Effects of dietary supplementation with different concentration of molasses on growth performance, blood metabolites and rumen fermentation indices of Nubian goats.

BACKGROUND: Molasses is a potential energy supplement; extensively used to improve growth performance, milk and meat characteristics in goats at relatively low concentrations of 5-40% of the diet. Few data are available concerning feeding molasses to goat kids; therefore, the current study aimed to investigate the effects of dietary supplementation with higher concentrations of molasses on growth performance, blood metabolites and rumen fermentation indices. Twenty male Nubian goat kids (4-6 months old; 9-10 kg BW) were randomly assigned to 4 groups receiving different concentration of molasses: 0% (M-0), 30% (M-30), 40% (M-40) and 45% (M-45) for 5 weeks. Feed (DFI) and water intake (DWI) were measured daily, while the blood and rumen liquor samples were collected weekly. RESULTS: The DFI increased and feed conversion ratio (FCR) decreased in all molasses-supplemented groups (P ≤ 0.05), whereas DWI increased in M-30 and decreased in M-45 (P ≤ 0.05). The final BW and average daily gain (ADG) increased (P < 0.0001) in groups M-30 and M-40 compared to the control and M-45. Blood pH was significantly influenced by dietary molasses concentration (MC) and the duration of molasses supplementation (MD), where it decreased in groups M-30 and M-45 compared to the control and M-40 (P < 0.05). The MC had no significant effect on blood Hb, HCT, TLC, albumin, [K+], AST, ALT and total protozoa count (TPC), as well as ruminal-[Na+], [K+], strong ion difference concentration ([SID3]) and [NH3]; however, only [NH3] was significantly affected by MD and the interaction between MC and MD (MC × MD). Serum TP, globulins, [Na+] and [Cl-] increased (P ≤ 0.05) in all supplemented groups, while A/G ratio and [SID3] decreased (P ≤ 0.05). Ruminal pH decreased (P < 0.0001) in M-40 and M-45 compared to the control and M-30. However, [VFAs] increased (P < 0.04) in M-30 and M-40 compared to the control and M-45, while osmolality increased (P ≤ 0.05) in M-30 compared to the other groups. CONCLUSIONS: Dietary supplementation with molasses at a concentration of 30% for 3 weeks improved growth performance, protein metabolism and rumen fermentation without compromising animal health, immunity, and electrolytes and acid-base homeostasis.

Studies on acid-base status (Stewart's model) of young camels (Camelus dromedarius) after acid-load with NH4Cl.

UNLABELLED: The identification of the reference values of Stewart variables and the changes in the acid-base status of the blood and urine in relation to the age after acid-load were studied in desert species of camels. 14 healthy young camels (age: 3-5 months) and 22 adult camels (age: 5-8 years) were used to provide the reference and percentile ranges of the Stewart variables. In the experiments, 24 healthy young camels (age: < 3-5 months) were infused with 5M NH4Cl solution (dose: 1.0 ml/kg) through a permanent intravenous catheter. Venous blood and urine samples were collected before infusion (0 hours). After the start of infusion, venous blood samples were collected at 2, 4, 6, 8 and 24 hours, and urine samples were collected at 8, 24 and 48 hours. Blood and urine samples were used for the determination of the various acid-base parameters, including the non-respiratory Stewart variables. The reference range of serum-[strong ion difference = SID3] was 39-52 mmol/l for all age groups. The reference values of serum-[acid total = A-] were between 10-17 mmol/l for all age groups. Serum-[Atotprotein] and -[Atot-albumin] showed a reference range of 19-24 mmol/I and 20-28 mmol/l, respectively. By 2-8 hours after the NH4Cl-load, the Stewart variables (serum-[SID3] and serum-[A(tot-protein)]) decreased significantly, and as a consequence, the blood pH decreased. Generally, the loaded young camels showed a transient moderate hyperchloraemic acidosis with a slight hypoproteinaemic alkalosis. These malfunctions were accompanied by increased renal fractional excretion of chloride and sodium and decreased urine pH. CONCLUSION: The identified reference values of the Stewart variables can be used for the clinical diagnosis of acid-base disturbances in camels. With the assistance of the non-respiratory Stewart variables ([SID3] and [Atot]), we can detect the determining influence of strong electrolytes (Na+, K+ and Cl-) and weak acids (proteins, Pi) on the physiological and pathological acid-base status of the animals.

Age-dependent response of the acid-base parameters (Henderson-Hasselbalch, Stewart) in healthy calves with experimentally induced metabolic acidosis.

UNLABELLED: The intensity of the response to acid-base parameters in relation to the age after a defined acid load was studied in calves. 32 clinically healthy calves (age: 4-104 days) were infused with 5M NH4Cl solution (dose: 1.0 ml/kg) through a permanent intravenous catheter. Before (0 hrs) and after starting the infusion (2, 4, 6, 8 and 24 hrs) venous blood samples were collected for the determination of the various acid-base parameters. The intensity of the response of the acid-base parameters was estimated by using the "area under curve (AUC)" procedure. By 2-6 hrs after the infusion of the NH4Cl solution, the Henderson-Hasselbalch parameters decreased significantly (decrease pH, decrease [HCO3-]) as did Stewart's variables (decrease [Strong ion difference=SID3], decrease [Acid total = A(tot) or A-]). A transient moderate hyperchloraemic acidosis with a slight hypoproteinaemic alkalosis was observed in all calves in association with a respiratory compensation (decrease PCO2). The younger calves (1st-3rd week) showed a similar pattern of response to the same dose per kg 0.75 acid load with significantly greater acid-base parameters response (higher AUC values) than the older animals. The calculated pH was determined by using the three Stewart variables PvCO2, serum-[SID3] and serum-[A(tot)]. The mean difference was -0.03 to -0.09 compared with the measured pH (7.32-7.40). CONCLUSION: The Stewart model appears to be more successful in providing a comprehensive evaluation of acid-base status compared with the traditional Henderson-Hasselbalch model. The younger calves during the first week of life reacted more sensitively to an equal acidotic condition than the older animals.