Eduardo Paulino da Costa

Eficiências Reprodutiva e Produtiva em Vacas das Raças Gir, Holandês e Cruzadas Holandês x Zebu

To evaluate the reproductive efficiency and its relationship with productive traits and genetic composition of a herd, in tropical climate, 113 cows were ssigned to seven crossbreeding levels: 1/2, 3/4, 7/8, 9/16 and 15/16 Holstein x Zebu, crossbreed pure Holstein and Gir. The studied traits were: age at calving, calving season, interval from calving to first service, interval from first service to fertile service, number of services, service period, interval calving, reproductive efficiency, lactation period, milk production by lactation order and genetic groups of the herd. Analyses of multiple regression, variance and comparison of averages using Tukey test were performed in statistical software SAEG. The reproductive efficiency was influenced by the age at calving, lactation period, calving interval and genetic composition of the cows, but it was not influenced by milk production and season. The productive indexes were not influenced by the calving season, but were influenced by the genetic composition of the animals. In this study, the reproductive indexes were satisfactory, the zebu cows presented the smallest productive indexes and the taurine ones the smallest reproductive efficiency, probably by larger sensibility to handling.

Use of complementary tests to evaluate the freezing ability of semen from goats under artificial photoperiod exposure

O congelamento do semen de bodes das racas Alpina e Saanen submetidos ao manejo de fotoperiodo artificial foi avaliado por meio dos testes de termorresistencia (TTR), hiposmotico (HOST) e de integridade do acrossoma. Foram utilizados oito machos caprinos (quatro da raca Alpina e quatro da raca Saanen) de duas idades diferentes (jovens e adultos). A qualidade do semen durante as etapas do congelamento foi superior em bodes jovens de ambas as racas. Avaliada pelo TTR, a motilidade do semen fresco apresentou longevidade pos-descongelamento. Os resultados de motilidade espermatica, obtidos imediatamente apos o descongelamento, tiveram reflexos positivos sobre o TTR, indicando que os semens que apresentaram maior motilidade pos-coleta (86,2% vs 79,3%) e pos-descongelamento (37,7% vs 32,0%) tiveram maior longevidade seminal. Os resultados do HOST, tanto para o semen fresco quanto para o congelado, nao diferiram entre racas e idades. Houve reducao na porcentagem de espermatozoides integros apos o congelamento e descongelamento do semen dos animais da raca Alpina e dos adultos Saanen. Houve reducao superior a 14% nos valores do HOST para o semen congelado em relacao aos valores observados para o semen fresco (38,0 vs 52,0%, respectivamente). A motilidade espermatica progressiva mostrou maior sensibilidade a criopreservacao que a integridade da membrana espermatica, indicando que a motilidade espermatica e mais afetada pelo processo de congelamento que a membrana plasmatica. A integridade do acrossoma nao foi influenciada pelo descongelamento. Os indices de danos acrossomais (edema, desprendimento parcial e ate perda total de acrossoma) mostraram-se dentro do padrao aceitavel (44,5%), tanto no pos-descongelamento como apos o termino do TTR.

Influence of Insulin-like Growth Factor I (IGF-I) on the survival and the in vitro development of caprine preantral follicles

The aim of this study was to investigate the effects of the insulin-like growth factor -I (IGF-I) on survival, activation (transition from primordial to primary follicles) and growth of caprine preantral follicles cultured in vitro. Fragments of ovarian cortex were cultured for one and seven days in the absence or presence of IGF-I (0, 50 and 100ng/ml). The non-cultured and cultured tissues were processed and analyzed by histology and transmission electron microscopy. The culture for one day in a medium with 100ng/ml of IGF-I showed 86.7% of morphologically normal follicles. These results were similar (P>0.05) to the percentage of normal follicles found in the control (96.7%). It was also found that this medium increased the percentage of follicular activation (developing follicles) with one day of culture. The oocyte and follicular diameters remained similar to the control by culturing for one day in a medium containing 100ng/ml of IGF-I. The ultrastructural analysis did not confirm the integrity of the follicular fragments in a medium containing IGF-I (100ng/ml) after one and seven days of culture. In conclusion, this study demonstrated that the addition of 100 ng/ml of IGF-I in the culture medium enables the development of preantral follicles of goats with one day of culture. However, it is not sufficient to maintain the follicular integrity and the follicular survival rate after seven days of culture.

Avaliação andrológica por pontos e comportamento sexual em touros da raça Nelore

The objective of this work was to study the relation between two reproductive potential evaluation methods - Andrologic Evaluation by Points - CAP and sexual behavior of Nelore bulls, and to verify the accuracy of these tests in predicting the reproductive potential of bulls through the gestation rate at the end of the breeding season, with average duration of ninety days. Fourteen bulls were used, all classified as able for reproduction, evaluated through andrologic examination, being submitted to CAP and observation of the sexual behavior at field (libido test) during 12 hours. Eleven bulls were evaluated in individual handling, with an average bull:cow ratio of 1:46 and the rest of the animals (three), evaluated in a multiple handling, with an average bull:cow ratio of 1:23. The average score obtained by CAP was 78.92 ± 8.92 (very good) and the score of 9.85 ± 0.36 (excellent) for the libido test. The longer the test was, the higher libido scores were obtained. At the first time of observation, the bulls were classified as with questionable libido and at the end of the test as with excellent libido. The correlations between libido, scrotal circumference (SC), physical and morphological characteristics of the semen and the gestation rate were low. The scores obtained through CAP was positively correlated with SC and physical characteristics of the semen; however, no correlation was observed for the morphologic characteristics. No correlation was observed between CAP and gestation rate or between libido and CAP. The overall gestation rate after the breeding period was 74.69%. The results suggest that both CAP and the libido test were not efficient to predict the reproductive potential of Nelore bulls and should be used as a complement to the andrologic evaluation.

Qualidade espermática do sêmen criopreservado de cães: I - efeito do meio diluidor

A study on two extenders on canine semen was performed, in order to evaluate their effects on in vitro characteristics of cryopreserved spermatozoa. The extenders studied were Tris-citrate and Tes-Tris. Semen from three stud dogs was collected weekly during five weeks for the experiment protocol. Semen samples were examined for sperm motility and forward progression, and plasmatic membrane and acrosome integrity using the hypo-osmotic swelling test and phase contrast microscopy, respectively, and semen longevity using the thermo-resistance test. A comparative analysis between the extenders has showed that Tris-citrate was superior (P<0.05) as compared to Tes-Tris based on the results of the hyposmotic swelling test, thermo-resistance test, sperm motility, forward progression and achrossome integrity after cryopreservation, all values 15% higher for the Tris-citrate

Organization and quantification of the elements in the intertubular space in the adult jaguar testis (Panthera onca, LINNAEUS, 1758).

The endocrine portion of mammal testicle is represented by Leydig cells which, together with connective cells, leukocytes, blood and lymphatic vessels, form the intertubular space. The arrangement and proportion of these components vary in the different species of mammals and form mechanisms that keep the testosterone level--the main product of the Leydig cell--two to three times higher in the interstitial fluid than in the testicular blood vessels and 40-250 times higher in these than in the peripheral blood. Marked differences are observed among animal species regarding the abundance of Leydig cells, loose connective tissue, development degree and location of the lymphatic vessels and their topographical relationship with seminiferous tubules. In the jaguar about 13% of the testicular parenchyma is occupied by Leydig cells, 8.3% by connective tissue and 0.3% by lymphatic vessels. Although included in standard II, as described in the literature, concerning the arrangement of the intertubular space, the jaguar has grouped lymphatic vessels in the intertubular space instead of isolated ones. In the jaguar the average volume of the Leydig cell was 2386 microm3 and its average nuclear diameter was 7.7 microm. A great quantity of 2.3 microm diameter lipidic drops was observed in the Leydig cell cytoplasm of the jaguar. The Leydig cells in the jaguar occupy an average 0.0036% of the body weight and the average number per gram of testicle was within the range for most mammals: between 20 and 40 million.

Parâmetros reprodutivos de bodes submetidos ao manejo de fotoperíodo artificial

This study aimed to evaluate reproductive characteristics (sexual behavior, scrotal perimeter and quali-quantitative aspects of semen) of young and adults Alpine and Saanen male goats exposed to an artificial photoperiod (16 hours of light and 8 hours of darkness for 2 months). The young animals showed greater libido than the adults, based on the smallest time of reaction. Frequency of manifestation of the behavior traits varied between breeds and ages and higher intensity was observed on adult animals. Scrotal perimeter was smaller for Alpine goats than for Saanen goats at the same age. The scrotal perimeter increased from 30.53 cm in the first period (15 days after the end of the photoperiod exposure) to 31.53 cm in the second period (to the end of the experiment). Quality of semen of Alpine goats was better than that of Saanen goats at the same age. According to the reproductive traits evaluated, Alpine and Saanen goats exposed to similar conditions of this study are sensible to seasonal variation during the year.

Níveis de proteína bruta na ração para porcas pluríparas em gestação

Forty crossbreed sows (1/2Landrace, 1/4Large White, 1/4Pietran) with average weight of 188,2 ± 18,81 kg at fourth and/or fifth reproductive cycles, in a total of 75 childbirths, were used to evaluate different crude protein (CP) levels in the gestation diet. It was used a completely randomized design, with five treatments (rations with 10,0; 11,5; 13,0; 14,5 e 16,0% of CP), fifteen replicates and being each childbirth an experimental unit. Sow gain was not affected by the CP levels in gestation diet. The pig weight and number of pigs born alive, the litter born weight and mortality were not affected by the treatments. The levels of CP in gestation diet did not influence the weight gain of the sow at lactation. The number of weaned pigs, pig average weight at weaning and pig weight gain were not affected by the CP levels in the gestation diet. It is concluded, based in the energy efficiency, that the requirement of CP for pluriparous sows, at fourth and fifth reproductive cycles, in the gestation phase is 11.5%, corresponds to a daily consumption of 207 g of protein and 10.5 g of lysine.

Energia digestível em rações para porcas primíparas em lactação

Forty-eight primiparous sows (PIC), weighting in average of 185.03±15.78kg, were used to evaluate different levels of digestible energy (3,350; 3,500; 3,650 and 3,800 kcal/kg) during lactation (19.98±1.04 days). A completely randomized design was used with four treatments, 12 replicates, being the sow considered as the experimental unit. The sows were daily fed with 4.0kg of the experimental diet. Energy intake increased linearly, according to the level of digestible energy in the diet. The energy level in the diet did not affect the mobilization of corporal reserve, the reproductive characteristics and the levels of insulin of the serum of the sows. Weight gain of piglets and litter increased linearly, according to the dietary energy levels. It was concluded that primiparous lactating sows need to intake at least 14,307kcal/day.

Teste da libido e atividade de monta em touros da raça Nelore

The effect of time evaluation of bull libido on sexual behavior and the bull breeding activity for different bull:cow proportions were studied. Correlations between libido and scrotal circumference and sperm quality were estimated. Twenty selected bulls based on andrologic evaluation and on libido test were randomly allotted to four treatments in the following bull:cow proportions: T1= 1:25; T2= 1:50; T3= 1:75; and T4= 1:100. The increase in the time of the libido test from 10 to 15min reduced the percentage of bulls classified as questionable and good libido, and increased the percentage of bulls with very good and excellent libido. Ten minutes of libido test negatively affected sexual activity of the bulls. Out of 1250 cows from all treatments, 738 (59.0%) were marked, according to the following numbers: by one bull, 624 cows (84.5%), by two bulls, 112 cows (15.2%) and by three bulls, 2 cows (0.3%), suggesting that in a natural multibull breeding 45-day-season-system most of the cows are mated by only one bull. The estimated correlations between libido and sperm quality and scrotal circumference were low.