GnRH'ye Karşı Aşılanan Erkek Kuzularının Yem Değerlendirme ve Karkas Özellikleri

Tez Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: University of Wyoming, Zootekni, Amerika Birleşik Devletleri

Tez Danışmanı: Prof. Dr. Garry E. Moss

Tezin Onay Tarihi: 1998

Tezin Dili: İngilizce

Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu

Desteklendiği Program: Diğer

Özet:

It was hypothesized that ram lambs immunized against GnRH possess the

desirable production and carcass traits of intact ram lambs. Intact male lambs received no

treatment (R), were immunized with GnRH linked to keyhole limpet hemocyanin in

either Freund’s complete adjuvant (FCA) or ISA adjuvant (ISA), or were castrated (C).

Anti-GnRH titers were higher in FCA immunized rams than ISA rams. Testicular

weights, function and sexual behaviors were reduced by immunization. Days on feed

were greater in C lambs than in R lambs, with FCA and ISA lambs intermediate. Average

daily gains were greater in R than C, FCA and ISA lambs. Feed efficiencies for R lambs

were better than in C, ISA and FCA lambs, but did not differ among C, FCA or ISA

lambs (p>.05). Ribeye area, lean and bone maturity, overall quality, muscling score, flank

streaking and color of fat did not differ among groups. Intact males, FCA, and ISA

lambs had more (p<05) desirable yield grades, less (p<05) back fat, and less (p<05)

marbling than C lambs. Body wall thickness for R, ISA and FCA lambs was less (p<05)

than C lambs, and for FCA were greater (P<05) than R lambs.

In summary, immunization against GnRH decreased testicular weight and

reduced (p<05) live animal performance and sexual behaviors to values comparable to

those of castrated males. Partitioning of nutrients for growth and deposition of fat

appears to differ among immunologically castrated and mechanically castrated lambs

probably due to residual testicular activity.