Effect of ovarian status on reproductive performance in dairy heifers inseminated with sexed semen

Background: The intensive reproductive management in the dairy farms requires inclusion of a large group of replacement heifers in the breeding program for a shorter period. In this aspect, a creation of effective estrus synchronization protocols with timed artificial insemination (TAI) by sexed semen and optimization of the current ones have a crucial role for obtaining high pregnancy rate. These protocols are beneficial, because they led to reduced interval to first AI, lack of need for estrus detection, and allow obtaining a large group of female calves for on time. Because of limited fertilizing potential of sexed spermatozoa this type of semen is applied mainly for heifers, as fertility is higher compared to lactating cows. The main objective of the present study was to investigate the effect of ovarian status on the reproductive performance in dairy heifers subjected to estrus synchronization and timed artificial insemination with sexed semen. Materials, Methods & Results: Forty-eight Holstein healthy heifers separated in 2 groups were subjected to PGF2α-GnRH pre-treatment and Ovsynch or PRID-5-day estrus synchronization protocol and timed artificial insemination (TAI) with sex-sorted semen, staring 6 days after end of the hormonal pre-treatment. The ovarian status (presence of follicles with or not a corpus luteum) of the heifers at the begin of the treatment, on day of TAI and pregnancy rate in different groups were determined and compared. Additionally, the ovarian status at the begin of the treatment, ovarian status and size of preovulatory follicle (PF) on day of TAI and total values for both groups according to reproductive performance (pregnant or non-pregnant) were also analyzed. On day of TAI the animals with PF and a lack of corpus luteum (CL) in both groups were more that those with PF and CL (39.3% and 30% vs. 60.7 % and 70%), with significant (P < 0.05) difference in PRID-5-day group. The pregnancy rate tended to be higher in PRID-5 day than Ovsynch treatment (65% vs. 35.7%). A higher percentage (100% and 67.9%) of the pregnant animals in both treatments had not CL on day of TAI, and the size of the PF (1.58 ± 0.12 cm and 1.64 ± 0.13 cm) was increased (P < 0.05). Similar effects of the ovarian status on reproductive performance were obtained after a comparison of the total values between pregnant and non-pregnant animals. The percentage of heifers with observed PF without CL on day of TAI was significantly greater (P < 0.05) in pregnant compared to non-pregnant group (91.3% vs. 40%). The opposite dependence was determined for the parameter presence of follicles and corpus luteum (8.7% vs. 60%; P < 0.05). Furthermore, the size of the PF measured immediately before TAI was increased in animals became pregnant (1.60 ± 0.12 cm vs. 1.34 ± 0.17 cm; P < 0.05). Discussion: The analysis of the obtained results showed that the ovarian status on day of TAI affects the reproductive performance in dairy heifers subjected to estrus synchronization and timed artificial insemination with sexed semen. Hormonal pre-treatment with onset of PRID-5-day protocol 6 days later and TAI with sex-sorted semen ensure acceptable pregnancy rate. The greater preovulatory follicle and a lack of corpus luteum before insemination provide significantly (P < 0.05) more pregnant animals, compared to the cases when CL is presented. Ultrasound determination of the ovarian function before insemination can be used in selection of heifers for TAI with sex-sorted semen.

Mycotoxin risk management for dairy cows by monitoring blood parameters, reproduction status and SCC in milk / [Gerenciamento de risco de micotoxinas para vacas leiteiras através do monitoramento de parâmetros sanguíneos, status de reprodução e SCC no leite]

The objective of this study was to determine the effectiveness of mycotoxin management with feed additive by monitoring biochemical blood parameters, reproduction status and udder health in cows. During the first 1-12-months, the reproduction performance was assessed. The cows were fed only total mixed ration (TMR) with naturally contaminated mycotoxins (ZEN;DON;AFB1;OTA) and the cows were regarded as a control group (CG). In months 13-15, two groups were created: control (CG)(n=30) and experimental (EG)(n=60). The CG was fed with contaminated TMR and the EG was fed with the same TMR+40g/cow mycotoxins management feed additive (TMXL1000). During this period, blood indicators and udder health were studied. Beginning with months 16-24, all cows were fed with contaminated TMR+40 g/cow (TMXL1000) and regarded as the EG. The IgA concentrations in the CG decreased in the 15th month (p<0.05). The concentrations of cortisol decreased by two times (p<0.05) in the EG. Ovarian cyst treatment was more effective by 14.98% (p<0.05) in the EG than in the CG (p<0.05). The EG performed an effective (18.02%) (p<0.05) response to applied ovsynch protocol compared with the CG. According to the obtained results, it can be concluded that feed additive for mycotoxins management had a positive impact on dairy cow health.

O objetivo deste estudo era determinar a eficácia do manejo de micotoxinas com aditivo alimentar através do monitoramento de parâmetros bioquímicos do sangue, estado de reprodução e saúde do úbere em vacas. Durante os primeiros 1-12 meses, o desempenho de reprodução foi avaliado. As vacas foram alimentadas apenas com ração total mista (TMR) com micotoxinas naturalmente contaminadas (ZEN;DON;AFB1;OTA) e as vacas foram consideradas como um grupo de controle (CG). Nos meses 13-15, dois grupos foram criados: controle (CG)(n=30) e experimental (EG)(n=60). O CG foi alimentado com TMR contaminado e o EG foi alimentado com o mesmo TMR+40g/ aditivo para o manejo de micotoxinas de vacas (TMXL1000). Durante este período, foram estudados os indicadores de sangue e a saúde do úbere. A partir dos meses 16-24, todas as vacas foram alimentadas com TMR+40 g/ vaca contaminada (TMXL1000) e consideradas como o EG. As concentrações de IgA no GC diminuíram no 15º mês (p<0,05). As concentrações de cortisol diminuíram duas vezes (p<0,05) no GE. O tratamento do cisto ovariano foi mais eficaz em 14,98% (p<0,05) no GE do que no GC (p<0,05). O GE realizou uma resposta efetiva (18,02%) (p<0,05) ao protocolo ovsynch aplicado em comparação com o GC. De acordo com os resultados obtidos, pode-se concluir que o aditivo alimentar para o manejo de micotoxinas teve um impacto positivo na saúde das vacas leiteiras.

Particularidades na inseminação artificial em tempo fixo de bubalinos na Amazônia / Particularities in fixed-time artificial insemination of buffaloes in the Amazon

A Inseminação artificial em bubalinos na Amazônia completa 39 anos, a primeira ocorreu 1981, na ilha do Marajó. Entre 1976 a 1980 pesquisas se concentraram nas particularidades do comportamento sexual e das estratégias de colheita do sêmen e posteriormente na criopreservação. Aproximadamente 6.000 búfalas já foram inseminadas, na Amazônia, e ainda não, insemina-se mais de 0,87% do rebanho. Na inseminação convencional em detrimento da fraca expressão no cio, o uso do rufião é fundamental. Em criações extensivas a inseminação deve ser precedida de vacinações e esterilização uterina. O dispositivo intra-vaginal de progesterona de 2° e 3° usos e dose única, apresentaram bons resultados. Búfalas com ECC 3,0 a 3,75 é dispensável o uso do eCG. A hidrografia do rio Amazonas influencia na logística da IATF. Setembro a dezembro (época de vazante) consideramos a estação de reprodução favorável em criações na várzea. Em criações de terra firme a estação favorável ocorre entre os meses de janeiro a junho, (estação mais chuvosa). O protocolo mais usado é o Ovsynch, Ovsynch associado aprogesterona e o protocolo (-D30) primeira dose de vacina; no dia zero (D0); reforço vacinal e dispositivo intravaginal de progesterona, BE ou GnRH; (D9) PGF2α, eCG; (D11) GnRH e no dia doze (D12), IATF. Evitar estresse e traumas antes das inseminações, usar locais sombreado, água a vontade e liberação imediata após o serviço, evitar novilhas imaturas sexualmente, usar vacas multíparas mantendo ou ganhando o peso. A taxa de prenhes está entre 20 a 70% e a média em 52,6%.

Artificial insemination in buffaloes in the Amazon is 39 years old, the first occurred in 1981, on the island of Marajo. Between 1976 and 1980, research focused on the particularities of sexual behavior and semen collection strategies and later on cryopreservation. Approximately 6.000 buffaloes have already been inseminated in the Amazon, and not yet, more than 0.87% of the herd were inseminated. In conventional insemination to the at the expense of weak expression in heat, the use of the heat detector bull is essential. In extensive breeding, insemination should be preceded by vaccinations and uterine sterilization. The intra-vaginal progesterone deviceof 2nd and 3rd uses and single dose, showed good results. Buffaloes with ECC 3.0 to 3.75 the use of eCG is not necessary. The hydrography of the Amazon River influences the logistics of the IATF. September to December (dry river season) we consider the breeding season to be favorable for breeding in the creations in flooded area. In high land creations, the favorable season occurs between the months of January to June, (rainiest season). The most used protocol is Ovsynch, Ovsynch associated with progesterone and the protocol (-D30) first vaccine dose; on day zero (D0); vaccine booster and intravaginal progesterone, BE or GnRH device; (D9) PGF2α, eCG; (D11) GnRH and on the 12th (D12) IATF. Prevent stress and trauma before insemination, use shaded places, water at will and immediate release after the service avoid sexually immature heifers, use multíparas cows to maintain orgain weight. The pregnancy rate is between 20 and 70% and the average is 52.6%.

Particularidades na inseminação artificial em tempo fixo de bubalinos na Amazônia / Particularities in fixed-time artificial insemination of buffaloes in the Amazon

A Inseminação artificial em bubalinos na Amazônia completa 39 anos, a primeira ocorreu 1981, na ilha do Marajó. Entre 1976 a 1980 pesquisas se concentraram nas particularidades do comportamento sexual e das estratégias de colheita do sêmen e posteriormente na criopreservação. Aproximadamente 6.000 búfalas já foram inseminadas, na Amazônia, e ainda não, insemina-se mais de 0,87% do rebanho. Na inseminação convencional em detrimento da fraca expressão no cio, o uso do rufião é fundamental. Em criações extensivas a inseminação deve ser precedida de vacinações e esterilização uterina. O dispositivo intra-vaginal de progesterona de 2° e 3° usos e dose única, apresentaram bons resultados. Búfalas com ECC 3,0 a 3,75 é dispensável o uso do eCG. A hidrografia do rio Amazonas influencia na logística da IATF. Setembro a dezembro (época de vazante) consideramos a estação de reprodução favorável em criações na várzea. Em criações de terra firme a estação favorável ocorre entre os meses de janeiro a junho, (estação mais chuvosa). O protocolo mais usado é o Ovsynch, Ovsynch associado aprogesterona e o protocolo (-D30) primeira dose de vacina; no dia zero (D0); reforço vacinal e dispositivo intravaginal de progesterona, BE ou GnRH; (D9) PGF2α, eCG; (D11) GnRH e no dia doze (D12), IATF. Evitar estresse e traumas antes das inseminações, usar locais sombreado, água a vontade e liberação imediata após o serviço, evitar novilhas imaturas sexualmente, usar vacas multíparas mantendo ou ganhando o peso. A taxa de prenhes está entre 20 a 70% e a média em 52,6%.(AU)

Artificial insemination in buffaloes in the Amazon is 39 years old, the first occurred in 1981, on the island of Marajo. Between 1976 and 1980, research focused on the particularities of sexual behavior and semen collection strategies and later on cryopreservation. Approximately 6.000 buffaloes have already been inseminated in the Amazon, and not yet, more than 0.87% of the herd were inseminated. In conventional insemination to the at the expense of weak expression in heat, the use of the heat detector bull is essential. In extensive breeding, insemination should be preceded by vaccinations and uterine sterilization. The intra-vaginal progesterone deviceof 2nd and 3rd uses and single dose, showed good results. Buffaloes with ECC 3.0 to 3.75 the use of eCG is not necessary. The hydrography of the Amazon River influences the logistics of the IATF. September to December (dry river season) we consider the breeding season to be favorable for breeding in the creations in flooded area. In high land creations, the favorable season occurs between the months of January to June, (rainiest season). The most used protocol is Ovsynch, Ovsynch associated with progesterone and the protocol (-D30) first vaccine dose; on day zero (D0); vaccine booster and intravaginal progesterone, BE or GnRH device; (D9) PGF2α, eCG; (D11) GnRH and on the 12th (D12) IATF. Prevent stress and trauma before insemination, use shaded places, water at will and immediate release after the service avoid sexually immature heifers, use multíparas cows to maintain orgain weight. The pregnancy rate is between 20 and 70% and the average is 52.6%.(AU)

Pre-TAI protocol strategies to increase reproductive efficiency in beef and dairy cows

Ovulation synchronization protocols are well established in beef and dairy cows. However, the protocol response rate is around 70-90%. In beef cows, factors such as inadequate nutrition and calf presence negatively impact the response of progesterone (P4)/estradiol-based ovulation synchronization protocols by interfering with GnRH release and consequently reducing LH pulsatility and final follicular development. In dairy cows, protocols based on GnRH and prostaglandin (Ovsynch) are the most widely used in the world. However, the efficiency of Ovsynch is dependent on the presence of a large follicle at the time of administration of the first GnRH. In these ovulation synchronization protocols, pre-synchronization protocols (Prostaglandins, Double Ovsynch and P4synch) are usually attempted in an effort to increase responses. Thus, the objective of this review was to discuss pre-ovulation synchronization strategies (administration of injectable P4 or energetic/protein supplementation or presynchronization with intra-vaginal progesterone devices) aiming to increase the LH pulsatility in beef cows or induce the formation of a GnRH-responsive follicle at the beginning of the Ovsynch protocol in dairy cows.

Pre-TAI protocol strategies to increase reproductive efficiency in beef and dairy cows

Ovulation synchronization protocols are well established in beef and dairy cows. However, the protocol response rate is around 70-90%. In beef cows, factors such as inadequate nutrition and calf presence negatively impact the response of progesterone (P4)/estradiol-based ovulation synchronization protocols by interfering with GnRH release and consequently reducing LH pulsatility and final follicular development. In dairy cows, protocols based on GnRH and prostaglandin (Ovsynch) are the most widely used in the world. However, the efficiency of Ovsynch is dependent on the presence of a large follicle at the time of administration of the first GnRH. In these ovulation synchronization protocols, pre-synchronization protocols (Prostaglandins, Double Ovsynch and P4synch) are usually attempted in an effort to increase responses. Thus, the objective of this review was to discuss pre-ovulation synchronization strategies (administration of injectable P4 or energetic/protein supplementation or presynchronization with intra-vaginal progesterone devices) aiming to increase the LH pulsatility in beef cows or induce the formation of a GnRH-responsive follicle at the beginning of the Ovsynch protocol in dairy cows.(AU)

Effect of live body weight and method of synchronization on ovulation, pregnancy rate and embryo and fetal loss in buffalo heifers

This study aimed to assess the influence of live body weight (LBW) and age on reproductive performance in buffalo heifers synchronized by different treatments. The study was carried out on 146 Mediterranean buffalo heifers (mean age 25.3±13.4 months, LBW 424±47 kg), divided into 2 homogeneous groups and synchronized by Ovsynch-TAI Program (OVS; n = 72) or double prostaglandin administered 12 days apart (PGF; n = 74). All the buffaloes were inseminated twice and follicle dimensions and ovulation rate (OR) were assessed by ultrasound 24 and 48 h post-insemination. Pregnancy was assessed on day 25, 45 and 90 post-insemination and the incidence of late embryonic (LEM) and fetal (FM) mortality were respectively recorded. Data were analyzed by ANOVA, Chi-square test and multiple logistic regression. The LBW was significantly (P<0.05) higher in inseminated animals, compared to those that did not respond to the treatments (450.0±3.2 vs. 423.2±9.6 kg in inseminated and not inseminated heifers, respectively). Total OR was similar between groups, although OR at 24 h tended to be higher (P = 0.06) in OVS (86.7 vs. 72.9% in OVS and PGF, respectively). A (P<0.01) higher LBW was observed in ovulated heifers of PGF, while no differences were recorded in OVS. LBW affected OR (odds ratio = 1,032; P<0.05) only in PGF, while no effects were recorded in OVS. Total pregnancy rate, LEM and FM were similar between groups. In conclusion, the LBW would be considered before including buffalo heifers in a synchronization program and both synchronization treatments can be useful.(AU)

Effect of live body weight and method of synchronization on ovulation, pregnancy rate and embryo and fetal loss in buffalo heifers

This study aimed to assess the influence of live body weight (LBW) and age on reproductive performance in buffalo heifers synchronized by different treatments. The study was carried out on 146 Mediterranean buffalo heifers (mean age 25.3±13.4 months, LBW 424±47 kg), divided into 2 homogeneous groups and synchronized by Ovsynch-TAI Program (OVS; n = 72) or double prostaglandin administered 12 days apart (PGF; n = 74). All the buffaloes were inseminated twice and follicle dimensions and ovulation rate (OR) were assessed by ultrasound 24 and 48 h post-insemination. Pregnancy was assessed on day 25, 45 and 90 post-insemination and the incidence of late embryonic (LEM) and fetal (FM) mortality were respectively recorded. Data were analyzed by ANOVA, Chi-square test and multiple logistic regression. The LBW was significantly (P<0.05) higher in inseminated animals, compared to those that did not respond to the treatments (450.0±3.2 vs. 423.2±9.6 kg in inseminated and not inseminated heifers, respectively). Total OR was similar between groups, although OR at 24 h tended to be higher (P = 0.06) in OVS (86.7 vs. 72.9% in OVS and PGF, respectively). A (P<0.01) higher LBW was observed in ovulated heifers of PGF, while no differences were recorded in OVS. LBW affected OR (odds ratio = 1,032; P<0.05) only in PGF, while no effects were recorded in OVS. Total pregnancy rate, LEM and FM were similar between groups. In conclusion, the LBW would be considered before including buffalo heifers in a synchronization program and both synchronization treatments can be useful.

Desempenho reprodutivo de novilhas acasaladas aos 14 e 27 meses de idade submetidas a diferentes protocolos para a inseminação artificial / Reproductive performance of beef cattle heifers mated to 14 or 27 months of age subject to different protocols for artificial insemination

Avaliaram-se os efeitos de diferentes protocolos de inseminação sobre o desempenho reprodutivo em 249 novilhas Britânicas e cruzas, acasaladas aos 14 e 27 meses de idade. Sessenta e duas novilhas de 27 meses foram submetidas à IATF após o tratamento OvSynch; 61 novilhas de 27 meses e 32 novilhas de 14 meses foram submetidas à IATF após o tratamento Crestar; 62 novilhas de 27 meses e 32 novilhas de 14 meses foram submetidas à inseminação artificial (IA) após detecção de estros por 7 dias, no 7º dia foi aplicado PGF2a nos animais não observados em estro postergando-se IA por mais 5 dias (grupo PGF2a). Foram avaliados o peso vivo (PIA), o escore de condição corporal (ECC), o escore de trato reprodutivo (ETR) ao início da estação reprodutiva, a taxa de concepção e a taxa de prenhez à IATF, a taxa de prenhez ao término da estação. Os tratamentos OvSynch e Crestar tiveram 100% dos animais inseminados (IATF), enquanto os grupos PGF2a-14 meses e PGF2a-27 meses tiveram, respectivamente apenas 21,9% e 43,5% dos animais inseminados, devido à ausência ou falhas na identificação de cio. Não houve diferença nas taxas de concepção entre tratamentos hormonais e idades (P>0,05), com valores respectivos de 46,5%, 56,3%, 64,7% para os tratamentos Crestar, OvSynch, PGF2a e de 44,4% e 57,1%, para as idades 14 e 27 meses. A taxa de prenhez à IA (TF) foi de 46,5%, 56,3%, 23,4% para os tratamentos Crestar, OvSynch, PGF2a, com superioridade significativa (P<0,05) a favor dos grupos Crestar e OvSynch. A taxa de prenhez à IA (TF) foi de 18,6% e 41,3% (P<0,01) para as idades 14 e 27 meses. A taxa de prenhez final, após o repasse com touros foi respectivamente de 93,0%, 96,9%, 90,4% para os tratamentos Crestar, OvSynch, PGF2a e de 97,7% e 90,5%, para as idades 14 e 27 meses, sem diferença significativa. O ETR influenciou a taxa de prenhez após a inseminação, respectivamente de 0%, 25,6% e 48,8% para os ETR 1, 2 e 3. Os tratamentos hormonais para a IATF resultaram em maior taxa de prenhez...(AU)

The effects of three insemination protocols were evaluated on the reproductive performance in 249 British and crosses beef heifers, mated to the 14 or 27 months of age. Sixty two heifers with 27 months were submitted to FTAI after the treatment OvSynch; 61 heifers with 27 months and 32 heifers with 14 months were submitted to FTAI after the treatment to Crestar; 62 heifers with 27 months and 32 heifers with 14 months were submitted to the artificial insemination (AI) after oestrus detection for 7 days, in the 7th day PGF2a was applied in the animals without oestrus observed being postponed AI during more 5 days (PGF2a group). The live weight and body condition score (BCS), the reproductive tract score (RTS) to the beginning of mating season, the conception and the pregnancy to FTAI and the pregnancy to the end of the mating season were evaluated. The treatments OvSynch and Crestar had 100% of the inseminated animals (FTAI), while the groups PGF2a-14 months and PGF2a-27 months had respectively, only 21.9% and 43.5% of the inseminated animals, due to the absence or fails in the oestrus identification. There was no difference in the conception rates between hormonal treatments and ages (P>0.05), with respective values of 46.5%, 56.3%, 64.7% for the treatments Crestar, OvSynch, PGF2a and of 44.4% and 57.1%, for the ages 14 and 27 months. The pregnancy rate to FTAI/AI it was of 46.5%, 56.3%, 23.4% for the treatments to Crestar, OvSynch, PGF2a, with significant superiority (P<0.05) in favor of the groups Crestar and OvSynch. The pregnancy rate to AI (FTAI) it was of 18.6% and 41.3% (P <0,01) for the ages 14 and 27 months. The final pregnancy rate, after clean-up bulls was respectively of 93.0%, 96.9%, 90.4% for the treatments to Crestar, OvSynch, PGF2a and of 97.7% and 90.5%, for the ages 14 and 27 months, without significant difference. RTS influenced the pregnancy rate after the insemination, respectively of 0%, 25,6% and 48,8% for RTS 1, 2 and 3. The hormonal...(AU)

Desempenho reprodutivo de novilhas acasaladas aos 14 e 27 meses de idade submetidas a diferentes protocolos para a inseminação artificial / Reproductive performance of beef cattle heifers mated to 14 or 27 months of age subject to different protocols for artificial insemination

Avaliaram-se os efeitos de diferentes protocolos de inseminação sobre o desempenho reprodutivo em 249 novilhas Britânicas e cruzas, acasaladas aos 14 e 27 meses de idade. Sessenta e duas novilhas de 27 meses foram submetidas à IATF após o tratamento OvSynch; 61 novilhas de 27 meses e 32 novilhas de 14 meses foram submetidas à IATF após o tratamento Crestar; 62 novilhas de 27 meses e 32 novilhas de 14 meses foram submetidas à inseminação artificial (IA) após detecção de estros por 7 dias, no 7º dia foi aplicado PGF2a nos animais não observados em estro postergando-se IA por mais 5 dias (grupo PGF2a). Foram avaliados o peso vivo (PIA), o escore de condição corporal (ECC), o escore de trato reprodutivo (ETR) ao início da estação reprodutiva, a taxa de concepção e a taxa de prenhez à IATF, a taxa de prenhez ao término da estação. Os tratamentos OvSynch e Crestar tiveram 100% dos animais inseminados (IATF), enquanto os grupos PGF2a-14 meses e PGF2a-27 meses tiveram, respectivamente apenas 21,9% e 43,5% dos animais inseminados, devido à ausência ou falhas na identificação de cio. Não houve diferença nas taxas de concepção entre tratamentos hormonais e idades (P>0,05), com valores respectivos de 46,5%, 56,3%, 64,7% para os tratamentos Crestar, OvSynch, PGF2a e de 44,4% e 57,1%, para as idades 14 e 27 meses. A taxa de prenhez à IA (TF) foi de 46,5%, 56,3%, 23,4% para os tratamentos Crestar, OvSynch, PGF2a, com superioridade significativa (P<0,05) a favor dos grupos Crestar e OvSynch. A taxa de prenhez à IA (TF) foi de 18,6% e 41,3% (P<0,01) para as idades 14 e 27 meses. A taxa de prenhez final, após o repasse com touros foi respectivamente de 93,0%, 96,9%, 90,4% para os tratamentos Crestar, OvSynch, PGF2a e de 97,7% e 90,5%, para as idades 14 e 27 meses, sem diferença significativa. O ETR influenciou a taxa de prenhez após a inseminação, respectivamente de 0%, 25,6% e 48,8% para os ETR 1, 2 e 3. Os tratamentos hormonais para a IATF resultaram em maior taxa de prenhez...

The effects of three insemination protocols were evaluated on the reproductive performance in 249 British and crosses beef heifers, mated to the 14 or 27 months of age. Sixty two heifers with 27 months were submitted to FTAI after the treatment OvSynch; 61 heifers with 27 months and 32 heifers with 14 months were submitted to FTAI after the treatment to Crestar; 62 heifers with 27 months and 32 heifers with 14 months were submitted to the artificial insemination (AI) after oestrus detection for 7 days, in the 7th day PGF2a was applied in the animals without oestrus observed being postponed AI during more 5 days (PGF2a group). The live weight and body condition score (BCS), the reproductive tract score (RTS) to the beginning of mating season, the conception and the pregnancy to FTAI and the pregnancy to the end of the mating season were evaluated. The treatments OvSynch and Crestar had 100% of the inseminated animals (FTAI), while the groups PGF2a-14 months and PGF2a-27 months had respectively, only 21.9% and 43.5% of the inseminated animals, due to the absence or fails in the oestrus identification. There was no difference in the conception rates between hormonal treatments and ages (P>0.05), with respective values of 46.5%, 56.3%, 64.7% for the treatments Crestar, OvSynch, PGF2a and of 44.4% and 57.1%, for the ages 14 and 27 months. The pregnancy rate to FTAI/AI it was of 46.5%, 56.3%, 23.4% for the treatments to Crestar, OvSynch, PGF2a, with significant superiority (P<0.05) in favor of the groups Crestar and OvSynch. The pregnancy rate to AI (FTAI) it was of 18.6% and 41.3% (P <0,01) for the ages 14 and 27 months. The final pregnancy rate, after clean-up bulls was respectively of 93.0%, 96.9%, 90.4% for the treatments to Crestar, OvSynch, PGF2a and of 97.7% and 90.5%, for the ages 14 and 27 months, without significant difference. RTS influenced the pregnancy rate after the insemination, respectively of 0%, 25,6% and 48,8% for RTS 1, 2 and 3. The hormonal...

Reproductive management of buffalo (Bubalus bubalis) in Italy / Manejo reprodutivo da búfala (Bubalus bubalis) na Itália

Livestock products in tropical areas play a crucial role, which extends beyond their traditional supply of meat and milk. Unprecedented economic growth in developing countries, accompanied by the increases in income and purchasing power and by changes in food preferences, together with the growth of human population, has increased demands on the livestock sector. Livestock products, such as milk and meat, have undergone great modification in response to these recent developments. In Italy, buffalo population has grown from 12 thousand heads in 1947 to 397 thousand in 2017. On the national territory there are 2212 farms concentrated for 74% in the Campania Region, which allow Italy to position itself in the 7th place for the production of fresh buffalo milk in the world, generating an economic induced linked to the Mozzarella di Bufala Campana DOP of 721 million euros for consumption. The Italian Mediterranean buffalo has undergone selection for efficiency of production in intensive dairy systems that aim to achieve milk production throughout the year. Continuous production of buffalo milk is required to meet the market demand for mozzarella cheese and other dairy food products derived from buffalo milk. In the Mediterranean region, female buffaloes show annual fluctuations in reproduction with distinct breeding and nonbreeding seasons. The decline in fertility during the transition from the breeding to nonbreeding seasons is associated with a greater incidence of anestrus, a decline in the function of the CL, and an increase in embryonic mortality Season affects oocyte developmental competence in buffalo, as indicated by higher cleavage and embryo yields recorded in autumn compared to spring, with intermediate results observed in summer and winter. The seasonal characteristic of this species, causes an increase in the phenomenon of embryonic mortality during the periods characterized by increasing daylight length. . In the farms that carry out TAI, absolute or associated with natural mated technique, different plans are used, based on the specific market needs of each farm, on the structures, the management and the reproductive season, preferring protocols such as ovsynch during the period of decreasing daylight length and protocols supported by progesterone during periods of anoestrous. The results obtained in the development and application of the most innovative techniques in the buffalo breeding sector, in synergy with the efficiency of the veterinary information systems, make of Italy a nation at the forefront in the international scene in the breeding techniques and health problems of the buffalo, to which many countries look as a model.(AU)

Reproductive management of buffalo (Bubalus bubalis) in Italy / Manejo reprodutivo da búfala (Bubalus bubalis) na Itália

Livestock products in tropical areas play a crucial role, which extends beyond their traditional supply of meat and milk. Unprecedented economic growth in developing countries, accompanied by the increases in income and purchasing power and by changes in food preferences, together with the growth of human population, has increased demands on the livestock sector. Livestock products, such as milk and meat, have undergone great modification in response to these recent developments. In Italy, buffalo population has grown from 12 thousand heads in 1947 to 397 thousand in 2017. On the national territory there are 2212 farms concentrated for 74% in the Campania Region, which allow Italy to position itself in the 7th place for the production of fresh buffalo milk in the world, generating an economic induced linked to the Mozzarella di Bufala Campana DOP of 721 million euros for consumption. The Italian Mediterranean buffalo has undergone selection for efficiency of production in intensive dairy systems that aim to achieve milk production throughout the year. Continuous production of buffalo milk is required to meet the market demand for mozzarella cheese and other dairy food products derived from buffalo milk. In the Mediterranean region, female buffaloes show annual fluctuations in reproduction with distinct breeding and nonbreeding seasons. The decline in fertility during the transition from the breeding to nonbreeding seasons is associated with a greater incidence of anestrus, a decline in the function of the CL, and an increase in embryonic mortality Season affects oocyte developmental competence in buffalo, as indicated by higher cleavage and embryo yields recorded in autumn compared to spring, with intermediate results observed in summer and winter. The seasonal characteristic of this species, causes an increase in the phenomenon of embryonic mortality during the periods characterized by increasing daylight length. . In the farms that carry out TAI, absolute or associated with natural mated technique, different plans are used, based on the specific market needs of each farm, on the structures, the management and the reproductive season, preferring protocols such as ovsynch during the period of decreasing daylight length and protocols supported by progesterone during periods of anoestrous. The results obtained in the development and application of the most innovative techniques in the buffalo breeding sector, in synergy with the efficiency of the veterinary information systems, make of Italy a nation at the forefront in the international scene in the breeding techniques and health problems of the buffalo, to which many countries look as a model.

Effects of blood beta-hydroxybutyric acid levels on the response to Ovsynch in primiparous cows

The aim of this study was to investigate the effects of low and moderate blood β-hydroxybutyric acid (BHBA) levels in primiparous cows during the early postpartum period on follicle development and pregnancy rate after the Ovsynch protocol. Holstein primiparous cows with low (n = 85) and moderate (n = 71) BHBA concentrations were used as experimental animals. At 7- 8 weeks postpartum, blood samples were collected and the Ovsynch protocol was performed on the same day. Ultrasonographic examination was performed to determine the dominant follicle (DF) diameter and presence of corpus luteum on the day of the first and second gonadotropin releasing hormone (GnRH1 and GnRH2) injections and prostaglandin F2 alpha (PGF2α) injection as well as 24 and 48 h after the GnRH1 and PGF2α injections. The ovulatory response to GnRH1 and pregnancy rate at day 30 and day 60 post insemination were also evaluated. No significant differences were observed between groups in the DF diameter on the day of GnRH1 and PGF2α injections, and at 24 and 48 h after these injections, as well as in the ovulation and atresia response to GnRH1 (P > 0.05). Significant differences were observed between groups in DF diameter (low-BHBA group, 13.8 ± 0.2 mm; moderate-BHBA group, 13.2 ± 0.2 mm; P = 0.039) at the time of insemination, and in pregnancy rates at 30 days (low-BHBA group, 38.82%; moderate-BHBA group, 21.13%, P = 0.017) and 60 days after insemination (37.6 and 18.3%, respectively; P = 0.008). Our findings suggest that moderate blood levels of BHBA (0.80-1.19 mmol/L) in primiparous cows during the early postpartum period affect the response to the Ovsynch protocol.

Effects of blood beta-hydroxybutyric acid levels on the response to Ovsynch in primiparous cows

The aim of this study was to investigate the effects of low and moderate blood β-hydroxybutyric acid (BHBA) levels in primiparous cows during the early postpartum period on follicle development and pregnancy rate after the Ovsynch protocol. Holstein primiparous cows with low (n = 85) and moderate (n = 71) BHBA concentrations were used as experimental animals. At 7- 8 weeks postpartum, blood samples were collected and the Ovsynch protocol was performed on the same day. Ultrasonographic examination was performed to determine the dominant follicle (DF) diameter and presence of corpus luteum on the day of the first and second gonadotropin releasing hormone (GnRH1 and GnRH2) injections and prostaglandin F2 alpha (PGF2α) injection as well as 24 and 48 h after the GnRH1 and PGF2α injections. The ovulatory response to GnRH1 and pregnancy rate at day 30 and day 60 post insemination were also evaluated. No significant differences were observed between groups in the DF diameter on the day of GnRH1 and PGF2α injections, and at 24 and 48 h after these injections, as well as in the ovulation and atresia response to GnRH1 (P > 0.05). Significant differences were observed between groups in DF diameter (low-BHBA group, 13.8 ± 0.2 mm; moderate-BHBA group, 13.2 ± 0.2 mm; P = 0.039) at the time of insemination, and in pregnancy rates at 30 days (low-BHBA group, 38.82%; moderate-BHBA group, 21.13%, P = 0.017) and 60 days after insemination (37.6 and 18.3%, respectively; P = 0.008). Our findings suggest that moderate blood levels of BHBA (0.80-1.19 mmol/L) in primiparous cows during the early postpartum period affect the response to the Ovsynch protocol.(AU)

Inseminação Artificial Em Tempo Fixo Em Búfalos / Fixed-Time Artificial Insemination In Buffaloes / Inseminacción Artifical A Tiempo Fijo En Búfalos

A bubalinocultura brasileira apresenta um rebanho em pleno crescimento, visando tanto a produção de leite quanto de carne. Uma vez que esta espécie possui características reprodutivas que dificultam sua reprodução como maturidade sexual tardia, baixa expressão de estro, duração do estro muito variável, grande intervalo entre partos e anestro sazonal durante dias longos, estratégias que buscam melhores resultados reprodutivos vêm sendo aplicadas e estudadas. A principal biotecnologia implementada atualmente é a inseminação artificial, obtendo-se melhores resultados com o advento da inseminação artificial em tempo fixo. Diversos protocolos hormonais são utilizados para este fim, entre eles o Ovsynch, Doublesynch, Heatsynch, Estradoublesynch e protocolos hormonais à base de progesterona e estradiol com ou sem a administração de gonadotrofina coriônica equina (eCG). O Ovsynch e suas derivações apresentam resultados satisfatórios durante a estação reprodutiva favorável, porém as taxas reprodutivas são desastrosas durante a estação reprodutiva desfavorável. Dessa maneira, buscou-se alternativas visando melhores resultados neste período, sendo que a associação de progestágenos, estradiol, prostaglandina e eCG apresentou capacidade de desestacionalização nesta espécie, melhorando os resultados reprodutivos. Essa melhora reprodutiva deve-provavelmente devido ao maior diâmetro pré-ovulatório de seus folículos, que geram corpos lúteos mais robustos, capazes de produzir uma maior quantidade de progesterona, a qual será responsável pela manutenção da prenhez no início da gestação. Dessa maneira cabe ao profissional a escolha do protocolo hormonal mais adequado à realidade do rebanho, visando o aumento da produtividade de leite e carne.(AU)

The buffalo farming in Brazil is in full growth, aiming at both milk and meat production. Since this species has reproductive characteristics that make it difficult to reproduce as late sexual maturity, low estrous expression, very variable estrus duration, large interval between births and seasonal anestrous during long days, strategies that seek better reproductive results have been applied and studied. The main biotechnology reproductive rates are disastrous during the unfavorable reproductive season. In this way, alternatives were sought for better results in this period, and the association of progestogens, estradiol, prostaglandin and eCG showed the capacity of currently implemented is artificial insemination, obtaining better results with the advent of fixed-time artificial insemination. Several hormonal protocols are used for this purpose, among them Ovsynch, Doublesynch, Heatsynch, Estradoublesynch and hormonal protocols based on progesterone and estradiol with or without administration of equine chorionic gonadotrophin (eCG). Ovsynch and its derivations present satisfactory results during the favorable reproductive season, but deseasonalization, improving the reproductive results, probably due to the greater preovulatory diameter of its follicles, which generate more robust luteal bodies, capable of producing a greater amount of progesterone, which will be responsible for the maintenance of pregnancy at the beginning of gestation. In this way, it is up to the professional to choose the most appropriate hormonal protocol to the reality of the herd, aiming to increase the productivity of milk and meat.(AU)

La bubalinocultura brasileña presenta un rebaño en pleno crecimiento, buscando tanto la producción de leche y de carne. Una vez que esta especie posee características reproductivas que dificultan su reproducción como madurez sexual tardía, baja expresión del celo, duración del celo muy variable, gran intervalo entre partos y anestro estacional durante los días largos, estrategias que buscan mejores resultados reproductivos vienen siendo aplicadas y estudiadas. La principal biotecnología implementada actualmente es la inseminación artificial, obteniéndose mejores resultados con el advenimiento de la inseminación artificial a tiempo fijo. Varios protocolos hormonales se utilizan para este fin, entre ellos Ovsynch, Doublesynch, Heatsynch, Estradoublesynch y protocolos hormonales a base de progesterona y estradiol con o sin la administración de gonadotropina coriónica equina (eCG). El Ovsynch y sus derivaciones presentan resultados satisfactorios durante la estación reproductiva favorable, pero las tasas reproductivas son desastrosas durante la estación reproductiva desfavorable. De esta manera, se buscó alternativas visando mejores resultados en este período, siendo que la asociación de progestágenos, estradiol, prostaglandina y eCG presentó capacidad de desestacionalización en esta especie, mejorando los resultados reproductivos, probablemente debido al mayor diámetro preovulatorio de sus folículos, que generan cuerpos lúteos más robustos, capaces de producir una mayor cantidad de progesterona, la cual será responsable del mantenimiento de la preñez al inicio de la gestación. De esta manera cabe al profesional la elección del protocolo hormonal más adecuado a la realidad del rebaño, visando el aumento de la productividad de leche y carne.(AU)

Inseminação Artificial Em Tempo Fixo Em Búfalos / Fixed-Time Artificial Insemination In Buffaloes / Inseminacción Artifical A Tiempo Fijo En Búfalos

A bubalinocultura brasileira apresenta um rebanho em pleno crescimento, visando tanto a produção de leite quanto de carne. Uma vez que esta espécie possui características reprodutivas que dificultam sua reprodução como maturidade sexual tardia, baixa expressão de estro, duração do estro muito variável, grande intervalo entre partos e anestro sazonal durante dias longos, estratégias que buscam melhores resultados reprodutivos vêm sendo aplicadas e estudadas. A principal biotecnologia implementada atualmente é a inseminação artificial, obtendo-se melhores resultados com o advento da inseminação artificial em tempo fixo. Diversos protocolos hormonais são utilizados para este fim, entre eles o Ovsynch, Doublesynch, Heatsynch, Estradoublesynch e protocolos hormonais à base de progesterona e estradiol com ou sem a administração de gonadotrofina coriônica equina (eCG). O Ovsynch e suas derivações apresentam resultados satisfatórios durante a estação reprodutiva favorável, porém as taxas reprodutivas são desastrosas durante a estação reprodutiva desfavorável. Dessa maneira, buscou-se alternativas visando melhores resultados neste período, sendo que a associação de progestágenos, estradiol, prostaglandina e eCG apresentou capacidade de desestacionalização nesta espécie, melhorando os resultados reprodutivos. Essa melhora reprodutiva deve-provavelmente devido ao maior diâmetro pré-ovulatório de seus folículos, que geram corpos lúteos mais robustos, capazes de produzir uma maior quantidade de progesterona, a qual será responsável pela manutenção da prenhez no início da gestação. Dessa maneira cabe ao profissional a escolha do protocolo hormonal mais adequado à realidade do rebanho, visando o aumento da produtividade de leite e carne.

The buffalo farming in Brazil is in full growth, aiming at both milk and meat production. Since this species has reproductive characteristics that make it difficult to reproduce as late sexual maturity, low estrous expression, very variable estrus duration, large interval between births and seasonal anestrous during long days, strategies that seek better reproductive results have been applied and studied. The main biotechnology reproductive rates are disastrous during the unfavorable reproductive season. In this way, alternatives were sought for better results in this period, and the association of progestogens, estradiol, prostaglandin and eCG showed the capacity of currently implemented is artificial insemination, obtaining better results with the advent of fixed-time artificial insemination. Several hormonal protocols are used for this purpose, among them Ovsynch, Doublesynch, Heatsynch, Estradoublesynch and hormonal protocols based on progesterone and estradiol with or without administration of equine chorionic gonadotrophin (eCG). Ovsynch and its derivations present satisfactory results during the favorable reproductive season, but deseasonalization, improving the reproductive results, probably due to the greater preovulatory diameter of its follicles, which generate more robust luteal bodies, capable of producing a greater amount of progesterone, which will be responsible for the maintenance of pregnancy at the beginning of gestation. In this way, it is up to the professional to choose the most appropriate hormonal protocol to the reality of the herd, aiming to increase the productivity of milk and meat.

La bubalinocultura brasileña presenta un rebaño en pleno crecimiento, buscando tanto la producción de leche y de carne. Una vez que esta especie posee características reproductivas que dificultan su reproducción como madurez sexual tardía, baja expresión del celo, duración del celo muy variable, gran intervalo entre partos y anestro estacional durante los días largos, estrategias que buscan mejores resultados reproductivos vienen siendo aplicadas y estudiadas. La principal biotecnología implementada actualmente es la inseminación artificial, obteniéndose mejores resultados con el advenimiento de la inseminación artificial a tiempo fijo. Varios protocolos hormonales se utilizan para este fin, entre ellos Ovsynch, Doublesynch, Heatsynch, Estradoublesynch y protocolos hormonales a base de progesterona y estradiol con o sin la administración de gonadotropina coriónica equina (eCG). El Ovsynch y sus derivaciones presentan resultados satisfactorios durante la estación reproductiva favorable, pero las tasas reproductivas son desastrosas durante la estación reproductiva desfavorable. De esta manera, se buscó alternativas visando mejores resultados en este período, siendo que la asociación de progestágenos, estradiol, prostaglandina y eCG presentó capacidad de desestacionalización en esta especie, mejorando los resultados reproductivos, probablemente debido al mayor diámetro preovulatorio de sus folículos, que generan cuerpos lúteos más robustos, capaces de producir una mayor cantidad de progesterona, la cual será responsable del mantenimiento de la preñez al inicio de la gestación. De esta manera cabe al profesional la elección del protocolo hormonal más adecuado a la realidad del rebaño, visando el aumento de la productividad de leche y carne.

Effects of Different Estrous Synchronization Methods on the Composition of Simmental Cows Milk

Background: Estrous synchronization is one of the primary applications performed to improve the fertility and to consolidate the parturition times in dairy cattle farms. Since the primary objective is to increase fertility regardless of the method of synchronization used, the effect of this process on the udder health and the quality of milk is generally ignored. Therefore, in the present study, the aim was to investigate the effect of different estrous synchronization methods t on the milk quality in a dairy cattle farm.Materials, Methods & Results: In this study, a total of 100 Simmental cows the same farm under good management practices were used. The animals were randomly divided into 4 groups of 25 cows each. The animals in the 1st group were used as a control group without any treatment. Progesterone-releasing intravaginal device (PRID) was inserted to the animals in the 2nd group, double dose of prostaglandin F2 alpha (PGF2-alpha) with 11 days apart was applied to the animals in the 3rd group, and the Ovsynch protocol was applied to the animals in the 4th group. Starting from the first day of the applications, milk samples from each milk tank belonging to the groups were taken, kept frozen for 3 months and analyzed for the levels of fat, nonfat solids, density, protein, lactose and minerals over the course of one month. According to the results, the minimum milk fat

Effects of different estrous synchronization methods on the composition of simmental cow’s milk

Background: Estrous synchronization is one of the primary applications performed to improve the fertility and to consolidate the parturition times in dairy cattle farms. Since the primary objective is to increase fertility regardless of the method of synchronization used, the effect of this process on the udder health and the quality of milk is generally ignored. Therefore, in the present study, the aim was to investigate the effect of different estrous synchronization methods t on the milk quality in a dairy cattle farm.Materials, Methods & Results: In this study, a total of 100 Simmental cows the same farm under good management practices were used. The animals were randomly divided into 4 groups of 25 cows each. The animals in the 1st group were used as a control group without any treatment. Progesterone-releasing intravaginal device (PRID) was inserted to the animals in the 2nd group, double dose of prostaglandin F2 alpha (PGF2 -alpha) with 11 days apart was applied to the animals in the 3rd group, and the Ovsynch protocol was applied to the animals in the 4th group. Starting from the first day of the applications, milk samples from each milk tank belonging to the groups were taken, kept frozen for 3 months and analyzed for the levels of fat, nonfat solids, density, protein, lactose and minerals over the course of one month. According to the results, the minimum milk fat content was found in the PRID group as 2.47 ± 0.354%, and the highest value was in the PGF2 -alpha group as 3.58 ± 0.207%. The difference in milk fat ratio between the groups was found to be significant (P .05).[...]

Effects of different estrous synchronization methods on the composition of simmental cows milk

Background: Estrous synchronization is one of the primary applications performed to improve the fertility and to consolidate the parturition times in dairy cattle farms. Since the primary objective is to increase fertility regardless of the method of synchronization used, the effect of this process on the udder health and the quality of milk is generally ignored. Therefore, in the present study, the aim was to investigate the effect of different estrous synchronization methods t on the milk quality in a dairy cattle farm.Materials, Methods & Results: In this study, a total of 100 Simmental cows the same farm under good management practices were used. The animals were randomly divided into 4 groups of 25 cows each. The animals in the 1st group were used as a control group without any treatment. Progesterone-releasing intravaginal device (PRID) was inserted to the animals in the 2nd group, double dose of prostaglandin F2 alpha (PGF2 -alpha) with 11 days apart was applied to the animals in the 3rd group, and the Ovsynch protocol was applied to the animals in the 4th group. Starting from the first day of the applications, milk samples from each milk tank belonging to the groups were taken, kept frozen for 3 months and analyzed for the levels of fat, nonfat solids, density, protein, lactose and minerals over the course of one month. According to the results, the minimum milk fat content was found in the PRID group as 2.47 ± 0.354%, and the highest value was in the PGF2 -alpha group as 3.58 ± 0.207%. The difference in milk fat ratio between the groups was found to be significant (P < .05). However, the differences between the groups for other parameters were not significant (P > .05).[...](AU)

Influences of different space allowance on reproductive performances in buffalo

The aim of this study was to evaluate the effect of two different conditions of space allowance on reproductive performance and oxidative parameters, biochemical and hormonal profiles in buffalo. The trial was carried out on one hundred pluriparous buffaloes divided into two different groups. Buffaloes in group HDG (high density group - n = 50) were maintained in open yards that allowed 10 m2/head while those in group LDG (low density group -n = 50) were maintained in 22 m2/head. After 60 days, 45 buffaloes in each group underwent synchronization of ovulation by Ovsynch and were artificially inseminated to assess the reproductive efficiency. On the day of AI blood samples were collected to evaluate oxidative stress, hormonal and metabolic profile. Furthermore, on the same day, blood, saliva and hair samples were collected to assess cortisol levels. Simultaneously, Five buffaloes/group, were synchronized but not inseminated and on the day of the hypothetical timed artificial insemination (TAI), follicular fluid was recovered by OPU and blood samples were collected from each animal to evaluate the redox status on both plasma and follicular fluid. Conception rate on day 70 post-AI was similar between the two groups (57.5 vs. 62.5%, in LDG and HDG, respectively). No significant differences were found on redox status, metabolic and hormonal profile and cortisol levels between the groups. In conclusion, on the conditions of this experiment it was observed that the space allowance of 10 m 2/head did not affect reproductive efficiency in buffalo cows.