Measuring responses to an oil drench and bypass protein (cassava foliage) in local (Yellow breed) cattle fed rice straw and a rumen supplement
 

Sypraseuth Khonglalien, Bounlieng Khoutsavang and Phonepaseuth Phengsavanh

Livestock Research Centre, National Agriculture and Forestry Research Institute,
Ministry of Agriculture and Forestry, P. O. BOX 7170, Vientiane, Lao PDR.
p.phengsavanh@cgiar.org

The experimental animals were 20 females of local “Yellow cattle” about one year of age, average 100 kg live weight, with 10 animals allocated to each of two experiments. In experiment 1, The treatments were a single drench on day 1 of soybean oil at levels of 2, 3, 4, 5 and 6 ml oil/kg LW.  In experiment 2, the treatments were cassava hay at 0, 0.3, 0.6, 0.9 and 1.2 kg DM/100 kg of LW (approximately 0, 0.75, 1.5, 2.25 and 3 g protein/kg LW). .In each case the design was a production function using regression analysis to relate responses (live weight gain and feed conversion) with inputs (oil drench or cassava hay). Animals in the group receiving different levels of cassava hay also received 5 ml of oil by drenching at the start of the trial. Animals in the group drenched with different levels of oil also received 1.2kg /day of cassava hay/100 kg live weight. All cattle were fed ad libitum rice straw and a rumen supplement block (13% urea, 3% diammonium phosphate, 1% sulphur, 5% salt, 5% CaO, 30% rice bran, 43% molasses).

Growth rate was significantly increased by oil drench and supplementing with cassava foliage. The mean values were 100, 241, 275, 225, 420 and 150, 175, 212, 225, 462 g/day (SEM ± 5.520) for the increasing levels of oil drench and cassava foliage, respectively. There was strong relationship between cassava foliage intake (X) and LWG (Y) represented by the equation Y= 262.17X + 87.5 (R² = 0.84), and a weaker relationship between levels of oil drench (X) and LWG (Y) represented by the equation Y = 60.45X + 6.6 (R² = 0.57). The oil drench significantly reduced the protozoa population. However, there was a rapid re-infestation of the small protozoa, mainly Entodinia,  to a level comparable to the control groups. Only a few large protozoa, mainly (Polyplastron and Holotrichs) were observed. In  the present study numbers of protozoa were significantly smaller in oil drench treatments. In addition, rumen ammonia concentrations tended to be lower in oil-drench animals.  Feed intake was not affected by level of cassava foliage nor  by the oil drench.

Keywords: Cassava foliage, growth, , oil drench, protozoa, rumen ecosystem, Yellow-cattle