Method for improving the metabolic stability and survival of newborn pigs

The disclosed invention concerns improving the metabolic stability of newborn pigs and increasing their survival rate by administering to a pregnant sow during its late stages of gestation an effective amount of a material selected from the group consisting of a dihydroxy alkanol having 3 to 10 carbon atoms, a triglyceride of glycerol and fatty acids containing 8 to 12 carbon atoms and the mono-and diol esters of said alkanols and said fatty acids.

BACKGROUND AND SUMMARY OF THE INVENTION 
The present invention relates to an improved method for increasing the 
survival rate of baby pigs. More particularly, the present invention is 
directed to a method of increasing the survival rate of baby pigs by using 
a food supplement in the diet of a pregnant pig. 
The low survival rate observed in baby pigs, e.g., 20 to 30% mortality 
between birth and weaning, is attributed largely to two factors: 
(1) the high degree of metabolic immaturity in the newborn pig and 
(2) an insufficient energy intake by the pig in its first 2 or 3 days of 
life. 
The magnitude of this loss can be emphasized by the fact that each 1% 
improvement in pig survival will generate an additional $4.00 to $7.00 
profit per litter. 
The major metabolic defects observed in the newborn pig are summarized as 
follows: 
1. A low level of phosphorylase potentially decreases the rate of 
production of glucose from glycogen stores; 
2. A defective gluconeogenic capacity limits the supply of glucose 
available to animals exposed to stress; 
3. A deficient hepatic mitochondria number limits the use of carbohydrates 
as well as fatty acids for energy production; 
4. A small amount of body fat impairs both thermoinsulation and the 
quantitative contribution of fat as a major energy source; and 
5. A defective amino metabolism tends to limit a source of substrate 
(carbon skeletons) for gluconeogenesis. 
More specifically, the high mortality rate observed in pigs is attributed 
largely to the newborn pigs impaired thermostability and defective 
gluconeogenic capacity and its inability to obtain a sufficient energy 
intake from the sow's milk during its first 2 or 3 days of life. Because 
of these major metabolic defects, as well as the others set forth 
hereinabove, particularly its low gluconeogenic capacity, the neonatal pig 
rapidly develops hypoglycemia after birth if not permitted to suckle or if 
subject to cold stress. 
This rapid onset of hypoglycemia in the newborn pig is the result of 95% of 
the pig's energy reserves in the form of glycogen being used within the 
first 72 hours of birth regardless of whether the pig is suckled or not by 
the sow. The significance of the baby pig's susceptibility to hypoglycemia 
is indicated by the 30 to 50% death loss observed within 72 hours after 
birth when baby pigs are fasted from birth or when baby pigs are fed for 6 
hours after birth and then fasted. 
Research has been conducted to identify factors which would reduce baby pig 
mortaility. These investigations have suggested that the existence of 
physiological conditions, i.e., diabetes, starvation, high dietary fat 
intake, etc., which are associated with elevated blood ketone levels in 
the sow, may result in heavier, more metabolically stable pigs at birth. 
Accordingly, an object of the present invention is to provide an improved 
method for increasing the survival rate of baby pigs. 
A further object of the present invention is to provide a method for 
improving the metabolic stability of the newborn pig by preventing the 
development of hypoglycemia in the neonatal pig shortly after birth. 
Still another object of the present invention is to provide a food 
supplement which is effective in elevating the ketone levels in blood of 
the pregnant pig. 
Other subjects and further scope of applicability of the present invention 
is to provide a food supplement which is effective in elevating the ketone 
levels in blood of the pregnant pig. 
Other objects and further scope of applicability of the present invention 
will become apparent from the detailed description given hereinafter. 
However, it should be understood that the detailed description and 
specific examples, while indicating preferred embodiments of the 
invention, are given by way of illustration only, since various changes 
and modifications within the spirit and scope of the invention will become 
apparent to those skilled in the art from this detailed description. 
Pursuant to the present invention, it has been found that the 
administration of specific alcohols and glycerides to female pigs during 
late stages of gestation effectively increases the liver glycogen stores 
in the pig at birth and prolongs the availability of the liver glycogen 
stores in the newborn pig. This increased availability of glycogen delays 
the onset of hypoglycemia in the pig and increases the survival rate 
(percent of pigs born alive that survive to weaning) of neonatal pigs. 
The alcohols which can be used according to the present invention include 
dihydroxy alkanols having 3 to 10 carbon atoms and the mono- and diesters 
of such diols and fatty acids containing 8-12 carbon atoms, such as for 
example, 1,3-butanediol monooctanoate. The preferred alkanol is 
1,3-butanediol. 
The glycerides which can be used in the present invention include the 
medium chain length triglycerides such as for example the reaction product 
of glycerol and fatty acids containing 8 to 12 carbon atoms. 
The alkanols and the glycerides are administered to the pregnant pig as a 
food supplement, for example, as an addition to a corn-soybean meal diet. 
The alkanol supplement, for example, 1,3-Butanediol, which is a ketone 
former, has been found to be palatable and efficiently utilized by the pig 
when included as a food supplement to provide about 6 to 20% of the 
dietary energy in the pigs diet as shown in the following table: 
TABLE 2 
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1,3-Butanediol Supplementation in Growing Swine. 
1,3-Butanediol, % of dietary energy 
Trait 0 8 17 25 33 42 
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Wt. gain, kg 19.5 20.5 21.4 11.9 4.3 1.1 
ME intake, Mcal 
197 212 219 157 85 77 
ME/wt gain, Mcal/kg 
10.1 10.3 10.2 13.2 19.8 70.0 
Plasma 
B-hydroxybutyrate, 
159 415 457 425 831 980 
nmole/ml 
Acetoacetate, nmole/ml 
69 100 115 183 150 198 
Glucose, mg/dl 75 72 95 97 142 119 
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As can be seen from the table, higher dietary levels of 1,3-Butanediol, 
e.g., greater than 25% of the dietary energy, tend to depress feed 
consumption and subsequent growth. 
Because ketones have shown to be readily transferred across the placenta, 
1,3-Butanediol, a ketone former, represents a potential `supplemental` 
energy source for the developing fetus. 
According to the present invention, it has been found that a short-term 
administration of 1,3-Butanediol in sows during late gestation results in 
an increased liver glycogen content in the newborn pig and an improved pig 
survival from birth to weaning. Advantageously, the administration of the 
specific food additive of the present invention can begin about 4 to 12 
days, advantageously about 9 days, before parturition and continue until 
parturition. After parturition, the sows are allowed to consume a standard 
lactation diet. 
The following example is provided as being exemplary of the present 
invention and should not be considered as being limitative of the present 
invention.

EXAMPLE 
Sixty-eight sows were fed isocaloric intakes (6000 kcal of metabolizable 
energy/sow/day) of a fortified corn-soybean meal diet plus an additional 
1600 kcal of metabolizable energy in the form of starch or 1,3-Butanediol 
beginning approximately 8 days before parturition. After parturition, all 
sows were allowed to consume a standard lactation diet ad libitum. The 
results are shown in the following table: 
TABLE 3 
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1,3-Butanediol Supplementation in Sows During Late Gestation..sup.a 
Prepartum Treatment.sup.a 
Trait Control 1,3-butanediol 
Change 
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Pigs/litter 
At birth 10.39 10.14 
At weaning 8.79 9.28 +.49 
Avg. Pig Wt. (kg) 
At birth 1.20 1.26 +.06 
At weaning 3.51 3.58 +.08 
Pig Survival, % 
85.30 92.00 +6.7 
Liver Glycogen, % 
11.10 16.20 +5.1 
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.sup.a Thirty-eight and 40 litters represented in the control and 
1,3butanediol treatments, respectively. 
As can be seen from the above table, the 1,3-Butanediol supplementation did 
not influence the number of live pigs born/litter (10.14 vs 10.39) or the 
average pig weights (g) at birth (1,259 vs 1,205) or at weaning (3575 vs 
3510) compared to those of litters from sows fed starch. However, 
1,3-Butanediol supplementation did increase liver glycogen levels in the 
newborn pig (16.2 vs 11.1%) and did increase the total number of pigs 
weaned/litter (9.28 vs 8.79) and the percent of pigs born alive (92.0 vs 
85.3) that survived to weaning compared to those of the starch treatment 
group. Sow feed intake and weight gain during lactation were not affected 
by dietary treatment. 
In a second experiment, the addition of 1,3-Butanediol to the diet of sows 
during late gestation was shown to increase the metabolic stability of the 
newborn pig by increasing the level of liver glycogen present in the pig 
at birth and delaying the onset of hypoglycemia in pigs which were allowed 
to nurse or were fasted from birth to 12 hr of age (table 4). In addition, 
the colostrum of sows fed 1,3-Butanediol contained a higher percent fat 
than that of sows fed the control diet (table 5). 
TABLE 4 
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Effect on 1,3-Butanediol Supplementation in Sows During Late 
Gestation on Plasma Glucose and Liver Glycogen Stores 
in Neonatal Pigs..sup.a 
Age of 
Feeding Prepartum Treatment.sup.a 
Pig, hr 
Regime Control 1,3-Butanediol 
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Liver glycogen, mg 
0 -- 3.47 4.30 
12 Nursed .70 .85 
12 Fasted .48 .96 
Blood glucose, mg/dl 
0 -- 137.6 128.7 
12 Nursed 92.7 124.2 
12 Fasted 84.7 93.8 
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.sup.a Thirty and 42 pigs represented in the control and 1,3Butanediol 
treatments, respectively. 
TABLE 5 
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Effect of 1,3-Butanediol Supplementation in Sows During Late 
Gestation on the Fat and Protein Content of Sow's Colostrum..sup.a 
Prepartum Treatment.sup.a 
Hr Postpartum Control 1,3-Butanediol 
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Colostrum fat, % 
0 2.7 4.3 
12 3.1 3.9 
Colostrum protein, % 
0 13.8 15.1 
12 10.5 10.5 
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.sup.a Ten and fourteen sows represented in the control and 1,3Butanediol 
treatments, respectively.