Pharmacokinetics of sulphamethoxazole in calves and cows

The kinetics of sulphamethoxazole (SMZ) in plasma and milk, and its metabolism, protein binding and renal clearance were studied in three newborn calves and two dairy cows after intravenous administration. SMZ was predominantly acetylated; no hydroxy and glucuronide derivatives could be detected in plasma and urine. Age-dependent pharmacokinetics and metabolism of SMZ were observed. The plasma concentration-time curves of the N4-acetyl metabolite in the elimination phase were parallel to those of the parent drug; the N4-acetyl metabolite plasma percentage depended on age and ranged between 100% (new-born) to 24.5% (cow). SMZ was rapidly eliminated (elimination half-lives: 2.0-4.7 h) and exhibited a relatively small distribution volume (VDarea: 0.44-0.57 l/kg). SMZ was excreted predominantly by glomerular filtration, while its N4-acetyl metabolite was actively eliminated by tubular secretion.     

Pharmacokinetics of sulphamethoxazole in calves and cows

Summary

The kinetics of sulphamethoxazole (SMZ) in plasma and milk, and its metabolism, protein binding and renal clearance were studied in three newborn calves and two dairy cows after intravenous administration. SMZ was predominantly acetylated; no hydroxy and glucuronide derivatives could be detected in plasma and urine. Age‐dependent pharmacokinetics and metabolism of SMZ were observed. The plasma concentration‐time curves of the N₄‐acetyl metabolite in the elimination phase were parallel to those of the parent drug; the N₄‐acetyl metabolite plasma percentage depended on age and ranged between 100% (new‐born) to 24.5% (cow). SMZ was rapidly eliminated (elimination half‐lives: 2.0–4.7 h) and exhibited a relatively small distribution volume (V_Darea: 0.44–0.57 l/kg). SMZ was excreted predominantly by glomerular filtration, while its N₄‐acetyl metabolite was actively eliminated by tubular secretion.     

Biologic quality of colostrum and calves from dairy cows injected with zinc during pregnancy]

The effects of an administration of the Zindep inj. preparation (Biotika) were evaluated in pregnant dairy cows as exerted on specific weight, total protein (TP) content, total immunoglobulin (IgC) and albumin (ALB) contents in colostrum. These parameters were also followed: calf's health, live weight, leucocyte (Lc) counts, T-lymphocyte (T-Ly) counts, contents of TPs, IgCs and ALBs in the blood serum of calves. Zinc concentrations were determined in colostrum, milk and calf blood serum. Our observations included 16 dairy cows in the seventh month of pregnancy in the second lactation and their calves in the winter feeding season. Eight experimental dairy cows were treated with the Zindep preparation in form of an injection to the neck muscles at a dose of 3 mg Zn/kg live weight in the mid-seventh month of pregnancy. Blood samples were taken from v. jugularis from all calves before their first drinking, on days 5, 15 and 30 of age. Colostrum, and/or milk samples were obtained by drawing of the colostrum or milk from the udder quarters within 60 minutes after parturition, on days 5 and 15 of lactation. Zn levels at birth were 16.48 +/- 2.67 mumol/l in experimental calves and 13.84 +/- 3.19 mumol/l in control calves. Zincaemia decreased slightly in both groups on days 5 and 15 of age, but it was insignificantly higher in calves coming from Zindep-treated dairy cows. Zn levels in the blood serum on the 30th day of age were 18.45 +/- 2.44 mumol/l in experimental animals and 15.73 +/- 3.11 mumol/l in control animals. Zn content in the colostrum of experimental cows was 2.40 +/- 0.42 mg/l and in the control it was 1088 +/- 0.52 mg/l (P < 0.05). On day 5 of lactation, Zn amounts in the milk of experimental dairy cows decreased to 0.95 +/- 0.12 mg/l and to 0.76 +/- 0.10 mg/l in the control (P < 0.01). Zn levels in the milk of experimental cows on day 15 of lactation were 0.95 +/- 0.13 mg/l and in the milk of control group they were 0.82 +/- 0.14 mg/l. Colostrum specific weight from zinc-treated cows was 1,067.86 +/- 0.75 g/cm3 and 1,056.8 +/- 13.53 g/cm3 in the control. TP and IgC concentrations were 137.81 +/- 38.11 g/l and 110.13 +/- 29.91 U ZST, respectively, in the colostrum of experimental group, and 105.98 +/- 32.02 g/l and 85.53 +/- 25.42 U ZST, resp., in control animals.(ABSTRACT TRUNCATED AT 400 WORDS)     

Metabolic reactions of calves to the feeding with Laktosan or unpasteurized whole milk]

The acid-base and other metabolic reactions to nutrition with Laktosan produced by two feed plants and with unpasteurized whole milk after transport to a dairy plant were studied in calves up to the ninth week of age. Laktosan feeding reduces the metabolic component of the acid-base balance; the use of a lower-quality Laktosan mixture, containing drum-dried milk, gives a picture of metabolic acidosis lasting about 11 days. The changes are cuased by an increased intensity of dissimilation, by the release of metabolic H+, and, in part, by the loss of bases during diarrhoea. With the use of low-quality Laktosan, the utilization of the nutrients of the feed ration is much lower than the utilization of the nutrients of unpasteurized milk or high-quality Laktosan. The use of high-quality Laktosan causes much lower acid-base changes, far from reaching pathological values. At the same time, the utilization of nutrients is higher than with the use of unpasteurized milk. This milk which cannot be considered microbially or chemically undamaged offers no advantages from the health-condition and economic point of view. The facts, revealed by the study, emphasize the high health and economic importance of the production of calf feed mixtures. At the same time the results show that enither milk nor Laktosan feeding provides enough magnesium for the calves to grow. Other metabolic aspects of different calf nutrition are discussed.     

The effect of energy-rich feed supplements for cows on the health of their calves]

Experiments were carried out with 24 pregnant cows and their calves. The cows were divided in 2 equal groups. One of these received a supplement of animal fat additional to the feed from 4 weeks a. p. to 6 weeks p. p. Apart from clinical examinations following laboratory investigations in the blood were performed: hematological parameters, cholesterol, lipids, free fatty acids, ketone bodies, protein, glucose, bilirubin, transaminases, alkaline phosphatase, Ca, Mg, P, K, Na, Cl. The addition of fat to the feed of cows influenced the energy metabolism of the cows, the body weight of the newborn ones and some hematological parameters (incl. protein) of the calves positively.     

Lysozyme in the colostrum and blood of calves and dairy cows

During examination of lysozyme concentration we have found out that 90.3% of calf sera had the lysozyme concentration to 0.5 microgram . ml-1, 5.7% of sera showed zero values and only 4.0% of sera values from 0.5 to 1.4 microgram . ml-1. A higher lysozyme content was recorded in sera of calves up to the age of ten days in comparison with sera of calves after the second week post natum. The lysozyme concentration showed in calves a two-phase increase in the age dynamics up to the seventh to eighth week of life with a peak in second and fifth to eighth week of age. The increase rate in the first phase and the time onset of increase in the second phase were in negative, and/or positive relation to the level of immunity obtained through colostrum. The lysozyme concentration in serum of dairy cows was on fourth day post partum as much as ten times higher than in serum of their progenies 48 hours after parturition. In first colostrum the lysozyme concentration fluctuated within the range of 0.15 to 0.65 microgram X ml-1, with an average of 0.30 microgram X ml-1. The concentration of lysozyme and immunoglobulins of the IgG and IgM class in colostrum showed a contrary trend in first and second milk yield, with a tendency towards increase for lysozyme and towards decrease for immunoglobulins.     

Evaluation of the morantel sustained release bolus in cows and calves

The efficacy of the morantel sustained release bolus (MSRB) in controlling gastrointestinal parasitism in beef cattle was assessed during the 1982 spring-autumn grazing season. Forty-eight cows and their calves were allotted to three equal groups. One group (T-1) served as a nonmedicated control group. One MSRB was administered to each calf of the T-2 group, and to each cow and calf of the T-3 group at the beginning of the study. The efficacy of the bolus was assessed by comparison of weight gain performance and parasitological data (fecal worm egg counts, herbage larval counts, worm counts from tracer and principal trial calves, and plasma pepsinogen level determinations). Though not statistically significant, treated calves from Group T-2 had a numerical mean weight gain advantage of 2.6 kg, and those from Group T-3 of 4.7 kg, over control calves. Average daily gains (ADG) for the three groups of calves were 0.69, 0.72, and 0.73 kg, respectively. Untreated cows from Group T-2 and treated cows from Group T-3 outperformed the control cows by 12.3 and 7.5 kg, respectively. Fecal worm egg counts from both groups of treated calves were significantly (P less than 0.01) lower than counts from control calves during the entire 169-day trial; notably, egg counts were reduced by 99% 28 days after MSRB administration to both groups of calves. There were no significant differences in the number of eggs counted from the three groups of cows, probably because of the very low numbers of eggs encountered. Mean total worm burdens of principal calves (six per group) necropsied at trial termination indicated a 91% (P less than 0.01) reduction in Group T-2 and an 87% reduction (P less than 0.01) in Group T-3. Worm-free tracer calves were introduced onto pastures every 28 days to monitor availability of infective larvae. The mean number of worms recovered at necropsy from tracer calves that grazed with control cattle increased as the season progressed. However, the numbers of parasites recovered each month from mid-August through mid-October from tracers that grazed pastures with treated cattle were lower (P less than 0.05) than those levels displayed at trial initiation. In addition, the mean numbers of worms from treated group tracers were lower than from the controls for each necropsy period.(ABSTRACT TRUNCATED AT 400 WORDS)     

Pharmacokinetics, metabolism and renal clearance of sulphatroxazole in calves and cows

The pharmacokinetic analysis of plasma concentration--time curves after a single i.v. dose of 20 mg/kg sulphatroxazole (STZ) to calves and cows revealed a small distribution volume of STZ (mean VD(area) = 0.22-0.26 l/kg) and an age dependent elimination (mean t1/2 6.6-18.8 h). In calves and cows, STZ was extensively metabolized into the N4-acetyl and 5-hydroxy derivatives. In the plasma of calves, the N4-acetyl metabolite (N4-STZ) was present in greater amounts than the hydroxy metabolite (5-OH-STZ), while in cows' plasma concentration of these two metabolites were similar. In the milk of dairy cows STZ concentrations paralleled those of the metabolites and were approximately 21 times lower than corresponding plasma concentrations. The mean plasma protein binding of STZ and its metabolites ranged from 36.4 to 82.5% of total concentration. The N4-STZ derivative was excreted by tubular secretion; the 5-OH-STZ and the parent compound, mainly by glomerular filtration. In calves the majority of STZ administered was excreted as N4-STZ (40-52%), while in cows the parent drug dominated the urinary excretion (36%).