Testicular parameters and spermatogenesis in different birthweight boars.
The present study investigated the effect of birthweight on testicular development and spermatogenesis in boars. Twenty-four pairs of littermate boars were selected: one piglet with the highest birthweight (HW) and the other with the lowest birthweight (LW) within the litter. Two subsets of 12 pairs of male littermates from each birthweight group were obtained after selection: one subset was orchiectomised at 8 days and the other at 8 months of age. HW boars had higher body and testicular weights at both ages (P<0.05). Testosterone concentrations and the relative expression of 17α-hydroxylase in the testis were similar between birthweight groups. Birthweight affected somatic and germ cell numbers in the neonatal testis, which were higher in HW boars (P<0.05). Moreover, a significant reduction in the number of pachytene spermatocytes and round spermatids was observed in LW boars (P<0.05) at 8 months of age, which caused a decrease in the total number of elongated spermatids and daily sperm production (P<0.05). Hence, HW boars have the potential to produce more spermatozoa and consequently more semen doses per ejaculate, and would be very valuable to an industry that relies on AI.
Biological Sciences Institute, Federal University of Minas Gerais, Av. Antônio Carlos 6627, 31.270-901, Belo Horizonte, MG, Brazil.
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PA
Auler
Veterinary School, Federal University of Minas Gerais, Av. Antônio Carlos 6627, 31.270-901, Belo Horizonte, MG, Brazil.
G H F A
GHFA
Moreira
The Roslin Institute and Royal (Dyck) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
C O
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Hogg
The Roslin Institute and Royal (Dyck) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
C J
CJ
Ashworth
Faculty of Veterinary, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9090, 91.540-000, Porto Alegre, RS, Brazil.
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FP
Bortolozzo
Biological Sciences Institute, Federal University of Minas Gerais, Av. Antônio Carlos 6627, 31.270-901, Belo Horizonte, MG, Brazil.
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H
Chiarini-Garcia
Biological Sciences Institute, Federal University of Minas Gerais, Av. Antônio Carlos 6627, 31.270-901, Belo Horizonte, MG, Brazil.
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FRCL
Almeida
D000818:Animals; D001724:Birth Weight / Q000502:physiology*; D048430:Cell Shape / Q000502:physiology; D008297:Male; D009929:Organ Size / Q000502:physiology; D013076:Sperm Count; D013087:Spermatids / Q000166:cytology / Q000502:physiology; D013090:Spermatocytes / Q000166:cytology / Q000502:physiology; D013091:Spermatogenesis / Q000502:physiology*; D013094:Spermatozoa / Q000166:cytology* / Q000502:physiology; D013552:Swine; D013737:Testis / Q000033:anatomy & histology* / Q000502:physiology*; D013739:Testosterone / Q000378:metabolism
D013739:Testosterone