A comparison of sorghum silage as roughage feed for lactating dairy cattle

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University of Dar es Salaam
Sisal pulp is a potential cattle feed as it is readily available at no cost on the sisal estates. The study was undertaken to investigate the effect of feeding sisal pulp silage to lactating dairy cattle fed at different levels with sorghum silage on milk yield and composition. Two experiments were conducted. In the first experiment in which the in vivo digestibility for the experimental diets were evaluated, 12 rams were fed sorghum silage (group 1), sorghum silage plus concentrate (group 2) and sorghum silage plus sisal pulp (group 3). The in vivo digestibility coefficients for sisal pulp silage and concentrate were obtained by difference. Sisal pulp silage was slightly superior to sorghum silage in form of chemical composition. The DM, OM, CWC and CP digestibility coefficients for sorghum silage were 44.4, 47.6, 46.0 and 44.5 respectively and the digestibility coefficients for sisal pulp silage in that order were 54.3, 56.5, 71.4 and 67.8 respectively. The CWC and CP digestibility coefficients for sisal pulp silage in that order were significantly higher (P 0.05) than the corresponding values for sorghum silage. The ME for sorghum silage and sisal pulp silage were 1.48 Mcal/kg and 1.95 Mcal/kg respectively and these were significantly different (p,0.05). In the second experiment, 18 lactating dairy cattle were used in a randomised block design in three treatment groups of six animals each. The experiment consisted of a pre-experimental period (4 weeks) during which all the animals were given 2/3 sorghum silage + 1/3 sisal pulp silage + concentrate. In the experimental period (6 weeks) the cows in-group 1 were offered 3/3 sorghum silage + concentrate but animals in group 2 continued to receive the same diet as in the pre-experimental period. Cows in group e were supplied with 1/3 sorghum silage + 2/3 sisal pulp silage + concentrate and in the post experimental period (4 weeks) all the cows were fed as in the pre-experimental period. Throughout the three feeding periods all the animals were allowed 2-3 hours grazing per day. The amount of concentrate offered to the three groups was the same. The voluntary roughage kg DM intakes per 100kg body weight were 1.31 for group 1, 1.19 for group 2 and 1.57 for group 3 animals. The differences were significant (P,0.01). The total DM intakes per metabolic body weight and the total ME consumed from the total diet followed the same trend. There were no significant differences (P,0.05) among the three treatment groups in form of actual milk yield, 4% FCM and milk composition. During the experimental period, the actual milk yield values for the three groups in the order of increasing sisal pulp silage in the diet were 8.4kg, 6.8kg and 8.1kg and the 4% FCM in that order were 8.9kg, 7.9kg and 8.9kg. However, animals in groups 3 gained more body weight but no significant (P,0.05) during the experimental period, followed by group 2 and group 1 gained the least. It is concluded that sisal pulp silage may be used as the major part of the roughage diet for lactating dairy cows without any adverse affect on animal health or production.
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Dairy cattle, Feeding and feeds, Sorghum silage, Sisal hemp
Majani, A.S (1980) A comparison of sorghum silage as roughage feed for lactating dairy cattle, Masters dissertation, University of Dar es Salaam. Available at (