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Biomedical subjects

P Chantaraprateep

Publications and source records attributed to P Chantaraprateep.

11 recordsLinked to original sources

Early embryonic development in Thai swamp buffalo (Bubalus bubalis ).

A total of 33 nonsurgical embryo collections was carried out to investigate early embryo development in Thai swamp buffalo. Collections were performed on Days 5.5, 6.0, 6.5, 7.0 and 7.5. The different stages of embryo development on these days were the 16-cell stage, compact morula, blastocyst, hatched blastocyst and hatched expanding blastocyst, respectively. In addition, some degenerating embryos and unfertilized ova were also recovered. A higher recovery rate was obtained with single embryo collection after natural estrus than after induced estrus or superovulation, 78% (7 9 ) vs 46% (6 13 ) vs 54.5% (6 11 ), respectively. A higher percentage of normal embryos was also obtained with single embryo collection after either natural or induced estrus than after superovulation, 71% (5 7 ), 83% (5 6 ) and 38% (6 16 ), respectively.

Journal Article↗

Investigation into the use of prostaglandin F2 alpha (PGF2 alpha) and oxytocin for the induction of farrowing.

This experiment was conducted in order to compare the effects of injecting PGF2 alpha alone, PGF2 alpha with oxytocin and placebo on the induction of farrowing in swine and to compare the relative effects of 3 different dosages of oxytocin (10, 20 and 30 iu per animal) when combined with PGF2 alpha (10 mg). The findings revealed that animals treated with 30 iu oxytocin farrowed within 10.6 h which was similar to those receiving PGF2 alpha only (9.4 h), but shorter than control animals (53.6 h). Animals receiving 20 and 10 iu of oxytocin farrowed within 1.4 and 1.7 h, respectively. Difficult farrowings requiring manual assistance occurred in 30%, 30%, 50% and 10% of sows given 30 iu, 20 iu and 10 iu of oxytocin and in the control group, respectively. Thirteen of 73 sows treated with PGF2 alpha farrowed within 12.6 +/- 5.3 h. Stillbirths were highest (10.2%) in the control animals whilst in the others it was under 7%. Oxytocin at dosages of 20 and 10 iu, seemed most promising in terms of synchronising farrowing following PGF2 alpha treatment in swine. However, farrowing complications were more common in these groups.

Animals↗

Milk progesterone levels in crossbred buffaloes (swamp x murrah) and a comparison to the original breeds.

Progesterone levels in milk fat and whole milk were determined in eight crossbred buffaloes (swamp x murrah). Progesterone peaks in milk fat and whole milk during the luteal phase ranged from 44.23 to 224.50 ng/ml and 8.58 to 20.22 ng/ml, respectively. Progesterone levels were measured in two murrah cows and seven swamp cows for comparison with the levels in the crossbred buffaloes. Variation in milk progesterone levels between breeds was indicated and discussed. Radioimmunoassay for progesterone in milk fat and whole milk of buffaloes was validated.

Journal Article↗

Circadian variations of plasma LH and testosterone in adult swamp buffalo bulls.

Three swamp buffalo bulls aged 1.5, 1.10 and 2 years were submitted to frequent blood sampling every 15 m during a period of 25 h using an indwelling infusion set. Plasma LH and testosterone were quantified by radioimmunoassay technique. The levels of the two hormones in each individual exhibited episodic and nonrhythmic patterns. The number of LH peaks varied according to individual, ranging from no peak in one bull to 2 in the other two bulls. The mean LH concentrations during the period of study for each bull were 0.74, 0.33 and 1.17 ng/ml. Whereas the number of testosterone peaks varied between 1-10 and the average testosterone concentrations were 0.1, 0.33 and 0.55 ng/ml for the younger to the older bulls respectively. The testosterone peaks related to the LH peaks in each individual bull.

Journal Article↗

Effect of dexamethasone and testosterone propionate on LH response to gonadoliberin (LRH) in young post-pubertal bulls.

LH and testosterone responses to gonadoliberin (LRH) were studied after previous dexamethasone and testosterone propionate combined treatment (treated group) compared with a single dexamethasone previous treatment (control group) in 12 Montbéliarde bulls aged 15 months. This experiment was performed on two occaisions 6 months apart according to the same schedule. They included each time 6 bulls, treated with intramuscular injections of 400 mg testosterone propionate and 6 hours later 0.25 mg gonadoliberin together with the other 3 bulls. Testosterone propionate did not influence the mean LH response to gonadoliberin although mean testosterone levels before gonadoliberin injection was very low in the controls. These data suggest that (1) the previously reported depressing effect of dexamethasone on LH is not mediated by the low peripheral testosterone level and (2) under the conditions of this study, there is no short term effect of testosterone at the pituitary level.

Animals↗

[Effects of testosterone propionate on LH and testosterone concentrations before and after the injection of gonadoliberin in young bulls pre-treated with dexamethasone].

This preliminary study has been performed on four young twin bulls, one pair aged 6 months and the other one aged 12 months. Plasma LH and testosterone were assayed from frequent blood sampling. Testosterone propionate (TP) following dexamethasone treatment did not significantly influence the LH response to gonadoliberin compared to the twin controls, although testosterone concentrations were high in those TP treated animals.

Animals↗

Effects of dexamethasone on the responses of luteinizing hormone and testosterone to two injections of luteinizing hormone releasing hormone in young postpubertal bulls.

Six young postpubertal bulls were studied in two experiments, 3 months apart. In experiment 1, three bulls received i.m. injections of dexamethasone (20 mg) and 5 h later these animals plus three control bulls received i.m. injections of luteinizing hormone releasing hormone (LH-RH, 250 microgram). In experiment 2, the controls from experiment 1 received dexamethasone and the treated animals from experiment 1 acted as controls for experiment 2. All bulls also received an i.m. injection of 250 microgram LH-RH on day 2 of each experiment. The concentrations of LH and testosterone in samples of jugular blood were determined by radioimmunoassay. There were no significant differences in the patterns of testosterone and LH release between the two experiments. On day 1, the response of LH to LH-RH was significantly (P less than 0.05) reduced by dexamethasone, but on day 2 values in the control and treated groups were similar although significantly (P less than 0.05) lower than values on day 1. The response of testosterone to LH-RH was not affected by dexamethasone. These results are discussed in terms of the site of action at which dexamethasone may act to depress the release of LH.

Animals↗