| || || Tamani, Eroni|
| || || Effect of molasses at different levels in the concentrate supplement on the milk yield of dairy cows grazing Setaria grass (Setaria sphacelata) pasture in the Central Division, Fiji |
Institution: University of the South Pacific.
Subject: Dairy cattle -- Feeding and feeds -- Fiji, Milk yield -- Fiji, Cows -- Feeding and feeds -- Fiji
Call No.: pac SF 203 .T25 2004
Copyright:Under 10% of this thesis may be copied without the authors written permission
Abstract: Farm born thirty milking cows (Friesian) with mean pre-experimental body weight of 428 6.48 kg, 6 - 7 years old, 3 – 4 lactations with an average of 92 days in lactation on 19 August 2002, were randomly allotted to five diets in a completely randomized design experiment to investigate the effect of supplementary concentrate diets with varying levels of molasses on milk yield of cows grazing Setaria grass pastures. Treatments were forage alone and forage + concentrate diets with molasses included at 0, 5, 10 or 15 % levels. These treatments were designated as T1, T2, T3, T4 and T5, respectively. Voluntary dry matter (DM) intake, average daily gain (ADG), milk yield, body condition score (BCS), blood glucose and urea-N, milk fat and protein and apparent nutrient digestibility coefficients were studied. DM and energy contents of Setaria were low compared to the concentrate diets. Concentrate diets had mean crude protein (CP) content of 18.1 %. Fibre fractions neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), hemicellulose and cellulose) and gross energy were higher in concentrate diets than in the forage. Total DM intakes (forage + concentrate diets) were significantly higher (P<0.001) for cows on concentrate diets. ADG was not different among cows. Average milk yield among cows in the treatments were significantly different ((P<0.05) from each other. Fat corrected milk (FCM) was similar among treatments. BCS was better (P<0.001) in cows on concentrate diets. Blood urea-N peaked at 18 d with a significant (P<0.05) difference between cows in T2, T3, T4, and T5 on one hand and T1 on the other. Differences between the former were not significant. Mean blood urea-N (BUN) concentration was 3.2±0.18, 4.4±0.33, 4.0±0.30, 3.9±0.23 and 4.0±0.43 mmol/l for T1, T2, T3, T4, and T5, respectively. Blood glucose peaked at 18 d and cows on concentrate diets had significantly higher (P<0.05) concentration. ix Mean blood glucose concentrations were 2.37±0.29, 2.63±0.32, 2.80±0.29, 2.80±0.40 and 3.00±0.33 mmol/l for T1, T2, T3, T4, and T5, respectively. Milk protein increased with time and reached the highest level between 60 and 70 days for all diets (P<0.05; P<0.001). Milk fat of cows on all treatments followed the same trend as milk protein (P<0.05). Digestibility of all components (DM, CP, NDF, ADF, ADL, OM, and energy) measured was significantly higher (P<0.001) in cows in T2, T3, T4 and T5 than those in T1. For cows on concentrate there were no differences in the digestibility of DM, CP, NDF, ADF and ADL (P>0.001). Based on production parameters, molasses levels that range between 5 - 10 % are recommended. Finally, molasses at the 10 % level is recommended in the concentrate diets for optimum milk yield, fat corrected milk, body condition score, milk and blood constituents and apparent nutrient digestibility coefficients of lactating dairy cows on a basal diet of Setaria sphacelata in Fiji. x