Fertility in Cebú × brown Swiss cows treated with prostaglandins, progesterone and eCG

Objective: To evaluate the application of 1 or 2 doses of prostaglandin F2? (PGF2?), the use of progestogen on different days of the estrous cycle, and the use of eCG in estrus and fertility synchronization of Zebu × Brown Swiss cows. Design / Methodology / Approach: The study was based on three protocols. Protocol 1 consisted of two treatments: PGI) 26 cows were injected with a single dose of 25 mg PGF2?, and 10 cows with two doses of 25 mg PGF2? with a 14 day interval. Protocol 2 consisted of two treatments: NG14) 11 cows were implanted with 3 mg Norgestomet on day 7 of the estrous cycle, and NG7) 11 animals received the same dose on day 14. In protocol 3, all the cows were implanted with 3 mg Norgestomet for 9 days, 48 h before removing the implant, 25 mg PGF2? was applied. Once the implant was removed, the cows were distributed into two treatments. Norgestomet (n=11) without eCG and Norgestomet + eCG (500 IU) (n=11).    Results: The application of PGF2? on two occasions had no influence (p> 0.05) on the percentages of estrus or pregnancies. NG7 achieved estrus synchronization in 81.8% of the cows between 24 and 36 h, compared with 45.4% of NG14; however, the pregnancy rate was lower (p<0.05). The application of eCG synchronized 90.9% estrus between 24 and 36 h, compared with 36.4% in the group where no eCG was applied. Study limitations / implications: The use of transrectal ultrasound is required to evaluate the ovarian structures present at the time of initiating an estrus synchronization protocol. Findings / conclusions: Cows that present corpus luteum do not require more than one injection of PGF2?, the percentage of pregnancy increases when Norgestomet is implanted on day 14 of the estrous cycle, in addition the application of eCG increases the percentage of synchronization of heat of the 24 to 36 h after withdrawal of progestogenObjective: To evaluate the application of one or two doses of prostaglandin F2?(PGF2?), the application of a progestogen on different days of the estrous cycle and theusage of eCG in the estrus synchronization and fertility of Zebu × Brown Swiss cows.Design / methodology / approach: The study was based on three protocols. The firstconsisted of two treatments: PGI) 26 cows were injected with a single 25 mg dose ofPGF2? and 10 cows with two 25 mg doses of PGF2? at a 14-day interval. Protocol 2consisted of two treatments: NG14) 11 cows were implanted with 3 mg of Norgestometon day 7 of their estrous cycle and NG7) 11 animals received the same dose on day 14.In protocol 3 all cows were implanted with 3 mg of Norgestomet for 9 days, 48 h beforeremoving the implant, 25 mg of PGF2? was applied. Once the implants were removed,they were distributed into two treatments. Norgestomet (n = 11) without eCG andNorgestomet + eCG (500 IU) (n = 11). Results: The application of PGF2? at two times had no influence (p > 0.05) in theestrous percentages and conception. The NG7 achieved estrous synchronization in 81.8% of the cows, in between 24 and 36 h, compared to 45.4 % of the NG14; however, theconception rate was lower (p ? 0.05). The eCG application synchronized 90.9 % ofestrous between 24 and 36 h, compared with 36.4 % of the group with no eCGapplication.Study limitations / implications: Transrectal ultrasounds are required to assess theovarian structures present at the time of the estrus onset in a synchronization protocol.Findings / conclusions: Cows that present corpus luteum do not require more thanone injection of PGF2?, the pregnancy percentage increases when Norgestomet isimplanted on day 14 of the estrous cycle, in addition the application of eCG increasesthe synchronization percentage of the heat between 24 to 36 h after the progestogenwithdrawal

Induction of estrus as a strategy to improve the economic efficiency of the sheep flock

Productivity and profitability in sheep production systems are strongly influenced by the reproductive capacity of the flock. Objective: To evaluate the use of reproductive biotechnologies (e.g., the induction of estrus) and its impact on the economic efficiency and the productive and reproductive performance of technified sheep production systems, during the seasonal anestrus. Design/Methodology/Approach: Four-hundred recently weaned (60 days postpartum) ewes of the Katahdin breed were randomly divided into two treatments: T1 = natural mating (n= 200) and T2 = induction of estrus (n=200). Estrus was induced through the application of intravaginal sponges, impregnated with 20 mg of chronolone, plus the injection of 400 IU of Equine Chorionic Gonadotropin. The aim was to evaluate the reproductive and economic efficiency of the flock. Results: The induction of estrus during the seasonal anestrus recorded increases (p<0.001) in prolificacy (32%), fertility (86%), and kilograms of lamb weaned per year per ewe (48%), while decreases (p <0.05) were recorded in the number of open days (25%), calving interval (11%), cost per open days (23%), and the kilograms of lamb required per ewe per year (10%). Study Limitations/Implications: The constant variations in the price of supplies and services caused changes in the economic indicators. Findings/Conclusions: The use of reproductive biotechnologies (such as estrus induction) has a positive impact on production units, improving their profitability

Heterophil/lymphocyte response of local Spanish breeds of laying hens to cold stress, heat stress, and water restriction

6 Pág.Environmental challenges may adversely affect poultry production. Autochthonous breeds are particularly valuable in a climate change context because of adaptation to the local environment. The objective of the present study was to determine the impact of cold stress, water restriction, and heat stress on the stress response quantified by the heterophil to lymphocyte ratio (H/L) of ten local Spanish breeds of laying hens. Hens of these local breeds were consecutively subjected to three treatments: natural cold stress (2, 4, 6, 7, 9, and 13 °C), water restriction (with a duration of 2.5, 4.5, 7, 10, and 12 h, respectively), and natural heat stress (23, 26, 28, 30, 34, 38, 40, and 42 °C). During cold stress, H/L was higher at 9 and 13 °C than at 2, 4, and 6 °C, and higher at 9 °C than at 7 °C (P < 0.05). H/L values were similar during all water restriction levels. During heat stress, H/L was particularly elevated at temperatures higher than 40 °C (P < 0.05). Overall, Andaluza Azul, Andaluza Perdiz and Prat Codorniz showed lowest resilience to stress based on their H/L response, whereas Pardo de Leon, Villafranquina Roja, and Prat Leonada showed highest resilience.This work was funded by INIA-CSIC [RGP2001-001 “Conservacion in vivo e in vitro de doce poblaciones de razas espanolas ˜ tradicionales de gallinas”].Peer reviewe

Effect of selenium on semen quality and fertility of rams

Objective: To evaluate the effect of different doses of selenium on seminal quality and fertility in rams. Design/methodology/approach: Nine rams were evaluated. Selenium was offered subcutaneously at two months of age of the rams each month. Treatments were T1= no selenium, T2= 0.1 mg/kg selenium, and T3= 0.3 mg/kg selenium. Seminal evaluation was performed at seven months of age on the rams using an electroejaculator, and a total of 180 ejaculates were analyzed. The rams with the best seminal quality (one per treatment) were submitted to mating. The variables evaluated were: volume (Vol), mass motility (MM), progressive motility (PM), sperm concentration per mL and per ejaculate, percentage of complete acrosome, percentage of live sperm, percentage of normal sperm and percentage of fertility. Variables with normal distribution were evaluated with an analysis of variance (ANOVA; Tukey, 0.05) and the percentages were raised to arcsine to perform the corresponding ANOVA. Fertility was analyzed with a Chi-square test. Results: Seminal quality and fertility percentage were not different (P &gt;0.05). Ejaculate volume showed differences (P &lt;0.05). Limitations/implications: The study with a larger number of rams and a previous practice in field work for the evaluation of semen parameters is necessary for a better estimation of semen quality and fertility and to verify the results. Findings/conclusions: Selenium did not improve seminal quality and fertility in rams. &nbsp;Objective: To evaluate the effect of different selenium (Se) doses on semen quality and fertility of rams. Design/Methodology/Approach: Se was administered subcutaneously each month to nine two-month-old rams (from April 2018 to February 2020). The treatments were: T1 = without Se, T2 = 0.1 mg Se kg-1, and T3 = 0.3 mg Se kg-1. Semen evaluations were carried out using an electroejaculator; a total of 180 ejaculations were analyzed. The rams with better semen quality (one per treatment) were subjected to a mating. The following variables were evaluated: volume (Vol), masal motility (MM), progressive motility (MP), sperm concentration per mL and ejaculation, acrosome integrity percentage, living spermatozoa, normal spermatozoa, and fertility percentage. The normal distribution variables were evaluated using an analysis of variance (ANOVA) and Tukey’s comparison test (Tukey, 0.05); the percentages were raised to the inverse sine in order to perform the appropriate ANOVA. Fertility was analyzed using a χ2 test. Results: There was no difference in semen quality and fertility percentage (p &gt; 0.05). The ejaculation volume showed differences between treatments (p ≤ 0.05). Study Limitations/Implications: A study including a higher number of rams and a previous fieldwork practice should be carried out, in order to evaluate semen parameters. These evaluations would help to accurately estimate semen quality and fertility, as well as to corroborate the results. Findings/Conclusions: Se did not improve semen quality and fertility of ram

Fatty Acids Profile and Healthy Lipids Indices of Native Mexican Guajolote Meat Treated to Two Heat Treatments

Meat is a complex food with a structured nutritional composition that makes it an essential component of the human diet. In particular, the meat of native guajolote that is traditionally raised in natural conditions is an important dietary source of proteins of high biological value for the rural population of Mexico. The study aimed to evaluate fatty acids (FAs) profile and nutritional indices of breast and leg meat of native guajolote subjected to two heat treatments. For the study, a total of sixty muscle samples (30 breast meat and 30 leg meat) from adult male native guajolotes were used. The FA profile and nutritional indices were evaluated in raw meat (control) and meat subjected to two heat treatments (boiled and baked). The heat treatments, independently of the type of muscle, increased (p ≤ 0.05) the concentration of saturated (SFA) and monounsaturated FA (MUFA); in contrast, polyunsaturated FA (PUFA) decreased. Likewise, the dietary FA index, which has a negative hypercholesterolemic effect, and the atherogenic index increased in guajolote meat from the effect of the heat treatments, while the essential and undesirable hypercholesterolemic FA indices decreased. In conclusion, heat treatments increase the content of SFA and MUFAs in breast and leg meat of native guajolote. Boiling or baking the meat deteriorates PUFAs but increases the nutritional indices. The present investigation would provide valuable information for the guajolote meat product processing

Effects of slaughter age and gender on carcase characteristics and meat quality of native Mexican Turkey (M. g. gallopavo) reared under an extensive production system

The study aimed to investigate the effects of slaughter age and gender on carcase characteristics and meat quality of native Mexican turkeys raised under an extensive production system. Forty-five native turkeys (36 males and 9 females) were used. They were sacrificed at 24, 32, and 40 weeks of age. Slaughter age significantly affected slaughter weight (SW), hot carcase weight (HCW) and cold carcase weight (CCW). Also, dressing percentages, non-carcase components, internal organs, abdominal fat, and most carcase parts and proportions were affected. Gender significantly affected SW, HCW and CCW, non-carcase components, internal organs, and carcase parts weights. Regarding the physical properties of breast and leg meat, pH values and colour parameters taken at 45 min and 24 h post-mortem, as well as the water-holding capacity (WHC), cooking (CL), and drip loss (DL), were significantly affected by slaughter age, except CL in leg meat. Meanwhile, gender influenced L*45min, b*24h, the pH24h values, and CL in breast meat. Concerning the chemical composition of the meat, slaughter age had a significant effect on the ether extract (EE) content of breast meat and on dry matter (DM), crude protein (CP), EE, ash, and energy contents of leg meat. Gender significantly affected the DM, CP, and energy contents of breast meat and DM, EE, and energy contents of leg meat. These results indicate that the carcase weight and yield, and its components, as well as meat quality, were better in older male turkeys than in adult females. HIGHLIGHTS Slaughter age and gender significantly influence carcase yield and composition and as well as meat quality in native Mexican turkeys raised under extensive traditional conditions. It is recommended that native turkeys be slaughtered at around 40 weeks to obtain more acceptable carcase yields and meat of better nutritional value. The native Mexican turkey is a viable poultry resource for ecological production systems