Animal Nutrition and Feed Technology

Devi, T.D., Ravi, A., Rao, D.S. and Babu, D.S. 2023. Evaluation of dry baker's yeast vinasse as a substitute for molasses in urea molasses mineral blocks fed to growing ram lambs. Animal Nutrition and Feed Technology, 23: 131–141.

The objective of the study was to evaluate dry baker's yeast vinasse (DBYV), a by-product of baking industry as a substitute of molasses in urea molasses mineral block (UMMB) for keeping quality of blocks, growth performance, nutrient digestibility and nitrogen balance in growing ram lambs. DBYV was included at 0 (UMMB1, T1), 5 (UMMB2, T2), 10 (UMMB3, T3) and 15% (UMMB4, T4) in UMMB, replacing molasses. In a completely randomized design, 24 growing ram lambs (3–4 month old) weighing 13.71+0.4 kg were divided into 4 groups of 6 animal each and allotted to four dietary treatments; T1 to T4, respectively. Lambs were fed Andhra Pradesh bajra napier (APBN) green fodder based diet ad libitum and concentrate mixture at 1% of live weight. The chemical composition (%) of the DBYV was 98.37 DM, 13.47CP, 0.24 EE, 0.01 CF, 56 total ash, 0.21 AIA, 30.18 NFE, 1.15 Ca, 0.55 P and the level of copper, cobalt, zinc and manganese was 1.43, 0.99, 10.42 and 92.09 mg/kg, respectively. There was no foul odour, colour change, mould and salmonella growth in the UMMB during the 4 month storage at room temperature. The hardness (kg/cm²) of the blocks decreased (P<0.01) as the inclusion level of DBYV to replace molasses increased and also with increase in the storage period. The pH was lower (P<0.01) in UMMB4 than in other treatments and it increased (P<0.01) as the storage period progressed. The yeast count of DBYV was 10.2x10⁴cfu/g and for blocks it ranged from 10.5 to 11.5x10⁴ cfu/g on the day of preparation and 8.5 to10.9x10⁴cfu/g at the end of 4 months storage period. The average daily gain (g) of lambs was significantly (P<0.05) higher in T3 than in T4. The feed efficiency, was lower (P<0.05) in T4 fed lambs. The digestibility of DM, CP, EE, and NFF among the treatments was comparable whereas, significantly (P<0.05) higher CF digestibility in T3 fed lambs was observed. The DMI (% body weight), CP and TDN% of the diet and nitrogen balance (% intake) were significantly (P<0.05) higher in T3 than in other treatments. It was concluded that DBYV can be included up to 10% to replace molasses in UMMB in the diet of growing ram lambs.