Nutritional value of carob (Ceratonica siliqua) pods from different growing sites for sheep

Abstract

The current experiment aimed to determine the effects of the growing site on the chemical composition and fermentation parameters of carob pods. Carob pods from ten different trees were hand harvested from seven different growing sites namely; Silifke, Akdeniz, Tarsus, Aydincik, Taşucu, Toroslar and Gülnar in Mersin, Turkey in 2019 and oven dried at 50°C for three days. After drying, the carob pods were ground through a 1 mm-wide sieve for analysis and in vitro gas production (GP) testing. The growing site had a significant effect on the chemical composition, GP, and digestion values of carob pods. The crude ash (CA), crude protein (CP), ether extracts (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), and condensed tannin (CT) contents of carob pods ranged from 2.49 to 3.51%, 5.58 to 9.14%, 2.88 to 3.38%, 17.67 to 28.03%, 11.17 to 17.94%, and 1.98 to 5.05%, respectively. The GP, methane (CH4 (mL), percentage of CH4, metabolizable energy (ME), and organic matter digestibility (OMD) ranged from 95.66 to 123.0 mL g-1 DM, 16.23 to 20.12 mL g-1 DM, 15.69 to 16.96%, 8.24 to 9.72 MJ kg-1 DM, and 54.53 to 63.40%, respectively. The GP, CH4 production, and ME contents of carob pods obtained from Silifke, Akdeniz, Tarsus, and Tasucu were significantly higher than those from the other growing sites, whereas the OMD of carob pods from Silifke and Tarsus was significantly higher than that from the other sites. The true digestible substrate (TDS), microbial protein yield (MPY), efficiency of microbial protein yield (EMPY), and true substrate digestibility (TSD) of carob pods ranged from 319.54 to 469.62 mg, 109.07 to 207.09 mg, 32.34 to 44.10%, and 68.43 to 96.11%, respectively. The TDS, MPY, EMPY, and TSD of carob pods from Tasucu were significantly higher than those from the other sites. The current study revealed valuable insight regarding the chemical composition and fermentation parameters of carob pods grown at different sites. Carop pods can be used in sheep diets to meet the energy requirement of mature sheep for maintenance and lactation whereas protein supplementation is essential when incorporating carob pods into the diets of lactating sheep to fulfill their dietary requirements.