Dharma Sahu D. K. Mandal Champak Bhakat Anupam Chatterjee Ajoy Mandal Mohan Mandal Vol 8(4), 272-280 DOI- http://dx.doi.org/10.5455/ijlr.20171012061118
The objective of the present study was to find out the effect of roof thermal insulation and soft flooring on microclimate of cow shed, physiological response and production performance of crossbred Jersey cows under loose housing system. Twenty crossbred Jersey cows were divided into two groups, ten in each. Two types of housing were compared- (i) Existing shed (T0)- having asbestos roof and concrete floor and (ii) Modified shed (T1)- thatch ceiling under asbestos roof and partial replacement of concrete floor with sand bed. The surface temperatures of the thatch ceiling at covered area and sand bed floor at open area were significantly lower in the modified shed (T1) in both the seasons as compared to existing shed (T0). Physiological indices viz. rectal temperature, pulse rate and respiration rate of crossbred Jersey cows were significantly higher in T0. The daily milk yield of T1 group cows was significantly higher than that of T1. Housing modification by thatch ceiling and soft flooring by sand bed helped improving micro-climate of shed, relieved stress conditions and showed enhanced milk yield in crossbred Jersey cows.
Keywords : Crossbred Cow Milk Yield Respiration Rate Sand Floor Thatch Roof Temperature
Introduction
In general, housing of dairy cows is done to keep them comfortable, protected and constructed as per local conditions. The housing despite the fact that exposes animals to climatic effects of high environmental temperatures, which may exceed their ability to dissipate body heat. Being homeo-therms, cows attempt to maintain the thermo-neutral zone regardless of the outside temperature and at initial level that can be achieved without expending extra energy. Solar radiation is being a major factor in heat stress, increases heat gain by direct and indirect means (Berman and Horovitz, 2012). Stress is one of great concern which deteriorates the animal welfare and ultimately affects the milk production and reproduction of dairy cows. Stress condition of cows may be a result of harsh climatic conditions and deprivation from feed intake and comfortable resting time. There is reduction in milk production and animal welfare due to the stress, climatic condition and improper housing comfort (Mandal et al., 2002; Upadhaya et al., 2009; Bharambe et al., 2013; Kamal et al., 2013; Kamal et al., 2014; Mandal et al., 2016; Mote et al., 2016). Modification of existing shelter can help in manipulation of microclimate towards improvement in production and livestock welfare without making much expenditure on modification / construction alteration. Animal productivity benefits should be reflected from the costs of improving the animal’s environment (Atkenson and Bickert, 1997). Shelter management is one of the important aspects for reducing stress to animals and improving welfare. Soft flooring provides pleasant resting and footage comfort. Because of very less thermal conductivity of paddy straw, thatching underneath the asbestos roof might be beneficial for reducing heat stress. So, the present study was conducted to find out the effect of roof thermal insulation and soft flooring on microclimate of cow shed, physiological response and production performance of crossbred Jersey cows under loose housing system.
Materials and Methods
Location of the Experiment
The present study was carried out at ICAR-National Dairy Research Institute (ICAR-NDRI), Eastern Regional Station (ERS), Kalyani, West Bengal. The weather of Kalyani is hot and humid; the maximum ambient temperature in summer goes up to 39oC and minimum temperature in winter comes down to about 8oC. The average annual rainfall is 1000-2000 mm, most of which is received from early June to September.
Experimental Cows
Twenty lactating crossbred Jersey cows were selected from the herd of ERS, Kalyani of ICAR-NDRI and divided into two groups consisting of ten cows in each group keeping best possible uniformity on their average age, parity, stage of lactation and milk yield. The average age (months), lactation number, stage of lactation (days) and average milk yield (kg/ day) of control group (T0) was 64.93 ± 9.21, 2.6 ± 0.62, 38.44 ± 9.02 and12.29 ± 1.47, respectively and that of treatment group (T1) the values were 58.88 ± 8.15, 2.4 ± 0.45, 37.56 ± 12.95 and 11.69 ± 0.85, respectively.
Experimental Design
Cows in control group (T0) were kept in existing loose housing condition i.e. concrete floor and asbestos sheet as roof material. Treatment group (T1) was provided with flooring comfort and roof thermal insulation. Flooring comfort was given by sand flooring (4-6ʺ depth), which was nearly 38% of total pen area. Roof thermal insulation was done by thatch (paddy straw) ceiling (4ʺ thick) under the asbestos roof as a part of housing modification. All other management activities were same for both the groups.
Design and Floor Space Requirement
Three sides of the paddock were surrounded by half brick wall and rest one side was fenced by manger and standing space. There was the drainage system in between covered and open space having adequate slope for better drainage. The standing space was moderate height and inclined with low slope. Water trough was provided in one corner of the paddock. This system of housing facilitated free movement and sufficient exercise to the animals. The measurements of floor space and roof thermal insulation area of modified house are given in the below Table 1.
Table 1: Floor space provided to experimental cows at control and modified shed
Space (m2) | Control | Experimental |
Covered Area | L*B=8.5*6.75=57.38 m2 | L * B = 8.5*6.75= 57.38 m2 |
Open Area | L*B = 11*8.5= 93.50 m2 | L*B = 11*8.5= 93.50 m2 |
Total Area | L*B=17.75*8.5= 150.88 m2 | L*B = 17.75*8.5= 150.88 m2 |
Total Sand Bed | – | L*B = 10.70*5.35= 57.25 m2
(37.94 % of total area) |
Sand Bed under Covered area | – | L * B = 8.5*2.3= 19.55 m2
(34.07 % of covered area) |
Sand Bed under Open Area | – | L * B = 8.3*5.35= 44.41 m2
(47.50% of open area) |
Total Roof Area | L*B = 8.5*6.75= 57.38 m2 | L*B = 8.5*6.75= 57.38 m2 |
Insulated Roof Area | – | L * B = 8.5*3.8= 29.75 m2
(51.85 % of total roof area) |
Feeding and Management of the Experimental Animals
All the feeding management practices and the feed ingredients were same as of the whole lactating herd. Concentrate ad libitum green fodder and straw was provided to complete the nutrient requirement of all the lactating animals. Clean palatable drinking water was provided ad-libitum 24 hours.
Milking Practices
Machine milking was done twice a day during morning from 6.00 to 8. 00 AM and evening from 2.30 to 4.30 PM. The milk was weighed and recorded in kilogram for individual animal. Before milking the animals were groomed and washed. Towels soaked with antiseptic solution were used for wiping of the udder and teats just before attaching the teat cups of milking machine.
Recording of Parameters
Microclimate in Different Experimental Shed
Both floor and inside roof surface temperatures of shed materials were measured by infrared digital thermometer (-32°C ˜ 320°C) of Metrix+TM , MT 2A. The surface temperatures were taken from a fixed distance of 10 inches from the objects. Surface temperature was recorded 4 times in a day at 7:00-8:00 am, 10:00-11:00 am, 2:00-3:00 pm and 5:00-6:00 pm for 2 consecutive days, in a week.
Physiological Parameters and Milk Yield
Rectal temperature, pulse rate and respiration rates of crossbred cows were recorded at weekly intervals at 9:00 AM and 2:00 PM. Rectal temperature was recorded by using a clinical thermometer. Pulse rate was taken from middle coccygeal artery without disturbing the animal and expressed as counts per minute. Respiration rate was counted from a distance by observing flank movements and expressed as counts per minute. Daily milk yield of twenty lactating animals were recorded.
Statistical Analysis
The data were analyzed by using SPSS software (16.0 versions). The statistical methods used to analyze the data were one way ANOVA and General Linear Model.
Results
The inside ceiling surface temperatures (ºC) of covered area of control (T0) and experimental (T1) sheds in different seasons are given in Table 2.
Table 2: Surface temperature (˚C) of ceilings of control and experimental sheds
Season | Winter | Summer | ||
Roof type | Control (T0)
Non-insulated (Asbestos) roof |
Experimental (T1)
Insulated (Thatch) roof |
Control (T0)
Non-insulated (Asbestos) roof |
Experimental (T1)
Insulated (Thatch) roof |
7:00-8:00 am | 16.20 ± 1.07a | 15.96 ± 0.89a | 24.56 ± 0.51a | 23.12 ± 0.98a |
10:00-11:00 am | 27.32 ± 1.56A | 19.46 ± 0.83B | 36.53 ± 1.22A | 27.41 ± 1.38B |
2:00-3:00 pm | 29.06 ± 1.42A | 22.72 ± 1.06B | 37.49 ± 1.51a | 32.33 ± 1.73b |
5:00-6:00 pm | 18.48 ± 0.78A | 22.52 ± 0.56B | 26.22 ± 1.82a | 28.33 ± 1.21a |
Row wise means within a season with different superscripts differ significantly (a,b Significant P<0.05; A, B Significant P<0.01)
There was significant difference between the surface temperature of T0 and T1 sheds in both winter and summer seasons. During winter season, there was significantly (P<0.01) higher temperature of asbestos compare to thatch during 10:00 AM and 2:00 PM. However, in the evening time between 5:00 – 6:00 PM, there was significantly (P<0.01) lower temperature in asbestos compare to thatch roof, probably because of slow release of heat by thatch ceiling. During summer season at 10:00 AM and 2:00 PM, there was significantly higher temperature in asbestos shed compare to thatch roof. The results indicated that insulation by paddy straw ceiling under the asbestos had less surface temperature of 5 to 9 ºC and hence, created better thermo-comfortable environment in the modified shed as compare to existing shed.
Floor Surface Temperature (˚C) of Opened Area
The floor surface temperatures (ºC) of open area of control (T0) and experimental (T1) sheds in different seasons are given in Table 3. Cement concrete and sand floor surface temperature differed significantly in both the seasons. During winter, significantly higher temperature in concrete floor was observed at 10:00 AM & 2:00 PM. During summer season, concrete floor was significantly (P<0.05) hotter than sand bed at 10:00 AM & 2:00 PM. Sand bed had the relative advantage of containing moisture in it and hence, surface temperature was significantly lower during peak hours of the day. Animals also turn up the sand in several places by pawing, which could also be the reason of overall lowered surface temperature of sand bed as compared to concrete floor.
Table 3: Floor surface temperature (˚C) at open area of the shed
Season | Winter | Summer | ||
Floor Type | Cement Concrete Floor | Sand Bed Floor | Cement Concrete Floor | Sand Bed Floor |
7:00-8:00 am | 14.38 ± 1.07a | 16.32 ± 0.87a | 24.33 ± 1.40a | 23.67 ± 1.63a |
10:00-11:00 am | 24.18 ± 0.96a | 21.10 ± 0.39b | 39.74 ± 1.73a | 36.97 ± 2.49a |
2:00-3:00 pm | 29.98 ± 1.51A | 23.76 ± 0.81B | 44.34 ± 2.45a | 35.70 ± 3.29b |
5:00-6:00 pm | 21.82 ± 1.19a | 20.10 ± 0.55a | 32.11 ± 1.85a | 26.83 ± 1.55b |
Row wise means within a season with different superscripts differ significantly (a,b Significant P<0.05; A, B Significant P<0.01)
Floor Surface Temperature (˚C) of Covered Area
During summer, floor surface temperature of covered area of experimental shed (T1) was about 2.5 ˚C lower than that of control shed. However, the magnitudes of differences were not statistically significant both during summer and winter season; however, in summer there was a higher difference in temperature between T0 (28.19 ± 1.7) and T1 (25.79 ± 1.14) sheds during peak hours of the day.
Physiological Response
The weekly physiological responses of crossbred cows viz. morning and evening rectal temperature, pulse rate and respiration rate were presented in Table 4. The morning and evening rectal temperature, pulse rate and respiration rate were significantly (P<0.01) higher in cows kept at conventional shed (T0) as compared to modified shed (T1). Better physiological indices showed comfort level of cows in modified shed. In non-modified shed, thermal loads induced stress on cows and it was reflected in their higher indices of cardinal physiological response.
Table 4: Cardinal physiological response of crossbred Jersey cows in different sheds
Particulars | Group/ Seasons | Control group
(T0) |
Treatment group (T1) | Total |
Morning rectal temperature (ºF) | Winter | 100.63±0.05 | 100.51±0.03 | 100.57±0.03A |
Summer | 101.22±0.07 | 100.66±0.04 | 100.94±0.05B | |
Over all | 100.86±0.04A | 100.57±0.03B | 100.72±0.03 | |
Morning pulse rate /minute | Winter | 63.98±0.46 | 63.76±0.34 | 63.87±0.29a |
Summer | 65.71±0.53 | 63.77±0.36 | 64.74±0.33b | |
Over all | 64.66±0.35a | 63.77±0.25b | 64.21±0.22 | |
Morning respiration rate /minute | Winter | 18.06±0.68 | 16.63±0.34 | 17.35±0.38A |
Summer | 29.00±0.49 | 22.06±0.45 | 25.53±0.44B | |
Over all | 22.32±0.61A | 18.75±0.34B | 20.54±0.36 | |
Evening rectal temperature (ºF) | Winter | 101.03±0.05 | 101.02±0.04 | 101.02±0.03A |
Summer | 101.91±0.07 | 101.48±0.04 | 101.70±0.04B | |
Over all | 101.38±0.05A | 101.20±0.03B | 101.29±0.03 | |
Evening pulse rate /minute | Winter | 67.98±0.41 | 67.65±0.31 | 67.82±0.26A |
Summer | 71.41±0.50 | 67.87±0.31 | 69.64±0.33B | |
Over all | 69.32±0.34A | 67.74±0.23B | 68.53±0.21 | |
Evening respiration rate /minute | Winter | 21.82±0.72 | 20.10±0.32 | 20.96±0.40A |
Summer | 34.96±0.42 | 26.30±0.57 | 30.63±0.51B | |
Over all | 26.93±0.67A | 22.53±0.37B | 24.73±0.40 |
Row wise means within a season with different superscripts differ significantly (a,b Significant P<0.05; A, B Significant P<0.01)
Milk Production
There was significantly (P<0.01) higher milk yield (kg /day/cow) in T1 (11.55±0.08) group than T0 group (11.17±0.10). In both the season (winter and summer) data showed that daily milk yield were significantly different. Daily milk yield in T1 group was higher than control group during both winter and summer seasons (11.75±0.10 vs 11.66±0.14 in winter and 11.27±0.12 vs 10.43±0.15 in summer). The study revealed that the housing modification by floor comfort and thermal stress amelioration by thatching showed significantly (P<0.01) higher milk yield (~380 gm/ day/cow) as compared to non-modified house.
Discussion
Micro climate in the covered area of shed generally depends on type of roofing material used in the shed. Problems related with housing are cost, scarcity of resources, ventilation, hygiene, diseases and environmental changes, which now become a major concern to animal productivity. In tropical conditions thermal stress is one of the major restraints to milk production and dairy cow welfare (Mandal et al., 2002; Upadhaya et al., 2009; Bharambe et al., 2013; Kamal et al., 2013; Kamal et al., 2014; Mote et al., 2016). Mandal et al., 2016 reported that in Crossbred Jersey cows there was a reduction of 170 gm milk per cow per day in the herd during high stressful conditions under tropical environment. Although durability of thatch is not longer, however, it acts as good insulator and also cheap as compared to the asbestos. Like present study, thermal amelioration by different roofing material showed improvement in milk yield with varying magnitude (Bharambe et al., 2013; Kamal et al., 2013; Kamal et al., 2014; Sivakumar et al., 2017) in loose housing system in different climatic conditions. In the present study, inside roof surface temperature (°C) was lower in thatch ceiling roof during morning (30.60±1.52 in thatch and 39.76±3.00 in asbestos) and afternoon (33.25±1.68 and 44.20±2.78, respectively). Similar findings were also reported by Singh et al. (1989). During summer season, roof inside surface temperature (°C) was lower in thatch roof as compared to asbestos and both thatch and agro-net shade material helped in better relieving the thermal stress in crossbred cattle (Kamal et al., 2014). Different types of housing comfort provided in different forms improved the dairy cattle productivity by protecting them from extreme climate (Dhiman et al., 1990; Sharma and Singh, 2002; Singh and Mishra, 2007; Bharambe et al., 2013; Kamal et al., 2014; Patil et al., 2014). In Danish Holstein-Friesian breed, cows kept on mattresses in the free stalls also had a significantly lower milk yield compared with cows kept on sand. The study suggested that sand had a positive effect on milk yield compared with other stall surfaces (Andreasen and Forkman, 2012). Soft bedding like sand bed can lead to improved body condition score, remove stress and that may ultimately improved milk yield (Buckley et al., 2003; Roche et al., 2009). Experiment carried out on lactating dairy cows in an experimental free stall barn (Calamari et al., 2009) comparing four different lying surfaces: straw bedded pack, rubber mat, mattress and sand. The results also highlight greater milk yield in cows kept in free stall pens with sand compared with cows kept in free stall pens with straw bedded pack, rubber mat or mattress, which corroborates our present findings in Crossbred Jersey cows. A soft floor surface contributed significantly to increased milk yield had also been reported by others(Singh et al., 1989; Buckley et al., 2003; Calamari et al., 2009; Roche et al., 2009; Madke et al., 2010; Roy and Chatterjee, 2010; Ruud et al., 2010). Comfortable shed condition enhanced the milk yield by relieving stress and arresting production loss, which usually happen due to thermal stress and uncomfortable staying because of hard and rough surface.
Conclusion
Provision of thatched ceiling under asbestos roof and flooring comfort by sand bed created favorable micro-environment to the crossbred Jersey cows. Improved microenvironment of the shed, removed the heat load and thus helped maintaining normal physiological indices and thereby showed more milk yield per cow per day. Asbestos sheet and concrete floor provided lesser comfort to cows and it was evident through production loss and higher cardinal physiological responses. It could be concluded that thatch ceiling under asbestos roof and soft flooring by sand bed could be used as important shelter improvement measures to reduce thermal stress and enhance staying comfort of dairy cows; however, durability of materials and daily maintenance cost of sand bed is need to be worked out.
Acknowledgments
The authors are grateful to Director, ICAR-NDRI, Karnal and Head, ERS-Kalyani of ICAR-NDRI, for providing necessary facilities.
References