Milk thistle (Silybum marianum, L., Gaertn.) in the feed of ketotic cows]

Two comparative trials were performed, each with 16 cows which in the period of 2-6 weeks after parturition had 7.9 mg and more acetone in 1 litre of milk. The cows, crossbreds of the Czech Red-Pied cattle with the Holstein cattle, were divided into control and test groups, eight in each using the system of pairs. The cows of test groups were given for a fortnight feed rations containing a meal of milk thistle (Silybum marianum, L., Gaert.) seeds, at a rate of 0.3 kg per head/day with the contents of 2.34% silybin and silydianin (substances of the so called silymarin complex of the flavonolignane group). In comparison with the control cows, in the blood and milk of the former ones a decrease was demonstrated in the sum of acetone + acetoacetic acid (up to P less than 0.01) and beta-hydroxybutyric acid in the blood (up to P less than 0.05). The ketonuria degree dropped remarkably. Although there were not observed any differences in the parameters of acid-base metabolism in the blood (pH, PCO2, BE, SB, BB), the pH values and net acid-base output in urine were higher in these cows. Milk production in the cows of control groups was decreasing during the trial (up to P 0.01), but in the test cows it was higher by 7.7% (trial 1) and by 3.4% (trial 2), in comparison with the milk yield at the beginning of the trials. Differences in metabolism parameters and milk production in favour of the cows which were given milk thistle in their feed rations were observed even in a fortnight after the diet stopped to contain this ingredient.     

Concentrations of ketones in milk in early lactation, and reproductive performance of dairy cows

Samples of blood and milk were taken from clinically ketotic cows at 12-hour intervals before and after treatment The concentration of beta-hydroxybutyrate was determined in plasma and milk, and the concentration of acetone was determined in milk. Measurement of milk acetone had the optimal combination of sensitivity, specificity and positive predictive value to identify ketotic cows and was subsequently used in a comparison of the fertility of ketotic and normal cows. Two samples of milk were taken approximately two weeks apart, between 12 and 60 days after calving, from 410 cows on three farms and the concentration of acetone in the milk was measured. Thirty cows with milk acetone concentrations of at least 0.4 mmol/litre were compared with paired control cows with milk acetone concentrations less than 0.3 mmol/litre. The ketotic cows had a significantly longer calving-to-conception interval and a significantly higher culling rate due to a failure to conceive (P<0.05).     

The orotic acid concentration in the blood, milk, and urine of dairy cows fed with urea supplemented diet

The experiment was performed on 4 cows Black and White, 550-650 kg of body weight, before and during 100 days after parturition. Two cows were fed with control and the next two with urea supplemented diet (urea-N constituting about 20% of total N in ration, 13% c.p. in DM). In cows fed with urea supplemented diet the considerable but unequal increase of urinary orotic acid excretion (particularly evident in first 30 days of lactation) was observed. There was however no influence of urea ration on the level of orotic acid in milk. The average orotic acid level in blood plasma (1.14 +/- 0.71 mumol X l-1 and 0.94 +/- 0.22 mumol X l-1 for control and urea fed cow respectively) established 0.01 and 0.001 of the average orotic acid concentration in urine and milk, respectively. Feeding with urea ration did not affect the level of orotic and UMP but increased the uridine concentration in blood plasma. During the parturition the lowest level of orotic acid in blood plasma, milk and urine was observed.     

The effect of feeding silage juices on selected hematologic and biochemical parameters in the blood (serum) and urine of feedlot bulls

The influence of silage juice feeding on the changes in 24 haematological and biochemical parameters in blood (blood serum) and urine of feeder bulls was evaluated in two comparative experiments in which no silage was included in feed rations. The supplement of 2 or 4 litres of juice per 100 kg of live weight represented a daily acidogenous stress of 0.79 to 1.93 moles of organic acids. In the first experiment this supplement was not proved to evoke any significant changes in the evaluated parameters. In the second experiment, in which the silage juices were enriched with sodium chloride, aqueous ammonia solution (26%) and molasses, a statistically significant increase in the level of beta-hydroxybutyric acid in blood and in the corresponding sum of ketone bodies (P less than 0.05 to 0.01) was observed in the experimental group of animals. The levels of sodium in serum were also increased (P less than 0.05). The average weight gains of bulls belonging to the experimental group were higher than those in the control groups.     

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.     

Effect of mastitis on macro-minerals of bovine milk and blood serum in Sudan

Milk and blood serum from clinically mastitis infected, subclinically mastitis infected and healthy Friesian cows (15 samples from each of 3 groups) were evaluated for macrominerals (sodium, potassium, calcium, magnesium and phosphorus). The milk from cows infected with subclinical mastitis revealed a significant decrease in potassium (P < 0.001) and a significant increase in sodium and phosphorus content (P < 0.01). Similarly, the milk from cows with the clinical form of the disease showed a significant increase in sodium (P < 0.001) and a significant decrease in potassium, magnesium (P < 0.001) and calcium (P < 0.01). Comparison of healthy cow's milk with that from cows with subclinical mastitis revealed a highly significant increase in sodium (P < 0.001). Comparison of healthy cow's milk with that of clinically mastitic milk showed a highly significant decrease in levels of calcium, magnesium (P < 0.001) and potassium (P < 0.01). However, sodium increased highly significantly (P < 0.001). Comparison of macro-minerals in milk from cows with subclinical and clinical mastitis revealed a significant decrease in potassium contents (P < 0.05) compared with that of healthy cows. Potassium levels were found to decrease significantly (P < 0.05) in subclinically infected cow's blood serum. However, calcium and phosphorus showed a significant decrease (P < 0.01) in blood serum samples from the clinically infected cows.     

Results of liver function tests in abomasal displacement and ketosis of cattle

Totally 187 cows were used in this research, 101 of these had left and 60 right abomasal displacement. The rest of them had ketosis. Blood and urine samples were collected from all of the cows for laboratory analyses. The amount of bile acid and total bilirubin and activity of aspartate aminotransferases (AST) in blood samples and the amount of ketone in the urine samples were determined. The results obtained from this study were as follows: The mean value of bile acid, total bilirubin and AST-activity were 38.37 mumol/l, 13.06 mumol/l and 92.26 U/l in right abomasal displacement cows and 37.93 mumol/l, 14.39 mumol/l and 68.39 U/l in left abomasal displacement cows respectively. Although important differences (P less than 0.05) were detected in AST-values between these three groups of diseases, there was no significant differences in bile acid and total bilirubin. There was a correlation between total bilirubin and bile acid and total bilirubin and AST in the right and left abomasal displacement cows. Same correlation was determined between total bilirubin and AST in acetonemic cows. But there was no correlation between total bilirubin and bile acid in acetonemic cows and between bile acid and AST in abomasal displacement and acetonemic cows. A very important connection was determined between the amount of total bilirubin and degree of the acetone in the urine (P less than 0.001) of the left abomasal displacement cows. The same connection (P less than 0.05) was determined between the degree of the acetone in the urine and AST-activity in the same cows.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of malic acid on feed intake, milk yield, milk components and metabolites in early lactation Holstein dairy cows

The objective of this study was to evaluate the effects of malic acid (MA) on feed intake, milk yield and composition, blood metabolites and energy balance in early lactation Holstein dairy cows from 1 to 63 day in milk (DIM). Twenty-eight multiparous Holstein dairy cows, blocked by lactation number, previous 305-d mature equivalent milk production, and expected calving date, were arranged into four groups in a randomized block design. Treatments were: control (without MA), LMA, MMA and HMA with 70, 140 and 210 g malic acid per cow per day, respectively. The supplement of food grade MA (99.8% of MA) 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. Milk yield increased (P = 0.04), but feed intake and milk components were not affected (P > 0.05) by MA supplementation. The energy balance, expressed as the difference between energy input and output, tended to be higher (P = 0.08) for MA supplemented cows during the 63-DIM period MA and supplemented cows showed a trend (P = 0.07) toward less loss of BW during the 63-day period, especially during the first 21-day of lactation. Concentrations of plasma glucose and serum insulin were higher for cows fed LMA, MMA, and HMA relative to control and linearly (P < 0.01) increased with increasing MA supplementation. Concentrations of non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA) and urine ketones were lower for MA-supplemented cows at 7, 14 and 21 DIM of lactation and linearly (P < 0.01) decreased with increasing MA supplementation. Although feed intake was not affected, milk yield increased, MA-supplemented cows experienced higher concentrations of plasma glucose and serum insulin, lower concentrations of plasma BHBA and NEFA, and lower concentrations of urine ketones, suggesting that nutrient digestibilities and energy availability may have been improved.     

The effects of subcutaneous injections of sodium selenate on blood composition and milk yield in dairy cows.

Three groups of four lactating cows received a subcutaneous injection of 0 . 05, 0 . 10 and 0 . 15 mg Se/kg body weighty respectively administered as sodium selenate. A fourth group was injected with saline. In all the cows injected with sodium selenate, the concentration of Se in blood increased rapidly and was significantly higher than in control cows for two days in the group receiving the lowest dose and for 182 days (the duration of the experiment) in the two other groups. The activity of glutathione peroxidase in blood increased slowly in all cows injected with sodium selenate and was significantly greater than in control cows after 15, 22 and 29 days respectively, and remained significantly greater for 63, 91 and 182 days respectively. In a second experiment a single subcutaneous injection of 0 . 15 mg Se/kg body weight had no effect on the mean milk yield of 37 animals (19 . 1 kg/day) compared with the milk yield of a similar group of control animals (19 . 1 kg/day) during 70 days. The concentration of Se in milk was significantly higher on the first (168 microgram/litre) and second (69 microgram/litre) day after injection than in control animals (mean 26 microgram/litre).     

The effect of feeding corn silage juices on selected indicators of metabolism in dairy cows given feed containing various proportions of silage and hay

In farm production conditions two comparative trials lasting 58 and 128 days were carried out. Acidogenic exposure to acids of silage juices, silage and haylage (lactic acid, acetic and butyric acids) in feed ration ranged from 0.33 to 2.85 mol per 100 kg live weight. It was proved that it was possible to include 9 to 10 litres of silage juices in feed ration under the condition that the total daily intake would not exceed 1.94 mol of acids per 100 kg live weight. This supplement of silage juices increased milk production. Higher amount of acid (2.65 and 2.85 mol) resulted in acidogenic and ketogenic type of silage juice enriched feed ration, which caused a more rapid decrease of lactation curve in dairy cows fed this feed ration than in those in the control group.     

A gas-chromatographic headspace method for the determination of acetone in bovine milk, blood and urine

An automated headspace gas-chromatographic method has been developed for the determination of acetone in the milk, blood and urine of dairy cows. Five ml samples were saturated with 2 g of sodium chloride and equilibrated for 30 min at 90 degrees C in a Hewlett-Packard HP 19395 A automatic headspace sampler. The headspace volatiles were transferred without splitting to a 25 m x 0.3 mm x 0.4 microns Carbowax column in a Shimadzu GC 9A gas chromatograph, operating isothermally at 50 degrees C. The coefficients of variation for the determination of acetone were 1.5-4.4% for urine, 10.0-24.9% for milk and 2.0-19.6% for blood. The detection limits were 0.0055 mg/100 ml for milk, 0.0072 mg/100 ml for blood and 0.0080 mg/100 ml for urine. The analysis time of 5 min per sample provided an adequate rate of throughput for routine monitoring.     

全混合日粮饲喂产奶牛经济效益试验

研究全混合日粮与非全混合日粮饲喂产奶牛,选择200头荷斯坦奶牛随机分为试验组和对照组,试验组饲喂全混合日粮,对照组饲喂相同配方和数量的草料,经30 d饲喂对比试验,结果表明：试验组日平均产奶量为23.52 kg,对照组日平均产奶量为21.78 kg,试验组比对照组日平均产奶量增加1.74 kg,日平均产奶量提高7.99%,差异极显著（P〈0.01）。饲喂全混合日粮组比饲喂非全混合日粮组奶牛增收17 760元,经济效益明显。     

Dynamics of clinico-biochemical indicators in cattle with ketonuria during the dry period and after parturition

The study was performed in eight high-pregnant cows in which medium to high ketonuria was repeatedly detected. The control group consisted of six cows free from ketonuria before parturition. Blood and urine were sampled from the cows two to eight weeks before parturition, on the day of parturition, 24 hours, three to five days and two to six weeks after parturition. The concentrations of oxidated ketone bodies and beta-hydroxybutyrate were determined by the distilling method. Further, the values of clinico-biochemical parameters in the urine and blood were determined within the range of the preventive diagnosis system. No marked changes in the health condition were found by the current clinical examination. The average concentration of total ketone bodies in the blood of the cows two to eight weeks before parturition was 29.2 mg per litre; the respective values recorded in the control cows were lower by about a half. The concentration of ketone bodies in the blood of the cows in the experimental group decreased on the day of parturition. The decrease was followed by a gradual rise of the total ketone bodies content in the blood up to 50.6 mg per litre two to six weeks after parturition. Alterations testifying to a disorder in the function of liver were observed in the cows of both groups throughout the period under study. The disorder was due to excessive administration of crude protein to the high-pregnant cows combined with the use of low-quality silage. After parturition the feed ration was not differentiated according to performance and was deficient in the basic nutrients and vitamins. Ketonuria was obviously due to the simultaneous intensification of hepatal and alimentary ketogenesis, caused by hepatopathy in combination with the intake of large amounts of poor-quality silage containing butyric acid.     

Isobutylidene diurea, a new NPN source for ruminants. 3. Excretion of isobutylidene diurea following feeding of N-15 isobutylidene diurea to lactating cows

2 experimental cows received isobutylidenedi urea added to a natural diet in amounts of 175 g (I) and 730 g (II) per day for a period of several weeks before the trial was started. On the 1st day of experiment the morning dose was labelled with 5.05 g of excess 15N. 8 hrs after the beginning of the trial of 15N level in the TCE soluble portion of blood plasma (TCE=trichloroacetic acid) increased and remained at an elevated level until the 36th hour of experiment. Similarly, the values for maximum urinary 15N concentrations were maintained for a prolonged period of time. Isobutylidenedi urea was excreted with the urine in rates related to its solubility. Only small percentages of the 15N intake were excreted in the TCE soluble portion of the milk (cow I: 0.03%; cow II: 0.05%). The 15N-labelling of milk protein provides evidence for the fact that nitrogen from IBDU is utilized for the synthesis of milk in the cows. The amount of urea in milk averaged 400 mg per litre. None of the milk samples tested contained IBDU.     

Red discolouration of the urine in cattle as a stock problem

After feeding a new batch of rapeseed meal (2.5 kg/cow/day) in the total mixed ration (TMR) of dairy cows on a dairy farm in Bavaria, numerous puddles of reddish fluid were found on the floor of the cubicle housing system. These were caused by a red discolouration of the urine. Directly after urination, the urine was macroscopically yellow and bright; the discolouration developed throughout the consecutive hours. Feed intake was markedly decreased and milk yield was lowered by 10%. No disturbances of the general health and blood key parameters were evident. After feeding two other cows with rapeseed meal of this batch (three times daily 1 kg each), the phenomenon occurred in one animal on the third and fourth days. Further analyses revealed evidence that the discolouration was due to substances which were excreted via the kidney and led to reddish urine after delayed reaction with the oxygen in the air.     

In vivo effects of a thymosin alpha 1-containing colostral whey product on neutrophils and lymphocytes from lactating cows without and with experimentally induced Staphylococcus aureus mastitis

Two separate experiments evaluated ID-1 (a commercial bovine whey product containing 5200 pg of thymosin alpha 1/ml) as an immunotherapeutic agent in lactating cows. In the first experiment, cows without mastitis were evaluated for blood leukogram, milk production, total and differential milk cell counts, lymphocyte (Lc) blastogenesis, and neutrophil (PMN) functions (random and directed migration under agarose, chemiluminescence, ingestion of bacteria, iodination, cytochrome C reduction, antibody-independent neutrophil-mediated cytotoxicity, and antibody-dependent cell-mediated cytotoxicity) before and after ID-1 therapy. ID-1 treatment resulted in a significant treatment group by time period interaction for the relative proportion of mononuclear cells (MNC) in milk (P less than 0.009) and for PMN random migration (P less than 0.01). Based on these interactions, ID-1 treatment appeared to slightly increase the proportion of small MNC in milk and to increase random migration from pretreatment levels by 73% more than increases observed in controls. No significant effect of ID-1 treatment on milk production, total milk somatic cell counts, Lc blastogenesis, or other PMN functions was observed. In cows with experimental Staphylococcus aureus intramammary infections, ID-1 treatment resulted in a significant decline in blood leukocyte count (P less than 0.001) and blood PMN count (P less than 0.02), and maintained PMN random migration (P less than 0.01) while controls declined and abrogated a depression in the ability of Lc to respond to mitogens (P less than 0.05) that developed in controls as a result of S. aureus mastitis. Injection of ID-1 into cows had no adverse effect on their overall health or level of milk production, but did cause subtle and potentially favorable changes in several in vitro immune parameters. In spite of these subtle changes which might indicate increased resistance to mastitis, cows actually developed a more severe S. aureus intramammary infection based on a 9% increase in log 10 bacterial shedding in milk.     

Effects of anionic salts in a pre-partum dairy ration on calcium metabolism

The effects of anionic salts in the transition diet on serum and urine calcium at calving and on peripartal health, subsequent milk production and fertility performance were studied in a well-managed, high-producing Friesland dairy herd. Over a period of a year, approximately 21 days before the expected date of calving, 28 pre-partum heifers and 44 multiparous dry cows were randomly allocated within parity to 1 of 2 transition diets, designated control and experimental anionic diets. The anionic diet contained the same quantities of the basic transition ration fed to the control group as well as a standard anionic salt mixture containing 118 g NH4Cl, 36 g (NH4)2SO4 and 68 g MgSO4 (total 222 g) per animal per day. This reduced the DCAD to -11.68 mEq/100 g dietary dry matter compared to +13.57 for the control diet. Blood and urine were randomly sampled from 7 to 8 animals within each category within 3 hours post-partum. Serum calcium (total and ionised) and creatinine, urine calcium and creatinine and the fractional clearance of calcium were assessed. Relevant clinical, milk production, and fertility data were collected. The total serum calcium (2.07 versus 1.60 mmol/l), serum ionised calcium (1.12 vs 1.02 mmol/l), urine calcium (0.92 vs 0.10 mmol/l) and the fractional clearance of calcium (1.88 vs 0.09%) were significantly higher(P <0.01) at calving for multiparous cows fed the anionic diet compared to those fed the control diet. In the primiparous cows there were no significant differences in serum calcium levels. However, the urine calcium (1.07 vs 0.43 mmol/l) and the fractional clearance of calcium was higher (1.75 vs 0.45%) in cows fed the anionic diet (P <0.05 and 0.01 respectively). These results illustrated that there were benefits, although no differences were demonstrated with respect to health, milk production or fertility. The supplementation of diets with anionic salts in the last 2-3 weeks before calving has the potential to significantly improve parturient calcium homeostasis.     

繁奶康对奶牛泌乳早期泌乳性能及血液指标的影响

选择20头荷斯坦高产牛,采用配对分组设计分为对照组和试验组,每组各10头。对照组使用原日粮,试验组产前21d每天在日粮中添加繁奶康125g,于分娩当天添加量增至300g直到试验结束,以探讨日粮添加繁奶康对奶牛泌乳早期产奶性能(产奶量及乳品质)的影响。结果表明,补充繁奶康,产奶量、乳脂校正乳产量试验组明显高于对照组(P0.05);奶牛采食量、乳脂率、乳蛋白率、乳糖率及乳干物质含量两组间差异不显著(P0.05)。血液指标谷草转氨酶、谷丙转氨酶活性两组间无显著差异(P0.05),高产奶牛补充繁奶康对泌乳早期产奶性能有较好的改善作用。     

Phagocytosis, bactericidal activity, and oxidative metabolism of milk neutrophils from dairy cows fed selenium-supplemented and selenium-deficient diets

Six primiparous Holstein cows were fed a Se-deficient diet, beginning at least 90 days before their first calving, and 6 other primiparous cows were given the same diet plus a supplement of 2 mg of Se/cow/d as sodium selenite. All cows were fed their diets for the duration of the experimental period. One uninfected quarter of each cow was injected with 25 micrograms of Escherichia coli endotoxin at postpartum week 5. Leukocytes were isolated by centrifugation from milk collected at postinjection hour 16. Isolated cells were 92 +/- 3% neutrophils and were incubated with Staphylococcus aureus or E coli in a 1:300 ratio. Phagocytosis and intracellular killing by neutrophils were assessed after 0, 30, 60, and 90 minutes by a fluorochrome assay, using acridine orange. Viability of neutrophils was assessed by use of trypan blue. Superoxide anion production and hydrogen peroxide production by neutrophils also were determined. Cows fed Se-deficient diets had significantly (P less than 0.05) lower blood Se concentration and blood glutathione peroxidase activity than cows fed Se-supplemented diets. Selenium status had no effect on the phagocytic capacity of neutrophils. Neutrophils obtained from cows fed Se-supplemented diets killed a significantly (P less than 0.05) higher percentage of ingested bacteria than did neutrophils from cows fed the Se-deficient diet. Viability was significantly (P less than 0.05) reduced by incubation with S aureus in neutrophils from both groups of cows, with neutrophils from Se-deficient cows having lower viability.(ABSTRACT TRUNCATED AT 250 WORDS)     

Experimental studies on the ketogenic effect of high doses of proteins in dairy cows]

A 14-month feeding experiment was conducted with 16 high-yielding cows, each given a daily supplement of 2 kg soya meal regardless of milk yield or the stage of lactation, in comparison with 8 normally-fed cows. At monthly intervals various parameters of carbohydrate, fat and protein metabolism and of liver function were determined. At the end of the trial, samples of liver were obtained by biopsy for morphological and histochemical examination. Supplementation had a pronounced effect on milk yield and fat content, averaging over 900 kg of milk and 0.2% fat content more than during the preceding year. The parameters of metabolism revealed clear signs of subclinical ketosis, particularly during the first third of the trial period. Changes were greatest during the 3rd and 4th months of the trial, when the protein content of the ration was particularly high (over 3 kg) and when the energy supply ratio was particularly unfavourable (PEQ 300). At the end of the trial some abnormalities were detected in individual animals in the biochemical properties of blood and urine, and the morphological, histochemical and ultrastructural appearance of the liver. These changes included increases in KK, BTS and bilirubin concentrations in the blood; ketonuria, proteinuria; perilobular fat infiltration with glycogen depletion; changes in succinate dehydrogenase and acid phosphatase activities. In most animals the liver seemed to have become adapted to a high protein intake.