The impact of evaporative cooling on the thermoregulation and sensible heat loss of sows during farrowing (original) (raw)
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Influence of thermal environment on sows around farrowing and during the lactation period
Journal of Animal Science, 2012
Our objective was to investigate the effects of fl oor heating duration (HEAT: 35°C for 12 or 48 h) after birth of fi rst piglet (BFP) under different room temperatures (ROOM: 15°C, 20°C, 25°C) on sows during farrowing and lactation. The study included 8 to 11 repetitions for each combination of ROOM and HEAT. There were no treatment effects on indicators of birth problems (duration of parturition, interbirth intervals, umbilical cord lactate concentration), BW changes of the sow, and litter size and weight until weaning. Sows at 15°C compared with 20°C and 25°C spent more time nest building (P = 0.015). The feed intake was reduced the fi rst 7 d after farrowing in sows at 25°C (P = 0.014); however, both daily feed intake (P = 0.018) and water consumption (P < 0.001) of these warm sows exceeded that at lower temperatures during the last part of the lactation. Sows at 15°C received more medical treatments until weaning at HEAT = 48 h only (ROOM and HEAT interaction, P = 0.005). Room temperature infl uenced prefarrowing water consumption (25°C > 20°C and 15°C; P < 0.017), sow surface temperature (15°C < 20°C < 25°C; P < 0.001), respiration rate (25°C > 20°C > 15°C; P < 0.001), and rectal temperature during the fi rst 12 h after BFP (15°C < 25°C; P = 0.009); additionally, long fl oor heating duration (HEAT = 48 h) increased the respiration rate by 50% d 1 and 2 after BFP (P < 0.001). The proportion of lying time on the unheated slatted fl oor increased with room temperature (P < 0.001) and, transiently, also for the HEAT = 48 h treatment 13 to 48 h after BFP (P < 0.001). The majority of piglets (82% to 95%) were born on the heated solid fl oor, regardless of room temperature (P = 0.46). Sows spent approximately twice as much time standing and walking at 15°C during 13 to 48 h after BFP at HEAT = 12 h only (ROOM and HEAT interaction; P = 0.002). In conclusion, long-term indicators of reduced sow performance were unaffected by room temperature, probably because the farrowing and lactating sows in the current pen design were able to perform thermoregulatory behavior and successfully adapt to room temperatures between 15°C and 25°C.
Heat Loss in Lactating Sows under Different Ventilation Systems and Diets during Summer
2012 IX International Livestock Environment Symposium (ILES IX), 2012
The experiment was conducted in a commercial farm and aimed to evaluate the heat loss and thermoregulation parameters from lactating sows under two ventilation system (natural or evaporative cooling) and two diets (natural or adjusted electrolyte balance) in the summer. Variables related to performance and thermal regulation were recorded during the 20-day lactation. Respiratory rate was recorded along with the recording of skin surface temperature and rectal temperature in the afternoon. Calculations were performed considering the heat exchange balance. Data were analyzed using Minitab 15 ® . Evaporative cooling led to a reduction (p<0.05) in respiratory rate, rectal temperature and skin surface temperature of the sows and increased the sow's heat loss. However, the dietary electrolyte balance did not cause significant difference in these variables. It was concluded that the use of evaporative cooling system helped to reduce heat effects on the sows' thermoregulation. In the diet with adequate nutritional levels for hot climates, the adjustment of the electrolyte balance did not show benefits in minimizing the effects of heat stress.
2017
A study was conducted to assess the effect of evaporative cooling system (ECS) on the performance of sows during summer season and to determine the temperature-humidity index (THI). Ninety-one sows were used in the study, 49 sows were housed with ECS throughout gestation (T1) and 42 in conventional housing system all throughout gestation period (T2). The THI in T1 and T2 ranges from 73.31-80.47 and 75.23-82.66 respectively. Results showed that ECS significantly affects the birth weight, back fat thickness at weaning, and weaning to estrous interval of sows but did not have a significant effect on the gestation period, weaning weight, back fat thickness at farrowing, litter size born alive, litter size at weaning, total pigs born, and number of born dead. There was also a 0.75-day difference in the weaning to estrus interval from T1 was also observed. Partial budget analysis revealed that Php 25,634.33 per year per house was added to the net profit of the farm due to the reduction in...
Journal of Animal Science, 2021
This study was conducted to evaluate whether cooled floor pads combined with chilled drinking water could alleviate negative impacts of heat stress on lactating sows. Thirty sows (Landrace × Yorkshire, Parity = 1 to 6) were housed in individual farrowing stalls in two rooms with temperatures being controlled at 29.4°C (0700–1900 hours) and 23.9°C (1900–0700 hours). Sows in one room (Cool), but not in the other room (Control) were provided cooled floor pads (21–22°C) and chilled drinking water (13–15°C). Behavior of sows (15 sows/treatment) was video recorded during farrowing, and days 1, 3, 7, 14, and 21 after farrowing. Videos were viewed continuously to register the birth time of each piglet, from which total farrowing duration and birth intervals were calculated. The number of drinking bouts and the duration of each drinking bout were registered for each sow through viewing videos continuously for 2 h (1530–1730 hours) each video-recording day. Postures (lying laterally, lying ve...
Cooling ventilation at farrowing for sows from first to third parturition
Comunicata Scientiae
This study aimed to evaluate the thermal comfort considering natural and cooling ventilation on the performance, physiological parameters and thermal comfort indices for sows from first to third parturition. A total of 30 sows from commercial lineage (genetic base Landrace x Large White) initially weighing 252.3±5.7, 280.8±9.5 and 324.5±4.8 kg at first, second and third parturition, respectively, were distributed in a 3x2 factorial arrangement, considering the three parturition orders and the two ventilation methods, with five replicas per treatment. The effect of ventilation methods and times of the day on relative humidity, radiant thermal load, temperature and humidity index and black globe humidity index. There was an interaction among ventilation methods and parturition order for sow weight at weaning and daily feed intake. Regarding the females physiological parameters, with the exception of rectal temperature, there was an interaction between ventilation methods and times of ...
Effect of floor cooling on performance of lactating sows during summer
Livestock Science, 2006
Forty Landrace × Large White lactating sows were used to evaluate the effects of cooling of the floor when maintained under high temperature conditions during summer on their productive and reproductive performance. The sows were allocated in a completely randomized design with two treatments with 20 replicates according to parity number and body weight, with each animal being considered an experimental unit. The treatments consisted of cooling of the floor under the sow with water circulation at about 17°C and no cooling. The resulting temperatures of the floor were 27.6 and 35.8°C for the cooled and the control treatments, respectively. The sows from both treatments were exposed to average maximum and minimum environmental temperatures of 26.9 and 20.8°C, respectively. Sows maintained on a cooled floor had a higher feed intake (6.47 vs. 5.61 kg/day; P b 0.01). Despite this higher intake, sows maintained on a cooled floor had higher body weight and body protein losses during the lactation period (P b 0.01) in connection with a higher milk yield and subsequent growth of the litter (2280 vs. 1798 g/day; P b 0.01). There was an effect of treatment on rectal temperature, surface temperatures and respiratory rate (P b 0.01) with lower values in sows submitted to floor cooling. It is concluded that floor cooling under the lactating sow improves its productive and reproductive performance, as well as the performance of its litter.
Journal of Thermal Biology, 1987
Al~rget--The aim of this work was to study to what extent surface temperatures of growing pigs are altered during acclimation to a change of the air temperature and to exposure to draught. 4 groups of 10 pigs (Large White × Dutch Landrace) of approximately 10 weeks old were used. They were housed in 2 calorimeters with 2 pens each. In the reference chamber air temperature was kept constant at 25°C, in the other chamber air temperature could be lowered to 15°C, and a draught was also applied. Surface temperatures of the pigs were measured by means of a Probey ~ Thermal Video System, with an accuracy of +0.3°C.
EFFECT OF A WATER-COOLED COVER ON THE THERMAL COMFORT OF PREGNANT SOWS IN HOT AND HUMID CLIMATE
In China, the hot and humid climate during the summer season has a strong impact on the production and health of pregnant sows. This prompted a design of a water-cooled cover purposely for heat stress relief for sows. The field experiment was conducted to test the cooling effect on 24 pregnant sows which were divided into 4 groups. The results showed that the sow-occupied zone ambient black globe temperature (BGT) of water-cooled cover with and without sows were 4.8 and 5.4°C lower on average than that of control respectively, when the indoor air temperature was 34.3°C. The temperature reduction of the cooled occupied zone was proportional to the temperature drop between inlet and outlet water. Moreover, the cooling effect was enhanced by increasing water flow during the hot period according to the economic and energy efficiency. All the respiratory rate and surface temperatures of sows underneath the cooled-covered were significantly lower than those exposed to the high ambient tem...
Livestock Science, 2009
Fifty nine primiparous sows PIC Camborough 23 were distributed in a completely randomized 2 × 2 (with and without floor cooling × two dietary treatments) factorial design with 16 sows/treatment, each sow being considered as an experimental unit. Four replicates of sixteen sows each were used during the trial with the objective of evaluating the effects of floor cooling and the use of dietary amino acid contents on their performance and behaviour during summer. The sows were distributed among the treatments according to body weight and backfat thickness after farrowing. The sows were maintained in the experiment until weaning at 21 days of lactation. The two experimental diets supplied the same levels of crude protein (22%), metabolizable energy (ME; 14.65 MJ/kg) and levels of essential digestible AA relative to digestive lysine and differed according to the digestible lysine to ME ratio (0.75 vs. 0.82 g/MJ of ME). The temperature of the water circulating in the cooled floor was maintained at about 17°C. Based on the average minimum and maximum temperatures (21.5 and 29.5°C) obtained during the experimental trial, it can be assumed that the sows were exposed to periods of heat stress. The replicate and the interaction between replicate and treatment effects on all the measurements were not significant. Similarly, no effect of diet or interaction between diet and floor cooling system was found for all criteria measured. An effect (P b 0.05) of floor cooling on average daily feed intake was observed and floor cooling sows showed a higher average (P b 0.05) digestible lysine (61.5 vs. 51.8 g/d) and ME (78.2 vs. 65.9 MJ/d) intakes. The sows submitted to floor cooling showed, consistently, higher absolute values for average weight (+ 8.5 kg) and backfat (+ 0.75 mm) at weaning, compared with the control sows. The sows submitted to the cooled floor showed a shorter (P b 0.01) weaning-to-oestrus interval. The piglet and litter's daily weight gain (DWG), average weight at weaning (AWW) and total weight gain during lactation (TWG) were higher (P b 0.01) for the floor cooling sows. The floor cooling sows showed a higher (P b 0.01) daily milk production. The respiratory rate and rectal temperature values were lower (P b 0.01) for the floor cooling sows. There were differences (P b 0.01) on the cutaneous temperatures measured on the different parts of the sow's body, with the animals submitted to the cooled floor having lower values. The sows submitted to floor cooling spent less (P b 0.01) time in lateral recumbency inactive, more time nursing (P b 0.05) and more time feeding (P b 0.01) compared with control sows. The floor cooling under the sows increased daily feed intake and lysine intake, leading to a lower body weight loss, a lower weaning-to-oestrus interval and also improved nursing behaviour of the sows, leading to a higher milk production and, consequently, higher weight gains of piglets and litter during the lactation period.