Effect of the environmental factors on physiological
parametters, feed intake and growth of mong cai and landrace pigs
in central vietnam
Le Van Phuoc, Le Duc Ngoan, TR. Preston
Hue University of Agriculture
Abstract
Experiment was conducted on 12 Mong Cai pigs (initial weight is 16 kg) and 12 Landrace pigs (initial weight is 24 kg). Pigs were kept individually in pen (1.5 m2/head). Every pig breed was fed by 2 diets with equal crude protein rate (16% for Landrace and 13% for Mong Cai) and equal ME (3000 Kcal/kg feed), but different crude fibre level: 6% and 9% (using sweet potato leaves and stem to adjust the fibre rate). Pigs were fed and drunk water ad libitum. The experiment lasts 90 days.Temperature and moisture were measured by magnetic humidity - thermometer hanging 1.5 m from the floor of the pen and canculate the mean of 3 measurements (at 6, 12 and 18 o'clock). The phisiological indeces such as respiratory rate, heart beat and body temperature were measured randomly at different temperature and moisture points. The weight of pigs were measured every month then canculated growth rate per day. Daily feed intake was identified by the difference between the amount of feed given at begining of the day and feed left at the end of the day. Feed digestibility was canculated by the rate of feed intake and daily growth.
Experiemtal resultes show that, There is a significant correlation between air temperature change and some physiological indeces of pigs such as: respiratory rate, heart beat and body temperature. Landrace breed is more sensitive by the change of environmental factors than Mong Cai breed. Air temperature significantly effected on feed intake of pigs: Pearson correlation in Landrace breed is - 0.679 and - 0.567 in Mong Cai breed (p < 0.01). With 6% and 9% fibre level in the diets, there is no significant difference in fibre level in dry matter of the manure, growth and feed consumption. However, dry matter in the manure of Landrace and Mong Cai breeds is significant different (p < 0.05)
Key words:
Introduction
Biological yield of domestic animals in general, especially of pigs is often affected by the factors of climate and nutrition.
In Central Vietnam due to difficulties of climate, low economics and poor knowledge of farmers, the yield of pig production is still considerably low.
In the past few years, due to the demand on pig lean meat of domestic market and for exportation is higher, the farmers have tendency to keep exotic and cross-breed pigs. Thus, research on environmental factors such as temperature, moisture and fibre rate in the ration in order to find out the suitable pig production model, as well as suitable use of local available feed to enhance economic effectiveness of pig production.
Materials and method
Experiment was conducted on 12 Mong Cai pigs (initial weight is 16 kg) and 12 Landrace pigs (initial weight is 24 kg). Pigs were kept individually in pen (1.5 m2/head). Every pig breed was fed by 2 rations with equal crude protein rate (16% for Landrace and 13% for Mong Cai) and equal ME (3000 Kcal/kg feed), but different fibre level: 6% and 9% (using sweet potato leaves and stem to adjust the fibre rate). Pigs were fed and drunk water ad libitum. The experiment lasts 90 days.
Temperature and moisture were measured by magnetic humidity - thermometer hanging 1.5 m from the floor of the pen and canculate the mean of 3 measurements (at 6, 12 and 18 o'clock). The phisiological indeces such as respiratory rate, heart beat and body temperature were measured randomly at different temperature and moisture points. The weight of pigs were measured every month then canculated growth rate per day. Daily feed intake was identified by the difference between the amount of feed given at begining of the day and feed left at the end of the day. Feed digestibility was canculated by the rate of feed intake and daily growth.
Data were analysed by ANOVA using Minitab software version 13.
Results and discussion
Effect of air temperature on respiratory rate of
pigs.
Among reactions of the body to temperature change, change of respiratory rate has the most important role, especially to the pigs (Figure 1).
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Figure 1. Effect of air temperature on
respiratory rate of pigs. |
When the temperature increased from 17oC to 34oC, the respiratory rate of both pig breeds was enhanced, however, when air temperature is in interval below 25oC respiratory rate slowly increased then it was increased considerably quick.
When air temperature is equal and above 35oC, respiratory rate was the most increased.
In this experiment when air temperature was above 25oC the respiratory rate of Landrace breed was higher than Mong Cai breed. Variousness on respiratory rate of Landrace and Mong Cai pigs is 17-110 times/minute and 17-101 times/minute respectively.
This confirms that Mong Cai breed is adapted to hot climate. The relation between air temperature and respiratory rate of pigs was described by following regression:
- Landrace breed: Y = 0.2547x2 - 10.101x + 120.54 (R2 = 0.8047)
- Mong Cai breed: Y = 0.2415x2 - 9.5018x + 114.45 (R2 = 0.8128)
Effect of air temperature on heart beat rate of
pigs
Besides the change of espiratory rate when air temperature increased, the heart beat of pigs increased as well. However, increasing of the heart beat is lower in comparision with the respiratory rate. Figure 2 discribes the relation between air temperature and heart beat of 2 pig breeds.
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Figure 2: Effect of air temperature on heart beat rate of pigs |
Variousness of the heart beat is on the same line with the variousness of the respiratory rate. The heart beat increased slowly when air temperature was below 25oC, then it in creased considerably quick.
When air temperature increased from 17oC to 36oC heart beat of Landrace and Mong Cai pigs increased from 91 to 132 beat/minute and from 86 to 122 beat/minute respectively. Thus, at the same point of air temperature heart beat of Landrace pigs is higher than of Mong Cai 7 - 10 beat/minute.
Effect of air temperature on body temperature (rectal
temperature) of pigs
When air temperature changed, body temperature of both pig breeds was changed. When air temperature increased from 17oC to 36oC, body temperature of both Landrace and Mong Cai pigs was enhanced from 38.3oC to 39.7oC. In conclusion, in the interval of air temperature during the time of experiment carried out, body temperature of both pig breed is still in normal phisiological limits.
Effect of air temperature on feed intake of
pigs
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Figure 3. Effect of air temperature on feed
intake of pigs |
Graphs 3 and 4 describes the opposite relation between air temperature and feed intake of pigs. The results show that daily average change of air temperature has effected on feed intake of Landrace pigs than Mong Cai (R2 = 0.5467 and 0.3022 respectively).
The correlation is significant at p < 0.01 (2 tails): Mong Cai pigs is - 0.567, Landrace pigs is - 0.691.
The results also show that when air temperature increased or decreased 1oC, feed intake of Landrace and Mong Cai pigs was increased or decreased 10% and 7% respectively.
Effect of fibre rate in ration on dry matter and
fibre rate in manure
With 2 different crude fibre level in diets: 6% and 9%, the result of experiment was displayed in table 1.
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Tab.1: Effect of crude fibre level in diets on contents
of dry matter and crude fibre in pig manure |
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Pigs |
Landrace |
Mong Cai |
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Fibre content rate (%) |
6 |
9 |
6 |
9 |
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DM manure (%) |
34.6 |
28.6 |
33.1 |
29.9 |
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Crude fibre rate/DM manure (%) |
20.1 |
22.7 |
21.4 |
20.8 |
Results in the Tab.1 show that different fibre rates in different rations of the same pig breed have given different dry matter rates in the manure (p < 0.05). Ration with high fibre rate gives low dry matter rate in the manure and vice versa. This could be explained that high fibre rate in the ration may be increase peristaltic of intestine, decrease water asorbability and shorten the time of feed keeping in the alimentary tract. However, fibre rates in the total dry matter of the manure from different levels of fibre in the ration are not significant different (p > 0.05). In conclusion, fibre digestabilities of both Landrace and Mong Cai pigs with different fibre levels (6 - 9%) in the ration are not significant different.
Effect of fibre rate in the ration on some production
indeces of pigs.
Productivity of pig is an important index to assess effectineness of pig production, especially to assess nutrition of feed. The result of 90-day-experiment was displayed in the
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Table 2. Effect of fibre level in the ration on some production
indices of pigs |
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Landrace |
Mong Cai |
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Crude fibre levels (%) |
6 |
9 |
6 |
9 |
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Initial weight (kg) |
24 |
23.5 |
16 |
15.5 |
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End weight (kg) |
81.5 |
78.9 |
49.2 |
47.5 |
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Daily weight gain (g/day) |
639 |
616 |
368 |
355 |
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Feed consumption/kg growth (kg) |
3.23 |
3.42 |
3.51 |
3.49 |
The result shows that there is no significant difference between 2 breeds in the rations with different fibre levels (6% and 9%) (p > 0.05). However, growth rate (g/day) of pigs with 6% fibre level in the ration is higher than 9% fibre level ration. It is not significant difference in feed consumption of both pig breeds.
The results in the Tab. 1 and 2 show that there is no significant difference on production indeces of Landrace and Mong Cai pigs given rations with different fibre levels (6% and 9%).
Conclusion
- There is a significant correlation between air temperature change and some physiological indeces of pigs such as: respiratory rate, heart beat and body temperature. Landrace breed is more sensitive by the change of environmental factors than Mong Cai breed.
- Air temperature significantly effected on feed intake of pigs: Pearson correlation in Landrace breed is - 0.679 and - 0.567 in Mong Cai breed (p < 0.01).
- With 6% and 9% fibre level in the rations, there is no significant difference in fibre level in dry matter of the manure, growth and feed consumption. However, dry matter in the manure of Landrace and Mong Cai breeds is significant different (p < 0.05)
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