Parturient paresis and hypocalcemia in ruminant livestock

Parturient paresis (hypocalcemia) is most likely to affect dairy cattle around the time of parturition. It causes progressive neuromuscular dysfunction and flaccid paralysis. Older dairy cows, cows with a history of parturient paresis during a previous lactation, high-producing cows, and cows from the Jersey and Guernsey breeds are at highest risk for developing parturient paresis. Nonparturient hypocalcemia may also occur and is related to events other than parturition, such as severe stress, that temporarily overwhelm the mechanisms of calcium homeostasis. Beef cattle, sheep, and goats are affected less frequently by hypocalcemia than are dairy cows. Because these species are not as stressed for milk production as dairy cattle, nonparturient hypocalcemia makes up a higher proportion of cases in nondairy ruminants. Clinical signs of hypocalcemia in beef cattle, sheep, and goats tend toward hyperesthesia and tetany rather than the classic flaccid paralysis that occurs in dairy cattle with parturient hypocalcemia. Prompt and effective treatment of hypocalcemia helps to reduce the incidence of secondary complications, such as muscle damage or mastitis. The standard treatment regimen of 500 ml of 23 per cent calcium gluconate, administered intravenously, will elicit a favorable response in approximately 75 per cent of recumbent cows within 2 hours of treatment. Relapses following successful initial therapy are common and may be prevented in part by supplementation of intravenous treatment with an additional 500 ml of 23 per cent calcium gluconate administered subcutaneously. Proper nursing care following treatment speeds recovery and reduces the incidence of secondary complications owing to hypocalcemia.     

Incidence of ovarian dysfunction in post partum dairy cows and the effectiveness of its clinical diagnosis and treatment

Ovarian function was assessed from milk progesterone profiles in 236 cows that were presented for clinical examination after parturition and in 227 unexamined herdmates. By 30 days after calving, 81 per cent of the cows had ovulated and by 42 days 92 per cent had resumed cycling. On average milk samples were taken for 155 days, and during this period 67 luteal cysts or cystic corpora lutea and 24 follicular cysts were recorded, and 88 cows were anoestrus for more than 30 days. Luteal cysts, follicular cysts and prolonged anoestrus all occurred twice as frequently in the cows which were clinically examined as in those which were not examined. Progesterone profiles indicated that at the time of clinical examination 72.4 per cent of the cows examined were cycling normally, 11.3 per cent were anoestrus, 6.7 per cent had follicular cysts, 8.0 per cent had luteal cysts and 1.6 per cent were pregnant. Rectal palpation correctly identified ovarian function in only 63.5 per cent of examinations, with 29.8 per cent of cows that were cycling normally, 58.1 per cent that were anoestrus, 70.3 per cent with follicular cysts and 25 per cent with luteal cysts being incorrectly diagnosed. Progesterone profiles confirmed normal oestrous cyclicity in 81.9 per cent of these cows diagnosed as cycling normally by the clinician. The clinical treatments administered included prostaglandin, gonadotrophin-releasing hormone (GnRH), progesterone (PRID) and the physical expression of ovarian structures. Cows diagnosed as cycling normally were left untreated. At the time of treatment, 28.8 per cent of prostaglandin-treated cows had low progesterone concentrations indicating that no luteal tissue was present.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects of calcium supplementation of dairy cattle after calving on milk, milk fat and protein production, and fertility

AIM: To determine the effect of calcium supplementation of dairy cattle after calving on serum concentrations of calcium, magnesium, and phosphorous after calving, and on reproductive and productive performance in the following lactation. METHODS: This was a double-blind randomised clinical trial using 356 dairy cows of parity 3 or greater from six seasonally calving commercial dairy herds. Cows were randomly assigned to a treatment and control group. The treatment group received two doses of 380 ml of calcium chloride in oil (49 g of elemental calcium); the first dose was given as soon as practical after calving and the second 12 hours later. Control cows received 380 ml of a placebo using the same treatment regime. Treatment and control cows had blood samples taken during the first 7 days after calving to determine serum calcium, magnesium and phosphorous levels. Treatment and control cows were monitored throughout the lactation to measure production and reproductive performance. RESULTS: Treatment had no effect on PSM to first service intervals. Treatment significantly reduced PSM to conception intervals in only one of the four herds with data available for analysis (p = 0.09). There was no difference between treatment groups for adjusted corrected milk yield calculated from the first herd test milk yield (p = 0.93) or 305-day milk solids production (p = 0.19). CONCLUSION: Further studies are required to identify reasons for the between-herd effectiveness of calcium chloride treatment in improving fertility.     

The milk progesterone test as an aid to the diagnosis of cystic ovaries in dairy cows

Two field trials were carried out by five experienced veterinary surgeons to evaluate the milk progesterone test as an aid to the differential diagnosis of cystic ovaries in dairy cows. Of 200 cystic cows, 71 per cent were diagnosed clinically as follicular and 29 per cent as luteal cases; 80 per cent of the cases occurred in the six winter months November to April. The progesterone assay indicated that the diagnosis was correct in 84 per cent of the follicular cases but only 54 per cent of the luteal cases. Seventy-four per cent of the confirmed cystic cases responded to treatment within two weeks according to milk progesterone tests and there were no significant treatment differences. Overall, 80 per cent of the cows became pregnant on average 38 days after treatment having received an average of 1.70 inseminations each. Milk yield data in the first trial indicated that the cystic cows were not significantly higher yielders than their herd-mates.     

Associations between types of lameness and fertility

Four hundred and twenty-seven cases of first-reported foot lameness were recorded in 17 dairy herds in Somerset during the winter housing period. Lameness was classified into three categories: sole ulceration, digital disease (white line abscess, foreign bodies in the sole and pricked or punctured sole), and interdigital disease (lesions of the skin between claws and heel including foul in the foot, interdigital fibroma and dermatitis). In addition, a 'clinical effect score' was calculated to take account of the severity of lameness, the structures involved and the time for which the cows were clinically affected. The fertility records of lame cows were compared with those of the healthy cows nearest in parity and stage of lactation. In the lame cows the interval from calving to first service was four days longer, and the interval from calving to conception was 14 days longer than in the control cows, the pregnancy rate to first service was 46 per cent (controls 56 per cent), 2.14 services were required per conception (controls 1.72) and 16 per cent of lame cows were culled (controls 5 per cent). Lameness, first reported in the period 36 to 70 days after calving, was associated with a significant (P less than 0.01) increase in the interval from calving to first service of eight days; and sole ulceration, in the period 71 to 120 days after calving, was associated with an increase of 11 days (P less than 0.05). Lameness in all periods up to 120 days after calving was associated with significantly increased intervals from calving to conception (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Treatment of persistent intramammary infections with Streptococcus uberis in dairy cows

A survey was conducted of the prevalence of environmental pathogens, especially Streptococcus uberis, as causes of clinical mastitis in dairy cows. The response of intramammary infections with S uberis to conventional treatment was monitored by taking milk samples for bacteriology and somatic cell counting seven, 14 and 21 days after the treatment. The results showed that 51 per cent of the infections failed to respond, and the odds of cases failing to respond was significantly increased when the individual quarter somatic cell count seven days after the treatment was greater than 201,000 cells/ml. Ninety-six per cent of the suspected S uberis isolates identified by culture were confirmed as S uberis by using the api 20 Strep system. Restriction endonuclease fingerprinting was used to type the strains of S uberis isolated from 75 milk samples from 32 cows. Analysis showed that 96 per cent of the cases of S uberis that failed to respond to conventional treatment were persistent infections with one strain rather than reinfections with different strains. The persistent cases of S uberis were treated further with an extended course of intramammary preparations containing either procaine penicillin with dihydrostreptomycin or cefquinome. There was no significant difference between the cure rates achieved by the two preparations, and 55 per cent of the cases that had failed to respond to conventional treatment responded to the additional treatment.     

Effects of prostaglandin on the reproductive performance of dairy cows

A single injection of a synthetic analogue of prostaglandin F2 alpha (fenprostalene; Syntex) on the day of calving or between days 14 and 21 after calving did not affect the calving to first service interval, the number of services per conception or the conception rate of dairy cows. In a second trial, cows calved more than 45 days were injected once weekly with prostaglandin F2 alpha (dinoprost; Upjohn) or fenprostalene until served at the first detected oestrus. The calving to first service interval and the conception rate were not affected. Following injection of either prostaglandin, the spread in the pattern of onset of oestrus and the range in the proportion of cows (75 to 98 per cent) seen in oestrus within seven days were similar. This variation in the time of onset of oestrus after the administration of prostaglandin precludes limiting oestrus detection to four or five days per week, and is a major limitation to the use of prostaglandins in breeding programmes in dairy cows.     

An economic assessment of twin births in British dairy herds.

The effect of twinning on the subsequent health, production and reproductive performance of dairy cattle was studied by analysing the data derived from 19,755 calvings which occurred during three years on 37 farms. The data formed part of the database of a veterinary practice operating the DAISY dairy cow recording scheme for its dairy farmer clients. The average twinning rate was 2.5 per cent. For first calf heifers the rate was 0.9 per cent, and the rate increased with increasing parity to over 5 per cent for cows calving for their sixth and subsequent lactations. Although they produced more milk than their contemporaries, twin-bearing cows suffered an increased incidence of retained placenta and vulval discharges and their calving to conception interval was extended by 33 days. Furthermore, 35 per cent of these cows were culled compared with 21 per cent of their contemporaries. The benefit of having more calves for sale was reduced owing to 15 per cent of them being born dead. It is calculated that producing twins resulted in an average loss of income of 74 pounds/cow, a deficit of 15 per cent compared with cows having single calves.     

Effect of mixed maize-legume silages on milk quality and quantity from lactating smallholder dairy cows

The study investigated the effect of the following maize:legume (70:30) mixed crop silages: maize:cowpea, maize:velvet bean, and maize:lablab on milk production during the 2016 dry season. Using a 5?×?5 double Latin square design, five Holstein-Friesian crossbred cows in early lactation (30?±?15 days) and five Jersey crossbred cows in early lactation (25?±?10 days) were given the supplementary mixed crop silage diets at 0.5 kg/l of milk produced over 105 days. Commercial dairy meal and sole maize silage were used as positive and negative controls, respectively. Milk yield was significantly higher (P?< 0.05) in cows given the dairy meal compared to mixed crop silages; however, milk yield was also significantly higher (P?< 0.05) for cows given the three mixed crop silages compared to cows given sole maize silage. Cows given mixed crop silages produced milk of significantly higher protein content (P?< 0.05) than those given sole maize silage. There was no significant difference (P?> 0.05) in butterfat content of milk across all the dietary treatments. The dietary cost of producing 1 l of milk was highest at 0.31USD/l for cows given commercial dairy meal and lowest for cows given maize:velvet bean and maize:cowpea silage at 0.19USD/kg. The highest dietary gross margins of 68% were observed when cows were given maize:velvet mixed silage compared to commercial dairy meal (47%) and sole maize silage (57%). The 70:30 maize:legume mixed crop silages showed the capability to increase milk quantity and quality at very low production costs in smallholder dairy schemes.     

Performance of tropical dairy cows fed whole crop rice silage with varying levels of concentrate

The objective of this experiment was to evaluate the effect of concentrate/milk yield ratios on feed intake, nutrient digestibility, rumen fermentation efficiency, and milk production in dairy cows fed with a basal diet of whole crop rice silage (WCRS). Sixteen crossbred cows (75 % Holstein-Friesian (HF) and 25 % Thai cows) in mid-lactation were assigned to four dietary treatments in a completely randomized design. Treatments corresponding to four concentrate/milk yield ratios (0, 1:1, 1:2, and 1:3 (kg/kg)) were used. All cows were offered WCRS (with 1.5 % urea and 3 % molasses) ad libitum. Silage and concentrate were fed individually twice a day. Results revealed that dry matter intake (12.8–14.5 kg/day), nutrient digestibility (62.5–68.7 %), and rumen fermentation efficiency were not significantly affected by concentrate supplementation. Milk yield (10.2–11.5 kg/day) and milk composition were similar between cows fed with sole WCRS and those supplemented with concentrate mixture, although milk fat tended to increase in cows fed with sole WCRS. In conclusion, sole WCRS fed to dairy cows without concentrate supplementation resulted in similar feed intake, nutrient digestibility, rumen fermentation, and milk production as compared to those supplemented with concentrate in lactating dairy cows. These results suggest that in tropical areas where rice crop is surplus, WCRS could sustain reasonable levels of milk production among dairy cows with little or no concentrate supplementation provided that urea and molasses are included in the silage.     

Rumen-protected choline administration to transition cows: effects on milk production and vitamin E status

We investigated the influence of rumen-protected choline (RPC) supplementation on milk production, lipid metabolism and vitamin E status in dairy cows receiving a silage-based diet. Twenty-six Italian Holstein multiparous cows were assigned by weight and average production in the previous lactation, to one of two groups: control (no RPC supplementation) and RPC (supplemented with 20 g/day rumen-protected choline chloride). Treatment began 14 days before expected calving and continued for 30 days after parturition. Choline administration significantly increased milk production during the first month of lactation and also the concentration (and total secretion) of choline in milk, but did not affect fat or protein concentrations in milk, or plasma levels of glucose, beta-hydroxybutyrate, cholesterol and non-esterified fatty acids (NEFA). However, around parturition, NEFA concentrations in plasma were lower in treated animals than in controls, suggesting improved lipid metabolism as a result of choline supplementation. Choline supplementation also increased alpha-tocopherol plasma concentrations, suggesting a novel aspect in dairy cows.     

Fertility of dairy cows in Northern Ireland

A comprehensive database was established on the milk production and reproductive performance of dairy cows in 19 selected herds in Northern Ireland, varying in size, management system and genetic merit. Data were obtained for 2471 cows, 1775 of which calved in a second year, and 693 were culled from the herd for specific reasons. The estimated mean rate of heat detection (assessed by the interheat interval during the main breeding season) in all the herds was 71 per cent, with a range from 53 to 92 per cent The average conception rate to first insemination was 37.1 per cent (range 21 to 66 per cent). The average calving interval for the retained cows was 407.2 days (range 359 to 448 days). Twenty-eight per cent of the cows that calved were culled, with infertility being the largest single reason (26.8 per cent of the cows culled). There were major differences in reproductive performance between the herds, but heat detection rate, conception rate and calving interval did not appear to be affeded by a herd's genetic merit. The herds with shorter calving intervals were characterised by better heat detection efficiency (83 v 61 per cent, P<0.01), a shorter interval from calving to first insemination (74 v 97 days; P<0.05), a higher conception rate to first insemination (45 v 34 per cent, P>0.10) and a lower removal rate (23 v 37 per cent, P<0.01). Furthermore, the cows in these herds had lower body condition scores (BCS) in the dry period (3.0 v 3.3; P<0.05) but lost less body condition in early lactation (0.3 v 0.6 BCS units, P<0.05). These results show that dairy herd fertility in Northern Ireland is generally low and similar to that previously reported for England and the USA, but that in some herds changes in herd management practices improved the cows' fertility.     

Milk fever prevention.

Milk fever is a disease of increasing importance. In dairy herds its incidence has doubled since 1950; today about 8 per cent of parturitions in Swedish dairy cattle are complicated by milk fever. At the same time, the clinical picture has changed and the effectiveness of calcium therapy has been markedly reduced. Thirty to 40 per cent of cows with milk fever need more than one treatment. These trends are obvious in Sweden and Norway and have been reported from many other parts of the world. However, there are also geographical and breed differences so that these figures might not be applicable under British conditions.     

Acute phase proteins in serum and milk from dairy cows with clinical mastitis

The serum concentrations of haptoglobin, serum amyloid A and alpha1 acid glycoprotein were determined in serum collected from healthy dairy cows and cows with clinical mastitis, graded as mild (clots in milk) or moderate (clots in milk and visible signs of inflammation in the mammary gland/s) to assess their relative diagnostic value in detecting the disease. The concentrations of haptoglobin and serum amyloid A were also measured in milk collected from infected and uninfected quarters. The concentrations of haptoglobin and serum amyloid A were higher in the serum and milk from the cows with mild or moderate mastitis. The diagnostic value of haptoglobin in differentiating between healthy animals and those with mastitis gave sensitivities and specificities of 82 per cent and 94 per cent respectively with serum and 86 per cent and 100 per cent with milk. The diagnostic value of serum amyloid A in differentiating between healthy animals and those with mastitis gave sensitivities and specificities of 83 per cent and 90 per cent with serum and 93 per cent and 100 per cent with milk. The diagnostic value of serum alpha1 acid glycoprotein in differentiating between healthy animals and those with mastitis gave sensitivities and specificities of 62 per cent and 91 per cent.     

Use of a heat detection paste on dairy cattle in France

The aim of the present study was to evaluate the merits of a coloured paste applied to cows as an aid to heat detection in a dairy herd. It was performed on 110 French Friesian cows under a loose housing system over one year. For comparison, the results of the previous year, with no paste application, were also computed. Results of heat detection by the herdsman and by paste removal were compared to expected ovulations assessed by regular rectal palpation and, or, plasma or milk progesterone patterns. The paste system improved the percentages of oestrus detection of post partum and post inseminated cyclic cows by 26 and 22 per cent respectively, compared to the previous year. Overall missed heat incidence was 15 per cent and over estimation was negligible (less than 5 per cent). The mean durability period of the paste in the absence of mounting was 13 days. This suggests that to achieve the above mentioned results, application of paste should be performed at least every two weeks when no previous heat has been recorded, or only once, two weeks after service to check for non-pregnancy.     

Errors associated with milk cell counting

The accuracy of somatic cell counts in milk samples was investigated in four studies. First, the counts recorded by one milk buyer in one supply over six months ranged from 105,000 to 401,000 cells/ml with no apparent changes in the volume of milk consigned or the level of mastitis in the herd that would explain this wide range. Secondly, the counts in daily samples from one bulk milk supply for 28 days ranged from 84,000 to 282,000 cells/ml, again with no apparent changes in the performance of the herd to explain the wide range. Thirdly, the replicated counts recorded for one sample by three separate laboratories agreed closely; however, when a sample with a high cell count was interspersed then two of the three laboratories reported high cell counts suggestive of 'carry-over' in excess of the 2 per cent 'allowable' Finally, cell count data from three separate laboratories on samples from 21 cows for 33 days revealed problems with the misidentification of samples on the farm in 1 per cent of the samples, and misidentification and mishandling of 1 to 2.6 per cent of the samples in the laboratories. All three laboratories differentiated samples from cows with subclinical and clinical mastitis, but the mean cell count of the uninfected cows varied between the laboratories with one of them recording statistically significantly higher counts over the period.     

Comparison of Productive Performance and Serum Biochemical Indices of Primiparous and Multiparous Dairy Cows During the Perinatal Period

In order to study the differences of productive performances and serum biochemical indices between primiparous and mulitiparous dairy cows during the perinatal period, ten primiparous and ten multiparous healthy dairy cows were selected and were fed the same total mixed ration.Blood samples were collected from the caudal vein before the morning feeding on -7, -4, -2, -1, 0, 1, 2, 4, 7 and 14 d after parturition, and serum glucose, triglyceride and calcium concentrations were determined. Milk yields were recorded every day from 11 to 40 days after parturition. Milk samples were collected from each experimental cow on 30th day after parturition and milk compositions and somatic cell counts were determined. The results indicated that no significant difference was observed in serum triglyceride, milk fat, milk protein, milk lactose and milk dry matter between primiparous and multiparous dairy cows (P>0.05). Mutiparous cows had greater daily milk yield and higher milk somatic cell count than primiparous cows (P<0.05). Primiparous cows had significant higher serum glucose level on -4, 2 and 4 d after parturition (P<0.05), but significant lower serum glucose level on calving date (P<0.05) when compared with multiparous cows. Higher serum calcium concentrations were found on -2, -1 and 2 d after parturition in primiparous cows than multiparous cows (P<0.05).     

头胎与经产奶牛围产期生产性能和血清生化指标的比较

为比较头胎奶牛与经产奶牛在围产阶段生产性能和血清生化指标的差异,本研究选取临床健康的头胎和经产奶牛各10头,在同等条件下饲喂全混合日粮,于预产期前7、4、2、1 d及产后0、1、2、4、7、14 d晨喂前尾静脉采血并分离血清,测定血糖、甘油三酯和血钙浓度,产后11~40 d记录产奶量,于产后第30天采集乳样,测定乳成分和体细胞数。结果显示,头胎奶牛与经产奶牛血清甘油三酯、乳脂、乳蛋白、乳糖和乳干物质等指标均无显著差异（P>0.05）;经产牛产后日均产奶量和乳体细胞数均显著高于头胎牛（P<0.05）;在分娩前第4天和分娩后第2、4天时,头胎牛血糖浓度显著高于经产牛（P<0.05）,但在分娩时,头胎牛血糖浓度显著低于经产牛（P<0.05）;头胎牛在产前第1、2天、分娩当天及产后第2天的血钙水平显著高于经产牛（P<0.05）。     

硫酸头孢喹肟乳房注入剂对泌乳期奶牛的安全性研究

为研究硫酸头孢喹肟乳房注入剂对泌乳期奶牛的安全性,试验选用12头健康泌乳奶牛(6头初产、6头经产),间隔12 h对每头奶牛的4个乳区分别注入硫酸头孢喹肟乳房注入剂(规格:8 g:75 mg/支)1支,连续给药3次,比较观察给药前后奶牛的临床症状、体细胞数、日产奶量及乳区病原菌变化情况。结果显示,与给药前相比,给药期间及停药后奶牛的临床症状、体细胞数、日产奶量、乳区病原菌检测结果均无显著性差异(P>0.05)。表明硫酸头孢喹肟乳房注入剂对泌乳期奶牛是安全的。     

Effect of oral administration of a calcium chloride gel on blood mineral concentrations, parturient disorders, reproductive performance, and milk production of dairy cows with retained fetal membranes.

OBJECTIVE: To assess the effect of oral administration of CaCl2 gel on blood mineral concentrations, parturient disorders, reproductive performance, and milk production of dairy cows with retained fetal membranes (RFM). DESIGN: Randomized field trial. ANIMALS: 20 cows that calved normally and were not treated with CaCl2 gel (group 1), 20 cows with RFM that were treated with CaCl2 gel (group 2), and 20 cows with RFM that were not treated with CaCl2 gel (group 3). PROCEDURE: Group-2 cows were treated orally with CaCl2 gel (54 g of calcium) 24 and 48 hours after parturition. RESULTS: Administration of CaCl2 gel 24 and 48 hours after parturition did not have a significant effect on serum normalized calcium, total calcium, magnesium, or phosphorus concentrations or on incidence of metritis or left displacement of the abomasum, days to first insemination, pregnancy status after first insemination, or milk production. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of CaCl2 gel 24 and 48 hours after parturition did not have significant effect on blood mineral concentrations, parturient disorders, reproductive performance, and milk production in dairy cows with RFM.