|Zootecnia Tropical > Sumario de la Colección > Volumen 18|
Zootecnia Trop., 18(2):163-176. 2000
Riopérez, J.1, A. Fuentes2 ,
C. de Alba3, C. Centeno1, R. Cidoncha3 and S.
Nutrición y Bromatología.
An experimental test has been carried out with 24 gills of Duroc breed, with 120 kg of body weight and 105 days of pregnancy. A rate of 0-50-100 g of glucose were included in feed during the last 10 days prior to furrowing. The optimum glucose rate was checked and also its influence on piglet weight at birth and on the nutritive colostrum and gilt milk composition. Results show a significant increase (P<0.05) on the total essential amino acid composition in milk of gilts supplemented with glucose, thus reaching Methionine, Aspartic acid and Leucine the biggest concentrations (P<0.01) within the group of gilts supplemented with the level-50 of glucose. No significant differences were observed on the gross protein and fatty acids of colostrum and milk, however, the highest rate is that of the oleic acid (C18:1). It is advisable to prolong the time of supplementation (25-30 days antepart) at a rate of 50 g of glucose per day.
Keywords: Glucose, Colostrum and milk, Porcine, Reproduction.
Gilt milk is rich in energy and protein, thus being the most economic, natural and physiological carrier of essential nutrients for the piglet. However, it is important to know the proportion of casein and essential amino acids of its composition, as well as the percentage of polyunsaturated fatty acids in its fatty fraction, due to both their direct influence on the immunity of piglet at weaning, and to the management of the gilt-litter binomial.
On the other hand, the feed supply during gestation (2 kg/day) in normal conditions, not only has incidence on the mother daily net gain and on piglet weight at birth, but also might affect the ulterior production and nutritive composition of milk and colostrum.
The feeding and management program for reproductive gilts in the different stages of production is essential in order to improve the reproductive profitability of a swine enterprise. The feeding level of a gilt during the last third of pregnancy is going to have influence over the development of the piglet during lactation (Dwyer et al., 1994) and over the productivity of the future reproductive gilt (fertile interval, litter size, etc.) An increased energetic and protein consumption during the last third of gestation increases the piglet weight at birth (Coma, 1997; Noblet and Etienne, 1986) and it favors the mothers adipose reserves. However, it might also exert influence over the composition of colostrum and maternal milk and in a determining way over immunity (Klobasa et al., 1987), growth of newly born piglets, body conformation and fertile post-weaning heat of gilt.
Feeding of the piglet is guaranteed by the maternal production of milk and by the successive usage of the most essential nutrients (proteins, lactose, fat, vitamins, minerals, etc.) On the contrary, the synthesis of milk and possibly its quality, are generally associated to a progressive decrease in insulin concentration in plasma. Insulin and glucose have an important role as mediators of the endocrine response and they influence markedly in the physiological processes of the reproductive system (ovaries, uterus, mammary glands, etc.), and it is important to know the level of tolerance of glucose and the effects of interaction of insulin with the secretion of LH on the weaning-fertile heat interval (Xue et al., 1997.)
The objective of this work is to determine the effect of the addition of several different glucose levels to gestation feed over the nutritive quality of colostrum and of milk in gilts.
MATERIAL AND METHODS
Animals. A band of 50 Duroc gilts in maternity was used, with an average weight of 120 kg and 105 days of gestation, and divided in three homogeneous groups according to the level of glucose administered in feed (0, 50 and 100g/day.) For the quality controls of colostrum and milk, 24 gilts were used (8 animals per treatment group.)
Feed. Base diet (table 1) at a rate of 2 kg per day. Glucose was administered daily in feed during the last 10 days of pregnancy, until furrowing.
Colostrum and milk analysis. Injection of 20 IU of oxitocine administered to gilts allowed for colostrum samples (24 hours post-farrowing) and for milk (4 days post-farrowing), by means of manual milking of the mammary glands. The following were analyzed: total solids (dry up method in stove at 37°C), total protein (Kjeldahl), essential amino acids (HPLC), polynsaturated fatty acids in fat (Gas phase capillary chromatography.) The amino acids analysis (except for proline, cysteine and tryptophan), was carried out according to Jones et al. method (1981), by means of high resolution liquid chromatography, automatic injector, fluorescence detector and Hypersil Amino Acid column of 5 m m and 150 x 4.6 mm. The fatty acids analysis was made in a Shimadzn GCM-3 chromatograph, equipped with split injector and flame ionization detector (FID), using a 2 m x 2 mm capillary column and an initial temperature (170°C) and final temperature (240°C) program with 8 and 5 minutes, respectively.
Statistical analysis. The PC-1 Harvey 1987
software was used for analysis of variance.
RESULTS AND DISCUSION
Table 2 shows the composition in essential amino acids of colostrum in Duroc gilts, according to the glucose rate administered in feed during the last 10 days of pregnancy. Results do not show a significant increase of total amino acids in gilts supplemented with glucose (P>0.05). Amino acids in the highest concentrations are: glutamic acid, leucine, aspartic acid, serine, lysine and threonine, for the most part. The rate of methionine, aspartic acid, leucine, phenilalanine and lysine increase in gilts with levels of 50 and 100 g of glucose/day, this is a tendency which might possibly increase in milk if the administration of glucose in feed would continue during all the lactation period, thus increasing the immune efficacy for the newly born piglets (Klobasa et al., 1987).
Table 3 shows the composition of saturated and polyunsaturated fatty acids in colostrum, being the highest percentages those corresponding to oleic acid, linoleic acid and palmitic acid. No statistical significance (P>0.05) is seen in the percentages of the different glucose levels studied. However, there is a high rate of linoleic acid, natural antioxidant and vitamin C and E potentiator, which give more protection to tissues (Batra and Hidiroglou, 1994), in this case, to mammary gland tissues.
The results in table 4 show a significant
increase (P<0.05) in total amino acid concentration in milk when glucose is
administered during pregnancy. Methionine, aspartic acid and leucine reach the highest
concentrations (1,45±0,12 ; 9,55±0,65 and 9,21±0,51 g/16 g N2 respectively),
when glucose level 50 is given, being different (P<0.01) to the control group. The
averages observed in glucose level 100, although lower than those of level 50, are not
different, but they are regarding the control group (P<0.01).
Table 5 does not show significant differences in the different fatty acids among groups. However, the percentage of linoleic acid decreases considerably in milk (12%) with respect to colostrum (24.5%), maintaining oleic acid the highest rate, as also stated by Herpin and Le Dividich (1995).
No significant differences are observed in
protein averages among the different levels of glucose (table 6), but between colostrum
and milk (P<0.001), linked to the high content in immunoglobulines (IgG) present in
colostrum. This content decreases considerably (over 60%) within the first 48 hours
post-farrowing (Klobasa et al., 1987). The results obtained, similar to those of
Herpin and Le Dividich (1995) and Davis et al. (1994), show a higher variation
percentage (P<0.001) with glucose level G-50 (Figure 1.) The decrease in milk is over
70 %, due to the higher protein content in colostrum, associated to a higher
immunoglobuline content, mostly IgG, and hence, better passive immunity in suckling
piglets (Klobasa et al., 1987).
Significant amino acid concentrations occurred in valine, threonine (P<0.05) and hystidine (P<0.001), respectively, with minor variations for glucose groups (Figure 2).
Figure 3 shows the percentage change in those
fatty acids which had more variation from colostrum to milk among groups: increase in
palmitoleic acid (202.87; 178.02 and 183.55 %), decrease in linoleic (55.78; 51.37 and
49.20 %) and in linolenic acid (59.18; 50.63 and 53.93 %) for glucose levels 0, 50 and
100, respectively. No differences are observed among the different glucose levels,
however, there is more decrease in linoleic and linolenic acid in level 0 with respect to
other levels. The addition of small glucose doses to the gestation feed might minimize the
loss of such nutrients in the gilt milk.
The daily glucose dose as supply in the diet of pregnant gilts is 50g/day, since the results obtained with 100g/day are equal or lower. The addition of small glucose quantities to the feed of gilts during the last third of pregnancy that might slightly stimulate the secretion of physiological levels of insulin, might increase the weight of piglets at birth and thus improve the quality of colostrum and milk. This would provide more protection and better development of the litter during lactation, assuring a favorable response in the following reproductive cycle of the gilt.
COMPOSICION NUTRITIVA DEL CALOSTRO Y LECHE DE CERDAS PRIMERIZAS SUPLEMENTADAS CON DIFERENTES NIVELES DE GLUCOSA
Se realizó una prueba experimental con 24 cerdas púberes de raza Duroc, con 120 kg. de peso corporal y 105 días de gestación. Niveles de 0-50-100 g de glucosa (G) fueron incluidos en el alimento durante los últimos 10 días previos al parto. Se verificó la proporción óptima de G así como su influencia en el peso del lechón al nacimiento y en la composición del calostro y leche de la cerda. Los resultados muestran un aumento significativo (P<0,05) en la composición de los aminoácidos totales en la leche de cerdas complementada con G, así como metionina, ácido aspártico y leucina con las concentraciones más altas (P<0,01) dentro del grupo de cerdas complementadas con el nivel 50 de G. Ninguna diferencia significativa se observó en la concentración de proteína y los ácidos grasos de calostro y leche, sin embargo, la proporción más alta fue para el ácido oleico (C18:1). Se sugiere prolongar el tiempo de suplementación (25-30 días pre-parto) a un nivel de 50 g de G por día.
Palabras clave: Glucosa, Calostro y leche, Porcino, Reproducción.
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