The experiment was conducted to evaluate the effect of effective microorganisms (EM) containing Lactobacillus spp. on production performances of cross-bred Jersey cows in dry zone of Sri Lanka. Six, cross-bred (Jersey × Sahiwal) milking cows were randomly assigned to the control and treatment groups. Animals in treatment group were daily given with EM after the milking. Higher average milk volume was observed in animals provided with EM (P < 0.05). However, higher milk fat contents were observed in the control group (P < 0.05). Solid non-fat content in milk was not significantly different (P > 0.05) between control and treatment groups. Body condition score of animals in both groups were similar (P > 0.05). Further, less unpleasant odour and fewer amounts of undigested feed materials were observed in cow dung of animals provided with EM. Therefore, results revealed that supplementing Lactobacillus spp. increases the milk volume and improves health of Jersey × Sahiwal cross-bred dairy cows, reduces cost of production and controlled malodor in the farms. The economic analysis for using EM in dairy cows indicates that EM is a cheaper product and could be used profitably in dairy farming.
Anuradhapura is a district in dry zone of Sri Lanka, which has a key importance to the dairy industry of Sri Lanka. Estimated daily cow milk production in the district is around 85,117 L (DAPH, 2016). Majority of the dairy farmers in the district are smallholders who maintain herds of 5 – 10 milking cows. Both indigenous and exotic crossbred cows are reared by these farmers (Ibrahim et al., 1999). Jersey crossbred cows are the most popular breed among the farmers in the area. However, in the dry zone, yield and composition of milk from Jersey crossbred animals are lower than their full genetic potential. Further, the industry should be further improved because Sri Lanka is not self-sufficient in milk (DCS, 2016). Lower milk yield and poor composition of milk are quantity and quality related constraints in the industry. These reduce the farmer income as milk with lower composition has a lower demand. Also unpleasant odour of cattle sheds due to cow dung and urine creates environmental issues in the area. By improving or modifying the rumen activities of cow, milk yield and composition can be enhanced (Wanapat et al., 2013). Also it reduces the unpleasant odour of cow dung through improved digestion (Sun et al., 2017). Effective microorganisms (EM) are naturally occurring microorganisms which have beneficial effects on cow health (Uyeno et al., 2015). Lactobacillus acidophilus and Lactobacillus plantarum are two common microorganisms used as EM and they can be used as a cost effective method for enhance the rumen activity (Retta, 2016; Seo et al., 2010). Hence, aim of this study was to evaluate the effect of EM on enhancing yield and composition of cow milk and on reducing the unpleasant odour of cow dung.
Materials and Methods
Field trials were done at small scale farm in Saliyapura, Anuradhapura, Sri Lanka. Milk analysis was done at Dairy Science Laboratory, Faculty of Agriculture, Rajarata University of Sri Lanka.
Experimental Animals and Design
Six, Jersey x Sahiwal crossbred lactating cows (2nd parity and average body weight of 300 kg) were selected. Three cows were randomly assigned in to EM treatment and other three cows were kept in control group. Experiment was conducted as a Complete Randomized Design (CRD). Cows were allowed to graze in the daytime and were kept in the shed in the night. Mixture of commercial cattle feed and rice bran was fed to cows once a day in the evening. Milking was done once a day in the morning. Product containing EM was fed to the cows in treatment group after milking every day, starting from d 01 to 45 days. Duration of the trial was 60 days; first 15 days were considered as an adaptation period and during the last 15 days no cow was fed with EM.
Product with EM were available in two forms as liquid and powder, where one gram of powder contains 107 cfu and 1 mL of liquid contains 107 cfu of EM. Effective microorganism product was not mixed with regular feeds or drinking water. Powder and liquid were mixed together and fed to the cows. From d 01 to d 15 of the trial, each animal in the treatment group was fed with 200 g of powder and 200 mL of liquid every day morning. From d 16 to the d 45 each cow in treatment group was fed with 100 g of powder and 100 mL of liquid every day morning.
Body weights of the cows were measured and recorded from d 1 to d 60 in two weeks interval using a weighing belt. At the beginning and the end of trial, body condition score (BCS) of cows were recorded and scale of 1 to 5 was used (Ferguson et al., 1994) . Milk volume was measured daily. Mass of the milk produced by each animal was measured at the field using a hanging scale and milk density was measured using an ultrasonic milk analyzer (Lactoscan, Bulgaria). Then, milk volume was calculated using following formula-
Milk samples of each animal were taken every day into 60 mL sample bottles and tested using ultrasonic milk analyzer to measure and record the milk fat and SNF contents.
Odour and appearance of the cow dung of each cow were observed and reported every day.
All parametric data like milk volume, fat content and SNF content were analyzed using two sample t-test procedure in Minitab 16.1.0 software package (Minitab, 2010). Non-parametric data (BCS) are analyzed using Wilcoxon rank sum test procedure. Statistical significant was declared at P < 0.05.
Results and Discussion
There was a significant difference (P < 0.05) in daily average milk yield of cows in control and EM treated groups during the study period of day 16 – 45 (Table 1 and Fig. 1). Average milk yield was higher (P < 0.05) in the cows fed with EM compared to the cows in control group. The results of the trial are in corroboration with the finding that the naturally occurring microorganisms contained in EM create more effective intestinal micro flora with a greater synthetic capability (Aemiro et al., 2014). After entering to the body as feedstuffs, EM can enhance the processes of synthesis of vitamins, hormones and enzyme systems that improve digestion (Dahal, 1999; Morowitz et al., 2011; Wei-Jionge et al., 1992). Also EM inhibits the growth of pathogenic microbes in the gut (Seo et al., 2010). So the digestion process inside the cow is supported by several ways while negative influences on the digestion processes are controlled.
Table 1: Daily average milk productions, milk fat and milk solid non fat (SNF) contents of cows in control and effective microorganism (EM) treated groups
|Parameters||EM Treated Group||Control Group|
|Average milk yield, (L/ day)||3.91 ± 0.56a||3.26 ± 2.02b|
|Average fat content, (%)||6.07 ± 1.08a||7.07 ± 1.93b|
|Average SNF content, (%)||7.86 ± 0.70a||8.03 ± 0.76a|
Data are presented as mean ± SD; a,b Means within the same row with different superscripts are significantly different (P < 0.05)
This increases the amount of nutrients produced and absorbed in the digestive tract. This gives more nutrients to the cow and eventually it leads to higher production of milk (Hanning and Diaz-Sanchez, 2015). This may be the reason for observed higher production of average milk in EM treated group compared to the control group.
Fig.1: Change of milk yield of the cows in control and effective microorganisms treated groups.
Milk Fat Content
There was a significant difference (P < 0.05) in daily average fat content of milk tested from cows in control and EM treated groups during the study period (Table 1 and Fig. 2) and average fat content in the milk was higher in cows in control group compared to the EM treated group. It is an established fact that EM provides more nutrients to the cow (Dahal, 1999). So, obviously the component of the milk should be enhanced with the supply of EM. However, the exact mechanism of how EM, once provided, elicits beneficial effects on animal health, growth and metabolism is not known. So, the performance of microorganism in EM inside the digestive tract may depend on several internal and external factors, such as climate, type of feeds, method of feeding, gut micro flora and genetic potential of cows (Hanning and Diaz-Sanchez, 2015). These factors may influence on the milk production of cows by altering the performances of microorganisms in EM. The influence of these factors on qualitative and quantitative parameters of milk may not similar as in the gut level those parameters are initiated by different procedures. That may be the reason for observed lower fat content of milk from EM treated group.
Fig. 2: Change of fat content of the milk from cows in control and effective microorganisms treated groups
Milk Solid Non Fat (SNF) Content
There was no significant difference (P > 0.05) in daily average SNF content of milk obtained from cows in control and EM treated groups during the study period (Table 1 and Fig. 3).
Even EM enhances the digestion process of the cow, it may not qualitatively increases the milk production as several external and internal factors may effect on the performances the cow. These factors can have both positive and negative influences on component of milk which determines the quality of milk. Tropical conditions in the dry zone of Sri Lanka are not much favourable for European cattle breeds (Ibrahim et al., 1999). So, the milk yield and composition of Jersey crossbred cows in the area are negatively influenced by tropical conditions. As an important component in cow milk, SNF content significantly influences on the quality of milk. With the enhancement of digestive process and nutrient supply, the SNF content of milk from cows in EM treated group should be increased. However, observed similar SNF content in milk in two groups may be due to the negative influences which hide the performances of EM in qualitative enhancement in milk production of cows.
Fig. 3: Change of solid non fat content of the milk from cows in control and effective microorganisms treated groups
Body Condition Score (BCS)
There was no significant difference between the BCS of cows at the beginning and end of the study. Further, BCS of cows in both control and EM treated groups were same (P > 0.05) during the study. Body condition score changes with the stage of lactation. During the early lactation period, cows lost BCS due to the negative energy balance (Sakaguchi, 2009). In the mid lactation, BCS shows no change as cows have a neutral energy balance. Usually, at the late lactation period, BCS increases as cows have a positive energy balance (Yamazaki et al., 2011). Therefore, the changes in BCS could be due to the level of available nutrients in the feed. As all the cows selected for this study were in mid lactation, they were in energy balance and most of the nutrients absorbed are used for the milk production. This reduces the amount of nutrient available for fattening. If the cows are treated with EM for longer period, they may show improvements in body conditions.
Visual Observations of Cow Dung
Comparatively less unpleasant odour and fewer amounts of undigested feed particles were observed in cow dung of EM treated group. The odour of cow dung is mainly depends on the amount of undigested feed in the cow dung. As EM increases the digestion and absorption process, ultimately the cow dung contains lower amount of undigested feed. So the cow dung of cows in EM treated group had lower amount undigested feed and less unpleasant odour.
Table 2: Body condition scores of cows in control and effective microorganisms treated groups
|Treatment||Replicate||Day 15||Day 46|
Scores were based on 1 -5 BCS scale (Ferguson et al., 1994)
Milk production is increased by providing EM (Lactobacillus spp.) to Jersey × Sahiwal crossbred lactating cows in dry zone. However, EM does not enhance the quality of milk and reduces the milk fat content. Also EM feeding does not change the milk SNF and influence the body condition of lactating cows. However, EM reduces the unpleasant odour of cow dung and amount of undigested feed particles in the cow dung.