Fábio José Carvalho Faria

Estrutura populacional do rebanho Tabapuã registrado no Brasil

Descreveu-se a estrutura da populacao do rebanho Tabapua registrado no Brasil. Foram geradas estatisticas descritivas da distribuicao do numero de progenies e estimados o intervalo de geracoes, estatisticas de F, numero efetivo de fundadores, de ancestrais e de genomas remanescentes, alem do tamanho efetivo da populacao, usando o registro genealogico de animais nascidos entre 1971-1998. Entre 1994 e 1998 foram registrados 37.778 animais, 18.736 machos e 19.042 femeas, pertencentes a 136 criadores. As medias dos intervalos de geracoes estimadas para os periodos de 1979-1983, 1984-1988, 1989-1993 e 1994-1998 foram, respectivamente, 6,26; 7,18; 7,68 e 7,56 anos para pais-filhos e 6,18; 6,43; 6,99 e 7,27 para pais-pais. O tamanho efetivo da populacao e o numero efetivo de fundadores, de ancestrais e de genomas remanescentes em cada um dos periodos foram, respectivamente, 378, 218, 213 e 181; 131, 254, 202 e 163; 73, 150, 119 e 94 e 55, 112, 78 e 61.

Parâmetros genéticos entre características de leite, de peso e a idade ao primeiro parto em gado mestiço leiteiro (Bos taurus x Bos indicus)

Genetic correlations between milk production (milk, fat, protein yield lactation length in 305-d lactation), live weight (average cow live weight, growth rate between 12-24 mo) and age at first calving traits were estimated in a population of Mestico Leiteiro Brasileiro (MLB) females using REML methodology and animal model. The estimates of heritability were respectively, 0.28± 0.08, 0.30±0.11, 0.28±0.09, 0.19±0.07, 0.18±0.06, 0.42±0.10 and 0.48±0.12 for those traits. Genetic correlations between milk, fat and protein yield with cow average weight were, respectively, -0.22±0.22, -0.49±0.31, -0.22±0.23, and between milk, fat and protein yield with heifer live weight gain, -0.59±0.35, -0.73±0.44, -0.62±0.37 as well. Genetic correlations between milk yield, cow average weight and heifer live weight gain with age at first calving were, respectively, 0.05±0.18, -0.05±0.18, 0.02±0.20. The high genetic correlation between milk production and lactation length (0.93±0.02) indicated that variation of the lactation length should not be removed when selecting tropical dairy cattle.

Intrinsic rate of spermatogenesis in free-ranging feral pigs (Sus scrofa sp)

The aim of this research was to evaluate the intrinsic rate of spermatogenesis in adult free-ranging feral pigs. Twelve adult male free-ranging feral pigs were captured, sedated, and orchidectomized, and then were released and observed to complete recovery and return to their natural environment. Fragments of the testes were embedded in plastic resin and used to prepare slides for histometric analysis. Characteristics investigated included cell populations in the seminiferous epithelium in stage 1 of the cycle of the seminiferous epithelium, intrinsic rate of spermatogenesis and Sertoli cell index. The efficiency coefficient of spermatogonial mitosis was 7.59, the meiotic index was 3.03, the overall yield of spermatogenesis was 23.97 and the cell loss ratio during the meiotic prophase was 1.04. Each Sertoli cell supported an average of 0.92 type A spermatogonia, 7.01 primary spermatocytes in preleptotene/leptotene, 7.30 primary spermatocytes in pachytene and 22.16 round spermatids. In conclusion, the results of the present study indicate that the supporting capacity of Sertoli cells in free-ranging feral pigs is among the greatest values reported for most domestic animals, and the overall yield of spermatogenesis is comparable to that reported in wild boars.

Pregnancy rate of Nelore females inseminated with male-sexed semen

Pregnancy rates of Nelore females inseminated with male-sexed semen and conventional semen from the same bulls were evaluated. The females included 433 heifers (2 years old) and 230 non-suckling cows, totaling 663 animals. Average body condition score was 3.5 (1-5 scale). Estrus was induced with prostaglandin F2α. The total pregnancy rate of females inseminated with male-sexed semen of bulls A, B and C was 38.8% (131/338) less (P<0.0001) than the total pregnancy rate observed for females inseminated with conventional semen from the same bulls (57.9% [188/325]). Pregnancy rates of non-suckling cows inseminated with male-sexed semen was 43.3% (49/113), which was similar (P≥0.05) to the values found for heifers inseminated with male-sexed semen from the same bulls (36.4% [82/225]). The pregnancy rate of females inseminated with male-sexed semen was less compared with females inseminated with conventional semen. In addition, there was no significant difference in the pregnancy rate of heifers versus non-suckling cows.

Somatic and germ cell proliferation during post-natal development of the testis in the wild boar (Sus scrofa scrofa)

This study aimed to investigate the proliferation of cells in the seminiferous epithelium, the intrinsic rate of spermatogenesis and Sertoli cell index in wild boars, during the period from birth to 12 months of age. A total of 52 animals raised in captivity were assigned to 13 experimental groups. After unilateral orchidectomy, fragments of the testes were embedded in plastic resin and used to prepare slides for histometric analysis. Variables assessed in each age group included the characterization of cell populations in the seminiferous epithelium, the intrinsic rate of spermatogenesis, Sertoli cell index and the stages of testicular development in each animal. Gonocytes were in greater numbers in newborn animals, and by the fourth month were no longer identified. The population of spermatogonias increased from 3 to 9 months, after that showed a tendency to stabilization. Primary spermatocytes in pre-leptotene/leptotene were first seen in 8-month-old animals. Primary spermatocytes in pachytene, and round spermatids increase gradually in frequency in animals from 9 to 12 months of age. Undifferentiated support cells were very frequent at birth to 7 months and increased between 7 and 8 months, after that there was a tendency for no further increase in this cell type. We conclude that the Sertoli cell population stabilized in the pre-pubertal phase and germ cell population increased after puberty. The overall yield of spermatogenesis and Sertoli cell index were greater in animals around 12 months of age.

Testis morphometry and kinetics of spermatogenesis in the feral pig (Sus scrofa)

The feral pig (Sus scrofa sp) also known as Monteiro pig, originated from a domestic pig breed that was introduced into Pantanal region in Brazil in the eighteenth century. Although the feral pig has commercial potential, there are few reports in the literature concerning the reproductive biology of this species. Therefore, the aim of this study was to further describe the feral pig testis parenchyma as well as characterize the stages of the seminiferous epithelium cycle by tubular morphology method, and to evaluate the number of differentiated spermatogonia generations in this species. Eight sexually mature feral pigs were analyzed. Fragments of testes were embedded in plastic resin and used to prepare slides for morphometrical studies. It was concluded that the feral pig has six generations of differentiated spermatogonials (A1, A2, A3, A4, In, B) and that the cellular composition in the eight stages of the seminiferous epithelium cycle of these animals were very similar to those reported in species of suidae and tayssuidae already studied.

Efficacy of caudal epidural injection of lidocaine, xylazine and xylazine plus hyaluronidase in reducing discomfort produced by electroejaculation in bulls.

To test the hypothesis that epidural administration of lidocaine, xylazine or xylazine plus hyaluronidase provides reduced pain and stress during electroejaculation in bulls, eight 30-month-old Nellore bulls received saline solution (control), 2% lidocaine, 2% xylazine or 2% xylazine plus hyaluronidase injected into the first intercoccygeal (Co1–Co2) epidural space in randomized order. Heart rate, respiratory rate, mean arterial pressure, analgesia, animal behavior and motor blockade were evaluated before treatment and at predetermined intervals during and after treatment. Pain and stress were scored subjectively, and semen quality was evaluated. The onset of anesthetic action was significantly faster with lidocaine (3.0 ± 1.2 min) than with xylazine or xylazine plus hyaluronidase (8.9 ± 1.5 and 5.5 ± 2.6 min, P=0.021 and P=0.012, respectively), and the onset of anesthesia with xylazine plus hyaluronidase was significantly faster than that with xylazine alone (P=0.032). Treatment with xylazine or xylazine plus hyaluronidase resulted in less discomfort than treatment with lidocaine, as indicated by animal behavior. Changes in heart rate, respiratory rate and arterial pressure were within acceptable limits. Penile protrusion and semen emission occurred in all animals during all four treatments. Our results suggest that xylazine plus hyaluronidase reduced discomfort during electroejaculation more effectively than xylazine or lidocaine alone. Further experiments are necessary to determine whether electroejaculation with xylazine plus hyaluronidase is feasible for obtaining semen from Nellore bulls unaccustomed to being handled or restrained.

Morphology and Morphometry of Seminiferous Tubules in Crioulo Horses

Abstract This study aimed to assess the biometrics of the testes and the morphology of the seminiferous tubules of Crioulo horses. We studied 10 sexually mature stallions (3–6 years of age). After orchiectomy, testes were perfused with Karnovskys solution and then embedded in glycol methacrylate. Testis sections (4 &mgr;m) were cut and stained with toluidine blue and a solution of 1% sodium borate. The histological images were digitized, and the morphometric analysis was performed using ImageJ software. The average weight of the stallions was 377.5 kg, and the average weight of both testicles was 162.9 g. The percentage of testicular parenchyma occupied by the seminiferous tubules and the intertubular tissue was 77.97% ± 6.34% and 22.03% ± 6.34%, respectively. The average tubular diameter was 205.00 ± 36.91 &mgr;m, whereas the average height of the seminiferous epithelium was 70.56 ± 2.82 &mgr;m. Average tubular length per testicle and average tubular length per gram of testicle were 4,085.10 ± 1,170.68 m and 26.09 ± 10.63 m/g, respectively. The characteristics of the eight stages of the seminiferous epithelium cycle were similar to those reported in other horse breeds. We conclude that the morphometry of the seminiferous tubules of Crioulo horse resembles what has been reported in other horse breeds. The volumetric proportion of the seminiferous tubules and the Leydig cells of the Crioulo horse is one of the highest ever reported for stallions. HighlightsThis is the first article describing the morphology of spermatogenesis Crioulo horses.The volumetric proportion of the seminiferous tubules of the Crioulo horse is one of the highest ever reported for stallions.The proportion of the Leydig cells of the Crioulo horse is one of the highest ever reported for stallions.

Testicular Histomorphometric Evaluation of Zebu Bull Breeds

ABSTRACT The objective of this study was to evaluate the quantitative histology and testicular biometrics in zebu bulls of different breeds. Testicular fragments of Nelore (n=10), Polled Nelore (n=6), Gir (n=5), Guzerat (n=5) and Tabapua bulls (n=5) were used. The fragments were perfusion-fixed in Karnovsky solution, embedded in glycol methacrylate and stained with toluidine blue-1% sodium borate. The Nelore animals had a higher tubular volumetric proportion (85.2%) and greater height of the seminiferous epithelium (73.2 µm) than the Gir, Guzerat and Tabapua breeds. The Nelore animals also had a higher volumetric proportion of Leydig cells (5.2%) than the Guzerat and Tabapua breeds. There was no significant difference for any of these parameters between the Nelore and Polled Nelore breeds. The gonadosomatic index, seminiferous tubule diameter, cross-sectional area of the seminiferous tubule and tubule length (total length and length per gram of testicular parenchyma) did not vary among the breeds studied. The morphometric parameters evaluated suggested that the genetic selection applied to the Nelore and Polled Nelore breeds improved the efficiency of spermatogenesis in these breeders. Key words: cattle, testis, volumetric proportion, seminiferous tubule

Efficiency of the Spermatogenesis in Zebu Bulls (bos taurus indicus)

The objective of the research was to evaluate the efficiency of the spermatogenesis through the morphology of the testicular parenchyma in bulls of different zebu breeds. We used testicular fragments from bull of the breeds Nelore (n = 10), Polled Nelore (n = 6), Gyr (n = 5), Guzerat (n = 5) and Tabapuã (n = 5). The tissue was perfused with Karnovsky solution, included in glycol methacrylate and stained with toluidine blue–sodium borate 1%. Animals of the Nelore breed presented higher population of primary spermatocyte in pre‐leptotene/leptotene (38.30) and in pachytene (38.14) and round spermatids (113.30), higher yield of spermatogonia mitosis (21.2) and higher daily spermatic production per gram of testicular parenchyma (32.8 × 106) than those from breeds Gyr, Guzerat and Tabapuã and higher general yield of spermatogenesis (62.4) than breeds Gyr and Tabapuã. There was no significant difference in any of the evaluated parameters between breeds Nelore and Polled Nelore. The rate of Sertoli cells did not vary between the studied breeds. Apparently, the genetic selection applied to the breeds has been improving the yield in the spermatogenic process by decreasing cellular loss, although it did not increase the support capacity of the Sertoli cells.