EFFECTS OF DIARRHOEA ON WATER CONSUMPTION OF PIGLETS WEANED ON THE FIRST DAY AFTER BIRm

Baranyiova Eva, A. Holub: Effects of Diarrhoea on Water Consumption of Piglets Weaned on the First Day after Birth. Acta vet. Bmo, 62, 1993: 27-32. Twenty-three Large White x Landrace piglets weaned on the first day after birth and kept individually in cages in a thermoneutral environment were offered a liquid diet similar in its macronutrient content to sow's milk at 2 h intervals nine times a day. They were divided into two groups: clinically healthy piglets and diarrhoeic animals. After each feeding the diarrhoeic piglets were offered in addition ' camomile tea. Water consumption at individual feedings was measured 514 times in diarrhoeic piglets and 441 times in the controls from 3 1010 days after birth. The intake of the offered diet changed with age as was repeatedly described in our previous studies. The diarrhoeic piglets supplemented their water consumption by intake of camomile tea only in 83 (16.1 %) cases. Therd'ore their mean water consumption was lower than that of the controls: by 15.8% per animal and by '9.2% and by 9.4% per live body mass unit and per metabolic mass unit, respectively. The difference in actual water ingestion was significant on dtYs 5, 6, 9 and 10. Relative 'water consumption per live body mass of diarrhoeic piglets was significantly lower on day 5 and 6, but higher on day 4 and 8; that per metabolic mass unit was lower on day 5, 6, and 10, but higher on day 4 and 8. Diarrhoeic piglets lose more water than clinically healthy animals during the postnatal period. In our experiments they could make up for their water defidency by increasing the intake of the diet and by additional consumption of camomile tea only relatively (expressed per live body mass and per metabolic mass) lInd for a limited length of time (only on 2 out of 8 days). Diarrhoeic piglets therefore increase their water turnover by oral ingestion, thus contributing relatively to the compensation of water loss in a partial way, but not attaining full compensation for the loss due to diarrhoea. Sucking, liquid diet, camomile tea, postnatal development, functional ontogeny Piglets kept with the sows show a higher water intake during the early postnatal period (Aumaitre 1964, 1965; Mount and Ingram 1971; Bauer et al. 1978; Bauer 1983). Their daily water intake from milk sucking or supplementary feeding or directly from drinking and su·,. Iementary feeding amounts to 23% of their live body mass or almost to 29% of their metabolic mass (Holub 1988, 1990). The water intake of early-weaned piglets is even higher, amounting to 27 % of their live body mass and to more than 40% of their metabolic mass (Holub and PoniZilova 1964; Holub. 1988, 1990, 1991; Holub and Dolezel in press). Under these rearing practices piglets are often affected with secretory and malabsorption diarrhoea (Leece 1986; Larsen I!Dd Schwartz 1987; Schmid and Walser 1991; Baranyiova and Holub in press), in consequence of which they utilize diet less efficiently and lose more water (Kelly et al. 1990). These adverse effects of diarrhoea are augmented by the fact that • diarrhoeic piglets we unable to compensate for them by consuming a larger quantity of diet

Twenty-three Large White x Landrace piglets weaned on the first day after birth and kept individually in cages in a thermoneutral environment were offered a liquid diet similar in its macronutrient content to sow's milk at 2 h intervals nine times a day.They were divided into two groups: clinically healthy piglets and diarrhoeic animals.After each feeding the diarrhoeic piglets were offered in addition ' camomile tea.Water consumption at individual feedings was measured 514 times in diarrhoeic piglets and 441 times in the controls from 3 1010 days after birth.
The intake of the offered diet changed with age as was repeatedly described in our previous studies.The diarrhoeic piglets supplemented their water consumption by intake of camomile tea only in 83 (16.1 %) cases.Therd'ore their mean water consumption was lower than that of the controls: by 15.8% per animal and by '9.2% and by 9.4% per live body mass unit and per metabolic mass unit, respectively.The difference in actual water ingestion was significant on dtYs 5, 6, 9 and 10.Relative 'water consumption per live body mass of diarrhoeic piglets was significantly lower on day 5 and 6, but higher on day 4 and 8; that per metabolic mass unit was lower on day 5, 6, and 10, but higher on day 4 and 8.
Diarrhoeic piglets lose more water than clinically healthy animals during the postnatal period.In our experiments they could make up for their water defidency by increasing the intake of the diet and by additional consumption of camomile tea only relatively (expressed per live body mass and per metabolic mass) lInd for a limited length of time (only on 2 out of 8 days).Diarrhoeic piglets therefore increase their water turnover by oral ingestion, thus contributing relatively to the compensation of water loss in a partial way, but not attaining full compensation for the loss due to diarrhoea.

Sucking, liquid diet, camomile tea, postnatal development, functional ontogeny
Piglets kept with the sows show a higher water intake during the early postnatal period (Aumaitre 1964(Aumaitre , 1965;;Mount and Ingram 1971;Bauer et al. 1978;Bauer 1983).Their daily water intake from milk sucking or supplementary feeding or directly from drinking and su•,.Iementary feeding amounts to 23% of their live body mass or almost to 29% of their metabolic mass (Holub 1988(Holub , 1990)).
The water intake of early-weaned piglets is even higher, amounting to 27 % of their live body mass and to more than 40% of their metabolic mass (Holub and PoniZilova 1964;Holub. 1988Holub. , 1990Holub. , 1991;;Holub and Dolezel in press).
Under these rearing practices piglets are often affected with secretory and malabsorption diarrhoea (Leece 1986;Larsen I!Dd Schwartz 1987;Schmid and Walser 1991;Baranyiova and Holub in press), in consequence of which they utilize diet less efficiently and lose more water (Kelly et al. 1990).These adverse effects of diarrhoea are augmented by the fact that • diarrhoeic piglets we unable to compensate for them by consuming a larger quantity of diet offered to them ad libitum.As a matter of fact, their consumption of the diet between the 3rd • and 10th postnatal days is even reduced (Baranyiova and Holub in press).In which way diarrhoea affects their water ingestion.during this period remains undisclosed.

Materials and Methods
Twenty-three Large White x Landrace piglets from clinically healthy sows kept in a large--scale production unit wete removed from the dams on the 1st day after birth and teared as described in our previous reports (Holub and Baranyiova 1989;Baranyio.va and Holub 1991 and in press).Their nutrition was modified in that diarrhoeic piglets were offered camomile tea fiavoured with Glukopur in addition to the diet fed ad libitum at 2-h intervals.
The intake of the diet was measured in 514 feedings in diarrhoeic piglets and in 441 feedings in clinically healthy controls.
Statistical analysis of the results of the measurements on individual days was performed with Student's t-test and their variability was expressed in terms of standard errors of the means.

Results
The actual water intake at individual feedings during the observation period increased with advancing age in both diarrhoeic and clinically healthy piglets; in the former it did so more than 1.5 times, in the latter it doubled.On the whole, however, diseased piglets consumed approximately 15% less water than healthy animals between 3 and 10 days after birth.However, this ratio varied from day to day and the difference proved significant (P < 0.01) only on days 5, 6,9 and 10 (Table 1).
Expressed per live body mass unit, the water consumption of diarrhoeic piglets during the same period was 9.2% lower than in healthy animals.The daily difference was even more conspicuous when the results were expressed per animal: it was lower only on days 5 and 6 (P < 0.01), but higher on days 4 and 8 (P < 0.05) (Table 2).
The diet, however, was not the exclusive source of water for diarrhoeic piglets.The 514 feedings offered to these animals were in 83 (16.1 %) cases supplemented by intake of camomile tea.Since great difference existed in the intake of this supplementation on individual days, its contribution to total ingested water varied from day to day, though it was not negligible.It was largest, accounting for more than one third (37%) on day 6, constituted more than a quarter (26.8%) on day 5 and almost a fifth (17.3%) on day 4. On the remaining days except day 10 on which no camomile tea was consumed at all the proportion of this additional ingested water was about 5 to 6% (Table 1).

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Similarly to the ingested quantities of diet, energy and macronutrients (B aranyiova and Holub in press) the intake of water was lower in diarrhoeic piglets than in the controls.Actually, expressed per animal, it was so on 4 out of the 8 days.Relatively, the results were less unequivocal: expressed per live body mass, the water intake was lower on 2 days, but higher on the remaining days; expressed per metabolic mass, it was lower on 3 days, but higher on 2 days.
Like other mammalian polycotous neonates, suckling piglets cover their hydration and nutritional requirements in inseparable union, the ratio of water to the other milk components being determined by the dam.Therefore also the coverage of hydration requirements of piglets is prandial in character, an observation pointed out in a previous report (Holub 1990); and this applies apparently also • to diarrhoeic piglets.Consideration was given to this fact by adjusting the proportion of water in the liquid diet to 176 g per 1 MJ energy and to 15.3 g per 1 g protein.By ingestion of water from camomile tea the proportion of water intake was naturally increased: on day 6 by as much as 60%, to 283 per 1 JM of energy and to 24.5 g per 1 g protein.
Therefore expressions such as hunger, thirst or satiety have a different meaning in neonates than in grown-up subjects (Adolph 1968;Holub 1968Holub ,1990Holub ,1991;;Phifer and Hall 1988).Neonates not only show considerable hydration and a high turnover of water, but also lose more water when diarrhoeic (Argenzio et al. 1984;Simmons and Bywater 1991;McLee et al. 1992).Moreover, the absorption activity of their small intestine undergoes an abrupt development (Henriquez de Jesus 1974ab;Burton et al. 1980;Smith 1988) and is affected in addition by diarrhoea-associated lesions.The colon shows a different activity that can compensate for water loss by increased resorption.This function, however, does not come into operation until piglets are older (Argenzio et al. 1984).Not even antisecretory factor which inhibits water loss • in enterotoxic diarrhoea is produced perinatally orin the early postnatal period (McEwan et al. 1990ab).
The afore-mentioned facts offer a possible explanation of the problems of oral rehydration which is otherwise regarded as a highly useful therapeutic procedure in the management of neonatal diarrhoea (Bywater and Woode 1980;Simmons and Bywater 1991).However, this procedure should be repeated daily (Anderson and Backstrom 1984), otherwise it fails.The finding that the intake of additional water offered to diarrhoeic piglets in camomile tea compensated for their water loss only relatively (expressed per live body mass unit and per metabolic mass unit) and for a limited length of time (for a quarter of the observation period) shows that during the first 10 postnatal days the capacity of piglets to make up for their water deficiency by increased fluid intake is limited.Similar observations have been reported also for older piglets (McLeese et al. 1992).Therefore rehydration route.sother than oral fluid therapy should not be left out of consideration.