Eny Endrawati et al. Carrying Capacity Estimation of Herbicide-Treated and Untreated Palm Oil Plantation 130 Doi: 10.21059/buletinpeternak.v43i2.38036 Carrying Capacity Estimation of Herbicide-Treated and Untreated Palm Oil Plantation for Bali Cows Eny Endrawati 1 , Panjono 2 , Bambang Suhartanto 2 , and Endang Baliarti 2* 1 Study Program of Animal Science, Faculty of Agriculture, Universitas Khairun, Maluku Utara, 97719, Indonesia 2 Faculty of Animal Science, Universitas Gadjah Mada, Bulaksumur, Yogyakarta, 55281, Indonesia Article history Submitted: 10 August 2018 Accepted: 13 May 2019 * Corresponding author: Telp. +62 811 2572 07 E-mail: bali_arti@ugm.ac.id ABSTRACT This study aims to estimate the carrying capacity of oil palm plantations with the use of herbicides based on the forage availability for Bali cows. The research was performed in palm oil plantation owned by PTPN V Riau, from March 2016 until March 2017. The parameters observed were 1) Forage production that grows between palm trees at 6 weeks cutting age. The forage sample was taken from 5 point of 1x1m 2 , then subjected to proximate analysis. Data were analyzed with one-way random design, 2) Forage consumption; obtained by observation of 5 pregnant Bali cow and 7 non- pregnant for seven consecutive days 3). Estimated carrying capacity for Bali cows, obtained from the calculation of forage production (/ha/year) divided by forage consumption. The result of the research showed that 1). The production of dry matter (DM) forage in herbicide-treated areas was 689.55 kg/ha/year, not significantly different compared to untreated areas (622.33 kg/ha/year). Crude protein (CP) forage content of forage obtained from herbicide-treated area was significantly higher (p<0.05) than untreated area, whereas the total content of DM and total digestible nutrients (TDN) was not significantly different. DM consumption of pregnant Bali cow was on average 3.68±0.29 kg/head/day or 1,343.20±105.85 kg/head/year and non-pregnant 4.02±0.36 kg/head/day or 1,467.30±131.4 kg/head/year. The estimated carrying capacity on herbicide-treated (0.51 head of pregnant cow/ha), did not show any significant difference compared to untreated area (0.46 head/ha). For non-pregnant, the carrying capacity of herbicide-treated area (0.47 head/ha) was not different with non- treated area (0.42 head/ha). It was concluded that the use of herbicide on palm oil plantation had no effect on the carrying capacity of the Bali cow. Keywords: Bali cattle, Carrying capacity, Herbicides, Oil palm plantations Introduction Palm oil plantation holds great potency for cattle production through integration system with it – as it provides various forages for ruminant (Sisriyenni dan Soetopo, 2013). Syahputra et al. (2011) reported, around young trees that have not yielded any fruit, at least 18 types of weed from 13 families were found. Meanwhile, more types of weed, as many as 21 types form 15 families were found around the fruit-producing trees. According to study performed by Adriadi et al. (2012), there are 3,934 forages, 56 species, 47 genus, and 20 family in the palm oil plantation. These numbers comprise of 7 types of sedge, 10 types of grass, 18 family with 38 types of large leaf plants, and 1 family with 1 type of fern. Among of them, Paspalum conjugatum is the most forage found (1,029 number) and Cuphea platycentra being the least (2 number). Chin (1998) reported that forages growing under young palm oil trees can yield 1,600 to 2,600 kg/ha of dry matter. It will fall off to 600 kg/ha along the age of the trees. The annual production of dry matter of forages growing under palm oil trees aged 3 to 4 years can be higher, up to 13,280 kg/ha (Abdullah, 2006). Theoretically, 2 hectares of palm oil trees aged 3 to 15 years can carry one unit of cattle with 250 kg of body weight (Liang, 2007). Carrying capacity of plant oil plantation with trees aged under 3 years is 1.44 unit/ha, while it will decline to 0.71 unit/ha for 6 years old trees (Daru et al., 2014). Forages on palm oil plantation are managed as weed and exterminated by using herbicide. The treatment is commonly performed annually. As a consequence, there is a certain time that forages and grasses could not be harvested. Unfortunately, the forage production on this herbicide-treated area has not been fully elucidated. One of important aspects on cattle-palm oil integrated system is the fulfilment of nutrient Buletin Peternakan 43 (2): 130-134, May 2019 Bulletin of Animal Science ISSN-0126-4400/E-ISSN-2407-876X Accredited: 36a/E/KPT/2016 http://buletinpeternakan.fapet.ugm.ac.id/