PubMed Health⌕ Search

Biomedical subjects

G J Rowlands

Publications and source records attributed to G J Rowlands.

At least 37 records · Page 2Linked to original sources
PubMed1990

The effect of udder preparation before milking and contamination from the milking plant on bacterial numbers in bulk milk of eight dairy herds.

The effect of teat washing and drying on bacterial numbers in bulk milk was compared with that of no teat preparation in eight commercial herds over one year. Using in-line milk samplers, milk was collected at various points during its passage through the milking plant and the samples were used to establish the relative significance of the sources of contamination of raw milk. Teat washing and drying of cows housed during winter reduced the total counts by 40% and streptococcal and coliform counts by 50%. Bacterial counts were significantly lower in cows at pasture during the summer and there was no reduction in count due to teat washing and drying. Bacteriological counts increased at each stage as the milk passed through the milking machine. The milking equipment significantly increased the total colony count by between 2000 and 3000/ml, and the bulk tank added a further 1500 to 2000/ml. The mean rinse bacterial counts of the milking equipment were higher in summer than winter, averaging 4.4 X 10(7) bacteria/m2 compared with 3.5 X 10(7)/m2 respectively. Although this level of bacterial contamination of the equipment is high by current standards, very low bulk milk bacterial counts were nevertheless achieved, particularly in the summer. This confirms that organisms from this source are not a major contaminant of the bulk milk. There was a very poor correlation between rinse counts and the bulk milk bacterial count, but a strong correlation (0.98) between total and streptococcal counts of the bulk milk. The unreliability of the use of rinse techniques to assess the contribution of milking equipment to bacterial counts of raw milk is emphasized.

Animals↗
PubMed1986

The association between lameness and fertility in dairy cows.

One thousand, four hundred and ninety-one lactations in 770 Friesian, Holstein and Ayrshire crossbred cows have been used to study the associations between lameness and fertility. Lameness was associated with a longer interval between calving and first service and a longer interval between calving and conception. The largest increases in these intervals, of 17 and 30 days, respectively, occurred in cows with either sole or white line lesions occurring between 36 and 70 days after calving. The conception rate during the 63 days before a diagnosis of lameness was made was lower (31 per cent) than at other times (40 per cent).

Animals↗
PubMed1986

Effect of wet weather on lameness in dairy cattle.

The incidence of lameness in cows recorded by five veterinary practices over one year and one practice over four years was plotted with rainfall and potential soil moisture deficit. Correlation coefficients calculated between lameness, rainfall and potential soil moisture deficit over two-week periods showed the incidence of lameness in summer to be significantly related to the potential soil moisture deficit in the same two-week period and rainfall in the previous two-week period. Differences in patterns of lameness incidence among practices and years were also partly explained by differences in rainfall and potential soil moisture deficit; however, these effects were small compared with those of other factors that affect lameness incidence such as herd size, age and stage of lactation.

Animals↗
PubMed1986

Short-term associations between disease and milk yield of dairy cows.

Short-term associations between disease and milk yield were studied in 1594 lactations occurring between 1977 and 1982 in 732 Friesian, Ayrshire and Holstein crossbred cows. Statistically significant differences in milk yield between one week before and one week after clinical diagnosis were observed for ketosis (5.1 kg/d), hypomagnesaemia (4.1 kg/d), mastitis occurring after peak yield (2.1 kg/d) and lameness (1.1 kg/d). Milk yield declined for as much as 2-4 weeks before diagnosis of disease, and total losses in milk yield associated with ketosis or hypomagnesaemia were estimated to be 60-70 kg. No significant differences were found for endometritis or for mastitis when it occurred before peak yield. Milk yield was suppressed for about 4 weeks after calvings with retained placenta, but there were no corresponding effects of dystocia or hypocalcaemia on milk yield. It is suggested that if automatic daily milk recording is available it may be possible to detect deviations from normal, and hence detect subclinical disease 2 or more weeks before its clinical appearance.

Animals↗
PubMed1985

Effects of stage of lactation, month, age, origin and heart girth on lameness in dairy cattle.

Lameness in herds during one year was commonest in the first month of lactation (15 per cent of all cases). Leg lesions were particularly common at this time (24 per cent of all cases of leg lesions) but white line abscess and sole ulcer were more common a month later. Foul-in-the-foot was one of the two most common lesions at all stages of pregnancy and lactation, and white line abscess the most common (20 per cent of all lesions) in late lactation. Both sole ulcer and underrun heel had lower incidence in the second half of the year than the first. White line abscess was particularly common in March and November although there were significant interactions between month and veterinary practice; foul-in-the-foot was most common in October. Susceptibility to lameness increased with age; 10-year-old cows were over four times more likely to develop lameness than three-year-old cows. This was due particularly to increased incidence with age of white line abscess and sole ulcer and, to a lesser extent, underrun heel. In contrast, foul-in-the-foot and leg lesions showed little change with age. Whereas these lesions accounted for 68 per cent of the total in cows up to two years old, they accounted for only 15 per cent of all lesions in cows over 10 years old. White line abscess was slightly commoner in cows with large heart girths.

Age Factors↗
PubMed1983

Effects of season, herd size, management system and veterinary practice on the lameness incidence in dairy cattle.

The incidence of lameness in herds visited by veterinary practitioners in winter (0.87 cases per 100 cows per month) was greater than in summer (0.71 cases per 100 cows per month). The relative proportions of leg lesions and underrun heel were higher, and those of foul-in-the-foot, interdigital hyperplasia and foreign body in the sole were lower in winter than in summer. In winter, leg lesions and aseptic laminitis were most common in cows housed in cowsheds, white line abscess in cows in strawyards and sole ulcer in cows in either cowsheds or cubicles with concrete yards. The overall incidence of lesions was lower in strawyard accommodation (0.71 cases per 100 cows per month) than in cubicles with yards (0.93 cases per 100 cows per month). Veterinary practitioners saw proportionally fewer cases of foul-in-the-foot but proportionally more cases of sole ulcer in larger than in smaller herds. The animal incidence of lameness ranged from 1.7 to 11.4 per cent among practices; in 20 practices which recorded a total of at least 100 lesions in both summer and winter there was a large variation in the proportions observed of each lesion. A principal component analysis contrasted those practices which tended to see mainly cases of white line abscess, white line separation, foul-in-the-foot and leg lesions with those which saw mainly cases of underrun heel, interdigital hyperplasia, punctured sole with pus and sole ulcer. Twenty-nine per cent of cases of underrun heel and 22 per cent of cases of both deep sepsis and interdigital hyperplasia occurred in conjunction with another lesion.

Animals↗
PubMed1983

Effects of selenium and copper supplementation on the growth of beef steers.

During the grazing seasons of 1978 and 1979, 126 Hereford cross Friesian and 25 Charolais cross Friesian steers were used in controlled trials of the effects of injecting them with copper and, or, selenium. In both seasons the unsupplemented steers had low blood concentrations of copper, selenium and glutathione peroxidase, whereas the supplemented steers maintained their serum copper concentrations within the normal range and had significantly higher whole blood concentrations of selenium and glutathione peroxidase than the unsupplemented animals. Supplementing the steers with 400 mg copper during 1978 increased their growth rate by 0.032 kg/day and supplementing them with 200 mg copper during 1979 increased it by 0.080 kg/day. Supplementing the steers in each year with two doses of selenium, each of 0.15 mg selenium/kg bodyweight, increased their growth rate by 0.041 kg/day in 1978 and by 0.060 kg/day in 1979. There was no interaction between the selenium and copper treatments and the total increases in liveweight gains due to both supplements were around 11 kg in 1978 and 16 kg in 1979.

Animals↗
PubMed1983

Use of COSREEL clinical codes in large animal veterinary practice.

COSREEL, a computerised animal health recording system with a versatile coding system for recording diagnoses, symptoms and medical and surgical treatments, has been tested by veterinary surgeons in practice. The codes were found to be logical and generally easy to use. The application of these codes, with particular reference to their use in infertility investigations, is illustrated.

Animals↗
PubMed1983

Use of COSREEL, a computerised recording system, for herd health management of two dairy herds.

COSREEL, a computerised animal health recording system, has been used since October 1980 by two agricultural colleges for the management of their dairy herds. Each college and the veterinary practice which served the college has had its own typewriter terminal connected to a remote computer. Management and milk data have been coded and entered at the college and clinical data at the veterinary practice. An average of just over one management and veterinary event per week has been coded for every three cows in milk. Error rates were on average 11 per cent by one pair of users and 4 per cent by the other pair. COSREEL has provided a valuable aid to the management of the health of the two herds, and the regular use of pregnancy diagnosis, infertility investigation and oestrus detection action lists resulted in a considerable improvement in herd fertility at the two colleges.

Animal Husbandry↗
PubMed1983

COSREEL: computerised recording system for herd health information management.

COSREEL (Computer System for Recording Events affecting Economically important Livestock) is an animal health recording system which has been designed for the management of cattle, sheep and pigs kept at the ARC Institute for Research on Animal Diseases. Unlike other, numerical, coding systems for the recording of disease, COSREEL has a versatile alpha-numeric coding system which can record diagnosis of disease, local and general symptoms, medical and surgical treatment, vaccination and antiserum therapy, therapeutic management changes and tests with their results. The system is used for recording management, veterinary and milk data, and is a terminal based system using a remote computer. Various lists for action are produced for both herd managers and clinicians including weekly reports of the production and fertility status of individual cows, and lists of cows due for pregnancy diagnosis or infertility investigation. This paper describes the general features of COSREEL, gives examples of the way diagnoses are coded and discusses the future potential of such a system for the development of a central data base for epidemiological analysis.

Animals↗
PubMed1983

Decline of serum albumin concentration at calving in dairy cows: its relationship with age and association with subsequent fertility.

Blood samples were collected weekly from Friesian cows between five weeks before and 10 weeks after calving in three consecutive years, and analysed for serum albumin (using two methods: a hydroxyazobenzene benzoic acid [HABA] dye-binding method and a bromocresol green [BCG] method), and serum bilirubin. At calving the decrease in HABA albumin concentration in cows was twice that for heifers but corresponding decreases in BCG albumin were similar. Bilirubin concentrations increased near calving, more so in cows than in heifers, and maximum post partum values were inversely correlated with minimum values of HABA albumin (r = 0.40) but not with BCG albumin (r = 0.01). Albumin concentrations were lower between zero and two weeks (P = 0.03 HABA, P = 0.13 BCG) and between seven and nine weeks (P = 0.07 HABA, P = 0.06 BCG) in cows requiring four or more services than in cows which conceived at first service. Over the three year period the repeatability of post partum albumin concentration was low. However, cows which were hypoalbuminaemic in the first year showed higher repeatability in subsequent years than those which were not.

Age Factors↗
PubMed1982

Survey of lameness in British dairy cattle.

During 1977 a survey was undertaken by practising veterinary surgeons of the incidence of different lesions causing lameness in dairy cattle. Forty-eight veterinary practices participated and they treated 7526 cases of lameness in 1821 herds. The average incidence of lameness among all cows was 5.5 per cent and the annual incidence among practices ranged from 1.8 to 11.8 per cent. Most lesions (88.3 per cent) occurred in the feet; the commonest were foul of the foot (16.7 per cent), white line abscess (15.6 per cent), sole ulcer (13.6 per cent), punctured sole and pus (10.4 per cent) and underrun heel (8.7 per cent). These proportions varied in different parts of the country. Eighty-four per cent of foot lesions occurred in the hind feet and of these lesions 85 per cent occurred in the outer claw; 42 per cent of foot lesions occurred in abnormally shaped claws. The remaining 11.7 per cent of lesions occurred in the legs and trunk, 76 per cent of which occurred in the hindlimb. Trauma was the main cause of leg lesions, which occurred most frequently in the joints and ligaments.

Animals↗
PubMed1981

A fat mobilisation syndrome in dairy cows in early lactation.

High yielding dairy cows undergo a period of energy deficit in early lactation and mobilise body reserves for milk production. In this period a high proportion of cows develop moderate or severe fatty liver. Fat is deposited in other tissues at the same time, particularly skeletal muscle. The relationship between measurements of fat mobilisation and fat deposition in liver and muscle has been investigated in a group of 19 cows in the post calving period. Cows with higher levels of indices of mobilisation, namely plasma free fatty acid and D(--) -3- hydroxybutyrate concentration and subcutaneous adipose tissue loss, had higher indices of fat deposition in liver and skeletal muscle. Statistical analysis of the data indicated that fatty liver was part of a more general fat mobilisation syndrome which was not specific to any one organ or tissue.

Adipose Tissue↗
PubMed1977

Relationships between blood composition and fertility in dairy cows--a field study.

Three hundred and fifty-one lactating dairy cows, which were between 40 and 100 d post-calving, were selected from cows sampled during metabolic profile testing of 21 herds. Blood samples were analysed for packed cell volume (PCV), blood glucose and haemoglobin, and serum urea-N, albumin, total protein, inorganic phosphate, Ca, Mg, Na, K, Cu and Fe. After adjusting for herd and date of sampling and each cow's age, stage of lactation, milk yield and interval from calving to first service, concentrations of albumin and K (P less than 0-01) and PCV (P less than 0-05) were inversely related and concentrantions of globulins (derived as the difference between total protein and albumin) directly related (P less than 0-05) to the number of services required for conception. Conception rates to first service were inversely related to lactation number but not to milk yield on day of sampling.

Animals↗
PubMed1977

The blood composition of different breeds of bulls undergoing beef performance tests.

Blood samples taken on three occasions from each of 66 bulls undergoing beef performance tests were analysed for packed cell volume, blood glucose, haemoglobin, serum albumin, urea nitrogen, total protein, inorganic phosphate, Ca, Ca, Mg, K, Na, Cu, Fe and total iron binding capacity. The bulls were individually fed and situated at two centres, one accommodating Lincoln-Red, Devon and Sussex breeds and the other, Hereford. Significant differences between the Lincoln-Red, Devon and Sussex breeds were observed in concentrations of glucose, urea nitrogen, total iron binding capacity (P less than 0.001), Ca (P less than 0.01), Na and Cu (P less than 0.05). There were no significant correlations between the growth rates of individual bulls and their blood composition.

Animals↗