Estrus Response Rate Research Articles

Respostas reprodutivas e metabólicas de ovelhas alimentadas com bagaço de caju desidratado, durante o pós-parto

Avaliou-se o efeito da adição de bagaço de caju desidratado (BCD), durante o pós-parto, em 41 ovelhas, alojadas com suas crias em baias, onde recebiam, à vontade, 75% de capim-elefante + 25% de concentrado (DI; n=17), ou 50% de BCD + 25% de capim-elefante + 25% de concentrado (DII; n=24). Cinquenta dias pós-parto, o estro foi sincronizado, e as ovelhas submetidas à monta natural. O grupo DI perdeu mais peso (P<0,05), e o consumo de proteína bruta e de fibra em detergente neutro foi maior nesse grupo (P<0,001). A inclusão de BCD na dieta II induziu ao aumento do consumo de matéria seca, extrato etéreo e fibra em detergente ácido (P<0,001) e redução significativa das concentrações de colesterol, lipídios totais, albumina e proteína total (P<0,001). Não houve diferença entre os grupos (P>0,05) no tempo de retorno do primeiro corpo lúteo funcional, na resposta à sincronização do estro e nas taxas de gestação e prolificidade. A inclusão de 50% de BCD amenizou as perdas de peso, foi bem consumida e não influenciou nas respostas reprodutivas após a sincronização do estro.

Induction of Fertile estrus in true anoestrus by re-utilization of Crestar implants in She buffales

The effect and economy of re-utilization of Crestar implant alone and in combination with PMSG for induction of fertile estrus in 30 true anoestrus she buffaloes was conducted in and around Bidar district of Karnataka state. The animals were randomly divided into three groups of ten animals each. The animals in Group 1 and 2 were injected with 500 mg progesterone intramuscularly followed by implantation of used Crestar on day 4 of progesterone administration and removed on day 9,whereas animals in Group 2 were injected with 500 IU PMSG on day 9 (the day of implant removal).whereas Group 3 served as control group. On removal of the implant, 70.00 % she buffaloes from Group 1 and 2 exhibited estrus (2.60 + 0.80 and 2.47 + 0.73 days )respectively. The animals were artificially inseminated twice with 12hrs interval and conception rate was 70% from animals of Group 1 and 2. No extra beneficial effect of PMSG was observed either on estrus response or conception rate. None of the animals from Group 3 (control) showed estrus. The animals of Group 1 and 2 exhibited 25 and 45 % and 50 and 20% intense and intermediate estrus respectively with absolute conception, while 30 % of the animals in both the treated groups exhibited weak symptoms of estrus and failed to conceive. 70 % of the animals from both the groups had satisfactory arborization patterns with 66.67 percent conception. Whereas only 20 percent of the animals in both the groups showed good arborization patterns of cervicovaginal mucus with absolute conception. None of the animals conceived expressing weak symptoms of estrus and missing arborization pattern in both the treated groups. It was concluded that utilized Crestar implant (for 7 days) can also be re-utilized to reduce the cost of treatment for induction of fertile estrus even with out PMSG in field conditions.

DESEMPENHO REPRODUTIVO DE OVELHAS SANTA INÊS APÓS SINCRONIZAÇÃO DE ESTRO E INDUÇÃO DA OVULAÇÃO COM PROGESTÁGENO E PROGESTERONA

This study evaluates the effect of natural and synthetic progesterone on incidence of estrus in ewes. A total of 48 females were randomly divided into four experimental groups of 12 animals each: T1 – sponge impregnated with 60 mg of MAP during 14 days and application of 300UI of eCG on the last day (D14); T2 – same device used in T1 during 6 days and application of 0,5mL of PGF2α and 300UI eCG (D5); T3 – CIDR (natural progesterone) during 14 days and application of 300UI eCG (D14); T4 – same device used in T3 during 6 days and application of 0,5mL of PGF2α and 300UI eCG (D5). Estrus activity was assessed by vasectomized teasers and laparoscopic AI sixty hours after treatment, using a semen frozen sample from one male sheep. Response to estrus synchronization varied depending on progesterone source used (p<0,05). Estrus response rates were better in animals treated with the CIDR (91,67% T3 and 100% T4) in comparison with MAP-impregnated sponges (50% T1 and 66,7% T2), regardless of duration of treatment.

Estrous Response and Fertility in Postpartum Suckled Female Yaks (Bos grunniens) Treated with an Intravaginal Device Containing Progesterone (CIDR), Pregnant Mares` Serum Gonadotrophin and Prostaglandin Analogue

The efficiency of a short-term treatment with an intravaginal device containing progesterone (CIDR) combined with pregnant mares' serum gonadotrophin (PMSG) and prostaglandin analogue (PGF2α) was evaluated for the induction of estrus, initiation of cyclic activity, and fertility in postpartum suckled yak cows. Seventy-five postpartum suckled yak cows were assigned to three treatments: (1) insertion of a CIDR intravaginal progesterone (1.9 g) (day 0), an administration of PGF2α (0.2 mg i.m.) on day 6 and PMSG (1,000 IU i.m.) at the time of CIDR withdrawal on day 7 (CPP group, n=28); (2) an administration of PGF2α (0.2 mg i.m.) on day 6 and PMSG (1,000 IU i.m.) on day 7 (PP group, n=21); (3) untreated animals served as the control (CG group, n=26). Seven yak bulls were placed in pastures with the cows for natural mating. Estrus rate in the CPP group (28/28) was higher (p<0.01) than in the PP group (6/21) and in the CG group (0/26) within 96 h after the end of treatment. The first service conception rate in the CPP group (21/28) was higher (p<0.01) compared with in the PP group (2/9) as judged by serum P4 concentration ≥2.35 ng/ml on day 21 after breeding. It is concluded that a short-term progesterone treatment combined with PMSG and prostaglandin increased the proportion of yak cows that exhibited behavioral estrus with more synchronized estrus response and satisfactory conception rate in postpartum suckled yak cows. (Asian-Aust. J. Anim. Sci. 2005. Vol 18, No. 4 : 470-474)

Reproductive responses following royal jelly treatment administered orally or intramuscularly into progesterone-treated Awassi ewes

An experiment was conducted to determine whether natural royal jelly (RJ) paste administered orally or intramuscularly (i.m.) in conjunction with exogenous progesterone is associated with improved reproductive responses in ewes. Thirty 3–6-year-old Awassi ewes were randomly allocated into three (RJ-capsule, RJC; RJ-injection, RJI and control, CON) groups of 10 ewes each. All ewes were treated with intravaginal progesterone sponges for 12 days. Ewes in the RJC and RJI were administered orally or i.m. with a total of 3 g of RJ given in 12 equal doses of 250 mg per ewe per day starting at the time of sponge insertion. At the time of sponge withdrawal (day 0, 0 h), ewes were exposed to three rams and checked for breeding marks at 6-h intervals for 3 days. Blood samples were collected from all ewes for analysis of progesterone concentrations. Pretreatment progesterone levels were <0.5 ng ml −1 in 16/30 and >1.3 ng ml −1 in the remaining ewes indicating luteal function and cyclicity. Similar reproductive responses and progesterone levels occurred in ewes of the RJC and RJI; therefore, data of the two groups were pooled. Following sponge insertion, progesterone levels increased rapidly and reached maximum values of 5.8±0.2 ng ml −1 within 2 days among ewes of the three groups, and then declined gradually to day 0 values of 1.6±0.1 and 1.9±0.1 ng ml −1 for the RJ-treated and CON ewes, respectively. The rate of progesterone decline was greater ( P<0.001) in RJ-treated than in CON. Mean progesterone levels during the 12-day period were lower ( P<0.001) in RJ-treated than in CON (2.8±0.2 ng ml −1 versus 3.3±0.2 ng ml −1). Treatment with RJ resulted in greater ( P<0.05) incidence of oestrus and shorter ( P<0.05) intervals to onset of oestrus than CON. Based upon progesterone levels, ovulation occurred following day 0 in all ewes. Progesterone increased on day 3 in RJ-treated and on day 4 in CON ewes. Progesterone remained elevated through day 18 in 8/20 RJ-treated and 1/10 CON ewes ( P=0.09). All pregnant ewes exhibited oestrus 14 h earlier ( P<0.02), ovulated approximately 1 day earlier and had higher ( P<0.001) luteal phase progesterone levels than non-pregnant ewes. Non-pregnant had higher ( P<0.04) body weights than pregnant ewes. In conclusion, results demonstrate that both RJ treatments in conjunction with exogenous progesterone were equally capable of improving oestrus response and pregnancy rate.

Detection of oestrus in Bunaji cows under field conditions.

The objective of this study was to determine the efficacy of some aids for detecting oestrus in 72 Bunaji cows synchronized using two injections of prostaglandin F2 alpha (PGF2 alpha) 13 days apart. Blood samples to determine the accuracy of the aids and ovarian activity by radioimmunoassay technique were collected daily from the day of the second PGF2 alpha injection until oestrus or for 168 hours for 'non-responders'. The aids for detecting oestrus, tail painting, KaMar detectors and a chin-ball mating device (CMD) were applied at the time of the second injection. The oestrus response rate was 73.6% and 61.1%, from the serum progesterone concentration and visual observation, respectively. Based on the total number of oestrus events observed, unaided visual observation, tail painting, KaMar and CMD detected 52.2%, 82.6%, 82.6% and 76.8%, respectively. Visual observation of standing oestrus alone failed to detect 47.8% of the occurrence of oestrus as shown by the concentration of progesterone in the serum and 30.4%, 30.4% and 24.6%, respectively, of the oestrus periods recorded by tail painting, KaMar and CMD. Twenty-eight cows showed abnormalities in progesterone concentration. These investigations showed that oestrus may be detected by using the aids in cows that have been regarded as 'anoestrous' by visual observation of standing heat.

Estrus synchronization in Holstein cows using reduced doses of prostaglandin F 2α

There is evidence that the dose of PGF 2α generally used to synchronize estrus (25 mg) is higher than required to induce luteolysis in cattle. To investigate this, 98 Holstein cows from three farms were assigned at random within farm to be treated with a single dose of 25 mg (n=33), 17.5 mg (n=33) or 10 mg (n=32) of PGF 2α on Day 10±0.5 (mean ± SEM) of the estrous cycle. Statistical analyses were conducted using analyses of variance and Chisquare test. Only 59.3% of the cows treated with 10 mg of PGF 2α were detected in estrus compared with 72.7 and 78.7% of the cows treated with 17.5 and 25.0 mg doses, respectively (P>0.05). There were no differences (P>0.05) in pregnancy rates at the first service (40.0, 66.6 and 50.0% for 25, 17.5 and 10 mg, respectively). Concentrations of progesterone in blood were different (P<0.05) for cows treated with 10 mg compared with those of cows treated with 17.5 or 25 mg of PGF 2α. The pattern of changes in progesterone concentrations between the last two groups was not different, and progesterone concentrations of less than 1 ng/ml of serum were observed within the first 36 h post PGF 2α administration. In cows treated with 10-mg dose of PGF 2α, concentrations of progesterone declined during the first 24 h, however, by the end of the experimental period, they were not different to pretreatment concentrations (treatment × time; P<0.05). It is suggested that reducing the dose of PGF 2α from 25 to 17.5 mg do not affect estrus response or pregnancy rate in Holstein cows.

Fertility of [formula omitted][formula omitted] and [formula omitted][formula omitted] × [formula omitted][formula omitted] crossbreed cattle after estrus synchronization

Ninety-five cows (79 Boran and 16 Boran-Brahman crossbreeds) and 107 heifers (55 Boran and 52 Boran × Friesian F1 crossbreeds) were used to determine estrus response, estrus response interval and pregnancy rate following synchronization with prostaglandin (PGF 2α), a progesterone-releasing intravaginal device (PRID) and Synchro-mate B (SMB). The proportion of cattle responding to synchronization treatment was 62.5, 43.5 and 57.7% for cows and 85.7, 68.0 and 81.5% for heifers using PGF 2α, PRID and SMB, respectively. The overall mean response was 59 and 81.8% for cows and heifers, respectively. The estrus response of the control animals over a 45-d breeding period was 72.7 and 90% for cows and heifers, respectively. The estrus response interval for cows was 31.8, 22.1 and 18.0 h and it was 51.1, 38.0 and 21.6 h for heifers with PGF 2α, PRID and SMB treatment, respectively. Mean pregnancy rate for cows was 50.0, 34.8, 46.2 and 68.8% and for heifers it was 60.7, 40.0, 55.6 and 77.8% in the PGF 2α, PRID, SMB and control groups, respectively. Based on these findings, it was concluded that both PGF 2α and SMB produce a satisfactory estrus response and pregnancy rate in the cattle studied.

Cloprostenol and Dinoprost Tromethamine in Experimental and Field Trials Treating Unobserved Estrus in Dairy Cows

There was little difference in the luteolytic activity of cloprostenol (0.5 mg) and dinoprost tromethamine (25 mg) when tested in controlled experimental conditions (65 cows) and in a field trial (245 cows). However, the experimental cows showed a better oestrus response (92.7% against 65.7%) and better pregnancy rate (55.1% against 33.5%) within 6 days of treatment than the cows in the field trial. Palpation accuracy and stage of dioestrus at treatment had a greater effect on the results than the type of prostaglandin used.