2011 (SBTE) 25th Annual Meeting Proceedings - International ...

Acta Scientiae Veterinariae, 2011. 39(Suppl 1): Abstracts - 25th Annual Meeting SBTE-Brazil. August 2011.
A031 MALE REPRODUCTIVE PHYSIOLOGY AND SEMEN TECHNOLOGY
IMPROVEMENT OF SPERM AND SEMINAL QUALITY IN NELORE VS. CANCHIM BULLS AFTER INCLUSION IN A FEEDLOT
SYSTEM
Monique Mendes Guardieiro 1 , José de Oliveira Carvalho Neto 1 , Fernanda Lavínia Moura Silva 2 ; Mariana Curci Martins Da Silveira 2 , Tito Nunes Rodrigues 1 ,
Marta Borsato 1 , Pedro Leopoldo Jerônimo Monteiro Jr. 1 , Ricardo Silva Surjus 1 , Alexandre Barbieri Prata 1 , Renato Shinkai Gentil 1 , Flávio Augusto Portela
Santos 1 & Roberto Sartori 1
1
ESALQ/USP, PIRACICABA, SP, BRAZIL. 2 UFRPE, PIRACICABA, SP, BRAZIL.
The objective was to compare the testicle biometry and semen and sperm characteristics between Canchim (3/8 Bos indicus x 5/
8 Bos taurus) and Nelore (Bos indicus) young bulls, during the transition from pasture to a feedlot system. Canchim (n = 15) and Nelore (n
= 13) bulls were 20.7±1.4 and 18.1±0.9 months old at the beginning of the experiment, respectively. All bulls that were managed at a
Brachiaria brizantha pasture system were moved to a feedlot system and fed the same nutritional regime (30.7% hay, 60.9% ground corn,
6.0% soybean meal, 0.9% urea and 1.5% limestone and mineral salt in dry matter). Data were analyzed as repeated measures by the MIXED
procedure of SAS (2009), using the initial body weight mean (IBW) of Canchim and Nelore bulls of 423.5±23.9 and 336.6±19.4 kg,
respectively, as covariate. Scrotal circumference (SC) measurement and semen collection by electroejaculation were performed in three periods
(P1, P2 and P3) with an interval of 15 days between P1 and P2 and 60 days between P2 and P3. Despite Canchim and Nelore bulls had
different IBW, the average daily weight gains were similar (1.86 vs. 1.56 kg, respectively; P > 0.10) and the breeds had the same profile of
sperm characteristics (vigorous movement, gross-motility, motility, concentration and % major or minor defects) during the three periods.
Among sperm abnormalities, Canchim bulls had less proximal cytoplasmic droplets (PD, 5.0±3.0%) than Nelore bulls (22.3±3.3%; P < 0.01)
in P1, suggesting that Canchim bulls were more sexually mature at the beginning of the evaluations. The % of major defects reduced 38.7%
from P1 to P2 and 50.6% from P1 to P3, on average, for both breeds. Similarly, the % of PD was significantly reduced from P1 to P2 and from
P2 to P3 (P < 0.01). Sperm concentration and motility increased from P1 to P2 and P3 (P = 0.08) and vigorous movement and gross-motility
were improved from P2 to P3 (P = 0.03). The SC increased continuously over time for both breeds and, as expected, Nelore had smaller SC
in all periods (P1: 29.4±0.7 vs. 33.6± 0.7; P2: 31.3±0.7 vs. 34.7±0.7; and P3: 33.4±0.7 vs. 37.7±0.7 cm, respectively; P < 0.01). We concluded
that, despite Nelore were younger and lighter than Canchim bulls, the feedlot regime that was employed has allowed a similar development
of sperm and semen characteristics between breeds, and potentially have hastened sexual maturity, especially in Nelore bulls. [Acknowledgements:
Financial supports from CNPq, FAPESP, ALLTECH and EMBRAPA (Innovation Network on Animal Reproduction - 01.07.01.002)].
Keywords: semen, pasture, feedlot.
A032 MALE REPRODUCTIVE PHYSIOLOGY AND SEMEN TECHNOLOGY
INFLUENCE OF SEXING ON BOVINE SPERM NANOROUGHNESS OUGHNESS MEASURED BY ATOMIC FORCE MICROSC
OSCOPY
OPY
Suelen Ribeiro Moita, , José de Oliveira Carvalho Neto, Margot Alves Nunes Dode & Luciano Paulino da Silva
EMBRAPA, BRASILIA, DF, BRAZIL.
The technique of sperm sexing applied to cattle increases economic advantages in systems in which production is favored by the
offspring of a particular sex. Currently, flow cytometry is the most used method for sperm sexing. The present study aimed to analyze and
characterize by atomic force microscopy (AFM) the surface of sexed sperm cells by flow cytometry, on a nanometric scale, since at this moment
there is no study involving this level of characterization. Semen samples were obtained from three Nelore bulls and divided into four experimental
groups: non-sexed (NS), X-sexed (SX), Y-sexed (SY) and pool of equal fractions of SX and SY (SXSY). To acquire the images of sperm cells,
the atomic force microscopy SPM 9600 (Shimadzu, Japan) was operated in contact mode. The plane-fit correction of images and segmentation
to isolate desired cells were performed, analyzing a total of 53 cells from each group/bull. Three distinct regions of the head of sperm cells were
delimited for evaluation: A region, next to the acrosome; B region, equatorial region; and C region, post-acrosomal region. ANOVA statistics was
performed and Tukey/Kramer test with a 5% (P < 0.05) of significance was used. The average value, median, maximum, minimum, mean
roughness (Ra), root mean square (Rms), skewness, and kurtosis were the measured parameters. The results were compared among the A, B,
and C regions, and among experimental groups. The average value, maximum, minimum, median, Rms and kurtosis parameters had no statistical
differences among the studied regions of the same experimental group. However, for Ra parameter, the A region showed higher roughness (NS:
51.9 ± 6.2 nm; SX: 55.9 ± 5.8 nm; SY: 60.2 ± 5.3 nm; e SXSY: 58.7 ± 5.7 nm) than the B region (NS: 14.2 ± 0.4 nm; SX: 16.8 ± 0.9 nm; SY:
14.3 ± 1.6 nm; e SXSY: 15.7 ± 1.4 nm) and C region (NS: 43.9 ± 2.9 nm; SX: 44.1 ± 2.7 nm; SY: 41.1 ± 2.4 nm; e SXSY: 42.7 ± 1.8 nm).
It was not possible identifying differences among experimental groups by ANOVA. It was concluded that atomic force microscopy is an
analytical method that allowed the characterization of sperm cells nanoroughness, identifying different topographic aspects along the head.
Keywords: atomic force microscopy, nanoroughness, sperm sexing.
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