USE OF CIDR AND ESTRADIOL CYPIONATE IN SYNCHRONIZATION PROTOCOLS ON ESTRUS PRESENTATION, PREGNANCY AND BIRTH RATE IN CREOLE SHEEP UNDER HIGH ALTITUDE CONDITIONS

The objective of this research was to evaluate the use of the intravaginal device (CIDR) and estradiol cypionate in synchronization protocols, on oestrus presentation, pregnancy and birth rate in Creole sheep under high altitude conditions. The study was carried out in a non-reproductive season, in the peruvian highlands, using 57 ewes. Four experimental groups were formed: group T1 (n=14) and T3 (n=14), CIDR progesterone device for 7 days and 12 days, respectively; group T2 (n=15) and T4 (n=14), CIDR progesterone device for 7 days and 12 days plus 1 mg of estradiol cypionate, 24 hours after removal of the device in both groups, respectively. Estrous presentation was observed from CIDR removal to 48 hours using vasectomized rams and IATF was performed with fresh semen 48 hours after device removal. The pregnancy rate was determined by ultrasonography at 46 and 90 days after FTAI and the birth rate was recorded. The chi-square test was used for statistical analysis. There was no difference (P>0.05) between groups, for estrous presentation, but there was difference (P<0.05) for pregnancy rate at 46 days between groups with: T1 (42.9%), T3 (38.5%), T4 (21.4%), with respect to T2 (0%) (The difference in results are shown in Table 2). There was a difference (P<0.05) for the pregnancy rate at 90 days: T1 (35.7%) and T3 (30.8%), with respect to T4 (7.1%) and T2 (0 %). The birth rate showed differences (P<0.05) for T1 (28.6%) and T3 (28.6%), with respect to T2 (0%) and T4 (0%). In conclusion, a high pregnancy rate was obtained with CIDR for 7 and 12 days, compared to the use of CIDR plus estradiol cypionate. However, no births were obtained with progesterone plus estradiol cypionate treatment.

The importance of bovine seminal plasma proteins in the sperm function and fertility

Bovine livestock is one of the most important economic and social sectors for many countries. In this sense, the development of strategies to improve reproductive bull fertility and reproduction rates is relevant. It's highlighted the role of seminal plasma proteins (SPP) in reproductive fertility, so it has found close relationships among studies on the structure and biological activity of SPP, with seminal quality, including viability, sperm motility, and morphology. In addition, they have been found to regulate sperm functions such as capacitation, acrosome reaction, and they are even related to protecting sperm against thermal and oxidative stress. Moreover, the methods of separation and protein identification and their contribution to characterizing the bovine SP proteome should be also highlighted. In this sense, the most recent studies have been directed towards developing supplements with SPP that improve quality sperm subjected to cryopreservation processes. Research has begun and should forward to establish how the networks or sets of proteins are related to the functioning and fertility of sperm, the search for biomarkers of fertility, and the use of proteins in biotechnological processes, to increase efficiency reproductive.

Comparison of two doses of eCG for obtaining embryos in llama

The study was developed at the Pampa del Arco Experimental Center of the National University of San Cristóbal de Huamanga, the objective was to evaluate doses of 800 IU (T1) and doses of 1000 IU (T2) of eCG to obtain embryos. Eight adult female llamas were used, distributed four in each treatment (T1 and T2), with a body condition of 2.5, these were evaluated by ultrasound with a 7.5 MHz rectal linear transducer. Hormonal treatments began when the animals had a follicle> 7 mm. The application of eCG was 72 hours after the induction of ovulation of the dominant follicle with GnRH, on day 7 PGF2α was applied, natural mounting was performed plus GnRH (1ml), on day 15 the collection and evaluation of embryos was performed. The results obtained were the pre-ovarian stimulation follicular diameter of 8.3 mm and 9.1 mm for T1 and T2 respectively, the number of pre-ovulatory follicles was 6.33 and 5.50 for T1 and T2 respectively, the diameter of follicles pre-ovulatory was 11.2mm and 10.6 mm for T1 and T2 respectively, average of embryos recovered per donor was 4.66 ± 0.81 and 3.50 ± 0.54 embryos for T1 and T2 respectively, with a significant difference (p <0.05) and the quality of embryos had 35.7% and 38.1% of embryos of excellent quality, 28.6% and 33.3% of good quality, 10.7% and 9 , 5% of regular quality, 10.7% and 0% of poor quality, for T1 and T2 respectively and 14.3% and 19.0% of non-transferable embryos for T1 and T2 respectively, with no statistical difference (p≥0, 05). It is concluded that the number of embryos recovered with a dose of 800 IU of eCG is higher compared to the dose of 1000 IU of eCG (p <0.05) and that there is no association between the applied dose of eCG and the quality of the llama embryos (p≥0.05)

IDENTIFICATION OF AQUAPORIN 7 GENE POLYMORPHISM AND IN-VIVO FERTILITY OF EGYPTIAN BUFFALO BULLS

This work aimed to investigate the genetic polymorphism of Aquaporin 7 (AQP7) gene and its association with the in-vivo fertility of Egyptian buffalo bulls. A total of 188 fresh semen ejaculates were collected from 47 buffalo bulls and subjected to semen evaluation. The bulls were grouped according to in-vivo fertility relying on sire conception rate (SCR) into high (SCR>50%, n=41) and low (SCR<50%, n=6) fertile bulls. DNA was extracted from semen and a 200 bp fragment of the AQP7 gene was amplified by PCR. The genetic polymorphism of AQP7 gene was detected by restriction fragment length polymorphism, the single strand conformation polymorphism and the nucleotide sequencing. The results revealed that SCR was significantly (p<0.001) increased in high (71.4±1.3) than low (44.7±2.8) fertile bulls while the ejaculate volume, individual motility%, lives sperm%, sperm concentration and sperm abnormalities showed a non-significant difference in both groups. The AQP7 gene showed no genetic variation in all bulls. The alignment of the resultant sequence with buffalo AQP7 gene sequence (ID: XM_006066699.2) showed 100% identity (122/122), however, deletion of A49 was discovered when the sequence was aligned with ID: XM_006066700.2 of buffalo in GenBank. In conclusion, the sire conception rate is not associated with any genetic variation in Aquaporin 7 gene. The Aquaporin 7 gene could be a highly conserved sequence in Egyptian buffalo bulls. Future research on large herd populations in different regions of AQP7 gene is required for evaluating the AQP7 gene polymorphism and its association with the fertility of Egyptian buffalo bulls.

DRY COW ANTIMICROBIALS USE TO CONTROL MASTITIS IN NORTHERN ALGERIA

The control of mastitis is a crucial step in the preparation of the next lactation in dairy cows. In order to assess the practices and attitudes surrounding the use of antimicrobials at dry-off, a survey was conducted among veterinary practitioners in fifteen provinces of Northern Algeria. The results revealed that 45.95% of the farms followed by the respondents were rather small in size comprising about ten cows per farm and that a large majority of the farmers practised gradual drying off (72.97%) without adjusting the feed ration (70.27%) to this stage. Antibiotic dry cow therapy (DCT) was a common practice and selectively performed in 86.49% of cases regardless of udder health status. Cefalexin was the most infused intra-mammary (IMM) antibiotic (40.54%), while tylosin was the one favoured for parenteral administration (48.15%). Analysis of factors influencing the antibiotic DCT efficacy showed that a frequent (13.51%) occurrence of new intramammary infections (IMIs) was related to farmers’ attitudes (self-medication) and the policy of blanket DCT. Although the use of a teat sealant was uncommon (71.43%) in the farming traditions, the substitution of antibiotics seems to be a plausible prospect, since the majority of participants (89.19%) agreed with the implementation of aromatherapy concept at dry-off, mainly as a complement to antibiotics. This survey gives an overview of risk practices regarding mastitis management in northern Algeria. Hence, further zootechnical, veterinary and organizational efforts need to be made to promote animal production and welfare as well as public health through improved udder health.

STRATEGIES TO INCREASE FERTILITY DURING FIXED-TIME ARTIFICIAL INSEMINATION IN BEEF CATTLE

The application of Fixed Time Artificial Insemination (FTAI) protocols has strongly boosted artificial insemination in Brazilian bovine herds. The control of the estrous cycle with protocols based on progesterone and estrogen involves synchronizing the emergence of a follicular wave, controlling the progesterone phase, and inducing ovulation in a synchronized manner. The increase in pregnancy rates starts with the preparation of the breeding season and the choice of protocols and females. Thereafter, based on the characteristics of the property and the lots of animals, small adjustments can be made to the hormonal protocols as needed. Finally, resynchronization can increase usability by allowing multiple inseminations within short periods. The search for new strategies is of paramount importance for the development of the FTAI protocol and the increase in final pregnancy rates. Thus, this review sought to highlight the main critical points and adjustments of the FTAI protocols and their applicability in the reproduction of beef cattle.

MAXIMIZING IN VITRO EMBRYO PRODUCTION IN CATTLE

In vitro embryo production (IVEP) is used to develop high-quality genetics associated with intergenerational genetic gain. It is characterized by acquisition (in vivo or post-mortem) and maturation (MIV) of oocytes from donors, followed by fertilization (FIV) of matured oocytes and culture (IVC) of embryos, which are then sent to transferred or cryopreserved. Even with extensive knowledge on IVEP, some biochemical and hormonal regulations that involve embryonic development are still unknown, leading to a low overall efficiency of the biotechnological process. Although in vitro developed embryos have a lower quality than that produced in vivo, in terms of resistance to challenging events, IVEP presents itself as a potential biotechnology. In cattle breeding, reproductive biotechnologies are key to increase and improve the genetic improvement of the herd, associated with productive and reproductive efficiency. In this article, the steps and strategies of IVEP and its contribution to reproduction in the cattle sector are discussed.

POST-PARTUM SUB-CLINICAL ENDOMETRITIS- ALTERATION IN UTERINE HAEMODYNAMICS, INFLAMMATORY MARKERS ON TREATMENT WITH MODIFIED ESTRUS SYNCHRONIZATION PROTOCOLS IN DAIRY COWS

Forty-one dairy cows (n=41) were enrolled to envisage the changes in uterine haemodynamics during sub-clinical endometritis (SCE) and its treatment with modified estrus synchronization protocols at 8 weeks post-partum. Trans-rectal Doppler sonography of both the middle uterine arteries (MUAs) was carried out for assessment of uterine perfusion whereas serum inflammatory markers i.e. IL-6 and C-RP were measured at 8 weeks post-partum and estrus (induced or spontaneous). Modified estrus synchronization protocols (MG6G and MG6GP) were used to adjudge their efficacy in post-partum dairy cows diagnosed with SCE and reproductive parameters were recorded. As a part of result, Doppler indices of both the MUAs at estrus i.e. TAMEAN, TAMAX, Blood flow volume-TAMEAN and TAMAX and diameter of MUA, were significantly lower (P<0.05) after application of MG6G and MG6GP protocols in SCEP as compared to SCEP control cows. Similarly, the IL-6, C-RP concentrations and PMNCs proportion (%) were significantly higher (P<0.05) in SCEP control as compared to cows treated with MG6G and MG6GP protocols. Moreover, on the day of estrus, the uterine haemodynamics, concentration of serum inflammatory markers and PMNCs proportion (%) in treated cows was at par with SCE negative control (SCEN) cows. In terms of reproductive performance, days open were recorded to be significantly lower (P<0.01) in treated and SCEN group as compared to SCEP control cows. In conclusion, sub-clinical endometritis led higher uterine perfusion, release of proinflammatory cytokines and PMNCs proportion which happened to plummet the post-partum reproductive performance was successfully managed with modified estrus synchronization protocols.

Influence of freezing temperature on semen quality of rainbow trout (Oncorhynchus mykiss)

Trout production in Peru has export potential. However, there are no fry available to maintain production throughout the year and there is also a lack of egg production at certain times of the year. Therefore, the alternative is to cryopreserve semen for the non-reproductive season. The objective of the study was to determine the influence of freezing temperature on the quality of rainbow trout semen. The semen of 12 reproductive males was collected in the facilities of the Chucuito Research and Production Center of the National University of the Altiplano of Puno, which underwent a macroscopic, microscopic pre and post thaw seminal evaluation and the fertility rate was measured. Due to the effect of three freezing temperatures (-80 °C, -100 °C, -120 °C), cryopreservation had a decline curve of -20 °C / min. The fresh seminal parameters were similar to those reported by other researchers. While freezing had unfavorable effects on semen quality, the best results for activation time (51.33 sec) and vitality (35.33%) were obtained with -100 °C, but the higher motility was obtained with -120 °C (36.33%). Regarding fertility, the higher rate was obtained with -100 °C (70.97%), followed by -80 °C and -120 °C in which 68.86% and 64.34% were obtained, respectively. In conclusion, the results suggest that the tolerable freezing temperature of rainbow trout semen is around -100 °C, which is shown as a favorable alternative for the reproductive management of rainbow trout under natural hypobaric conditions of the Peruvian highlands

Genealogical analyses in open population of Silla Argentino horses belonging to the national police of Colombia

This study aimed to evaluate population parameters, genetic diversity and identify the ancestors with the highest genetic contribution of an open population of Silla Argentino horses in Colombia using pedigree data. 508 horses born between 1998 and 2018 were evaluated, called reference population (RP). The ancestors of the RP were added, defining the total population (TP) whit 1,861 horses born since 1905. Population parameters were estimated, including inbreeding coefficient (F), effective population size (Ne), effective number of founders (fe), ancestors (fa), and founder genomes (fg) and generation interval (GIN). The GIN was 10.1 (TP) and 7.7 (RP) years. The estimate of F for the RP was 0.3%, indicating control in mattings. The Ne was 317 (RP) and 179 (TP). The probability of genes origin indicated values for fe, fa and fg of 386, 187 and 351 (TP), and 161, 64 and 56 (RP), respectively, evidencing a reduction of genetic variability in the RP. Half of the genetic variation in the equine population studied was explained by 40 ancestors. The results show loss of genetic diversity in the RP and the genetic contribution of the ancestors suggests the need to increase the number of stallions for breeding and guide mating to increase genetic diversity in the new generations of Silla Argentino horses of the Colombian National Police