Superovulation and egg recovery in goats in the tropics

The superovulatory response to gonadotropin treatment during different months of the year was investigated in Kambing kacang goats, a tropical breed, in Malaysia. 63 cycling does, fitted with progesterone impregnated intravaginal sponges for 17 days, received 2 days before sponge withdrawal, an i.m. injection of either 10, 15 or 20 mg of follicle stimulating hormone (FSH) or 500, 1000 or 1500 iu of equine chorionic gonadotropin (eCG). The dose of FSH was divided into 4 decreasing daily doses and each daily dose was subdivided into 2 and administered at 07.00 and 19.00. 54 does detected in oestrus were mated with fertile bucks. The ovarian response was determined by laparoscopy and eggs were recovered surgically 5 or 6 days after oestrus. The ovulatory response (mean+or- standard deviation) based on corpora lutea was higher in the FSH (13.4+or-8.4 corpora lutea per doe, n = 20) than the eCG-treated groups (6.4+or-5.1 corpora lutea per doe, n = 25) but the difference was not significant. Does responded to gonadotropins throughout the year with more than 50% of doses responding during the rainy months compared with less than 35% responding during the dry months. This difference was statistically significant. Egg recovery was better in the FSH (6.8+or-5.3 per doe, n = 20) than the eCG groups (3.0+or-3.8 per doe, n = 21) but the difference was not significant

Gene Expression Profiling of Preovulatory Follicle in the Buffalo Cow: Effects of Increased IGF-I Concentration on Periovulatory Events

The preovulatory follicle in response to gonadotropin surge undergoes dramatic biochemical, and morphological changes orchestrated by expression changes in hundreds of genes. Employing well characterized bovine preovulatory follicle model, granulosa cells (GCs) and follicle wall were collected from the preovulatory follicle before, 1, 10 and 22 h post peak LH surge. Microarray analysis performed on GCs revealed that 450 and 111 genes were differentially expressed at 1 and 22 h post peak LH surge, respectively. For validation, qPCR and immunocytochemistry analyses were carried out for some of the differentially expressed genes. Expression analysis of many of these genes showed distinct expression patterns in GCs and the follicle wall. To study molecular functions and genetic networks, microarray data was analyzed using Ingenuity Pathway Analysis which revealed majority of the differentially expressed genes to cluster within processes like steroidogenesis, cell survival and cell differentiation. In the ovarian follicle, IGF-I is established to be an important regulator of the above mentioned molecular functions. Thus, further experiments were conducted to verify the effects of increased intrafollicular IGF-I levels on the expression of genes associated with the above mentioned processes. For this purpose, buffalo cows were administered with exogenous bGH to transiently increase circulating and intrafollicular concentrations of IGF-I. The results indicated that increased intrafollicular concentrations of IGF-I caused changes in expression of genes associated with steroidogenesis (StAR, SRF) and apoptosis (BCL-2, FKHR, PAWR). These results taken together suggest that onset of gonadotropin surge triggers activation of various biological pathways and that the effects of growth factors and peptides on gonadotropin actions could be examined during preovulatory follicle development

Influência da estação do ano sobre a estrutura testicular em ovinos explorados no sul do Estado do Piauí

RESUMO: Objetivou-se avaliar a influência da estação do ano sobre a estrutura testicular de ovinos SRD. Foram utilizados 10 animais com idade entre dois e três anos. Os testículos foram seccionados e fixados em solução de Bouin por 24h. Os fragmentos foram submetidos ao processamento histológico, emblocados em parafina e corados com hematoxilina eosina. Foram avaliadas a proporção volumétrica dos compartimentos testiculares, o diâmetro dos túbulos seminíferos, altura do epitélio seminífero e frequências dos estágios do ciclo do epitélio seminíferos. Os dados foram submetidos à análise de variância a 5% de probabilidade, do programa estatístico SAS 9.0. Os resultados revelaram todos os valores pesquisados sofreram influência da estação do ano. O valor do diâmetro tubular foi de 143,98±17,83 e 170,37±26,64μm, a altura do epitélio seminífero foi de 44,92±9,23 e 50,06±13,61μm e a proporção volumétrica foi de 78,32±13,68 e 80,13±15,14% nos períodos seco e chuvoso, respectivamente. A quantificação das células germinativas e de Sertoli mostrou todos os valores foram maiores no período chuvoso quando comparados com o seco. Concluiu-se que a estação do ano interferiu na estrutura testicular, tendo em vista que todos os valores da proporção volumétrica dos componentes testiculares mostraram diferença significativa entre as estações do ano, pois os valores foram mais acentuados no período chuvoso

Chromosome studies related to fertility in crossbred buffaloes in Malaysia.

Chromosome analysis was undertaken on Murrah, Swamp, F1 crossbred (Murrah x Swamp) and first generation backross (F1 female x Murrah male) buffaloes using the leukocyte culture method combined with Giemsa (G) and centromeric (C) and nucleolar organiser region (NOR) banding procedures. The F1 crossbred had a diploid chromosome complement(2n=49)intermediate to its two parents (Murrah,2n=50 ; Swamp, 2n=48). Two backross animals were 2n=49 and 2n=50 respectively. Construction of G,C NOR and conventional karyotypes revealed that the largest two metacentric chromosome in the Swamp buffalo resulted from a telomere-centromere tandem fusion between chromosomes 4p and 9 of the Murrah karyotype. The F1 crossbred and backross animals with 2n=49 showed a similar tandem fusion, occuring however between one member each of chromosome pairs 4p and 9. The two X chromosome (acrocentric) in female buffaloes had large masses of centromeric heterochromatin and one pair of dark bands in their arms proximal to the centromere, while in the Y chromosome of males, centromeric heterochromatin was not stained. The Y chromosome was not the smallest chromosome in the buffalo karyotype. The implications of the 2n=49 chromosome complement on fertility via inter se and backcross matings is hypothesised and discussed

Plasma progesterone levels following cloprostenol treatment in bovine fetal mummification

Progesterone levels before and after cloprostenol (a synthetic analogue of prostaglandin F 2α) treatment for termination of pregnancy complicated by fetal mummification were studied in three imported Jersey heifers. A marked decline in plasma progesterone level was observed within 24 hours after treatment in all cases but cervical dilation did not commence until 48 hours after treatment and was complete within 96 hours. In Cow No. 1, progesterone levels dropped from 6.5 ng/ml before treatment to 1.5, 0.8 and 0.5 ng/ml at 1, 2 and 3 days after teratment. In Cow No.2, daily pre-treatment values ranged from 4.5 to 7.8 ng.ml but were 2.8, 2.0, 1.4 and 0.6 ng/ml for the next 4 days after treatment. In Cow No.3, daily pre-treatment values ranged from 6.8 to 14.7 ng/ml, falling to 1.5, 1.8 and 0.3 ng/ml at 1, 2 and 3 days post-treatment, respectively. Hourly samplings indicated that the decline was most rapid during the first 12 hours after treatment, reaching undetectable levels by the 4th or 5th day. In Cow No.1, the fetal size suggested a 4-month pregnancy while in Cows No.2 and No.3, the fetuses were approximately 6 to 7 months of age

Plasma progesterone profiles in relation to postpartum ovarian activity in the swamp buffalo

Ovarian activity in 38 suckled swamp buffaoes (Bubalus bubalis) was monitored by rectal palpation, oestrus detection and plasma progesterone radio-immunoassay from calving to approximately 150 days postpartum. Three categories of ovarian activity were diagnosed clinically : A corpus luteum (CL) with detected oestrus (21%), a CL with nondetected oestrus (42%) and no CL with non-detected oestrus or anestrus (37%). Plasma progesterone levels confirmed the clinical diagnosis of the presence or absence of a palpable CL except that progesterone levels were low (<0.2ng/ml) when a CL was palpable in 67% of the cows between Day 30 and 60 postpartum. During the oestrous cycle, plasma progesterone levels were low (0.24±0.12ng/ml) during oestrus (Day 0), rose to detectable levels (0.42±0.21ng/ml) by Day 6, reached a peak concentration (1.51±0.35ng/ml) on Day 15 and then declined to basal levels (0.2ng/ml) on Day 22. A synthetic prostaglandin F₂α analog induced oestrus and ovulation in cycling buffaloes but neither a synthetic gonadotropin releasing hormone nor a progesterone releasing intravaginal device was effective in initiating ovarian activity in anestrous buffaloes