Effect of Microclimate Alteration on Temperature-Humidity Index (THI),
Physiological Parameters and Reproductive Performance of Murrah Buffaloes
S.S.Reddy1*, K.A.Rao2, Ch.V.Seshaiah3 and B.E.Rao4
1-3
Department of Livestock Production Management, NTR CVSc, Gannavaram, Sri
Venkateswara Veterinary University, Tirupathi, A.P. (521101), INDIA
4
Department of Livestock Products Technology, CVSc, Proddutur, Sri
Venkateswara Veterinary University, Tirupathi, A.P. (516360), INDIA
*E-mail: sandeep.vety@gmail.com
Abstract
A study was conducted to find out the effect of microclimate alteration on
Temperature-Humidity Index (THI) in buffalo sheds, physiological parameters and
reproductive performance in Murrah buffaloes during summer season from March to
May 2014 at Buffalo Research Station, Venkataramannagudem, West Godavari
district of Andhra Pradesh for a period of 90 days. Forty lactating Murrah buffaloes
were divided in 4 groups of 10 each, housed in loose houses. Group I buffaloes
(control) were housed without any microclimate alteration, while group-II, III and
IV buffaloes were provided with foggers, fans and foggers and fans in their houses,
respectively from 11.00 A.M. to 4.00 P.M. Significantly lower (P<0.001) THI and
rectal temperature (RT), respiration rate (RR) and pulse rate (PR) values were
observed in groups II, III and IV buffalo sheds and buffaloes, respectively compared
to control group. Among the treatments, lower (P<0.001) THI and RT, RR and PR
values were observed in group II and IV buffalo sheds and buffaloes, respectively
compared to group III, while significant difference was not observed between group
II and IV buffalo sheds and buffaloes. The estrus % was 10, 80, 50 and 80 in groups
I, II, III & IV respectively. The conception rate % was 10, 60, 30 and 70 in groups I,
II, III and IV respectively. No early embryonic mortality was recorded. These results
indicate that microclimate alteration using foggers and fans in tropical conditions is
highly effective for optimum reproduction (estrus and conception rate) during
summer in buffaloes.
Key Words: Temperature-humidity index, rectal temperature, respiration rate, pulse
rate, oestrus, conception rate, early embryonic mortality
1. Introduction
Buffaloes (Bubalis bubalis) have immense agricultural importance by virtue of their
high production potential through meat and milk for mankind besides being a source
of sustenance to the poor and marginal farmers as well as landless laborers in the
developing world. Buffaloes alone contribute approximately 96.8% of the total milk
to the dairy industry in Asia and approximately 12.8% of the total world milk
production in spite of being only 11.6% of the total cattle population in the world
(FAOSTAT 2007). One of the greatest challenges being faced by producers and
livestock around the world is thermal stress. Thermal stress is a major limiting factor
in livestock production under tropical climate and also during summer season in
temperate climates. Thermal stress strongly affects animal bioenergetics, with
adverse effects on the performance and well being of livestock. In tropical and
subtropical areas, high ambient temperature is the major constraint on animal
productivity and the effect of heat stress is aggravated when heat stress is
accompanied with high humidity (Marai and Habeeb 2010). Heat stress affects the
physiological systems governing thermal regulation and the maintenance energy of
buffalo during extreme summer.
Exposure of buffaloes to the hot conditions evokes a series of drastic changes in the
biological functions that include depression in feed intake, efficiency and utilization,
disturbances in metabolism of water, protein, energy and mineral balances,
enzymatic reactions, hormonal secretions and blood metabolites. Garcia (2007)
reported that the impact of the heat stress on the female buffaloes can be observed
on the sexual behavior, with less estrous cycle identification, low conception rate,
high embryonic dead rates and reduction in the reproductive efficiency. Use of water
as a cooling agent is an effective method for reducing heat stress of livestock
particularly under high ambient temperature and to keep their body temperature as
cool as possible. Foggers disperse very fine droplets of water which quickly
evaporate and cool the surrounding air. If air is flowing over the animal with a
velocity between 2 and 3 m/s, it increases convective heat loss during stressful
conditions; this can be achieved with air circulators. Sprinkling maximizes the
amount of heat removed from the animal through evaporative cooling at reduced
water costs (Gaughan et al. 2008). In addition, the ambient air temperature is
lowered in the area immediately surrounding the animal, increasing the heat gradient
and increasing the effectiveness of non-evaporative cooling mechanism (Morrison et
al. 1981). High pressure irrigation-type sprinklers can improve inexpensive wetting
of animals, especially when coupled with fans, to increase air movement (Nienaber
and Hahn 2007). However, scarce information is available on the effects of
microclimate alterations on THI and physiological responses of Murrah buffaloes in
summer. Hence, the research work was undertaken to find out the exact effects of
microclimate alterations to counteract the heat stress effects of summer.
2. Materials and Methods
2.1. Topography of study area
The
present
study
was
conducted
at
Buffalo
Research
Station,
Venkataramanagudem, West Godavari district of Andhra Pradesh. The institute was
located at upland area where the water source is mainly dependent on rainfall and
borewell. The institute is situated at 16.49' N latitude and 81.30' E. The average
annual rainfall is around 750 mm. The average temperature ranges from 25-45°C.
The experiment was conducted for 90 days during the months of March, April and
May (hot-humid season) in 2014.
2.2. Management of Buffaloes
The buffaloes in Group-I were kept without foggers and fans (control), while GroupII buffaloes were provided with foggers, while Group-III buffaloes were provided
with fans and Group-IV buffaloes were provided with both foggers and fans from
11.00 A.M. to 4.00 P.M. daily. Plastic foggers (BLUESTAL Agri equipment) with
four way anti-leak technology with nozzle size 0.5mm and droplet size-80-100
micron are used in experimental Murrah buffalo houses. The experimental buffaloes
were housed under loose housing system (asbestos roof over mangers). All the
experimental buffaloes were offered 20kg chopped hybrid Napier and adlibitum
chopped maize straw as roughage source to meet their dry matter requirements.
Concentrate feed was given at the time of milking as per the milk production of
buffaloes (1kg concentrate per 2kg of milk).
2.3. Temperature Humidity Index (THI)
Temperature Humidity Index was calculated by using the following formula.
THI = db°F−{(0.55−0.55 RH) (db°F−58)}
(LPHSI, 1990).
Where Tdb : Dry bulb temperature (0F) & RH: Relative humidity (RH %).
Dry bulb temperature was recorded using dry bulb thermometer and wet bulb
temperature from a wet bulb thermometer (Zeal, UK). Relative humidity was
calculated from dry bulb and wet bulb temperatures by using Psychrometric chart
(Indian Meteorological Department). THI was calculated thrice per day and the
average value of the three readings was taken as THI of the day.
The physiological responses viz. rectal temperature, respiration rate and pulse rate
were measured by clinical thermometer, measuring the flank movements minute-1
and observing the pulsation of middle coccygeal artery at the base of tail with the
help of finger respectively, at 8.00 A.M. in the morning for all the experimental
buffaloes before providing fogger cooling and fans. Thereafter observations were
recorded at 4.00 P.M. from the experimental buffaloes after provision of cooling
through foggers and fans.
The reproductive performance was recorded during the study period in all the four
groups of buffaloes for the parameters of oestrus expression and cyclicity using a
use of teaser bull daily. Conception rate by per rectal palpation after 45-50 days of
insemination. The experimental buffaloes which were confirmed positive for
pregnancy after diagnosis were observed for any early embryonic deaths through
close observation. The data was analyzed statistically for the mean and standard
error and subjected to analysis of variance (ANOVA) using SPSS IBM, version
22.0, SPSS Chicago (US).
3. Results and Discussion
The environmental parameters viz. dry and wet bulb temperature (°F), RH%
recorded during the study period of 90 days were used for calculation of THI and the
data was depicted (Table 1). The average THI values recorded in experimental
Murrah buffalo houses were 82.45±0.16, 77.04±0.10, 80.00±0.14 and 76.78±0.10
for group I (control), group-II (foggers), group-III (fans) and group-IV (foggers &
fans), respectively. The peak THI in group I, II, III and IV were 86.25±0.16,
79.72±0.13, 83.40±0.17 and 79.32±0.13, respectively and was reached at 12th week
of the experiment during May month in all the experimental buffalo sheds.
Significant (P<0.001) difference was observed in the THI values among all the
groups, except between II and IV. This might be due to decrease in THI due to
cooling effect caused by provision of foggers, fans, foggers and fans for the groups
II, III and IV, respectively. The reports of decreasing THI values from 84.1 to 82.78
in Murrah buffalo houses (Agarwal, 2004) and 81 to 77 in cattle houses
(Chanpongsang et al. 2010) due to mister cooling corroborated the present results.
Significant (P<0.001) difference in THI was also observed in II and IV groups of
buffalo houses compared to group III buffalo house. Since all the experimental
buffaloes are housed in loose houses, evaporative cooling effect caused by foggers
in II and IV buffalo houses might lower the THI values compared to III buffalo
house which was equipped with fans alone. Frazzi et al. (2000) reported dairy cattle
barns equipped with fans and fans plus misting recorded temperatures of 31.5°C and
30.9°C, respectively supporting the findings of effectiveness of evaporative cooling
system in decreasing the temperature in cattle houses over air circulation by fans
alone. However, the difference in THI between II and IV groups of buffalo houses
were not significant due to free circulation of air in loose houses which aids
evaporative heat loss without fans and THI was reduced on par with group IV. The
non significant difference of THI in cattle houses equipped with universal oscillating
fogger system and misting with Schaffer fan system, respectively reported by
Noniponimo (2004) were consistent with present findings.
The peak THI in group I, II, III and IV was reached at 12th week of the experiment
during May month in all the experimental buffalo houses. This might be due to
increased atmospheric temperatures from March to May month during the
experimental period. Upadhyay et al. (2012) reported increased THI from February
onwards and exceeded 75 from March onwards and in April ranged between 81-85
and THI exceeded 85 (86-95) during May in Murrah buffalo houses in India.
Table 1. Effect of microclimate alteration on Temperature-humidity indices (THI)
in Murrah buffalo houses during summer
Period of
Group - I
Group – II
Group - III
Group - IV
experiment
(Control)
(Foggers)
(Fans)
(Foggers &
(weekly
Fans)
interval)
1st
79.10±0.16
74.21±0.21
75.62± 0.16
74.00± 0.21
2nd
79.71±0.16
74.75± 0.14
76.21± 0.13
74.41± 0.14
3rd
79.34±0.10
75.27± 0.12
76.83± 0.18
74.91± 0.12
4th
79.92±0.14
75.64± 0.10
77.22± 0.23
75.42± 0.10
5th
80.20±0.16
75.28± 0.10
78.51± 0.08
76.01± 0.08
6th
81.42±0.29
76.57± 0.08
79.32± 0.08
76.41± 0.07
7th
82.53±0.10
77.38± 0.08
79.74± 0.09
76.70± 0.07
8th
83.24±0.30
77.93± 0.09
80.40± 0.09
77.50± 0.08
9th
84.71±0.10
78.47± 0.18
81.11± 0.22
78.11± 0.18
10th
85.43±0.25
79.19± 0.08
82.60± 0.10
78.72± 0.08
11th
85.75±0.13
79.21± 0.19
82.81± 0.14
78.82± 0.14
12th
86.25±0.16
79.72± 0.13
83.40± 0.17
79.32± 0.13
13th
84.63±0.16
78.62± 0.14
81.90± 0.10
77.90± 0.05
Mean±SE
82.45±0.16c
77.04±0.10a
80.00±0.14b
76.78±0.10a
Values with different superscriptsa, b, c in a row differ significantly (P<0.001)
3.1. Physiological parameters
The effect of microclimate alteration on mean rectal temperature (°F), respiration rate/min
and pulse rate/min were presented (Table 2-4).
Significantly (P<0.001) lower mean rectal temperature (°F), respiration rate min-1 and pulse
rate min-1 was observed in II, III and IV groups of buffaloes compared to group I. This might
be due to decrease in heat stress due to cooling effect caused by provision of foggers, fans,
foggers and fans for the groups II, III and IV, respectively. Similar findings of decreased
rectal temperature of 102.2°F was reported by Agarwal (2004) in dairy cows kept in houses
equipped with mister cooling compared to without mister cooling system (103.84°C). Similar
rectal temperature values of 38.5°C and 39.3°C in cows (Boonsanit et al. 2010) and 38.7 and
39.4°C in crossbred cows (Chanpongsang et al. 2010) and 38.5±0.3°C and 39.3±0.3°C in
dairy cattle (Siriwat et al. 2013) provided with and without supplemental cooling system,
respectively were consistent with the present results.
Respiration rate was the important physiological response that is clearly evident and
increased with the heat stress. Decreased respiration rate due to provision of foggers reported
in dairy cows (Correa-Calderon et al. 2002; Boonsanit et al. 2010) and buffaloes (Agarwal,
2004; Ambulkar et al. 2011) were corroborated with the present findings.
Pulse rate is a stress indicator which can be altered with thermal stress. Decreased pulse rate
(68.7 min-1) in buffaloes kept under showers compared to buffaloes without showers (87.8
min-1) was reported by Aggarwal and Singh (2008).
Significant (P<0.001)difference in mean rectal temperature (°F), respiration rate min-1 and
pulse rate min-1 was also observed in II and IV groups of buffaloes compared to group III
might be due to evaporative cooling effect caused by foggers in experimental buffaloes
housed in group II and IV compared to group III. Rectal temperatures of 38.64 and 39.49°C
reported by Frazzi et al. (2000) in cattle and 99.98 and 101.39°F reported by Das et al. (2014)
in buffaloes equipped with fans plus misting and fans, respectively corroborated the present
findings. Similar results of respiration rate and pulse rates of 29.38 and 37.82 and 57.82 and
68.12 min-1, respectively in Nili Ravi buffaloes reported by Das et al. (2014).
However, difference in mean rectal temperature (°F), respiration rate min-1 and pulse rate
min-1 between II and IV groups of buffaloes were not significant. Even though the fans were
not provided in group II buffalo house, evaporative cooling had taken place due to free
circulation of air and the rectal temperature of group II buffaloes were comparable with group
IV buffaloes.
Non-significant difference in rectal temperatures of 39.4±0.07°C and 39.6±0.04°C in dairy
cows housed in universal oscillating fogger system and misting with Schaffer fan system,
respectively reported by Noniponimo (2004) corroborated with the present findings.
Similarly, non-significant difference in respiration rate of 28.78 and 28.49 counts min-1 in
splashing and wallowing groups of Murrah buffaloes (Rahangdale et al. 2011) and pulse rate
of 77.10 and 78.58 min-1 in crossbred cattle (Ankush et al. 2014) reported. The highest mean
rectal temperature (°F), respiration rate min-1 and pulse rate min-1 in experimental buffaloes
of group I, II, III and IV, respectively was reached during last week of May of the
experiment. This was due to increased ambient temperatures from March to May during the
experimental period which might be responsible for increase in rectal temperature of the
experimental buffaloes. Koubkova et al. (2002) reported the rectal temperature of 39.3°C in
Holstein cows exposed to high ambient temperature conditions during peak summer.
Increased rectal temperature in dairy cows during peak summer reported by Padilla et al.
(2006) and Alam et al. (2010) and Burfeind et al. (2012) during summer corroborated the
present findings. Padilla et al. (2006) recorded higher respiration rate of 71.5 min-1 during
summer compared to 38.8 min-1 in winter in lactating cows and Chandra et al. (2012)
reported pulse rate of 56.50±0.63 and 64.50±0.42 in adult Sahiwal cattle in spring and
summer seasons, respectively were consistent with present findings.
Table 2: Effect of microclimate alteration on rectal temperature (°F) in Murrah
buffaloes during summer
Period of
Group - I
Group – II
Group – III
Group - IV
experiment
(Control)
(Foggers)
(Fans)
(Foggers &
(15-days
Fans)
interval)
15
101.7± 0.10
101.5±0.08
101.4±0.08
101.5±0.04
30
102.0± 0.10
101.6±0.04
101.4±0.06
101.5±0.04
45
102.5± 0.03
101.6±0.05
102.3±0.07
101.6±0.04
60
102.7± 0.09
101.5±0.05
102.4±0.07
101.4±0.04
75
103.1± 0.03
101.6±0.02
102.6±0.07
101.5±0.02
90
103.2± 0.04
101.7±0.01
102.8± 0.10
101.6±0.02
Mean±SE
102.5± 0.06c
101.6±0.02a
102.1±0.06b
101.5±0.02a
Values with different superscripts a, b, c in a row differ significantly (P<0.001)
Table 3: Effect of microclimate alteration on respiratory rate (breaths min-1) in
Murrah buffaloes during summer.
Period of
Group - I
Group – II
Group – III
Group - IV
experiment
(Control)
(Foggers)
(Fans)
(Foggers &
(15-days
Fans)
interval)
15
32.17±0.54
19.83±0.31
23.41±0.26
20.50±0.26
30
34.63±0.52
21.32±0.36
23.02±0.22
21.88±0.29
45
39.28±0.46
21.65±0.34
24.28±0.70
22.01±0.27
60
39.73±0.28
22.92±0.31
30.93±0.95
23.29±0.24
75
40.42±0.16
23.18±0.38
33.16±0.33
23.04±0.33
90
40.64±0.15
24.02±0.90
35.14±0.51
24.29±0.88
Mean±SE
37.81± 0.37c
22.15±0.26a
28.32±0.58b
22.50±0.23a
Values with different superscripts a, b, c in a row differ significantly (P<0.001)
Table 4: Effect of microclimate alteration on pulse rate (beats min-1) in Murrah
buffaloes during summer
Period of
Group - I
Group – II
Group – III
Group - IV
experiment
(Control)
(Foggers)
(Fans)
(Foggers &
(15-days
Fans)
interval)
15
63.16± 0.45
46.74± 0.27
53.53± 0.28
47.72± 0.25
30
64.47± 0.39
48.92± 0.35
54.72± 0.30
50.37± 0.24
45
66.16± 0.37
51.90± 0.31
54.66± 0.35
53.01± 0.33
60
68.77± 0.67
53.77± 0.51
56.69± 0.30
53.25± 0.40
75
72.21± 0.26
53.26± 0.31
60.08± 0.71
53.37± 0.22
90
72.38± 0.29
53.77± 0.38
63.07±0.39
54.28± 0.22
Mean±SE
67.86± 0.41c
51.39± 0.32a
57.12± 0.40b
52.00± 0.26a
Values with different superscripts a, b, c in a row differ significantly (P<0.001)
3.2. Reproductive Performance
The effect of microclimate alteration in the experimental buffalo houses on reproductive
performance viz. estrus induction, conception rate and early embryonic deaths in buffaloes
were presented (Table 5). The estrus induction of 10, 80, 50 and 80 % were recorded in group
I, II, III and IV experimental buffaloes, respectively. The conception rate of 10, 60, 30 and 70
% were recorded in group I, II, III and IV experimental buffaloes, respectively. No early
embryonic mortalities were recorded.
Increase in % of estrus induction and conception rate was observed in group II, III and IV
compared with group I. This might be due to decrease in heat stress in experimental buffaloes
provided with foggers, fans and foggers plus fans in buffalo houses of group II, III and IV,
respectively which might be responsible for increased ovarian activity resulting in oestrus
induction. Similar findings of the effect of heat stress causing hyper-prolactinemia, reduced
luteinizing hormone (LH) frequency, poor follicle maturation and decreased oestradiol
production in anoestrus buffaloes leading to ovarian inactivity (Palta et al.1997) supporting
the present findings. Similarly conception rate of 92 and 50% in dairy cows housed with and
without spray plus fan, respectively reported by Correa-Calderon et al. (2002) also
corroborated the present study. Aggarwal (2009) reported conception rate of 83 and 66% for
dairy cows with and without showers also corroborated with the present study. Conception
rate of 43.8 and 23.5% in crossbred primiparous cows kept under evaporative cooling
housing system and open housing system reported by Chanpongsang et al. (2010) which were
consistent with the present findings.
Difference in % of buffaloes showing estrus and conception rate was observed in group III
compared to II and IV groups of buffaloes. This might be due to evaporative cooling effect
caused by foggers which was responsible for decreased heat stress in II and IV group
buffaloes compared to fans alone provided for group III buffaloes. The results obtained in the
present study were in consistent with the findings of Moghaddam (2009) who reported
pregnancy rates of 56.7%, 40% and 23.3% in cows provided with sprinklers, fans and without
sprinklers and fans, respectively. However, the difference between II and IV groups of
buffaloes were not significant. Even though the fans were not provided in group II buffalo
house, evaporative cooling had taken place due to free circulation of air and the reproductive
performance was comparable with group - IV.
Table 5: Effect of microclimate alteration on reproductive performance in Murrah
buffaloes during summer
Parameter
Group – I
Group – II
Group - III
Group - IV
(Control)
(Foggers)
(Fans)
(Foggers &
Fans)
Estrus expression (%)
10
80
50
80
Conception rate (%)
10
60
30
70
4. Conclusion
Summer anoestrus is one among the major obstacles hindering the reproductive efficiency in
buffaloes causing huge economic losses to dairy industry. The present results revealed that
evaporative cooling effect through foggers in loose houses improved the reproductive
efficiency. Therefore, supplementation of foggers for 5 hours/day from 11.00 am to 4.00 pm
in loose houses is beneficial under hot and humid environment during summer to combat heat
stress and improve fertility in buffaloes.
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