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

Acta Scientiae Veterinariae, 2011. 39(Suppl 1): Abstracts - 25th Annual Meeting SBTE-Brazil. August 2011.
A177 EMBRYOLOGY, BIOLOGY OF DEVELOPMENT AND PHYSIOLOGY OF REPRODUCTION
REPRODUCTIVE PERFORMANCE OF TWO
WISTAR RATS GENERATIONS SUPPLEMENTED WITH THE OMEGA-3 FATTY ACID
Carolina Bespalhok Jacometo 1 , Simone Halfen 1 , Francielle Bado 1 , Fernanda Trindade da Rosa 1 , Eduardo Schmitt 1 , Luiz Francisco Machado Pfeifer 2 , Augusto
Schneider 1 , Marcio Nunes Corrêa & Nelson José Laurino Dionello 1
1
UFPEL, PELOTAS, RS, BRAZIL. 2 EMBRAPA, PORTO VELHO, RO, BRAZIL.
The long-chain polyunsaturated fatty acids are not strictly necessary in the diet, but are important during the embryonic period,
acting on cell division, growth and differentiation. The aim of this study was to evaluate the effect of a diet enriched with omega-3 fatty acids
on reproductive performance of successive generations. Diets were prepared in accordance to the requirements of AIN-93, being isoenergetic
and isoproteic. Adult Rattus norvegicus - Wistar/UFPel female rats were used. In the F0 generation the animals received diets with linseed oil
(Om Group, n = 18) or soybean oil (CTL Group, n = 18) throughout pregnancy. F1 generation was divided into three groups: females from
Om Group of the F0 generation were supplemented with linseed oil (Om/Om Group, n = 16) or soybean (Om/CTL Group, n = 16) and
females from CTL Group of the F0 generation were supplemented with soybean oil (CTL/CTL Group, n = 16). In both generations the
females were mated in a male:female ratio of 1:3. From the F0 offspring, progenies were selected at weaning (day 21 postpartum) to compose
the F1. The variables evaluated in both generations were: pregnancy rate, number of pups per litter and average weight at birth. Statistical
analyses were performed using SAS. The pregnancy rate was compared among groups and generations by Chi-square, and number and weight
of pups by ANOVA and Tukey Test was used to compare means. There was no difference for the pregnancy rate among groups (P > 0.05).
Also, no difference was observed for the number of pups per female between group and generations (P > 0.05). However, in the F1 offspring,
higher weight at birth was observed in the Om/Om Group than CTL/CTL Group (7.3±0.2g vs. 6.6±1.3g; P = 0.01). Previous studies
demonstrated that pregnant rats subjected to diets enriched with omega-3 delivered higher weight at birth offspring. These effects could be
associated to the reduction of gestational hypertension and intensity of inflammatory effects, due to the inhibition of PGF2α and E2
synthesis (Church et al., Neurotoxicology and Teratology, 30: 107-117, 2008). Regarding performance between generations, the OmG
maintained the mean weight at birth from F0 to F1. However the CTLG reduced the mean weight of the offspring (0.84 g, P = 0.01). In
conclusion, a diet enriched with omega-3 fatty acids, in successive generations, did not affect the pregnancy rate nor the number of pups per
female, despite the offspring had a higher birth weight.
Keywords: generations, linseed oil, progenies.
A178 EMBRYOLOGY, BIOLOGY OF DEVELOPMENT AND PHYSIOLOGY OF REPRODUCTION
THE ONSET OF PUBERTY IN EWE LAMBS AFTER BIOSTIMULATION TION AND MEDROXYPR
YPROGESTER
OGESTERONE ONE ACET
CETATE TE OR LONG-
ACTING PROGESTERONE
Claudia Dias Mon
onteir
eiro Toma,
Son
ony Dimas Bicudo
icudo, Hugo Shisei
Toma,
Car
armo Emanuel Almeida Bisc
iscar
arde
de, Tiago Matos Oliv
liveir
eira,
Mar
arcel Barb
arbosa Falleir
alleiros
os,
Luana de Cassia Bicudo & Leandro Rodello
UNESP BOTUCATU, BOTUCATU, SP, BRAZIL.
The aim of this study was to evaluate the response of prepubertal ewe lambs to exogenous administration of either
medroxyprogesterone acetate (MAP) or long-acting progesterone (LAP) together with biostimulation under both male/female (MF) and
female/female (FF) effect for eight weeks. Two Pool Dorset adult males and 75 mixedbreed prepubertal ewe lambs (average of 179 ± 1,20 daysold
and 30.0 ± 0,124kg) were used. The females were randomly assigned to three different groups. Twenty five ewe lambs were submitted to
the insertion of intravaginal sponges containing MAP (60 mg) for 12 days and were then biostimulated. Twenty five other females were
submitted to a single dose of LAP (225 mg, IM) and then to biostimulation. The rest of the females (n = 25) were only submitted to
biostimulation. The cycling was demonstrated by evaluation of plasma progesterone (P4) = 1ng/mL concentration exceeded 1.0 ng/mL in at
least one of two consecutive blood samples taken within a 7-day interval (Shabankareh et al., 2009) in the pre and post-hormone treatment
and final period of biostimulation in all lambs, a total of 450 samples was collected and assayed. Data are submitted to the variance analysis
and compared by the Tukey test with 5% of probability at the SAS program System. After treatments 93.3% (70/75) of the females
disregarding their group started their cyclicity and most of them (92.0% 69/75), remained cycling until the end of the period (63 days)
biostimulation with or without the use of MAP or LAP. We conclude that employment at six months old, protocols with administration of
MAP for 12 days or a single dose of LAP, followed by biostimulation trigger puberty and maintance of cyclicity in lambs. It can be deducted
that the biostimulation MF and FF effects trigger puberty and maintance of cyclicity in untreated lambs.
Keywords: puberty, ewe lambs, progesterone.
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