The effect of concentrate feeding on calcium metabolism and plasma gastrin concentration in parturient cows

The effect of concentrate feeding on calcium metabolism was studied in pregnant cows. The concentrate (5 kg/day) was added to the diet about three weeks before expected calving. A control group was fed only hay during the whole dry period. It was earlier observed in sheep that concentrate feeding was followed by a disturbance in calcium homeostasis, but no such disturbances were observed in the cows. The concentrate fed cows consumed 50 % more calcium than the controls and were found to mobilize less calcium from the skeleton immediately after calving. There was no evidence for the theory that the gastro-intestinal hormone gastrin is involved in calcium homeostasis in the parturient cow.     

The concentration of ionized magnesium in serum during the periparturient period of non-paretic dairy cows

Ion-selective electrodes have recently been designed for determining the ionized concentration of magnesium (Mg²⁺) in serum. This development may allow new insights into some metabolic diseases of cattle. For this report, the concentrations of Mg²⁺, total magnesium (Mg_tot), ionized calcium (Ca²⁺), total calcium (Ca_tot), and inorganic phosphate (P_i) were determined in sera from seventeen 3-to 16-year-old Brown Swiss and crossed Simmental/Red Holstein cows during the periparturient period. In each animal, a transient increase of Mg²⁺ and Mg_tot serum concentrations was observed in association with the transient decrease in serum concentrations of Ca²⁺, Ca_tot and P_i after parturition. On average, throughout the study, the serum Mg²⁺ concentrations were 68.5% of those of Mg_tot, whereas the serum Ca²⁺ concentrations were 52% of those of Ca_tot. The possible mechanisms involved in the transient increase of Mg²⁺ and Mg_tot serum concentrations are discussed.Abbreviations Ca²⁺ ionized calcium - Ca_tot total calcium - Mg²⁺ ionized magnesium - Mg_tot total magnesium - P_i inorganic phosphate - PTH parathyroid hormone - PTHrP parathyroid homrone related protein     

Cholinesterase Levels in Blood Plasma and Erythrocytes from Calves,Normal Delivering Cows and Cows Suffering from Parturient Paresis

Plasma cholinesterase (pChE) levels and erythrocyte acetylcholinesterase (eAChE) levels were studied in 6 cows before, during and after parturition (Group I), their calves (Group II), 38 cows suffering from parturient paresis (Group III) and 14 newly delivered non-paretic cows (Group IV).The mean of the pChE level in Group I was 1.5 μkat/1 ± 0.20 before parturition and decreased significantly (P ≦ 0.05) to 1.2 ukat/1 ± 0.16 after parturition. The eAChE level was before parturition ≅ 140 ukat/1 and decreased to ≅ 130 μkat/1 4–5 weeks after parturition.At birth the pChE level was 12.8 ukat/1 ± 5.9 in Group II. After 4 weeks the level had decreased to 2.3 ukat/1 ±0.3. In the bull calves the pChE level started to increase when they were 6 weeks old and reached a level of 5.7 μkat/1 ± 0.6 before slaughter at 6 months of age. The heifers did not show this increase. They had a level of around 2 μkat/1 throughout the investigation. The eAChE level at birth was 119 μkat/1 and increased slowly to a level of 145 μkat/1 at 6 months. No differences between the sexes were found.The cows suffering from parturient paresis had a pChE level of 1.80 μkat/1 ± 0.30 before treatment with calcium (Ca). The level decreased significantly (P ≦ 0.001) after Ca-infusion to a level of 1.67 ukat/1 ±0.29. Group IV had a pChE level of 1.65 μkat/1 ± 0.42 at parturition. Two to 4 months later the cows that had recovered from milk fever had a level of 1.61 μkat/1 ± 0.31 and the control cows 1.66 ukat/1 ± 0.48. No differences between the groups were found for the eAChE level.The findings show that parturition influences the pChE level in cows and that sex influences the pChE level in calves between 6 weeks to at least 6 months of age. Furthermore the elevated pChE level found in the cows suffering from parturient paresis before Ca infusion may be a further sign of a disturbance in the cholinergic system with a special preference to the neuromuscular junctions.     

An epidemiological and genetic study on registered diseases in Finnish Ayrshire cattle. III. Metabolic diseases

The epidemiology of clinical ketosis, hypocalcaemia and hypomagnesaemia was examined. In addition, the genetic variability of ketosis and parturient paresis was investigated. The data set consisted of the lactation records of 70,775 Finnish Ayrshire dairy cows. Each cow was under observation for 2 days before and for 305 days after calving. Lactation incidence rates (%) were: ketosis 6.0, parturient paresis 3.8, non-parturient paresis 0.6, hypomagnesaemic tetany, outdoor 0.6, and indoor 0.2. These diseases formed 22 % of all first treatments by veterinarians during farm visits. 92 % of the cases of ketosis occurred with 8 weeks of parturition, with the highest occurrence 3–5 weeks after calving. Four % of cases of parturient paresis occurred before, and 45 % within 24 h after calving. When cases were categorized by month of calving the risk of ketosis was higher during indoor feeding (October-April) than during outdoor feeding (May-September). The risk of parturient paresis did not significantly vary with month of calving. The occurrence of ketosis increased with parity up to the 4th and decreased thereafter. The occurrence of parturient paresis increased with parity. Both the increase in herd milk yield and the increase in individual milk yields were positively associated with the occurrence of ketosis and parturient paresis. The cows with a history of the reproductive tract infection had a higher risk of contracting ketosis. Heritability estimates for ketosis in various parity groups were from 1.6 % to 4.1 % on the binomial scale (corresponding to 7.3 %–14.4 % on the normal scale), and for parturient paresis from 3.5 to 10.5% (corresponding from 18.3 % to 27.4 %). The genetic correlation between ketosis and parturient paresis, and these and current milk production for all material were insignificant.     

Packed cell volume (PCV) in connection with uterine prolapse and in parturient paresis in cows.

Packed cell volume was determined in 317 cows with uterine prolapse, the condition being in more than half of these cases associated with varying degrees of hypocalcaemia, in 133 cows with parturient paresis and in 73 clinically healthy newly calved cows. Independently of each other uterine prolapse and fall in plasma calcium were associated with a significant rise in PCV. The present investigation demonstrated a marked fall in circulating blood volume in a considerable number of cows suffering from uterine prolapse. The risk of irreversible hypovolemic shock developing in connection with uterine prolapse is not to be neglected, and may be aggravated by the simultaneous occurrence of hypocalcaemia, as several of the compensatory mechanisms are calcium dependent.     

丙酸钙对泌乳早期奶牛泌乳性能和代谢产物的影响

选用32头经产奶牛,根据泌乳期、上个泌乳期305 d产奶量和预产期,采用随机区组设计分为4组,对照组饲喂基础日粮,处理1、2、3组分别在基础日粮基础上添加丙酸钙100、200、300 g/d.结果显示,日粮添加丙酸钙对奶牛的采食量、乳脂率、乳蛋白率、乳糖率和乳干物质率无显著影响,200、300 g/d组产奶量和饲料转化效率显著高于对照组(P<0.05).200、300 g/d组血浆葡萄糖和胰岛素浓度显著高于对照组(P<0.05),而血浆游离脂肪酸和β-羟丁酸浓度显著低于对照组(P<0.05);200、300 g/d组尿酮浓度显著低于对照组和100 g/d组(P<0.05).试验结果表明,丙酸钙适宜添加量为200 g/d.     

Plasma Levels of Immunoreactive Parathyroid Hormone in Relation to Starvation Hypocalgaemia in Dairy Cows

The hypocalcaemia caused by parturition and onset of lactation in high-production dairy cows was mimicked by subjecting cows to starvation periods before and after partus. The changes in plasma calcium, phosphate and magnesium were followed and compared with immunoreactive parathyroid hormone (iPTH) in 2 cows. During the starvation periods before partus, the cows developed hypocalcaemia with no or only small changes in the plasma concentration of magnesium. After the onset of hypocalcaemia, the concentration of iPTH increased on the average 3–4-fold and the raised hormone levels lasted about 24 h after start of refeeding. An increase in plasma phosphate occurred somewhat later than the rise in iPTH and lasted longer. After partus hypocalcaemia developed, together with smaller increases in iPTH concentration (about 2-fold). The post-partum starvation period again resulted in hypocalcaemia and raised iPTH concentrations.In conclusion, starvation and parturition induced inverse changes in plasma calcium and iPTH in dairy cows. The increases in plasma iPTH were reversible and considered secondary to the hypocalcaemia. Through the effect of paratyroid hormone, plasma calcium was normalized and phosphate concentration increased. Therefore, fatal hypocalcaemia which may occur following the course of parturition and onset of lactation is not due to impaired PTH secretion.     

Half-lives of sulphadoxine and trimethoprim after a single intravenous infusion in cows

DAVITIYANANDA, DANIS and FOLKE RASMUSSEN: Half-lives of sulphadoxine and trimethoprim after a single intravenous infusion in cows. Acta vet. scand. 1974, 15, 356–365. — The half-life of sulphadoxine in plasma (11 hrs.) is much longer than that of trimethoprim (50–103 min.) and in accordance to this traces of sulphadoxine are demonstrated in the milk 3 days after the infusion, while trimethoprim could not be detected in milk 2 days after the infusion. The apparent volume of distribution is 0.37 for sulphadoxine and 1.14 for trimethoprim, i.e. 37 % and 114 % of the body weight, respectively.sulphadoxine; trimethoprim; half-life; cow.     

ORIGINAL ARTICLE: Effects of calcium propionate supplementation on lactation performance,energy balance and blood metabolites in early lactation dairy cows

To evaluate the effects of calcium propionate (CaP) supplementation on feed intake, milk yield and milk composition, energy balance, blood metabolites and urine ketones in early lactation Holstein dairy cows from 1 to 63 days in milk (DIM), 32 multiparous Holstein dairy cows, blocked by lactation number, previous 305‐day milk production, and expected calving date, were arranged into four groups in a randomized block design. Treatments were control, LCaP, MCaP and HCaP with 0, 100, 200 and 300 g calcium propionate per cow per day respectively. The supplement of food grade CaP (99.8% of CaP) was hand‐mixed into the top one‐third of the daily ration. Cows were fed ad libitum a total mixed ration consisting of equal proportion of forage and concentrate. Feed intake, milk yield and components were not affected by CaP supplementation. The energy balance, expressed as the difference between energy input and output, tended to be higher (p = 0.08) for CaP‐supplemented cows during the 63‐DIM period, especially during the first 21‐DIM lactation. Calcium propionate‐supplemented cows showed a trend (p = 0.09) towards less loss of body weight (BW) during the 63‐DIM period. Concentrations of glucose in plasma and insulin in serum were higher for cows fed CaP relative to control and linearly (p < 0.01) increased with increasing CaP supplementation. Concentrations of non‐esterified fatty acids (NEFA), beta‐hydroxybutyrate (BHBA) and urine ketones were lower for CaP‐supplemented cows at 7, 14 and 21 DIM of lactation and linearly (p < 0.01) decreased with increasing CaP supplementation. These results indicated that nutrient digestibilities and energy status may have been improved.     

Increasing selenium supply during the close-up dry period improves nutrient metabolism and attenuates inflammatory response after calving in dairy cows

The objective of this study was to investigate whether feeding selenium (Se)-replete cows a Se-yeast supplement in late pregnancy affects nutrient metabolism and inflammatory response during the periparturient period. Twenty cows were randomly assigned to two groups with 10 cows each. Cows in one group received Se-yeast at 0.3 mg Se/kg DM during the last 4 weeks before calving in addition to fed a TMR containing supplemented sodium selenite at 0.3 mg Se/kg DM (Se-yeast), while cows in another group were only fed a TMR containing supplemented sodium selenite at 0.3 mg Se/kg DM (Control). Blood samples were collected and analyzed for nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), glucose, insulin, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, serum amyloid A (SAA), haptoglobin (Hp), and albumin. In control cows, plasma NEFA, IL-1β, IL-6, SAA, and Hp levels increased after calving, but glucose, insulin, and albumin levels decreased after parturition. Se-yeast supplemental cows had lower postpartum concentrations of NEFA, TNF-α, IL-1β, IL-6, SAA, and Hp, and higher postpartum levels of glucose, insulin, and albumin compared with control cows. The results indicate that feeding Se-replete cows a Se-yeast supplement in late pregnancy improves nutrient metabolism and attenuates the inflammatory response after calving.     

Comparative pharmacokinetics of enrofloxacin and ciprofloxacin in lactating dairy cows and beef steers following intravenous administration of enrofloxacin

The comparative pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin were investigated in lactating cows and beef steers. The plasma elimination half-life of either enrofloxacin or ciprofloxacin was shorter in cows than in steers. The overall production of ciprofloxacin was slightly higher in steers than in cows (metabolite ratio: 64% and 59%, respectively). There was no significant difference in plasma protein binding of enrofloxacin between cows (percent bound: 59.4%) and steers (percent bound: 60.8%). Ciprofloxacin was more extensively bound to plasma proteins in steers (percent bound: 49.6%) than in cows (percent bound: 33.8%). The steady state volume of distribution of enrofloxacin is comparable in cows (1.55 L/kg) and steers (1.59 L/kg). Within either bovine class, plasma elimination half-life of enrofloxacin and ciprofloxacin are comparable, while plasma protein binding was higher for enrofloxacin than for ciprofloxacin. Ciprofloxacin was more concentrated in milk than enrofloxacin.     

不同生理状态对荷斯坦奶牛钙、磷表观消化率的影响

本试验研究了不同生理状态下荷斯坦牛Ca、P表现消化率的变化规律.结果表明:生长期内不同生长阶段对奶牛Ca、P表观消化率影响显著(P<0.05),12月龄和24月龄奶牛Ca表观消化率显著高于18月龄(P<0.05);12月龄和24月龄奶牛P表现消化率极显著高于18月龄(P<0.01);泌乳2月与干奶期奶牛Ca、P表观消化...     

Effects of cortisol secreted via a 12-h infusion of adrenocorticotropic hormone on mineral homeostasis and bone metabolism in ovariectomized cows

To evaluate the effects of endogenously secreted cortisol on mineral homeostasis and bone metabolism in cows, 4 ovariectomized Holstein cows were infused for 12 h with either an adrenocorticotropic hormone (ACTH) solution (0.5 mg/2 L isotonic NaCl solution per cow) or isotonic NaCl solution in a 2 × 2 crossover design. ACTH infusion stimulated cortisol secretion and increased plasma cortisol concentrations for 18 h (P < 0.001), leading to an elevated plasma glucose concentration until 36 h (P < 0.001). Plasma calcium and magnesium concentrations in ACTH-infused cows fluctuated within normal ranges, whereas hypophosphatemia was observed unequivocally. The biochemical bone resorption markers tartrate-resistant acid phosphatase 5b and hydroxyproline decreased following ACTH infusion (P < 0.001 and P = 0.003, respectively). Similarly, the bone formation marker, bone-specific alkaline phosphatase, decreased continuously until 72 h after the ACTH infusion (P < 0.001). These results demonstrate that increased secretion of cortisol via a 12-h ACTH infusion disrupted homeostasis of inorganic phosphate and suppressed bone metabolism in ovariectomized cows without involving gonadal steroid hormones.     

The effects of calcium,phosphorus and zinc supplementation on reproductive performance of crossbred dairy cows in Tanzania

The effects of calcium (Ca), phosphorus (P) and zinc (Zn) supplementation on reproductive performance of grazing dairy cows was studied. Forty-eight cows in their first to third parity were allocated to eight groups of 6 animals each, based on stage of lactation and milk yield. Groups 1 (control), 2 (Ca), 3 (P) and 4 (Zn) received, respectively, no mineral supplement, 10 g Ca, 8 g P and 400 mg Zn. The rest of the groups received a combination of Ca/P, Ca/Zn, P/Zn or Ca/P/Zn. Animals were drenched daily. Ovarian activity was determined by progesterone concentrations in milk. Prepartum body condition score (BCS) measured using scale 1–5 was 2.5–3.5. Reproductive problems were observed in all groups except that supplemented with Ca. Cows supplemented with Ca, P, Ca/P, Ca/Zn and Ca/P/Zn had significantly (p < 0.05) shorter interval (30 days) from calving to resumption of oestrus as compared to control (69 days). Intervals from calving to conception and between calvings did not differ significantly between groups (p > 0.05), but were shorter in Ca-supplemented cows. Furthermore, cows in groups 2 and 3 needed an average of 2 services per conception against 3 for cows in other groups. Hence, supplementation with Ca, P and Zn of deficient dairy cows appears to improve reproductive performance.     

Ovarian and uterine arteries blood flow waveform response in the first two cycles following superstimulation in cows

To investigate the ovarian and uterine blood flow responses, hemodynamic, circulating ovarian hormones and nitric oxide (NO) after end of treatment by Folltropin. Holstein Friesian (12) cows previously synchronized with CIDR underwent Doppler ultrasound after administrating of FSH daily for 4 days in eight injections started on day 10 of the second ovulation (day −5). Oestradiol (E2), progesterone (P4) and nitric oxide (NOMs) were measured. During the follicular phase, follicle area and antrum area of the second cycle reached maximum value on the day of ovulation compared with that in the first cycle, while during the luteal phase, both showed a pattern of increase and decrease. The luteal area and total coloured area increased till day 10 in the first and second cycle. The first cycle ipsilateral ovarian artery (Ov.A) had higher pulsatility (PI) (p = .001), resistance (RI) (p = .001), peak velocity (PSV) (p = .009) and lower end-diastolic velocity (EDV) (p = .003) compared with the second cycle. The increased ipsilateral Ov.A PSV (p = .009) was accompanied by lower EDV. The first cycle ipsilateral middle uterine artery (MUA) had higher PI (p = .001) and RI (p = .001), with lower PSV (p = .001) and EDV (p = .001). It was concluded that blood flow of ovarian and middle uterine arteries changed after the end of superstimulation as the increased ipsilateral Ov. A and MUA PSVs accompanied by lower EDV and both Doppler indices that reflect the amount of ovarian and uterine blood flow waveform.     

Effects of continuous low dose infusion of lipopolysaccharide on inflammatory responses,milk production and milk quality in dairy cows

The objective of this study was to evaluate the effects of continuous low dose infusion of lipopolysaccharide (LPS) on inflammatory responses and milk production and quality in lactating dairy cows. Eight Holstein cows were assigned to two treatments in a cross‐over experimental design. Cows were infused intravenously either with saline solution or with saline solution containing LPS from Escherichia coli O111:B4 at a dose of 0.01 μg LPS/kg body weight for approximately 6 hr each day during a seven‐day trial. The clinical symptoms and milk production performance were observed. Milk samples were analysed for conventional components, fatty acids and amino acids. And jugular vein and mammary vein plasma samples were analysed for concentrations of cytokines and acute phase proteins. LPS infusion decreased feed intake and milk yield. An increase in body temperature was observed after LPS infusion. LPS infusion also increased plasma concentrations of interleukin‐1β, serum amyloid A, LPS‐binding protein, C‐reactive protein and haptoglobin. LPS infusion decreased the contents of some fatty acids, such as C17:1, C18:0, C18:1n9 (trans) and C18:2n6 (trans), and most amino acids except for methionine, threonine, histidine, cysteine, tyrosine and proline in the milk. The results indicated that a continued low dose infusion of LPS can induce an inflammatory response, decrease milk production and reduce milk quality.     

日粮添加过瘤胃保护胆碱对喀斯特山区奶牛泌乳性能的影响及其延续效应研究

研究日粮添加过瘤胃胆碱(RPC)对喀斯特山区奶牛泌乳性能及其延续效应的影响。以10头喀斯特山区泌乳盛期奶牛为试验动物,进行自身对照试验设计。试验按照对照期、正试期(试验Ⅰ期、试验Ⅱ期)、延续效应期(试验Ⅲ期)连续进行,每期12 d。其中,正试期RPC每头奶牛的添加水平为40 g/d;试验Ⅲ期停喂RPC以观察其是否可对奶产量产生延续效应。结果表明,对照期、试验Ⅰ期、试验Ⅱ期、试验Ⅲ期奶牛干物质采食量差异不显著(P>0.05)。试验Ⅰ期奶产量显著高于其他3期(25.5∶27.7∶26.5∶24.8 kg/d,P<0.05);正试期(试验Ⅰ期、试验Ⅱ期)奶产量显著高于对照期、延续效应期(25.5∶27.2∶24.8 kg/d,P<0.05);当停喂RPC后,延续效应期奶产量即下降至对照期水平(25.5∶24.8 kg/d,P>0.05)。奶成分不受日粮添加RPC的影响(P>0.05),乳脂、乳固型物含量数值上较对照期有所增加。由此可见,日粮添加RPC有利于提高喀斯特山区奶牛泌乳性能,但未对奶产量表现出延续效应,生产实践中需持续添加。     

Effect of meloxicam administration after calving on milk production,acute phase proteins,and behavior in dairy cows

Calving is an intrinsically risky process that can cause welfare and economic problems. The objective of this study was to assess the effect of the nonsteroidal anti-inflammatory drug meloxicam on various physiological and behavioral measures which can be related to pain in cattle. Sixty Friesian dairy cows from first to sixth parity were studied around calving and were randomly allocated into 2 homogeneous groups relative to parity and treated with either meloxicam or a placebo after calving. Treatments were administered on average 3.4 hours after calving, within a maximum of 6 hours. Calf positions at calving and calving assistance (unassisted or easy manual pull) were recorded. Milk production, rectal temperature, and activity (calculated as the number of steps per hour) were measured on each cow. From a subsample of 20 cows, haptoglobin (Hp) and serum amyloid A (SAA) concentrations were also obtained. The following behaviors were observed on video recordings: posture, changing posture, location of cow in pen, feeding, and tail up behaviors 2 days before and after calving. Statistical analysis was carried out with the SAS software using MIXED or GENMOD procedures. Most variables showed a parity and/or time effect around calving. This study did not demonstrate any significant effect of meloxicam on milk production or on acute phase responses of Hp and SAA. However, postcalving activity was significantly increased in meloxicam-treated heifers.     

Phagocytic and oxidative burst activity of phagocytic cells in peripheral blood and uterine washings in cows with clinical endometritis before and after intrauterine use of cephapirin and methisoprinol

The aim of the study was to evaluate phagocytic and killing activity of phagocytic cells in blood and uterine flush of cows with endometritis before and after intrauterine (i.u.) administration of cephapirin and methisoprinol. The research was carried out on 28 cows with clinical endometritis. Animals were divided into four groups, each composed of seven cows, depending on the i.u. treatment used: Group A—cephapirin; Group B—methisoprinol; Group C—cephapirin and methisoprinol at the same time; and a control group—without medication. Using flow cytometry technique, the phagocytic activity of granulocytes and monocytes was identified, as well as the oxidative burst activity of neutrophils in the peripheral blood and uterine washings. Summarizing the results of the research, i.u. infusion of cephapirin caused a reduction in the phagocytic and killing activity of phagocytes. The i.u. use of methisoprinol increased phagocytic and killing activity of phagocytes in the uterus. Administering both listed substances simultaneously showed a decrease in phagocytosis, presumably due to the dominating inhibitor effect of the antibiotic. However, also an increase of mean fluorescence intensity was observed, presumably caused by the methisoprinol. Intrauterine use of immunostimulatory substances, can improve the effectiveness of the treatment of endometritis in cows.     

持久黄体性不孕奶牛用复方缩宫素乳剂处理后血清中孕酮和雌二醇水平的变化

选择患持久黄体的不孕奶牛14头进行复方缩宫素乳剂的临床治疗试验,并利用放射免疫方法对部分患牛治疗前后血清孕酮（P