, but not in OVX, E and G. In D, only the highest doses were efficient. In a second experiment, 20 intact animals were s.c. injected with either genistein (G; n=5; 10 microg/g BW) or daidzein (D; n=5; 10 microg/g BW) or estradiol benzoate (E; n=5; 23 microg/kg BW) or vehicle (C: controls; n=5), and killed 24 h later. In C and E, OT (10(-15) to 10(-10) M) or L (10(-12) to 10(-7) M) stimulated uterine contractile activity in a dose-dependent manner until a maximal level. On the opposite, in G and D, contractile agents (except the highest luprostiol doses) did not stimulate myometrium contractions. Moreover, radioligand binding assays showed that genistein or daidzein inhibited the specific binding of [(3)H] estradiol to the calf uterus estrogen receptor (ER). Therefore, it could be postulated that both genistein and daidzein might bind to the rat uterus ER, inducing either anti-estrogenic or very weak estrogenic effects (depending on the experimental conditions) on in vitro uterine responsiveness to OT and PGF(2)alpha or luprostiol.     

Fasting-induced suppression of pulsatile luteinizing hormone secretion is related to body energy status in ovariectomized goats

The effect of energy status on the response of luteinizing hormone (LH) pulse frequency to acute short-term energy deficiency created by fasting in estradiol-treated ovariectomized Shiba goats was studied in two experiments. In experiment 1, eight goats whose mean body weight (BW) was 25.6 +/- 5.8 (mean +/- S.D.)kg were fed 500 g hay cubes daily for 1 week. Then they were fasted for 3 days. Blood samples were collected for 4 h at 6 min intervals on the last day of feeding, first, second and third day of fasting for LH analysis. The goats were divided into light (<24 kg, n = 4) and heavy (> or =24 kg, n = 4) groups for data analysis. There was no difference in LH pulse frequency between the last day of feeding and each day of fasting in the heavy group. LH pulse frequency was significantly (P < 0.05) suppressed on the second day (3.3 +/- 1.3 pulses/4 h) and on the third day (2.3 +/- 1.9 pulses/4 h) relative to the day prior to fasting (4.8 +/- 1.5 pulses/4 h) in the light group. In experiment 2, BW plus a body mass index (gBMI: (body weight (kg)/withers height (m)/body length (m)) x 10) were measured to define energy status. Nine goats (BW, 25.6 +/- 5.8 kg) were fed 500 g hay cubes daily for a week and then fasted for 3 days. Then they were divided into two groups offered either a maintenance (n = 4) or a restricted (n = 5) level of feeding for 4 weeks. The restricted level of feeding was 30% of maintenance requirement based on the BW recorded weekly. The feeding level was then adjusted to maintain BW for a further week followed by 3 day fasting for restricted animals. Blood samples were collected for 6 h at 10 min intervals on the day prior to fasting and on third day of fasting before and after the dietary manipulation. BW (26.6 +/- 2.2 to 26.8 +/- 3.8 kg) and gBMI (8.4 +/- 0.4 to 7.8 +/- 0.3) remained constant over the period prior to fasting for the maintenance animals but were significantly lower (P < 0.05) after 4 weeks for the restricted goats (BW, 26.3 +/- 2.1 to 21.5 +/- 2.4 kg; gBMI, 8.4 +/- 0.9 to 6.9 +/- 0.7). There was no significant difference in the LH pulse frequency between feeding and fasting day in both sampling periods in the maintenance group. In the restricted group, LH pulse frequency was not suppressed by fasting in the first sampling period (6.8 +/- 2.9 to 5.2 +/- 2.5 pulses/6 h), whereas it tended to be suppressed (4.8 +/- 3.1 to 1.6 +/- 2.3 pulses/6 h; P < 0.06) and was significantly (P < 0.05) correlated to body weight (r = 0.70) and gBMI (r = 0.81) after the dietary manipulation. These results suggest that the suppressive effect of short-term energy restriction (fasting) on pulsatile LH secretion is related to body energy status.     

Effects of 4 weeks of creatine supplementation in junior swimmers on freestyle sprint and swim bench performance

To determine whether 4 weeks of oral creatine (Cr) supplementation could enhance single freestyle sprint and swim bench performance in experienced competitive junior swimmers, 10 young men and 10 young women (x age = 16.4 +/- 1.8 years) participated in a 27-day supplementation period and pre- and posttesting sessions. In session 1 (presupplementation testing), subjects swam one 50-m freestyle and then (after approximately 5 minutes of active recovery) one 100-m freestyle at maximum speed. Blood lactate was measured before and 1 minute after each swim trial. Forty-eight hours later, height, mass, and the sum of 6 skinfolds were recorded, and a Biokinetic Swim Bench total work output test (2 x 30-second trials, with a 10-minute passive recovery in between) was undertaken. After the pretests were completed, participants were divided into 2 groups (n = 10, Cr; and n = 10, placebo) by means of matched pairs on the basis of gender and 50-m swim times. A Cr loading phase of 20 g x d(-1) for 5 days was then instituted, followed by a maintenance phase of 5 g x d(-1) for 22 days. Postsupplementation testing replicated the presupplementation tests. Four weeks of Cr supplementation did not influence single sprint performance in the pool or body mass and composition. However, 30-second swim bench total work scores for trial 1 and trial 2 increased after Cr (p < 0.05) but not placebo ingestion. Postexercise blood lactate values were not different after supplementation for the 50- and 100-m sprint trials either within or between groups. It was concluded that 4 weeks of Cr supplementation did not significantly improve single sprint performance in competitive junior swimmers, but it did enhance swim bench test performance.     

A 6-month supervised employer-based minimal exercise program for police officers improves fitness

The purpose of the study was to determine the effects of a 6-month supervised, job-specific moderate exercise program in police officers on body composition, cardiovascular and muscular fitness. Body weight (BW), body mass index (BMI), and cardiovascular and muscular fitness were assessed at baseline, after a 6-month supervised fitness program and at 12-month follow-up (18 months). One hundred sixty-five (n = 131 men and n = 34 women) young (mean ± SEM, 26.4 ± 1.9 years), overweight (BMI = 26.2 ± 1.2 kg·m) police officers participated. Aerobic exercise progressed from 3 d·wk, 20 minutes per session at 60% of the heart rate reserve (HRR) to 5 d·wk, 30 minutes per session at 75% of HRR at 3 months, and this level was maintained until 6 months. Muscular strength training progressed using 8 different calisthenics exercises from 3 d·wk, 2 sets of 5 repetitions using the participant's own BW to 5 d·wk, 3 sets of 15 repetitions of the participant's own BW at 3 months, and this level was maintained until 6 months. Cardiovascular and muscular fitness was measured using a 0.25-mile obstacle course incorporating various job-specific exercises and expressed as the physical abilities test (PAT) time. There was a significant reduction in BMI (-0.6 ± 0.2 kg·m, p < 0.001) and BW (-2.8 ± 2.3 kg) and reduction in PAT time (-11.9 ± 2.1%, p < 0.01) from baseline to 6 months. However, BMI (1.4 ± 1.1 kg·m, p < 0.001), BW (5.1 ± 3.0 kg, p < 0.01), and PAT time significantly increased (12.8 ± 2.2%, p < 0.01) from 6 to 18 months. There were no sex by time differences. The practical applications of this study indicate that a supervised, job-specific exercise program for police officers improves fitness and body composition after 6 months in both men and women, but continued supervision of exercise program may be necessary for maintenance of health benefits.     

Effect of a defined lacto-ovo-vegetarian diet and oral creatine monohydrate supplementation on plasma creatine concentration

This study examined the effects that preceding creatine supplementation with a lacto-ovo-vegetarian diet would have on plasma creatine concentration. Twenty-six healthy moderately fit omnivorous men were assigned to either a 26-day lacto-ovo-vegetarian (LOV; n = 12) or omnivorous (Omni; n = 14) diet. On day 22, subjects were also assigned in a double-blind manner either creatine monohydrate (CM; 0.3 g.kg(-1).day(-1) + 20 g Polycose) or an equivalent dose of placebo (PL) for 5 days. Blood samples were taken on days 1, 22 and 27. Consuming a LOV diet for 21 days was effective in reducing plasma creatine concentration (p < 0.01) in the LOV group. Regardless of diet, the CM group showed an increase in plasma creatine concentrations from day 22 to 27, whereas the PL group's levels remained the same (p < 0.05). Although the LOV diet caused a deprivation effect in plasma creatine concentration relative to the Omni diet, concurrent supplementation with creatine resulted in no difference in plasma creatine concentrations between the LOV and Omni diet groups. Dietary advice should be provided to LOV athletes that supplementation with creatine may help to increase their muscle stores of creatine, and thus their ATP resynthesis capabilities, to levels similar to those of omnivores.     

Serum thyroid hormones and reproductive characteristics of Rambouillet ewe lambs treated with propylthiouracil before puberty

Twenty-four Rambouillet ewe lambs (average weight=43.7+/-1.2 kg, approximately 6 months of age) were used to examine the effect of thyroid suppression before the onset of puberty on serum thyroid hormones, body weights (BW), and reproductive performance. Beginning in early September, ewe lambs were randomly assigned to three treatments (n=8 lambs/treatment). All animals remained in a single pen (4 x 12 m) with access to salt, water, shade and alfalfa hay (2.5 kg per animal per day) throughout the experiment. Beginning on Day 0 (first day of treatment), all ewe lambs received daily treatments (gavage) for 15 days consisting of 0, 20, or 40 mg 6-N-propyl-2-thiouracil(PTU)/kg BW per day. Beginning on Day 15, the 20 and 40 mg treatments were lowered to 10 and 20 mg PTU/kg BW, respectively. All animals were treated for 28 days. Ovarian cyclicity was determined by twice weekly progesterone (P(4)) analysis. Thyroxine (T(4)) concentrations were similar on Day 0 (61.6, 54.8 and 56.9+/-2.5 ng/ml, P=0.17) in ewe lambs receiving 0, 20 and 40 mg PTU/kg BW, respectively. By Day 7, both PTU-treated groups had T(4) values less than 20 ng/ml (9.0 and 15.4+/-2.5 ng/ml) compared with 78.5 ng/ml in controls (P<0.01). By 7 days after termination of PTU treatment, serum T(4) had risen to 29.1 and 26.9 (+/-2.9)ng/ml in the 20/10 and 40/20 PTU groups, respectively. On Day 66, control ewes had 55.0 ng T(4)/ml compared with 43.1 and 39.0 (+/-2.6 ng/ml) for ewes in the 20/10 and 40/20 groups, respectively (linear, P<0.01). Serum triiodothyronine (T(3)) followed a similar pattern to that observed for T(4). Ewe lamb BW were similar (P>0.50) among groups throughout the treatment period. However, following the treatment, PTU-treated ewes tended (P<0.10) to weigh less than controls. Average Julian day of puberty was also similar (P>0.50) among treatments (286, 288 and 288+/-5 days; control, 20/10 and 40/20, respectively). Control ewes had a pregnancy rate of 75%, while both PTU-treated groups had pregnancy rates of 88% (P>0.20). The administration of PTU resulted in a rapid decline in serum T(4) and T(3) but neither time of puberty nor pregnancy rates were affected by lowered thyroid hormones.     

Absence of brain opioid peptide modulation of luteinizing hormone secretion in the prepubertal gilt

Three experiments were conducted to evaluate the role of endogenous opioid peptides (EOP) in modulating luteinizing hormone (LH) secretion in the prepubertal gilt. In Experiment I, 8 prepubertal (P) gilts, 160-170 days of age (puberty = 197 +/- 10 days), received either 1 (n = 2), 3 (n = 3), or 6 (n = 3) mg/kg BW of naloxone (NAL), an opiate antagonist, in saline i.v. Blood was collected by jugular vein cannula every 15 min for 2 h before and 2 h after NAL. All doses of NAL failed to alter serum LH concentrations. In Experiment II, 21 P gilts 160-170 days of age and 21 mature (M) gilts were ovariectomized (OVX). At the time of OVX, gilts were classified as prepubertal if their ovaries were devoid of corpora albicantia and corpora lutea. Three weeks after OVX, P and M gilts were injected twice daily for 10 days with either 0.85 mg/kg BW of progesterone (P4) or oil vehicle (V), resulting in the following groups: PP4 (n = 11), PV (n = 10), MP4 (n = 11), and MV (n = 10). All gilts received 1 mg/kg BW of NAL on the last day of treatment. Blood samples were collected via a jugular cannula every 15 min for 4 h before and 2 h after NAL treatment. NAL treatment resulted in an increase (p less than 0.05) in serum LH concentrations only in the MP4 gilts. In Experiment III, 15 OVX gilts 280 days of age were used. Ten of the 15 gilts were OVX prior to puberty at 160 days of age and were classified as chronologically mature (CM) at the time of treatment. The remaining 5 gilts were OVX after puberty, and were classified as sexually mature (SM) at the time of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of creatine supplementation and exercise training on fitness in men 55-75 yr old.

effect of oral creatine supplementation (CR; 5 g/day) in conjunction with exercise training on physical fitness was investigated in men between 55 and 75 yr of age (n = 46). A double-blind randomized placebo-controlled (PL) trial was performed over a 6-mo period. Furthermore, a subgroup (n = 20) completed a 1-yr follow-up. The training program consisted of cardiorespiratory endurance training as well as moderate resistance training (2-3 sessions/wk). Endurance capacity was evaluated during a maximal incremental bicycle ergometer test, maximal isometric strength of the knee-extensor muscles was assessed by an isokinetic dynamometer, and body composition was assessed by hydrostatic weighing. Furthermore, in a subgroup (PL: n = 13; CR: n = 12) biopsies were taken from m. vastus lateralis to determine total creatine (TCr) content. In PL, 6 mo of training increased peak oxygen uptake rate (+16%; P < 0.05). Fat-free mass slightly increased (+0.3 kg; P < 0.05), whereas percent body fat slightly decreased (-1.2%; P < 0.05). The training intervention did not significantly change either maximal isometric strength or body weight. The responses were independent of CR. Still, compared with PL, TCr was increased by approximately 5% in CR, and this increase was closely correlated with initial muscle creatine content (r = -0.78; P < 0.05). After a 1-yr follow-up, muscle TCr was not higher in CR than in PL. Furthermore, the other measurements were not affected by CR. It is concluded that long-term creatine intake (5 g/day) in conjunction with exercise training does not beneficially impact physical fitness in men between 55 and 75 yr of age.     

Antitesticular activity of DL-6-(N-2-Pipecolinomethyl)-5-Hydroxy-Indane maleate (PMHI) in coyotes (canis latrans)

The ban on toxicants for coyote control has created a need for alternative control methods. Reproductive inhibitors may provide a means of maintaining coyote populations at levels where impact on live-stock is acceptable. Therefore, the effects of PMHI on testicular activity of coyotes were evaluated. Twelve mature, male coyotes were weighed and allotted randomly to 1 of 4 treatment groups: (1) controls, (2) 5, (3) 10, and (4) 20 mg PMHI/kg body weight (BW). PMHI was dissolved in 2 ml distilled water and ethanol (1:1) and administered as a single sc injection. All coyotes were observed for 1 hr after treatment and any adverse effects recorded. Fifteen days after treatment, a testicle and epididymis from each coyote was selected at random, ablated, weighed, fixed in formalin, and prepared for histologic examination. The remaining testicle was prepared similarly 30 days post-treatment. Data were analyzed by a balanced factorial in a split-plot arrangement. Unlike controls, coyotes given PMHI exhibited signs of nausea and diarrhea within 15 to 30 min, which subsided after 45 to 60 min. PMHI temporarily increased (P<.01) serum glutamic-pyruvate transaminase (SGPT) but did not alter other blood chemistry or hematologic values. PMHI reduced (P<.01) testicular weights (wet weights) from 10±1.0 g (controls) to 6.3±0.2 g after 5 mg, 4.4±0.2 g after 10 mg, and 6.0±0.5 g after 20 mg/kg BW. Testicular weights were not different among the 3 treatments of PMHI. Histological changes in seminiferous tubules were consistent with absence of spermatogenesis at 15 and 30 days after all treatment levels of PMHI. Only occasional intact spermatozoa were present in sections of epididymis at 15 and 30 days after PMHI treatment. We conclude that PMHI may cause infertility in the male coyote from 15 to at least 82 days after treatment without apparent chronic damage to vital organs.     

Comparison of caloric expenditure in intermittent and continuous walking bouts

This study compared the caloric expenditure of 30 consecutive minutes (30 minute) of moderate intensity walking with 3 intermittent 10-minute bouts (3 x 10 minutes) of moderate intensity walking in healthy, unfit men (40-49 years). Screening consisted of VO(2)max testing, which was measured using the Balke graded exercise test. Criteria for participation in this study included a measured VO(2)max less than 33.8 ml.kg(-1).min(-1) (<25th percentile for cardiorespiratory fitness). Twenty men participated in this study. Testing consisted of 4 trials with a minimum of 5 days between each trial. The 30-minute and 3 x 10-minute bouts were each performed twice to measure test-retest reliability. Once reliability was found, the 2 30-minute and the 2 3 x 10-minute trials were averaged for further data analyses; t-tests showed no significant differences in energy expenditure between 1 continuous 30-minute and the 3 x 10-minute walking bouts at 274 and 279 kcal (p = 0.09), respectively. Thus, 3 x 10-minute intermittent walking bouts throughout the day are equally beneficial, in terms of caloric expenditure, as 1 30-minute continuous walking bout.     

The effect of colostrum period management on BW and immune system in lambs: from birth to weaning

The aim of this study was to investigate the BW and immune status of lambs reared under natural conditions or under artificial conditions fed two different colostrum amounts. In this study, 60 lambs were randomly divided into groups according to treatment. Twenty lambs remained with their dams (natural rearing (NR) group). Forty lambs were removed from their dams at birth. Lambs were bottle-fed with a pool of sheep colostrum, receiving either 4 g of IgG/kg of BW at birth (C4 group) or 8 g of IgG/kg of BW at birth (C8 group). The total colostrum amount was equally divided into three meals at 2, 14 and 24 h after birth. After this period, lambs were bottle-fed a commercial milk replacer. Blood plasma sample analysis and BW recordings were carried out before feeding at birth and then at 1, 2, 3, 4, 5 and 20 days after birth. Another blood sample analysis and BW recording was carried out when animals reached 10 kg of BW. During weaning (30 days), sampling was carried out every 5 days. Blood plasma was used to determine the concentrations of IgG and IgM and the complement system activity – total and alternative pathways. The NR group showed greater BW than the C4 and C8 groups during milk feeding period, whereas the C4 and C8 groups had greater BW than the NR group at the end of weaning period. The C8 and NR groups had greater plasma IgG and IgM concentrations than the C4 group during milk feeding period. In addition, C4 and C8 groups showed similar IgG concentrations and greater IgM concentrations than the NR group at the end of the weaning period. Complement system activity was greater in the NR group than in the C4 and C8 groups during the first 3 days after birth. In conclusion, lambs fed amounts of colostrum equivalent to 8 g of IgG/kg of BW showed similar immune variables compared to lambs reared under natural conditions, obtaining a greater BW at the end of the weaning period. Nevertheless, this study shows that not only the colostrum amount but also the management during the milk feeding and weaning period, such as stress produced by dam separation, milk quality and suckling frequency, can affect the final immune status of lambs.     

Effect of medroxyprogesterone acetate on the efficiency of an oral protein-rich nutritional support in HIV-infected patients

We have examined the effect of a medroxyprogesterone therapy in HIV-infected patients under appropriate nutrition for anabolism. The experiments were performed on 12 men (mean age 40 y), HIV seropositive but free of any clinically active opportunistic infection for at least one month. The patients underwent a 2-week baseline diet period (1.2 g protein x kg(-1) body weight (BW) x d(-1)) and then a 5-week experimental period with again the baseline diet in conjunction with supplements including Tonexis HP (0.7 g protein x kg(-1) BW) x d(-1)), L-threonine (0.018 g x kg(-1) BW x d(-1)) and L-methionine (0.013 g x kg(-1) BW x d(-1)). Indeed HIV-infected patients showed deficiencies in these amino acids. They were randomly divided into groups I and II under double-blinded condition. Group II was given medroxyprogesterone acetate (0.4 g x d(-1)) during the last 3 weeks whereas group I received a placebo. All the patients significantly increased their body weight (P < 0.05) during the experimental periods. Those under medroxyprogesterone tended to show a higher but not significant weight gain (+3.1 +/- 1.0 kg in group II and +1.9 +/- 0.3 kg in group I). Blood free amino acids were used as rough indicators of amino acid utilization and were analyzed prior and during acute 150 min intravenous infusion of a complete glucose-amino acid mixture. This test was done before and at the end of the experimental periods. Basal essential blood free amino acids were similar in the two groups and did not change during the experimental period. Most essential amino acids increased following glucose-amino acid infusions. The incremental increase was of less magnitude after the experimental period than before when medroxyprogesterone was present (P < 0.05 for valine, leucine, lysine, threonine and methionine). This was not the case in the absence of the hormone. We concluded that medroxyprogesterone might improve the efficacy of an oral protein-rich nutritional support in HIV-infected patients.     

Effects of creatine supplementation and three days of resistance training on muscle strength, power output, and neuromuscular function

Previous studies have demonstrated increases in peak torque (PT) and decreases in acceleration time (ACC) after only 2 days of resistance training, and other studies have reported improvements in isokinetic performance after 5 days of creatine supplementation. Consequently, there may be a combined benefit of creatine supplementation and short-term resistance training for eliciting rapid increases in muscle strength, which may be important for short-term rehabilitation and return-to-play for previously injured athletes. The purpose of this study, therefore, was to examine the effects of 3 days of isokinetic resistance training combined with 8 days of creatine monohydrate supplementation on PT, mean power output (MP), ACC, surface electromyography (EMG), and mechanomyography (MMG) of the vastus lateralis muscle during maximal concentric isokinetic leg extension muscle actions. Twenty-five men (mean age +/- SD = 21 +/- 3 years, stature = 177 +/- 6 cm, and body mass = 80 +/- 12 kg) volunteered to participate in this 9-day, double-blind, placebo-controlled study and were randomly assigned to either the creatine (CRE; n = 13) or placebo (PLA; n = 12) group. The CRE group ingested the treatment drink (280 kcal; 68 g carbohydrate; 10.5 g creatine), whereas the PLA group received an isocaloric placebo (70 g carbohydrate). Two servings per day (morning and afternoon) were administered in the laboratory on days 1-6, with only 1 serving on days 7-8. Before (pre; day 1) and after (post; day 9) the resistance training, maximal voluntary concentric isokinetic leg extensions at 30, 150, and 270 degrees x s(-1) were performed on a calibrated Biodex System 3 dynamometer. Three sets of 10 repetitions at 150 degrees x s(-1) were performed on days 3, 5, and 7. Peak torque increased (p = 0.005; eta(2) = 0.296), whereas ACC decreased (p < 0.001; eta(2) = 0.620), from pretraining to posttraining for both the CRE and PLA groups at each velocity (30, 150, and 270 degrees x s(-1)). Peak torque increased by 13% and 6%, whereas ACC decreased by 42% and 34% for the CRE and PLA groups, respectively, but these differences were not statistically significant (p > 0.05). There were no changes in MP, EMG, or MMG amplitude; however, EMG median frequency (MDF) increased, and MMG MDF increased at 30 degrees x s(-1), from pretraining to posttraining for both the CRE and PLA groups. These results indicated that 3 days of isokinetic resistance training was sufficient to elicit small, but significant, improvements in peak strength (PT) and ACC for both the CRE and PLA groups. Although the greater relative improvements in PT and ACC for the CRE group were not statistically significant, these findings may be useful for rehabilitation or strength and conditioning professionals who may need to rapidly increase the strength of a patient or athlete within 9 days.     

Effect of inland water salinity on growth performance and nutritional physiology in growing milkfish, Chanos chanos (Forsskal): field and laboratory studies

To investigate the effect of inland groundwater salinity on growth performance, feed conversion efficiency, nutrient retention and intestinal enzyme activity in milkfish, two experiments were conducted. In the first experiment (Expt I), a 100‐day monoculture of Chanos chanos [mean body weight (BW): 2.2 g] at different salinities (0, 10, 15, 20 and 25‰) was carried out in ponds fertilized with cowdung (about 10 000 kg ha^?1 year^?1) and poultry droppings (about 3000 kg ha^?1 year^?1). The fish were fed a compounded supplementary diet (containing 40% protein) at 5% BW day^?1. Studies have revealed that growth increased with each increase in the salinity level; the highest values in weight gain and energy assimilated were observed in ponds maintained at 25‰ salinity [weight: 322.2 g and specific growth rate (SGR): 8.3]. Highest values of condition factor (0.7) and exponential value (n) of the length–weight relationship (LWR; n = 3.25) were also observed in ponds maintained at 25‰ salinity. Dissolved oxygen (DO), biological oxygen demand (BOD), pH and nutrient release remained at the optimal level during the culture period. High values of chlorophyll a, net primary productivity (NPP), phytoplankton and zooplankton population coincided with the highest values of alkalinity and turbidity in ponds maintained at 25‰ salinity. Multivariate analysis revealed a significant positive correlation of chlorides (r = 0.91), conductivity (r = 0.89) and hardness (r = 0.96) with fish growth. Productivity indicating parameters viz. NPP (r = 0.45), nitrate (r = 0.94) and o‐PO₄ (r = 0.52) also showed a significant positive correlation with fish weight gain. In the second experiment (Expt II), milkfish (mean BW: 3.7 g) fry were exposed to different levels of salinity (0.0, 10, 15, 20, 25 and 30‰), and maintained for 90 days in the laboratory. Significantly (P < 0.05) high growth (percentage increase in BW: 183.1 and SGR: 1.2), feed conversion efficiency (64.5%) and intestinal enzyme activity (protease 5.1, amylase 4.1 and cellulolytic 3.2) were observed in the group maintained at 25 ppt salinity in comparison with other groups similarly maintained at low or high salinity levels. Carcass composition, muscle and liver glycogen levels were also significantly (P < 0.05) affected by salinity changes. The significance of these findings is discussed in this paper.     

Effect of dietary intake on pattern of growth of dominant follicles during the oestrous cycle in beef heifers

Friesian x Hereford heifers (n = 19; mean +/- s.e.m. body weight (BW) = 375 +/- 5 kg) were used in a randomized incomplete block design. Heifers were fed 0.7 (n = 7; L), 1.1 (n = 7; M) or 1.8% (n = 5; G) of BW in dry matter (DM)/day for 10 weeks. Ovaries were examined by ultrasound, for one oestrous cycle, from week 5 of treatment. Maximum diameter of dominant follicles was smaller (P less than 0.05) in L (11.8 +/- 0.1 mm) than in M (13.7 +/- 0.2 mm) or G (13.2 +/- 0.3 mm) heifers. Growth rate (mm/day) of dominant follicles during the oestrous cycle was not affected (P greater than 0.05) by dietary intake. Persistence of dominant follicles was shorter (P less than 0.05) in L (9.8 +/- 0.2 days) than in M (11.9 +/- 0.3 days) or G (12.7 +/- 0.4 days) heifers. Three dominant follicles were identified during the oestrous cycle of 5 of 7 L, 3 of 7 M and 1 of 5 G heifers (P less than 0.10); 2 dominant follicles were identified in the remaining heifers (n = 2 of 7, 4 of 7 and 4 of 5, respectively). Length of the luteal phase and luteal-phase concentrations of progesterone were not affected (P greater than 0.05) by treatment. Low dietary intake reduced the diameter and persistence of dominant follicles during the oestrous cycle of beef heifers and tended to increase the proportion of oestrous cycles with 3 dominant follicles.