ผลการเติมกลีเซอรีนดิบในอาหารข้น และการตอนต่อการกินได้ การย่อยได้ สมรรถภาพการเจริญเติบโต ลักษณะซากและผลตอบแทนจากการเลี้ยงแพะเพศผู้

Abstract

The objectives of this study were to investigate the effect of adding crude glycerin (CG) and castration on feed intake, digestibility, growth performance, carcass characteristics, and production return of 50%Thai native x 50% Anglo-Nubian (TA x AN) goats. Total of 20 male goats, 11-13 months of age with 25.16±1.99 kg initial live weight, were assigned to 2x2 factorial arrangement in a Completely Randomized Design (CRD). This study consisted of two factors. Factor A assigned for 2 types of adding crude glycerin (control diet and diet supplemented with 10% of crude glycerin), and factor B assigned for castration (intact male and castrated male). During 90 days of the study, goats were intensively raised in individual pens while fresh Atratum grass (Paspalum atratum) and water were ad libitum fed, and 2% of concentrate diet was daily provided. At the end of the experimental period, 3 goats from each treatment combination were randomly sampled for carcass characteristics determination. From the study, there was no significant interaction (P>0.05) between adding crude glycerin and castration on digestion coefficient, digestible nutrient, live weight gain, feed conversion ratio weight, and carcass percentage. Goats fed diet supplemented with 10% CG had a higher total feed intake (TFI) (g DM/h/d), organic matter intake (OMI) (g DM/h/d), crude protein intake (CPI) (g DM/kg BW. 75/h/d), neutral detergent fiber (NDF), acid detergent fiber (ADF) intake (g DM/kg BW. 75/h/d), and metabolizable energy than those fed the control diet (P<0.05). However, there was no significant between goats fed with different adding crude glycerin on nutrient digestion coefficient (P>0.05). Moreover, live weight gain, feed conversion ratio, slaughter weight, hot carcass weight, chilled carcass weight of the goat fed diet supplemented with 10% CG were better than those fed control diet (P<0.05). However, they had more abdominal fat percentage and carcass fat percentage than goat fed control diet (P<0.05). In addition, goat fed supplemented diet with 10% CG gain more production return than those fed control diet. In terms of castration effect, castrated goats had better TFI, OMI, CPI, NDF, ADF, live weight gain, feed efficiency, slaughter weight (P<0.05), but more abdominal fat percentage and carcass fat percentage could be observed in the castrated group (P<0.05). Neither intact males difference nor castrated goats had influenced on the apparent nutrient digestion coefficient (P>0.05). Considering the production return, castrated goats had better return than the intact males. From the results, it could be concluded that goats fed diet with adding crude glycerin and castration could lead to better feed intake, digestibility, growth performance, carcass characteristics, and production return than the intact male goats fed with the control diet. However, higher fat content in the abdominal part were indicated in castrated group fed with 10% CG addition.