10. Mulberry (Morus alba) leaves as protein source for young pigs fed rice-based diets: Digestibility studies
Authors: Chiv Phiny, Preston T R and Ly J 2003
Livestock Research for Rural Development (15) 1. Retrieved, from
Summary: Mulberry (Morus alba) leaves were obtained from a plantation on the Ecological Farm of the University of Tropical Agriculture at Chamcar Daung that was periodically harvested (every two months). The mulberry leaves and petioles were used as fresh material or after being sun-dried. In each case the leaves were either chopped or ground. The mulberry cultivar was of an unknown variety. Two experiments were conducted to study the effect of the inclusion of mulberry leaves on the nutritive value of rice-based diets fed to growing pigs.
Experiment 1: A double 4x4 Latin square design in a 2x4 factorial arrangement was used to study the effect of including graded levels of mulberry leaf meal replacing rice bran and fish meal in diets based on broken rice. Eight young castrate male Mong Cai or Large White pigs weighing on average 14.2 kg were distributed at random into four treatments consisting of four diets containing different levels of mulberry leaves. Mulberry leaves were sun-dried, then ground and mixed with the other components of the diets. The pigs were housed in metabolism cages in an open house. The adaptation period was five days, followed by another five days for total faeces and urine collection. Feed offered was fixed at 50 g DM/kg body weight. Feed ingredients, feed refusals and faeces were assayed for DM ash and N.
Experiment 2: Six young Mong Cai x Large White castrate male pigs weighing on average 15 kg were allocated, according to a balanced two period change-over design (Gill 1978; Gill and Magee 1976), to two diets based on rice and wheat products where mulberry leaves, either sun-dried and then milled, or fresh and chopped. The same procedures as described in Experiment 1 were used for animal housing, feeding and collection of excretion outputs. In the case of the treatment with fresh mulberry leaves, the amount of foliage needed was harvested every day, and then offered to the animals after chopping and before giving the supplement containing the dry components of the diet. Feed offered was 40 g DM/kg of body weight. The same analytical methods as in Experiment 1 were used for the determination of the amounts feed offered and refusals, and faeces and urine ouputs. Representative samples of fresh and dried mulberry leaves were analysed for DM solubility and for water holding capacity (WHC). Other determinations consisted of faecal pH measurements using a glass electrode connected to a digital precision pH meter.
Abstract: Two experiments were conducted to study the effect of the inclusion of mulberry leaves in diets for pigs on digestibility indices and N balance. In experiment 1, a double 4x4 Latin square design in a 2x4 factorial arrangement was used to study the effect of graded levels of mulberry leaf meal (0, 15, 30 and 50% on a dry basis, respectively) in diets based on rice products on the N balance of eight young castrate male Mong Cai or Large White pigs with a mean weight of 14.2 kg. Mulberry leaf meal (MLM) contained DM 30.4 % and in the dry matter: ash 16.9, crude fibre 20.1 and crude protein (Nx6.25) 25.4%, respectively. Feed intake was calculated to be 50 g DM/kg body weight. Although not significant, DM and organic matter digestibility appeared to increase with increasing levels of dietary MLM. Organic matter was significantly (P<0.05) better digested in Large White than in Mong Cai pigs. N balance indices improved with the inclusion of MLM in the diet, and this effect was significant for N retention (P<0.05) when expressed as proportion of N digested. Mong Cai pigs appeared to have lower N digestion and retention as compared to the Large White. In experiment 2, six young Mong Cai x Large White castrate male pigs, weighing on average15 kg, were allocated according to a balanced change over design, to two diets where mulberry leaves, either in milled, sun-dried or chopped, fresh, contributed about 45% of the total daily N intake in iso-nitrogenous diets (Nx6.25, 13.7% on a dry basis). There were no significant effects of treatment on DM, organic matter and N digestibility but dry leaves were associated with slightly lower digestibility values. N balance tended to be better in pigs fed fresh mulberry leaves compared to mulberry leaf meal. It can be concluded that in rice-based diets for, it is possible to use mulberry leaves as the main protein source.