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Okeoma CM, Williamson NB, Pomroy WE, Stowell KM, Gillespie L. The use of PCR to detect Neospora caninum DNA in the blood of naturally infected cows. Vet Parasitol 2004; 122:307-15. [PMID: 15262009 DOI: 10.1016/j.vetpar.2004.06.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2004] [Revised: 05/18/2004] [Accepted: 06/02/2004] [Indexed: 10/26/2022]
Abstract
Twelve 2-year old heifers in their fifth month of gestation when pregnancy tested were used in this study. Six heifers aborted at approximately 4 months of gestation and had blood samples drawn less than 6 weeks after the abortions were identified. Blood samples were also drawn from three sero-positive pregnant and three sero-negative pregnant heifers. DNA was isolated from the samples and a 350 bp fragment of the Nc-5 gene was PCR amplified using primer pair Np21+ and Np6+. Also, the Internal Transcribed Spacer 1 (ITS1) was PCR amplified using Tim 3 and Tim 11 primer pair. The Nc-5 gene fragment was cloned, sequenced and the sequence BLAST-tested. Similarly, the ITS1 product was sequenced and BLAST-tested. The BLAST test results revealed that Neospora caninum DNA was present in these blood samples indicating that polymerase chain reaction can be used in the detection of N. caninum DNA in the blood of sero-positive cows.
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Okeoma CM, Williamson NB, Pomroy WE, Stowell KM. Recognition patterns of Neospora caninum tachyzoite antigens by bovine IgG at different IFAT titres. Parasite Immunol 2004; 26:177-85. [PMID: 15367295 DOI: 10.1111/j.0141-9838.2004.00699.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This study describes qualitative and quantitative antibody response in cows naturally infected with Neospora caninum. The study was carried out with 269 serum samples obtained from 24 cows over a period of 15 weeks. Prior to sample collection, the cows were tested with ELISA. The 269 samples were screened with IFAT and categorized into seven IFAT titre groups (< 1 : 80, 1 : 80, 1 : 200, 1 : 600, 1 : 1000, 1 : 2000, > 1 : 2000). The samples were finally analysed by Western blotting. Seven immunodominant antigens (approximately 18-, approximately 25-, approximately 33-, approximately 35-36-, approximately 45-46-, approximately 47-, approximately 60-62 kDa) and five minor antigens (approximately 25, approximately 51, approximately 64, approximately 77, approximately 116 kDa) were recognized by cow sera. The recognition of approximately 46 kDa antigen by cow sera was common to samples with IFAT titre 1 : 80 and above. Another common antigen was the approximately 18 kDa antigen, which was recognized by samples with IFAT titre 1 : 200 and above. The most remarkable observation was the presence of the 45-46 kDa, the 77 kDa, and absence of the 18 kDa antigenic bands in samples with IFAT titre 1 : 80. This observation was consistent even in the face of fluctuating antibody titre where serum antibody titres from an animal exceeded then failed to reach 1 : 80. Antibody fluctuation was observed across all cows (pregnant and aborted) with no discernible fluctuation pattern. However, the fluctuation in antibody titre observed appeared to be most remarkable in initially ELISA-negative pregnant cows, and to a lesser extent in ELISA-positive pregnant cows, and ELISA-positive aborted cows. Although there was fluctuation in antibody titre, the banding patterns of N. caninum tachyzoite antigens by cows within the same IFAT titre group remained similar.
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Stevenson MA, Williamson NB, Russell DJ. Nutrient balance in the diet of spring-calving, pasture-fed dairy cows. N Z Vet J 2003; 51:81-8. [PMID: 16032304 DOI: 10.1080/00480169.2003.36344] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AIMS To report the nutrient composition of pastures fed to spring-calving dairy cows in the Manawatu region of New Zealand, and describe changes in the nutrient composition of these pastures over a 12-month period. Having done this we sought to: (1) compare the nutrient composition of the pasture offered with the nutrient requirements of spring-calving dairy cows; (2) identify periods when individual nutrient surpluses and deficits are likely; and, (3) identify nutrients that demonstrate a high level of variability between sampling occasions. METHODS Seven farms took part in the study. Each farm was visited monthly from August 1996 to July 1997. Samples of pasture were taken at each visit and submitted for estimation of dry matter (DM), metabolisable energy (ME), crude protein (CP), non-structural carbohydrate (NSC), neutral detergent fibre (NDF), acid detergent fibre (ADF), calcium (Ca), phosphorus (P), magnesium (Mg), sodium (Na), potassium (K), chlorine (Cl), sulphur (S), iron (Fe), copper (Cu) and zinc (Zn), and dietary cation-anion differences (DCAD). RESULTS Sampled pastures were characterised by low to marginal ME, NSC, Ca, Mg, and Zn concentrations when compared with recommended dietary nutrient concentrations for lactating and non-lactating dairy cattle in New Zealand. Analyses revealed relatively high CP, NDF and K concentrations, and DCAD. CONCLUSIONS These analyses identify broad trends in the nutrient balance of a pasture-only feeding regime and provide a useful reference for planning feed strategies for spring-calving, pasture-fed dairy herds in this region. Recommended changes to on-farm practice should be made after considering the whole farm system, rather than being made solely on the basis of perceived deficiencies or excesses of individual nutrients.
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Pfeiffer DU, Williamson NB, Reichel MP, Wichtel JJ, Teague WR. A longitudinal study of Neospora caninum infection on a dairy farm in New Zealand. Prev Vet Med 2002; 54:11-24. [PMID: 12062516 DOI: 10.1016/s0167-5877(02)00011-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A 600-cow New Zealand dairy herd experienced an abortion storm in 1997 and was monitored (blood sampling at about 3-month intervals) from May 1997 until January 1999. Abortion risk reached 9% in 1997 and was highest in heifers at 19%. The abortion risk decreased in 1998 to 3.2% (still somewhat higher than during the years prior to the outbreak). The serological reaction pattern for Neospora caninum showed an association with abortion risk only around the time of the 1997 outbreak when seropositive cows were 4.2 times more likely to abort than negative ones. Over the whole study period, only 27% of cows that were sampled on all nine visits always tested negative. Offspring from dams which had positive tests for Neospora caninum were 2.4 times more likely to abort than those from dams testing consistently negative. Controlling for age and breed, seropositive cows produced more milk than those that were consistently negative. Infection might have been present endemically within this herd prior to the epidemic, but in 1997 an additional factor appeared to have triggered the outbreak.
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Douglas VL, Fenwick SG, Pfeiffer DU, Williamson NB, Holmes CW. Genomic typing of Streptococcus uberis isolates from cases of mastitis, in New Zealand dairy cows, using pulsed-field gel electrophoresis. Vet Microbiol 2000; 75:27-41. [PMID: 10865150 DOI: 10.1016/s0378-1135(00)00184-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Three hundred and forty-two Streptococcus uberis isolates were cultured from milk samples from subclinical and clinical cases of dairy cattle mastitis. The samples were collected from 15 different New Zealand farming regions, including eight specific farms, during field research trials and veterinary diagnostic investigations. Pulsed-field gel electrophoresis was used to determine and compare the degree of genetic dissimilarity between the restriction endonuclease fragment pattern of the 342 New Zealand and a single United States S. uberis isolate. The 343 isolates exhibited 330 different restriction endonuclease fragment patterns. The United States isolate had a pattern unlike any of the New Zealand isolates. Most of the isolates were genetically different strains (pattern deferred by at least 33%), but identical patterns were noted within the same or different quarters of an individual cow, different cows within the same farm, and from different cows from the same or different districts, farming regions or islands. Seven of the eight selected farms had at most only one pair of isolates with banding patterns, which differed by less than 33%. A high degree of dissimilarity was noted in individual herds in which all the samples were collected on the same day or over a 2-year period. The high degree of dissimilar isolates is an indication that S. uberis infections in New Zealand dairy cattle are largely due to the opportunistic nature of the organism in the cows' environment. Prevention and treatment of S. uberis mastitis will therefore need to be directed at a multitude of different strains present throughout the country as well as in individual herds.
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Stevenson MA, Williamson NB, Hanlon DW. The effects of calcium supplementation of dairy cattle after calving on milk, milk fat and protein production, and fertility. N Z Vet J 1999; 47:53-60. [PMID: 16032071 DOI: 10.1080/00480169.1999.36111] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
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.
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Hanlon DW, Williamson NB, Steffert IJ, Wichtel JJ, Pfeiffer DU. Re-insertion of a progesterone-containing intravaginal device to synchronise returns to oestrus in dairy heifers. N Z Vet J 1997; 45:15-8. [PMID: 16031942 DOI: 10.1080/00480169.1997.35982] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Recommendations for oestrus synchronisation of dairy heifers using progesterone-containing intravaginal devices suggest re-insertion of used devices 16 days after first insemination for a period of 5 days to allow a second opportunity for artificial insemination. Controlled studies on the effectiveness of re-using intravaginal devices to synchronise returns to oestrus in non-pregnant dairy heifers are lacking. A clinical trial was conducted involving 750 Friesian heifers in 13 herds. After an initial synchronisation programme, the used intravaginal devices were re-inserted 14 or 16 days after first insemination into half of the heifers in each herd for a period of 5 days. After the first synchronisation programme, 47.5% of heifers remained non-pregnant. Re-insertion of used intravaginal devices for 5 days significantly increased the number of non-pregnant heifers detected in oestrus and inseminated by 48 hours after device removal compared to heifers in which devices were not re-inserted (45.2% v. 27.3%, p < 0.05, in herds where intravaginal devices were re-inserted on day 14; 48.8% v. 13.6%, p < 0.05, in herds where intravaginal devices were re-inserted on day 16). Re-insertion at 14 or 16 days after first insemination was equally effective in increasing visible returns to service. However, the number of non-pregnant heifers synchronised for a second round of artificial insemination was less than expected. Conception rate to the re-synchronised oestrus was unaffected by the treatment. It is concluded that the additional procedures of CIDR re-insertion, removal, tailpainting and insemination involved in there-synchrony programme, and the relatively low in-calf rate to the re-synchronised round of insemination, reduced the potential benefits of re-synchronisation.
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Wichtel JJ, Craigie AL, Freeman DA, Varela-Alvarez H, Williamson NB. Effect of selenium and lodine supplementation on growth rate and on thyroid and somatotropic function in dairy calves at pasture. J Dairy Sci 1996; 79:1865-72. [PMID: 8923257 DOI: 10.3168/jds.s0022-0302(96)76554-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The effects of Se and I supplementation on growth rate and on thyroid and somatotropic function were examined for heifer calves from two herds fed pasture. Supplementation of calves with intraruminal Se pellets increased the basal plasma concentration of 3,5,3'-triiodothyronine and reduced the basal plasma concentration of thyroxine for both herds. For one herd, supplementation with Se increased the triiodothyronine response to challenge with thyrotropin-releasing hormone, increased BW gain, and tended to increase the plasma concentration of IGF-I. The plasma concentration of growth hormone was unaffected by Se supplementation. Supplementation with I increased the response of thyroid hormones to thyrotropin-releasing hormone but did not increase BW gain. Interaction between Se and I treatment within the herds was not apparent for any outcome variable. These data suggest that the effects of Se deficiency in grazing calves may be mediated by alterations in thyroid hormone metabolism but apparently are not mediated through modulation of the peripheral concentration of growth hormone.
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Wichtel JJ, Craigie AL, Thompson KG, Williamson NB. Effect of selenium and a-tocopherol supplementation on postpartum reproductive function of dairy heifers at pasture. Theriogenology 1996; 46:491-502. [PMID: 16727917 DOI: 10.1016/0093-691x(96)00171-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/1995] [Accepted: 01/29/1996] [Indexed: 10/18/2022]
Abstract
The objective of this study was to investigate the effects of selenium (Se) and alpha-tocopherol supplementation on uterine involution and ovarian function in dairy heifers fed a prepartum diet containing low concentrations of Se and alpha-tocopherol. Twenty-four pregnant Friesian heifers were randomly allocated to one of four experimental groups in a 2 x 2 design balanced for age and body weight. Prepartum treatments consisted of supplementation with either 2 intraruminal Se pellets or 3600 mg of alpha-tocopherol p.o. 4 times per wk, or both. Control animals received no supplementation. For 8 wk before calving, the heifers were fed exclusively on pasture hay which contained less than 10 microg/kg of Se and 19 mg/kg of alpha-tocopherol. After calving, the heifers grazed perennial ryegrass and white clover pasture. Concentrations of Se and alpha-tocopherol in serum for the prepartum heifers of the control group were 10 ng/ml and 1.3 microg/ml, respectively, indicating deficiencies of these nutrients. Treatment with Se and alpha-tocopherol increased prepartum serum concentrations of Se and alpha-tocopherol to 74 ng/ml and 5 microg/ml, respectively (P < 0.001). However, treatment with Se, alpha-tocopherol, or both, failed to enhance uterine involution, hasten resumption of postpartum ovarian activity or reduce the incidence of clinical postpartum abnormalities. These findings suggest that postpartum reproductive dysfunction is not a primary feature of moderate Se or vitamin E deficiency of cattle at pasture.
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Wichtel JJ, Thompson KG, Williamson NB. Serum glutathione peroxidase activity reflects short-term increases in selenium intake in goats. N Z Vet J 1996; 44:148-50. [PMID: 16031919 DOI: 10.1080/00480169.1996.35959] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The objective of this study was to determine if serum glutathione peroxidase activity reflects short-term changes in the selenium status of goats. Angora goat kids (n=14) were fed pelleted luceme containing 20 microg/kg of selenium, and treated orally with either selenium (0.1 mg/kg of liveweight weekly, as sodium selenate) or de-ionised water. Serum activity of glutathione peroxidase was increased in response to supplementation and differed from that of controls within 24 hours of supplementation. The change in serum glutathione peroxidase activity during the 21 days after the start of weekly supplementation closely followed changes in serum selenium concentration. The results of this study suggest that serum glutathione peroxidase activity reflects the short-term improvement in the selenium status of Angora goat kids following oral supplementation with sodium selenate.
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Hayes DP, Pfeiffer DU, Williamson NB. Effect of intraruminal monensin capsules on reproductive performance and milk production of dairy cows fed pasture. J Dairy Sci 1996; 79:1000-8. [PMID: 8827463 DOI: 10.3168/jds.s0022-0302(96)76451-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Cows from three herds calving in spring that were fed on pasture were paired by herd, production index, predicted calving date, and age. One cow from each pair was allocated randomly to the treatment group and received a controlled-release capsule of monensin 1 mo prior to the start of AI. A random sample of 20 matched pairs of cows was selected within each herd to monitor BW and metabolic parameters. Treated cows produced more fat, protein, and liters of milk per day during the 2nd mo of monensin activity and produced a greater total milk volume than did control cows. Treated cows gained less BW during the 1st mo after treatment. No significant differences were identified in submission rates, overall pregnancy rates, or pregnancy rate to first or second AI. Blood urea nitrogen was elevated in the treatment group as a main effect, and NEFA were elevated in the 2nd and 3rd mo after treatment. There was no significant effect on blood concentrations of glucose, albumin, or BHBA.
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Hanlon DW, Williamson NB, Wichtel JJ, Steffert IJ, Craigie AL, Pfeiffer DU. The effect of estradiol benzoate administration on estrous response and synchronized pregnancy rate in dairy heifers after treatment with exogenous progesterone. Theriogenology 1996; 45:775-85. [PMID: 16727840 DOI: 10.1016/0093-691x(96)00007-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/1995] [Accepted: 09/26/1995] [Indexed: 10/16/2022]
Abstract
The objectives of this trial were to determine the effects of 0.5 mg estradiol benzoate administered intramuscularly 24 h after the removal of progesterone-containing intravaginal devices on the occurrence and timing of estrus, synchronized pregnancy rate and synchronized conception rate in dairy heifers. A clinical trial was conducted involving 750 dairy heifers in 13 herds. Within each herd heifers were randomly allocated to 1 of 2 estrus synchronization treatments. All heifers received a CIDR-B progesterone-containing intravaginal device containing a 10 mg estradiol benzoate capsule for 12 d. Twenty-four hours after CIDR-B removal one group received 0.5 mg, im estradiol benzoate while the other group received an intramuscular injection of a placebo. Estrus detection was performed at 48 and 72 h after intravaginal device removal, and heifers detected in estrus at those times were inseminated. Administration of estradiol benzoate 24 h after removal of CIDR-B devices significantly increased the number of heifers exhibiting estrus within the observation period (96.1 vs 90.5%; P < 0.01). It also altered the onset of estrus so that significantly more heifers were in estrus (86.6 vs 72.3%; P < 0.01) and conceived (47.1 vs 37.5%; P < 0.05) by 48 h after CIDR-B device removal. The synchronized conception rate was unaffected by treatment. The distribution of estrus was such that fixed-time insemination after estrus synchronization with this treatment program may be recommended.
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Wichtel JJ, Freeman DA, Craigie AL, Varela-Alvarez H, Williamson NB. Alpha-tocopherol, selenium and polyunsaturated fatty acid concentrations in the serum and feed of spring-calving dairy heifers. N Z Vet J 1996; 44:15-21. [PMID: 16031885 DOI: 10.1080/00480169.1996.35925] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The objectives of this study were to provide baseline data for alpha-tocopherol, selenium and polyunsaturated fatty acid concentrations in the serum and feed of New Zealand dairy cattle, and to assess the likelihood that abnormal peroxide metabolism has a role in the impaired lactational and reproductive performance noted in selenium-deficient cattle. Twenty-four Friesian heifers were randomly allocated one of four winter diets consisting of hay with or without selenium supplementation, or pasture and silage with or without selenium supplementation. A winter diet consisting exclusively of hay (alpha-tocopherol concentration 19 mg/kg of dry matter) resulted in a pre-calving serum alpha-tocopherol concentration of 1.2 mg/l compared to 4.5 mg/l for pastured heifers (p<0.01). The pre-calving alpha-tocopherol concentration for the heifers fed hay fell into the range considered deficient (<2.0 mg/l), whereas heifers fed pasture and silage remained in the range considered adequate throughout the study period. Serum fatty acid concentration, and the proportion of fatty acids that were polyunsaturated, were lowest in the hay-fed heifers before calving (1.0 mg/ml, 37.1% respectively), and remained unchanged following re-introduction to pasture after calving in late July and August. Serum fatty acid concentration did not increase following the re-introduction of the heifers to pasture because of the unexpectedly low fatty acid concentration (4.8 g/kg of dry matter) of the mature winter pasture. In October, however, the proportion of fatty acids in serum that were polyunsaturated increased (50%) as did serum cy-tocopherol concentrations (greater than 13 mg/l). Mean serum selenium concentrations in the unsupplemented heifers ranged from 139 to 204 nmol/l, being lowest in October (p<0.01). Supplementation with intraruminal selenium pellets (two pellets delivering about 3 mg of selenium/day) increased serum selenium concentration and glutathione peroxidase activity (p<0.01) whereas the type of winter diet had no effect (p>0.05). These results suggest that dairy cattle wintered on hay can become Vitamin E-depleted, whereas the feeding of pasture and silage should provide adequate Vitamin E. The pasture offered following calving during July and August provided a low dietary polyunsaturated fatty acid challenge, suggesting that abnormal peroxide metabolism is unlikely to be an important mechanism in the impaired performance of selenium-deficient adult cattle which calve at this the of year.
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Wells SJ, Trent AM, Marsh WE, Williamson NB, Robinson RA. Some risk factors associated with clinical lameness in dairy herds in Minnesota and Wisconsin. Vet Rec 1995; 136:537-40. [PMID: 7660557 DOI: 10.1136/vr.136.21.537] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
An observational study of the relationships between clinical lameness and herd-level risk factors was made in 18 dairy herds in Minnesota and Wisconsin. Lameness in the lactating cows was assessed by two observers during herd visits made in the summer of 1989 and the spring of 1990, using a uniform scoring system. A questionnaire was used to obtain information about the general management, routine hoof care, nutrition, housing and flooring on the farms. Factors associated with the prevalence of clinical lameness in the summer included stall moisture, the size of the exercise area for the lactating cows and the amounts of dry concentrates and fresh forages fed to them. Factors associated with clinical lameness in the spring included the use of parlour milking facilities and the frequency with which the rations for the lactating cows were balanced.
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McDougall S, Burke CR, MacMillan KL, Williamson NB. Patterns of follicular development during periods of anovulation in pasture-fed dairy cows after calving. Res Vet Sci 1995; 58:212-6. [PMID: 7659843 DOI: 10.1016/0034-5288(95)90104-3] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The ovaries of 17 Friesian cows aged two to seven years were examined daily by transrectal ultrasound from one week after calving. The position and size of all follicles more than 2 mm in diameter were recorded. A large (more than 9 mm in diameter) follicle was present on at least one ovary by six to 17 days after calving, and in two of the cows it ovulated; the remaining cows had from two to nine large follicles before they ovulated. The mean (SEM) interval from calving to the first ovulation was 43.4 (5.3) (range 13 to 93) days, after 4.2 (0.6) waves of follicles.
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Wenzel JG, Williamson NB, Seguin BE. Factors associated with use of prostaglandins in reproductive herd health programs for dairy cows. J Am Vet Med Assoc 1995; 206:347-53. [PMID: 7751245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Use of prostaglandin F2 alpha products (PG) in dairy cows was studied by use of computerized reproductive herd health data compiled from 29 dairy herds in Minnesota and Wisconsin during 1983 through 1988. Treatment with PG was recorded in 1,856 of 7,139 (26.0%) complete lactations. More than 1 treatment with PG was administered in 534 of the 1,856 (28.8%) lactations in which PG were used. The proportion of lactations in which treatment was used varied among herds and years, and was associated with the proportion of cows in which natural breeding was attempted and, to a lesser extent, with estrus detection index and conception rates; these associations were potentially modified by time between veterinary herd health visits. Calving-to-treatment intervals (mean +/- SD) were 100.4 +/- 55.1 days for first treatments only, and 116.2 +/- 66.1 days for all treatments. These values varied considerably among herds and years and among reasons for treatment. Much of the variation in proportions of lactations in which treatment was used and in the time of treatment within lactations could not be accounted for with the variables included in this study, and was probably related to individual considerations for each cow.
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Wichtel JJ, Craigie AL, Varela-Alvarez H, Williamson NB. The effect of intra-ruminal selenium pellets on growth rate, lactation and reproductive efficiency in dairy cattle. N Z Vet J 1994; 42:205-10. [PMID: 16031784 DOI: 10.1080/00480169.1994.35824] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In each of two dairy herds (A and B), rising yearling heifers (Trial 1) and adult cows (Trial 2) were assigned to three treatment groups. Untreated animals were compared to animals treated with either two or four intra-ruminal pellets containing 3 g of elemental selenium. The administration of pellets at the recommended dose (two pellets per animal) was effective in elevating whole blood glutathione peroxidase activity and selenium concentration to over 10 times those of control animals. In Trial 1, a 15% response in liveweight gain (p<0.001) occurred in yearling heifers in the herd with the lowest pre-treatment selenium status. In Trial 2, cows receiving two pellets produced a greater milk volume (p=0.06) and more milk solids (p=0.02) than untreated controls; an increase in volume of 5.4% and 8%, and in milk solids of 6.5% and 6.4%, were noted in herds A and B respectively. There was a trend towards decreasing somatic cell counts in milk from the treated cows when compared to controls, the four-pellet group in Herd A and the two-pellet group in Herd B being significantly different from their respective control group. No between-group differences were noted in calving-first service or calving-conception intervals, nor in the proportion of animals pregnant to first or all services. The administration of selenium at twice the recommended dose rate yielded no additional response above that noted after the administration of the recommended dose. The results of this study support the use of currently recommended Ministry of Agriculture and Fisheries selenium reference ranges in cattle for the prediction of a response to supplementation.
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Abstract
A longitudinal study of the feet of cows from a seasonal dairy herd was conducted over a 12 month period to measure the occurrence of subclinical hoof lesions. Eleven 2-year-old cows, entering the herd for the first time, and eleven mature cows were randomly selected from a herd of 415 cows at the end of winter (July 1989) prior to calving. The incidence of lameness in the herd over the 12 months was 2%. None of the trial cows became lame during the study. Cows were examined monthly. The type, severity and location of any hoof lesions were recorded. Sole haemorrhage, erosion of the heel bulb and minor white line separation were the most commonly observed lesions. These lesions were observed with specific claw distributions in the cow and at specific times of the year and breeding season, with waves of each type of lesion passing through the herd at a particular time. White line separation was observed commonly during spring (up to 37% of digits affected), disappeared almost completely over the dry summer months and reappeared in autumn, increasing to 40%' again over winter. Lesions were more commonly observed in the lateral digits, with fore feet being more commonly affected than hind feet. Erosion of the heel bulbs was common in August (65% of digits affected, more common in mature cows than 2-year-olds), disappeared quickly during spring, and reappeared in all cows during the following winter (88% of digits; no age differences). There were no differences in distribution between digits. Sole haemorrhages were concentrated over the mid-sole and abaxial sole zones. They were more common in the hind feet than the front feet and more common in the outside claws (p < 0.001). Haemorrhages were not observed prior to or soon after calving, appeared in October and reached a peak of 40% in December, then gradually disappeared by the time of drying-off in May. The 2-year-olds were more frequently affected than the mature cows (p <0.001).
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Udomprasert P, Williamson NB. The DairyCHAMP program: a computerised recording system for dairy herds. Vet Rec 1990; 127:256-62. [PMID: 2238397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The DairyCHAMP program is an animal health and management software program that helps daily animal management, herd performance monitoring and problem analysis. Data entry to the program uses a data dictionary and includes an error-checking system that ensures the consistency and appropriateness of data entered. DairyCHAMP performs health management functions, provides a convenient user interface, ensures uniform data across farms by using a standard data dictionary, can be fully integrated with decision-making software programs like DairyORACLE, and is flexible enough to be useful for many types of dairy facilities. Data are entered via a menu-based system. Animal events are organised around reproduction and lactation cycles and health records. Farm records include inventories for drug, feed and semen. Farm parameters can be established which customize the program for an individual farm. The database system is an integration of three schemas: the individual user's view, the community view and the storage system. The individual user's view must be easy to use, while the storage system must be compact enough to fit within the disc storage space on a microcomputer. This conflict requires a translation from one schema to another. The DairyCHAMP program accomplishes this through a coding system which assigns a code number to each event. The program can add synonyms to this event dictionary by assigning the same code number to the synonym the user chooses. The DairyCHAMP program provides access to the large amounts of data required to aid in daily animal management, allow performance monitoring and analyse problems. Its highly integrated system is efficient and easy to use and maintain.
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Abstract
This article discusses the developmental stages involved in moving the concept of faculty practice from theory to reality. Bennis, Benne, and Chin's theories for planned change and Hage's theory for organizational change with a dominant coalition form the theoretical bases for this redical innovation. Smith's Time Line serves as the framework for tracing the development of the plan over its 6-year history. The political, logistic, and financial promoters and constraints at each stage of development are identified. Faculty reaction to the idea of faculty practice is presented, and the mechanisms used to bring about group consensus are described. The key elements for the successful transition of this plan are a small and resilient group of faculty planners and adaptation of existing organizational systems to accommodate nursing's interests. Finally, the practice plan is presented at its present stage of development with its future goals.
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Morrow W, Leman AD, Williamson NB, Moser R, Pijoan C. Improving Parity-Two Litter Size in Swine. J Anim Sci 1989. [DOI: 10.2527/jas1989.6771707x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Udomprasert P, Williamson NB. Seasonal influences on conception efficiency in Minnesota dairy herds. Theriogenology 1987; 28:323-36. [PMID: 16726315 DOI: 10.1016/0093-691x(87)90020-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/1986] [Accepted: 07/07/1987] [Indexed: 11/25/2022]
Abstract
This study was undertaken to investigate the influence of climatological factors on the conception efficiency of cows in 23 Minnesota dairy herds between March 1982 and March 1985. It was found that year of insemination (P < 0.005), herd (P < 0.005), linear and quadratic terms of days open (P < 0.05), and linear and quadratic terms of minimum temperature (MNT), maximum temperature (MXT) and temperature humidity index (THI) were similarly related to observed monthly variations in first service conception rates. The year of insemination (P < 0.005), herd (P < 0.005), and linear and quadratic terms of MNT, MXT and THI were also related to the variation in overall conception rate. Conception rate declined from April to August and increased from August to January. There was an 11% difference between the month of lowest fertility (August) and the month of highest fertility (November). It can be concluded that climatological factors appear to depress herd fertility in the northern United States as well as in the warmer southern areas. Thus, consideration should be given to strategies which will minimize the impact of the observed fertility depression due to these climatic factors.
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Vahdat F, Bey RF, Williamson NB, Whitmore HL, Zemjanis R, Robinson RA. Effects of intrauterine challenge with serovar on fertility in cattle. Theriogenology 1983; 20:549-57. [PMID: 16725871 DOI: 10.1016/0093-691x(83)90078-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/1983] [Accepted: 09/15/1983] [Indexed: 11/28/2022]
Abstract
The purpose of this study was to determine the effects of Leptospira interrogans serovar hardio on fertility in cattle. Twenty seronegative mature dairy cows were assigned to two groups. Group I (challenged cows) was bred by a seronegative bull followed by intrauterine infusion (within 30 minutes) of Leptospira interrogans serovar hardjo. Group II was bred by the same bull followed by intrauterine infusion of 5 ml of sterile culture medium. Blood samples were collected at two-day intervals to monitor serum antibody titers. Daily blood cultures for 10 days and weekly urine cultures for five weeks were performed to monitor the animals for leptospiremia and leptospiuria. Cows were slaughtered 35 days post-breeding, and their reproductive tracts were examined. All animals remained clinically normal following intrauterine challenge. There was no difference in pregnancy rates (Group I, 7/10; Group II, 6/10). All embryos, reproductive tracts, and kidneys appeared normal. A microscopic agglutination test (MA) showed that 4 of 10 challenged cows developed serum antibody titers between 8 and 20 days after challenge. However, on the basis of the hamster passive protection test, all challenged cows had serum antibodies present. All blood and urine cultures were negative through the experimental period, as were the final kidney and uterine cultures. In a second experiment, six seronegative cows were infused with killed microorganisms immediately after insemination. Results of a microscopic agglutination test and a hamster passive protection test indicated that these cows did not develop humoral antibodies against serovar hardjo. These results indicated that intrauterine inoculation of Leptospira interrogans serovar hardjo (hamster-adapted strain) following breeding did not affect pregnancy rates despite an intrauterine challenge which caused the development of humoral antibodies.
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Williamson NB. The use of records in reproductive health and management programs for dairy herds. THE VETERINARY CLINICS OF NORTH AMERICA. LARGE ANIMAL PRACTICE 1981; 3:271-87. [PMID: 7201179 DOI: 10.1016/s0196-9846(17)30130-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Williamson NB, Anderson GA, Blood DC, Malmo J. Extensions to a veterinary health and management program data system for dairy herds. Aust Vet J 1980; 56:474-6. [PMID: 7225004 DOI: 10.1111/j.1751-0813.1980.tb02557.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
This paper reports additions to our previously described veterinary health and management program for dairy herds. These include a graphical representation of mean milk production per cow per day, a current and historical record of the distribution of the herd in reproduction states, a standardised index of clinical mastitis and an index of the degree of nutritional anoestrus in a herd. For seasonally-calving herds, new categories of cows requiring examination or consideration have been added to selection lists. These are cows which have no oestrus recorded for 30 days preceding a nominated date for the commencement of breeding and those which have no oestrus recorded for 30 days after the nominated date.
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