Use of fat tail dimensions for prediction of fat in tail and carcass in Egyptian ram lambs

Abstract EN

Forty five Egyptian ram lambs, 15 of each of Ossimi, Barki and Rahmani were used to investigate the influence of breed and body weight on fat tail measurements and carcass composition.

Fat tail measurements were also used to establish prediction equations to predict weights of fat tail (FTW), dissected carcass fat and total body fat (TBF).

Fat tail measurements were upper (UFTT) and lower (LFTT) tail thickness, upper (UFTW) and lower (LFTW) tail width, upper (UFTC) and lower (LFTC) tail circumference as well as tail length (FTL).

Body weight (BW), Empty body weight (EBW), hot carcass weight (HCW), fat tail weight (FTW), pericardial fat weight, omental fat weight, mesenteric fat weight and perinephric and pelvic fat weight were also recorded.

The left half carcasses were dissected into conventional cuts.

Barki ram lambs had significantly (P < 0.01) the least all fat tail dimensions.

Ossimi ram lambs had significantly (P < 0.01) the highest LFTW, UFTC and LFTC.

However, HCW was significantly (P < 0.05) the highest in Ossimi ram lambs (21.3 kg) followed by Rahmani (20.5 kg) and Barki ones (20.2 kg).

The highest dressing percentage was that of Ossimi carcass (52.0 %) which was significantly (P < 0.05) more than those of Rahmani (50.1 %) and Barki (49.3 %) carcasses.

Carcass of Ossimi significantly (P < 0.05) excelled that of Barki and Rahmani breeds in total fat stores.

Carcasses of Barki ram lambs had significantly (P < 0.05) higher non-carcass fat and dissected carcass fat and lower fat tail weight as a percentage of total body fat than that of both Ossimi and Rahmani.

FTW was positively and highly significant (P < 0.01) correlated with UFTC in Rahmani ram lambs (r = 0.93) and Barki ones (r = 0.89).

However, LFTC was positively and highly significant (P < 0.01) correlated with FTW in Ossimi ram lambs (r = 0.95).

It was found that positive and significant correlation coefficients were obtained between FTW of all breeds studied and TBF and dissected carcass fat.

Moreover, the upper circumference of tail accounted for 79 % and 86 % of the total variation in tail weight of Barki and Rahmani ram lambs, respectively.

In Ossimi, both lower circumference and thickness of fat tail accounted for 94 % of the total variation in FTW.

The obtained results cast light on the fat tail dimensions as the accurate parameters for prediction of fat weight in carcass of Egyptian sheep.