Full text
| |
| Author(s): |
Fabio Celidonio Pogliani
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD) |
| Defense date: | 2006-08-25 |
| Examining board members: |
Eduardo Harry Birgel Júnior;
Wanderley Pereira de Araujo;
Wilmar Sachetin Marçal
|
| Advisor: | Eduardo Harry Birgel Júnior |
| Abstract | |
In order to establish the reference values for the lipid profile of Holstein cattle, bred in the state of São Paulo, we collected and analyzed samples of blood serum and plasma of 413 clinically healthy animals. We determined the concentrations of cholesterol, triglycerides, nonesterified fatty acids (NEFA), β-hydroxibutyrate (β-HBO) and glucose and analyzed the influence of age, gender and gestation on those biochemical parameters. The influence of age was studied through 273 samples of serum and plasma, divided in 7 experimental sub-groups: G1 - 20 heifer calves up to 3 months old; G2 - 20 heifer calves between 3 and 6 months; G3 - 20 heifer calves between 6 and 12 months; G4 - 40 heifers between 12 and 24 months; G5 - 73 cows between 24 and 48 months; G6 - 55 cows between 48 and 72 months; G7 - 45 cows with more than 72 months of age. The influence of gender was studied through serum and plasma of blood samples collected from 30 adult males and 30 adult females. The influence of gestation and puerperium was studied through serum and plasma from 75 animals divided into 5 experimental subgroups: G1 - 16 non pregnant females; G2 - 18 females in the initial phase of gestation, up to 3 months; G3 -15 pregnant females, with gestation between 3 and 6 months; G4 - 15 females in the last stage of gestation, between 6 and 9 months; G5 - 16 females soon after delivery, up to 30 days in puerperium. Due to lactation, we observed that in the first 3 months of life, the calves' lipid profile has particularities in some of its constituents, such as higher levels of cholesterol and glucose and lower levels of β-HBO, if compared to those observed in weaned calves between 3 and 6 months of age. After weaning, the lipid profile continued to be influenced by age; in the early stages of puberty, after 12 months of age, the serum cholesterol concentration increased gradually reaching its peak between 24 and 48 months - after this stage, the serum cholesterol concentration was no longer influenced by the animals' age. Also concerning the age, we observed that the serum triglyceride concentration in animals older than 48 months was lower than that of younger animals and the glucose concentration in the plasma diminished gradually with age. The lipid profile of healthy Holstein cattle was influenced by the gender of the animals. The serum concentrations of cholesterol and β-HBO for adult males were lower than those for adult females. The plasma glucose in adult males was higher than that in adult females. The lipid profile of healthy Holstein cows was influenced by gestation. The serum concentration of NEFA was higher in the last trimester of gestation while the serum concentration of β-HBO was higher in the first trimester of gestation. The puerperium had a significant influence on the lipid profile. In the first 30 days after delivery, the serum concentrations of NEFA and β-HBO were higher, while the triglycerides were lower when compared to those of cows during gestation. According to the results of this research and considering its variability factors, we suggest, based on the confidence interval, the use of the following reference values for the lipid profile of Holstein cattle bred in the state of São Paulo: serum cholesterol concentration - between 86.5 and 120.8 mg/dL for lactating calves up to 3 months old; between 46.3 and 79.7 mg/dL for weaned calves between 3 and 12 months; between 86.4 and 105.0 mg/dL for heifers between 12 and 24 months; between 116.0 and 147.9 mg/dL for adult cows older than 24 months; serum triglycerides concentration - between 16.3 and 34.8 mg/dL for animals up to 48 months; between 14.9 and 24.0 mg/dL for animals older than 48 months; serum NEFA concentration - between 91.3 and 294.0 μM/L regardless of the age; serum β-HBO concentration - between 1.1 and 2.1 mg/dL for calves up to 3 months old; between 3.37 and 6.2 mg/dL for animals older than 3 months; plasma glucose concentration - between 75.1 and 88.3 mg/dL for lactating calves up to 3 months old; between 64.0 and 76.1 mg/dL for animals between 3 and 24 months; between 60.6 and 67.2 mg/dL for adult cows older than 24 months. For adult males, older than 24 months, we suggest different reference values for the following constituents of the lipid profile: Serum cholesterol concentration between 73.9 and 90.2 mg/dL; serum β-HBO concentration between 3.1 and 3.6 mg/dL and plasma glucose concentration between 71.9 and 76.5 mg/dL. The reference values that were previously presented should not be used for cows in the last month of gestation and in the first 45 days of lactation. In this case, the reference values should be specific for animals around parturition. (AU) | |