In Situ Degradation Of Poor Quality Hay In The Rumens Of Mature Heifers As Influenced By Sugar, Starch And Nitrogen Supplements And An Ionic Feed Additive

The impact on rumen degradation of hay dry matter from dacron bags of supplements traditionally used by smallholder dairy farmers in Tanzania is reported. The supplements included sources of energy and protein (maize bran, molasses, cassava flour and sunflower cake) and an ionic feed additive called “Magadi”. The experimental layout was a 5x5 Latin square with 21 days for adaptation to diets followed by in sacco incubation of hay DM for 0, 2, 4, 8, 16, 24, 48, 96 and 144h. Treatments were: Poor quality hay with 2.7 kg (DM) maize bran (HMB) (control), hay with 2.7 kg (DM) maize bran further supplemented with (DM) 0.25 of “Magadi” (HMG), 1.3kg (DM) sugars (molasses) (HMO) or 0.9 kg (DM) starch (HCA) and hay supplemented with 2.8 kg (DM) of farm made concentrate mixture containing maize bran (68), sunflower cake (31) and mineral powder (1% DM) (HFC). Five mature heifers (Boran x Friesian) were used during the trial. DM and organic matter intake was significantly higher with sugars (HMO), starch (HCA) and nitrogen (HFC) supplements compared to the control. Sugars and starch led to significantly lower degradation rate compared to nitrogen and \"Magadi\". It is hereby concluded that the use of energy rich supplements can have depressive effects on the utilisation of poor quality roughage while nitrogen rich supplements and “Magadi” have positive effects on plant fibre degradation. Tanzania Veterinary Journal Vol. 24 (1) 2007: pp. 23-37