Whey protein dynamics in goat mammary secretions during colostrum and early lactation periods.

The protein composition in goat milk undergoes changes throughout the different lactation periods, displaying distinct characteristics that are influenced by the dynamic nature of protein composition and concentration during the transition from colostrum secretion to mature milk. To evaluate the dynamics of whey proteins of Saanen goats during the colostral phase and the first month of lactation, 110 milk samples from 11 healthy mammary halves of seven Saanen goats were selected through a clinical evaluation. Whey was obtained by rennet coagulation of the mammary secretion. The biuret method determined total protein concentration, and their fractions were identified by 12% dodecyl sulfate-polyacrylamide gel electrophoresis. Maximum concentrations of all protein fractions were observed in the first 12 h of lactation, reducing throughout the study. Modification of the protein predominance was also observed. The transition from colostrum secretion to milk occurred 5 or 7 d postpartum.

The dynamics of individual whey protein concentrations in cows' mammary secretions during the colostral and early lactation periods.

The bovine whey consists of more than 200 different types of proteins, of which ß-lactoglobulin, α-lactalbumin, serum albumin, immunoglobulins and lactoferrin predominate. However, their concentrations are not stable due to the existence of protein dynamics during a transition from colostrum secretion to mature milk. To evaluate the dynamics of whey proteins of Jersey cows during a colostral phase and first month of lactation and an influence of the number of lactations, 268 milk samples from 135 Jersey cows were selected through a clinical evaluation. Whey was obtained by rennet coagulation of the mammary secretion. The concentration of total proteins was determined by the biuret method and their fractions were identified by 12% dodecyl sulfate-polyacrylamide gel electrophoresis (12% SDS-PAGE). Maximum concentrations of all protein fractions were observed in the first 12 h of lactation, reducing over the course of the study. Modification of the protein predominance was also observed. The transition from colostrum secretion to milk occurred between 24 and 72 h postpartum. There was an influence of the number of lactations on the dynamics of whey proteins, indicating that multiparous cows had better immunological and nutritional quality when compared to primiparous cows.

Proteínas do soro lácteo de vacas da raça Jersey durante a lactação / Whey proteins from Jersey cows during lactation

Para avaliar as proteínas do soro lácteo durante a lactação, o soro obtido a partir de 48 amostras de leite coletadas de 12 vacas da raça Jersey antes da ordenha foi estudado. Os animais foram distribuídos em três grupos: terço inicial (30-120 dias de lactação), terço médio (121-210 dias de lactação) e terço final da lactação (mais de 211 dias de lactação). O proteinograma consistiu da concentração de proteína total do soro lácteo, determinado pelo método de biureto e da eletroforese em gel de poliacrilamida (SDS-PAGE). A diminuição gradual e significativa de algumas frações do soro de leite foi observada durante a lactação, albumina, lactoferrina, imunoglobulinas, β-lactoglobulina e α-lactoalbumina. Os valores de normalidade obtidos para as proteínas do soro do leite de vacas Jersey foram: proteína total do soro de leite 569,0-713,0mg/dL, lactoferrina 36,0-49,0mg/dL, albumina 24,0-34.0mg/dL, cadeia pesada de imunoglobulina 38,0-51,0 mg/dL; cadeia leve de imunoglobulina 59,0-95,0mg/dL, β-lactoglobulina 207,0-256,0mg/dL, α-lactoalbumina 117,0-157,0mg/dL, proteína com 226 KDa 5,80-12.0mg/dL, e proteína com 118 kDa 2,30-6.80mg/dL.

To evaluate the whey proteins during the lactation, whey obtained from 48 milk samples collected from 12 Jersey cows before milking were studied. Cows were distributed into three groups as follows: early (30-120 days), middle (121-210 days) and end of lactation (more than 211 days). The proteinogram consisted of total proteins concentration determined by biuret method and polyacrymalide gel electrophoresis (SDS-PAGE). A gradual and significant decrease of some fractions of the whey was observed during the lactation cycle albumin, lactoferrin, immunoglobulins, β-lactoglobulin and α -lactoalbumin. The normal ranges obtained for the whey proteins of Jersey cows were: whey total proteins 569.0 to 713.0mg/dL, lactoferrin 36.0 to 49.0mg/dL, albumin 24.0 to 34.0mg/dL, immunoglobulin's heavy chain 38.0 and 51.0mg/dL; immunoglobulin's light chain 59.0 to 95.0mg/dL, β-lactoglobulin 207.0 to 256.0mg/dL, α-lactoalbumin 117.0 to 157.0mg/dL; protein with 226 KDa 5.80 to 12.0mg/dL, and protein with 118 KDa 2.30 to 6.80mg/dL.

The normal electrocardiogram in the clinically healthy Saanen goats / Eletrocardiograma normal de cabras Saanen clinicamente sadias

The purpose of this study was to establish normal reference electrocardiographic (ECG) values for standard limb lead II in Saanen goats. For this, were used 19 healthy adult female Saanen goats. And for reference values for the ECG parameters, were used 95% confidence level. The overall P, Q, R, S and T durations (seconds) were 0.03±0.01, 0.02±0.005, 0.03±0.014, 0.03±0.011, 0.06±0.014 respectively, and the reference values were 0.01-0.04, 0.01-0.02, 0.01-0.06, 0.02-0.04 and 0.04-0.08 respectively. The amplitudes (milivolts) of these waveforms were 0.1±0.031, 0.06±0.023, 0.44±0.312, 0.39±0.434, 0.26±0.164 (T negative) and 0.15±0.071 (T positive), respectively. The reference values were 0.05-0.15, 0.05-0.1, 0.05-1.2, 0.05-1.1 and -0.2-0.7 respectively. The PR and QT interval, the QRS complex and the ST segment durations (seconds) were 0.08±0.018, 0.26±0.03, 0.05±0.008, 0.15±0.041 respectively. The reference values were 0.06-0.12, 0.2-0.32, 0.04-0.07 and 0.11-0.26, respectively. It was possible to observe differences in ECG of Saanen goats regarding the amplitude and duration of the constituents when compared to the results of other breeds. Therefore it is necessary to conduct further studies to allow comparisons, detect and diagnose cardiac arrhythmias and help the development of therapies.

O objetivo deste estudo foi de estabelecer os valores de referência para o eletrocardiograma normal de derivação II de cabras Saanen sadias. As durações totais (segundos) das amplitudes de P, Q, R, S e T foram 0.03±0.01, 0.02±0.005, 0.03±0.014, 0.03±0.011, 0.06±0.014, respectivamente, e os valores de referência foram 0.01-0.04, 0.01-0.02, 0.01-0.06, 0.02-0.04 e 0.04-0.08, respectivamente. As amplitudes (milivolts) dessas formas de onda foram 0.1±0.031, 0.06±0.023, 0.44±0.312, 0.39±0.434, 0.26±0.164 (T negativo) e 0.15±0.071 (T positivo), respectivamente. Os valores de referência foram 0.05-0.15, 0.05-0.1, 0.05-1.2, 0.05-1.1 e -0.2-0.7, respectivamente. As durações (segundos) dos intervalos PR e QT, do complexo QRS e do segmento ST foram 0.08±0.018, 0.26±0.03, 0.05±0.008, 0.15±0.041, respectivamente. Os valores de referência foram 0.06-0.12, 0.2-0.32, 0.04-0.07, e 0.11-0.26, respectivamente. Foi possível observar diferenças em relação à duração e amplitude dos constituintes do ECG quando comparados com os resultados de outras raças. Portanto, torna-se necessário a realização de mais estudos para se permitir comparações, detectar e diagnosticar arritmias cardíacas bem como auxiliar no desenvolvimento de terapias.