Water parameters correlated with the zootechnical performance of shrimp Litopenaeus vannamei grown in oligohaline waters

The present study aimed to correlate the influence of water quality, cultivation time, area, and density of ponds on the zootechnical performance of shrimp Litopenaeus vannameiin oligohaline waters. It was demonstrated that, under the conditions of this research, better control of temperature, pH and water alkalinity can be employed. Ammonia levels were within the normal range and correlated positively with the growth rate (ρ= 0.69859) and production (ρ= 0.66362) of the ponds. There was also a positive correlation between cultivation time and pond density with shrimp weight (ρ= 0.75305 and 0.68933) and pond productivity (ρ= 0.74763 and 0.79367, respectively). Negative correlations were observed between: I) pH with shrimp survival (ρ= -0.73238) and pondproduction (ρ= -0.68696); II) alkalinity and pond production (ρ= -0.66162). The results show that the cultivation of shrimp L.vannameiin oligohaline waters is viable and there is potential for increased productivity associated with better hydrologicalmonitoring and use of higher density and cultivation time by some producers.(AU)

In vitro embryo production in buffaloes: from the laboratory to the farm

Transvaginal follicular aspiration technique together with in vitro embryo production are the biotechnological alternatives currently available to support genetic improvement breeding programs in buffalo species. However, aspects related to animal management, lack of knowledge of the metabolic needs and biochemical peculiarities of gametes and embryos, as well as the reproductive physiology characteristics have hampered progress in the results. Despite the low availability of good quality oocytes collected after OPU in donors as a physiological characteristic of buffalo species, high rates of oocyte maturation, modest embryo cleavage, blastocyst production and pregnancy rates after transvaginal embryo transfer in recipients could be obtained in buffalo in vitro embryo production programs. The results of implementing an in vitro embryo production program in buffaloes in the northern region of Pará state, Brazil, and results published by other groups demonstrate the feasibility of implementing this biotechnology in the routine of breeding programs. Nevertheless, in order to achieve better and consistent results, it is necessary to deepen the knowledge on the peculiarities of reproductive biology in this specie. Selection of donor animals based on ovarian size and ovarian follicular reserve and on the rate of blastocyst production is presented as an effective alternative to increase the efficiency of the in vitro embryo production technique applied to the buffalo species.

In vitro embryo production in buffaloes: from the laboratory to the farm

Transvaginal follicular aspiration technique together with in vitro embryo production are the biotechnological alternatives currently available to support genetic improvement breeding programs in buffalo species. However, aspects related to animal management, lack of knowledge of the metabolic needs and biochemical peculiarities of gametes and embryos, as well as the reproductive physiology characteristics have hampered progress in the results. Despite the low availability of good quality oocytes collected after OPU in donors as a physiological characteristic of buffalo species, high rates of oocyte maturation, modest embryo cleavage, blastocyst production and pregnancy rates after transvaginal embryo transfer in recipients could be obtained in buffalo in vitro embryo production programs. The results of implementing an in vitro embryo production program in buffaloes in the northern region of Pará state, Brazil, and results published by other groups demonstrate the feasibility of implementing this biotechnology in the routine of breeding programs. Nevertheless, in order to achieve better and consistent results, it is necessary to deepen the knowledge on the peculiarities of reproductive biology in this specie. Selection of donor animals based on ovarian size and ovarian follicular reserve and on the rate of blastocyst production is presented as an effective alternative to increase the efficiency of the in vitro embryo production technique applied to the buffalo species.(AU)

Indução a Maturidade Sexual e Taxa de Prenhez com Progesterona de 3° uso em Fêmeas Nelores de 22 meses / Induction of Sexual Maturity and Prenature Rate with Progesterone of 3rd use in Females Nelores of 22 months

The objective of this study was to evaluate if the progesterone device (P4) of 3rd use would be efficientto induce the cyclicity and consequent pregnancy rate in nelore heifers. We used 65 animals with a mean weightof 338 kg. All kept in the same environmental and handling conditions. The induction of estrus was performed in33 females with P4 implant of 3rd use, thus forming Group 1 (G1 = 33), those that did not receive the implantwere allocated in Group 2 (G2 = 32). Thirty-two days post-induction protocol was performed on all animals forTAI. The data collected were tabulated in electronic spreadsheets and evaluated in the SAS software (2010). TheTAI pregnancy rate was 21.21% (G1) (7/33) and 46.88% (15/32) for (G2) (P < 0.05). Thus suggesting that priorinduction to puberty with P4 device of 3rd use was not effective.(AU)

Indução a Maturidade Sexual e Taxa de Prenhez com Progesterona de 3° uso em Fêmeas Nelores de 22 meses / Induction of Sexual Maturity and Prenature Rate with Progesterone of 3rd use in Females Nelores of 22 months

The objective of this study was to evaluate if the progesterone device (P4) of 3rd use would be efficientto induce the cyclicity and consequent pregnancy rate in nelore heifers. We used 65 animals with a mean weightof 338 kg. All kept in the same environmental and handling conditions. The induction of estrus was performed in33 females with P4 implant of 3rd use, thus forming Group 1 (G1 = 33), those that did not receive the implantwere allocated in Group 2 (G2 = 32). Thirty-two days post-induction protocol was performed on all animals forTAI. The data collected were tabulated in electronic spreadsheets and evaluated in the SAS software (2010). TheTAI pregnancy rate was 21.21% (G1) (7/33) and 46.88% (15/32) for (G2) (P < 0.05). Thus suggesting that priorinduction to puberty with P4 device of 3rd use was not effective.