Influence of season and housing on ovarian activity of indigenous goats in Zimbabwe

Summary Progesterone profiles were monitored in goats housed in single (n=9) or group (n=14) pens during winter (JJA) and spring (SON). Normal cycles (n=97) were 30 days. Extended cycles (n=45) were > 30 days and, except for one cycle with a persistent corpus luteum, had periovulatory periods of 10 to 20 days (n=29) or averaging 65·1 days in length (n=15), mostly characterised by recurrent oestrus and/or occasional transient rises in progesterone.The proportion of normal cycles occurring in winter was 87.5% (28/32) and 77·7% (42/54) for goats in single and group pens respectively, falling to 62·5% (15/24) and 37·5% (12/32) respectively in spring. The distribution of normalvs extended cycles according to season was significant (P<0·05, single;P<0·001 group pens). Goats housed communally experienced a greater fall in the percentage of normal cycles in spring, possibly due to increased stress associated with group feeding. Within each season, however, housingper se did not influence the distribution of normalvs extended cycles.For normal cycles, Harvey's Analysis of Variance showed that season was significantly associated with length of the periovulatory period (3·99 days (JJA)vs 5·79 days (SON);P<0·001), oestrus detection rate (87% (JJA)vs 55% (SON);P<0·01) and oestrus duration (1·94 days (JJA)vs 1·13 days (SON);P<0·05). In contrast, luteal phase length was not affected by season, but was significantly associated with housing (16·93 days (single pens)vs 18·32 days (group pens);P<0·01). The reduction in ovarian activity observed in spring may reflect a seasonal reduction in fertility, possibly linked with increasing temperature and photoperiod.

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Influencia De La Estacion Y El Alojamiento Sobre La Actividad Ovarica De Cabras Indigenas En Zimbabwe

Resumen Se registraron los niveles de progesterona de cabras alojadas individualment (n=9) o en grupos (n=14) en invierno (JJA) y en primavera (SON). Los ciclos normales (n=97) fueron de 30 días. Los ciclos alargados (n=45) fueron de > 30 dias y, excepto por un ciclo con un cuerpo lúteo persistente, los periodos preovulatorios fueron de 10 a 20 días (n=29) o tuvieron un promedio de 65·1 días de duración (n=15), caracterizándose la mayoría por estro recurrente y/o por incrementos transitorios ocasionales de progesterona.La proporción de ciclos normales durante el invierno fue de 87·5% (28/32) y 77·7% (42/54) para cabras alojadas individualmente y en grupos respectivamente, disminuyendo a un 62·5% (15/24) y 37·5% (12/32) respectivamente en primavera. La distribución de ciclos normalesvs alargados de acuerdo a las estaciones fue significativo (P<0·05, individuales;P<0.001, en grupos). Las cabras alojadas en grupos experimentaron una caída mayor en el porcentaje de ciclos normales en primavera, posiblemente debido al mayor estrés de la alimentación en grupo. Dentro de cada estación, sin embargo, la estabulaciónper se no influyó en la distribución ciclos normalesvs ciclos alargados.En los ciclos normales el análisis de varianza de Harvey mostró que la estación estaba significativamente asociada con la duración del período periovulatorio (3·99 dias JJAvs 5·79 días SON;P<0.001), la tasa de detección del estro (87% JJAvs 55% SON;P<0·01) y la duración del estro (1·94 dias JJAvs 1·13 dias SON;P<0·05). Por el contrario, la duración de la fase lútea no se vió afectada por la estación, aunque sí estuvo significativamente asociada con el tipo de alojamiento (16·93 días (cubículos individuales)vs 18·32 días (en grupo);P<0·01). La reducción en la actividad ovárica observada en primavera podria reflejar una reducción en la fertilidad estacional, posiblemente ligada al incremento de temperatura y al fotoperíodo.

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Influence De La Saison Et Du Logement Sur L'Activite Ovarienne Des Chevres Indigenes Au Zimbabwe

Résumé Les profils de la progestérone ont été survis sur des chèvres logées en enclos soit individuellement (n=9), soit en groupe (n=14), durant l'hiver (JJA) et le printemps (SON). Les cycles normaux (n=97) ont été à 30 jours. Les cycles prolongés (n=45) ont été supérieurs à 30 jours. A l'exception d'un seul cas avec persistance ducorpus luteum, ils ont présenté des périodes pré-ovulatoires de 10 à 20 j (n=29), ou d'une durée moyenne de 65, 1 j, caractérisées le plus souvent par un oestrus récurrent et/ou des montées transitoires et occasionnelles de la progestérone. La proportion des cycles normaux survenant en hiver a été de 87,5 p. 100 (28/32) et de 77,7 p. 100 (42/54) respectivement pour les chèvres logées en enclos individuel ou en groupe. Elle est tombée respectivement à 62,5 p. 100 (15/24) et à 37,5 p. 100 (12/32) au printemps. La distribution des cycles dits normaux face aux cycles prolongés en fonction de la saison s'est révélée significative (P<0,05 pour le logement individuel, etP<0,001 pour les enclos de groupe). Les chèvres logées collectivement ont présenté une chute plus élevée du pourcentage des cycles normaux au printemps, peutêtre due à un accroissement du stress, associé à l'alimentation en groupe. Cependant, à l'intérieur de chaque saison, le logement en soi n'a pas influencé la distribution du facteur cycle normal/cycle prolongé. Pour les cycles normaux, l'analyse de la variance de Harvey a montré que la saison était associée de façon significative à la longueur de la période péri-ovulatoire: 3,99 j (JJA) contre 5,79 (SON) avecP<0,001; taux de détection de l'oestrus de 87 p. 100 (JJA) contre 55 p. 100 (SON) avecP<0,01, et durée de l'oestrus de 1,94 j (JJA) contre 1,13 j (SON) avecP<0,05. A l'inverse, la durée de la phase lutéale n'a pas été affectée par la saison, mais s'est trouvée significativement associée avec le mode de logement (16,93 jours, en enclos individuel contre 18,32 jours en enclos de groupe pourP<0,01). La réduction de l'activité ovarienne observée au printemps peut refléter une réduction saisonnière de la fertilité, éventuellement liée à l'élévation de la température et à l'accroissement de la photopériode.

     

Plasma luteinizing hormone and progesterone concentrations in goats with estrous cycles of normal or short duration after prostaglandin F2 alpha administration during diestrus or pregnancy

Plasma luteinizing hormone (LH) and progesterone concentrations were compared in does experiencing short-duration estrous cycles and in does with estrous cycles of normal duration. The short-duration estrous cycles were observed immediately after induction of abortion in pregnant does by use of prostaglandin (PG) F2 alpha. Intramuscular administration of 5 mg of PGF2 alpha was accomplished in 8 does that were 52 to 63 days into gestation and in 9 cycling does at 7 to 10 days after estrus. In both groups, the mean plasma concentration of progesterone decreased from a luteal phase concentration immediately before to less than 1 ng/ml by 24 hours after PGF2 alpha administration. Of the 8 does that aborted, 6 experienced short-duration estrous cycles, and 4 of these 6 had an LH surge during the time of blood sample collection. The mean time from PGF2 alpha administration to the LH surge was significantly (P less than 0.05) longer in does with short-duration estrous cycles (71 hours) than that in does with estrous cycles of normal duration (58 hours). The mean area under the LH concentration curve was significantly (P less than 0.005) less for does with short-duration estrous cycles. Short-duration estrous cycles were associated with delayed preovulatory LH surges of reduced magnitude.     

Plasma insulin-like growth factor-I concentrations increase during the estrous phase in goats

The objective of this study was to characterize plasma insulin-like growth factor-I (IGF-I) profiles during the estrous cycle in goats. Frequent blood samples were drawn during the day of estrus and during the luteal phase on Day 10 after estrus, and plasma growth hormone (GH) and IGF-I profiles were examined. Then, daily blood samples were drawn throughout the estrous cycle or during induction of estrus by prostaglandin F(2alpha) (PGF(2alpha)) to further clarify the IGF-I profiles. GH was secreted in an episodic manner in the estrous and luteal phases in goats. There were no significant differences in the mean concentrations, pulse amplitude and pulse frequency of GH between the estrous and luteal phases. IGF-I concentrations during estrous phase were higher than those in the luteal phase (P<0.05). Plasma IGF-I increased approximately two days before behavioral estrus, and the IGF-I peak was observed in accordance with the appearance of estrus. The elevated IGF-I levels then declined to basal values 4 to 5 days after estrus. When estrus was induced by PGF(2alpha), plasma IGF-I concentrations increased after treatment, and the concentration 2 days after treatment (day of appearance of behavioral estrus) was significantly higher than concentrations before treatment (P<0.05). The elevated IGF-I levels then declined during the 3 days after treatment. These results indicate that plasma IGF-I concentrations increase during estrus in goats.     

Prolactin and progesterone concentrations during early pregnancy and relationship to pregnancy loss prior to day 45

Eleven multiparous Quarter Horse and Thoroughbred mares were used to determine the plasma concentrations of progesterone and prolactin during early pregnancy and to examine the relationship of plasma progesterone and prolactin to pregnancy loss prior to d 45 of gestation. Plasma samples were collected at two day intervals beginning on d 14 of pregnancy (d 0 = ovulation) and countinued to d 80. Ovulation and pregnancy status were determined by ultrasonography. Four mares experienced pregnancy loss between d 28 and 44 and plasma samples were collected for 10 days beyond the detected loss. Seven mares had successful pregnancies (Term group).Plasma progesterone concentrations peaked by d 28 in the Term group, with individual peak values ranging from 14.9 to 31.9 ng/ml. Values then declined until d 36, followed by a rise until d 80. Prior to d 45 of gestation 5 of the 7 mares had a peak in excess of 15 ng/ml and 3 of these had brief periods, ranging fron 1 to 8 days when progesterone dropped to less than 2 ng/ml. The other 2 mares had peak plasma progesterone concentrations of less than 7 ng/ml, but maintained concentrations in excess of 2 ng/ml during this period.Within the mares experiencing pregnancy loss, 2 mares had a decline in plasma progesterone concentrations prior to pregnancy loss, while the other 2 had typical progesterone patterns beyond the detected loss. Differences in individual patterns of plasma progesterone concentration were observed in both groups (P<.01).Plasma prolactin concentrations ranged from less than .32 to 4.58 ng/ml in the Term group and from .31 to 1.9 ng/ml in the mares experiencing pregnancy loss. Differences in the individual patterns of prolactin secretion were observed in both groups (P<.01).A correlation between progesterone and prolactin was observed in the Term group between day 14 and 37 (P<.01, r²=.88).     

Relationship between plasma progesterone and pregnancy-associated glycoprotein concentrations during early pregnancy in dairy cows

The relationship between the concentration of plasma progesterone (P4) during embryo attachment or at recognition of pregnancy, and that of pregnancy-associated glycoprotein (PAG) was assessed in dairy cows. The outcome of artificial insemination (AI) was classified as positive (AI+), negative (AI?), or late embryonic mortality (EM) by measuring circulating PAG concentrations and by ultrasonography. Based on P4 concentrations at either day 21 or day 15, AI+ and EM cows were classified into ‘low’ (P4 concentrations < mean) and ‘high’ (P4 concentrations > mean) P4 groups. In both experiments, the threshold of P4 concentration between the ‘low’ and ‘high’ groups was approximately 6 ng/mL. PAG concentrations were lower in the ‘low’ group only when P4 concentrations were below the threshold. The study findings suggest that a possible P4 threshold exists below which PAG secretion may be impaired.     

Coccidia of goats in Zimbabwe

Faecal samples from goats were collected per rectum from February 1989 to January 1990. The numbers of oocysts per gram (OPG) of faeces were determined by the McMaster technique and identification of oocysts was made on sporulation. Infection was seen throughout the year, infecting on average 89.9% of 1092 adults and 94.0% of 151 kids. OPG of less than 1000 were found in 61.2% of adults and 43.3% of kids, whereas OPG of 1000-5000 were observed in 29.0% of adults and 34.6% of kids. Two kids showed over 10(6) OPG. Twelve species of Eimeria coccidia were identified. The percentage of animals harbouring different species were: E. alijevi and E. ninakohlyakimovae, 99%; E. hirci, 83.5%; E. arloingi, 80.6%; E. caprina, 77.6%; E. aspheronica, 64.8%; E. ahsata, 63%; E. christenseni 60%; E. granulosa, 42.8%; E. pallida, 6.2%; E. intricata, 2% E. punctata, 0.3%. Two percent of goats harboured three species, 5.6% four, 9.5% five, 26.3% six, 25.7% seven, 23.7% eight, 6.3% nine, 0.6% ten and 0.3% eleven species. E. alijevi was the most predominant species, followed by E. ninakohlyakimovae, E. ahsata, E. arloingi, E. granulosa, E. caprina, E. christenseni, E. hirci, E. aspheronica and E. pallida in decreasing order. E. intricata and E. punctata never showed predominance. All the species are reported from Zimbabwe for the first time.     

Plasma progesterone in mares showing oestrus during early pregnancy (author's transl)]

Sixtyfour mares were examined 3 and 6 weeks after mating. Progesterone was measured in 22 mares 3 weeks after mating in order to see if this could be of any help in the oestrous diagnosis. None of the pregnant mares had plasma progesterone below 2 ng/ml. Pregnant mares that did not show oestrus had higher levels of plasma progesterone than pregnant mares showing signs of oestrus 3 weeks after mating. Clinical findings in pregnant and nonpregnant mares 3 weeks after mating is compared, and oestrus in pregnant mares is discussed.     

Plasma concentrations of oxytocin,prostaglandin and ovarian steroids during spontaneous luteolysis in the cow

Fifteen, non-milking cyclic Holstein heifers and cows were used to study possible hormonal correlations during spontaneous luteal regression. Peripheral plasma samples were assayed for oxytocin, 13,14-dihydro-15-keto-prostaglandin F₂α (PGFM), estradiol-17β and progesterone. On day 9, when luteolysis does not normally occur, no significant elevation in oxytocin or PGFM values occurred in five cows sampled for 12 hr at 15 min intervals. A correlation did not exist (P>.05) between PGFM and oxytocin values nor between estradiol and oxytocin values at this time. Of 10 cows bled on day 18 or 19 for 12 hr at 15 min intervals or 34 hr at 1 hr intervals, five animals exhibited pulsatile elevations of PGFM and oxytocin. The elevations in plasma concentrations of these two hormones were coincident and significant correlation coefficients (P<.01) were calculated (range 0.62 to 0.85). No significant correlation was present in the remaining 5 cows. These results suggests that ovarian oxytocin is secreted concomitantly with uterine prostaglandin production at the time of spontaneous luteolysis in the cow.     

Plasma concentrations of folic acid, vitamin B12 and progesterone of cyclic bitches, bitches during pregnancy and induced abortion and bitches with pyometra

The aim of this study was to investigate the plasma concentrations of folic acid, vitamin B12 and progesterone at different stages of the sexual cycle and pregnancy, during induced abortion and in bitches with pyometra. Bitches (n = 97) were assigned to groups as follows: a) oestrous cycle (n = 42) b) pregnancy (n = 25) c) induction of abortion (n = 10 and d) pyometra (n = 20). Oestrous cycle stages were determined by vaginal inspection and cytology. Pregnancies were estimated by ultrasound (5.0 Mhz; linear transducer; Schimadzu) at days 15-25, 35-45 and 46-63 of pregnancy. Treatments for the induction of abortion were started between days 25 and 35 after mating (5 microg/kg cabergoline daily, Galastop; 5-10 microg/kg Alfaprostol every other day, Gabbrostim). Diagnosis of pyometra was confirmed by ultrasound and vaginoscopy. Folic acid and vitamin B12 concentrations did not differ among different stages of the oestrous cycle. The mean concentration of folic acid during early pregnancy (days 15-25) exceeded levels of later stages (days 46-63): 9.4 +/- 3.7 microg/ml and 4.7 +/- 1.8 microg/ml, respectively (p < 0.01). A positive correlation between folic acid and vitamin B12 was determined in pregnant dogs ( r = 0.925; p < 0.02). Before the induction of abortion, the concentration of folic acid was 9.6 +/- 5.2 microg/ml; during abortion it decreased to 5.0 +/- 3.2 microg/ml (p < 0.01). A significant correlation (r = 0.925; p < 0.02) between progesterone and folic acid was obtained in bitches with abortion. The mean concentration of folic acid in bitches with pyometra significantly differed from that of bitches at different stages of the oestrous cycle (p < 0.05). The mean concentration of folic acid was significantly lower in metoestrous bitches when compared to bitches with pyometra (p < 0.05). The decrease of serum concentrations of folic acid during pregnancy and induced abortion show that fetal growth and abortion caused higher consumption of folic acid. Concerning bitches did not show any deficiency symptoms, which is why it can be concluded that this decrease is physiological.     

Endometrial inositol phosphate turnover in pigs is reduced during pregnancy and estradiol-induced pseudopregnancy

Three experiments were conducted to examine inositol phosphate (IP) turnover in response to treatments applied in vitro to endometrium from cyclic (CYC), pregnant (PREG) and estradiol-induced pseudopregnant (PSP) gilts. In Exp. 1, treatments (in 25 microliters .1 M NaHCO3) were 1) control (NaHCO3), 2) 125 ng oxytocin, 3) .25 micrograms prolactin, 4) 2.5 micrograms prolactin and 5) 5 micrograms pig conceptus secretory proteins (pCSP). Basal IP turnover on d 14 (estrus = d 0) for CYC was 3.9 to 5.0-fold greater than for PREG gilts and .6 to 1.1-fold greater than for PSP gilts (P less than .05). Oxytocin increased IP turnover 23 to 42% in CYC gilts (P less than .05), but not in PREG or PSP gilts. The treatment x reproductive status interaction (P less than .05) indicated that pCSP increased IP turnover 74 to 140% in PREG gilts but decreased it 18 to 22% in CYC and 17 to 50% in PSP gilts. In Exp. 2, treatments were applied in a 2 x 2 x 2 arrangement: 1) 0 or 125 ng oxytocin; 2) 0 or 2.5 micrograms prolactin and 3) 0 or 5 micrograms pCSP. Basal IP turnover on d 14 was 3.3 to 5.4-fold greater (P less than .05) in CYC than in PSP gilts and was affected by interaction (P less than .05) of pCSP and prolactin. Inositol phosphate turnover was increased by prolactin (12 to 22%) and by pCSP (7 to 34%) but, when combined, the stimulatory effects of each were eliminated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Plasma progesterone levels during oestrous cycle and their relationship with the ovulation rate in Red Sokoto (Maradi) goats

Twenty-five 2-3-year-old cycling does weighing 17-25 kg were obtained from semi-nomadic farmers and managed under controlled conditions while simulating the traditional management system. Oestrus was synchronized using progestogen impregnated vaginal pessaries. Blood samples were collected daily for progesterone assay from the day of pessary withdrawal up to one complete oestrous cycle. Oestrus was checked twice daily using vasectomized bucks. Ovulation rate was determined by direct observation of the ovaries following laparotomy on day 5-7 of the oestrous cycle. Following oestrus synchronization, mean ovulation rate was 1.68 +/- 0.13. Mean oestrous cycle length and duration of oestrus were 21.30 +/- 0.28 days and 21.37 +/- 0.24 hours respectively. Plasma progesterone concentrations ranged from non-detectable levels on the day of oestrus to 5.2 +/- 0.28 ng ml at mid-cycle. The duration of elevated progesterone level (greater than 2 ng/ml) was about 12 days. The peak progesterone values did not differ between animals with different ovulation rates. However, the plasma progesterone concentration during the early cycle (days 0-6) was significantly lower in the single ovulators compared with others. There were no major differences in plasma progesterone levels during the oestrous cycle of Red Sokoto does with different ovulation rates.     

Plasma concentrations of cortisol, testosterone, glucose and blood gases in male goats during anaesthesia with pentobarbitone sodium

Fasting for 24 h had no statistically significant effect on cortisol, glucose or testosterone concentrations. A dose of pentobarbitone sodium which induced light anaesthesia resulted in an immediate decrease in cortisol values from 5.0-11.1 ng/ml to 2.2-3.6 ng/ml until waking-this latter event was accompanied by an excessive release of cortisol (up to 16.6 ng/ml). In two out of three goats testosterone concentrations decreased from 4.0-9.0 ng/ml to less than 0.5 ng/ml after pentobarbitone; low values were maintained for 4.5-6 hours. Glucose concentrations were unaffected. Precise doses of pentobarbitone (20 mg/kg or 30 mg/kg) resulted in similar cortisol profiles as above but with higher concentrations achieved upon waking from the higher dose of pentobarbitone. On two out of nine occasions increased PCO2 values were recorded concurrently with increased cortisol concentrations during the period of anaesthesia, suggesting that a sufficiently strong stressful stimulus can break through the pentobarbitone blockade.