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The objectives of the study were to evaluate the effects of digit amputation and arthrodesis surgery performed in the field on culling and milk production during the early post-surgical period. Cows from three commercial dairy farms in New York State were recruited for the study. A total of 49 cows that had digit amputation were matched with 68 control cows, while 17 cows that had arthrodesis surgery were matched with 20 control cows according to lactation, days in milk, and lactating at time of treatment of the case. Cumulative milk production for the first 60 days after the procedure was calculated in DC305 (Dairycomp305) for controls and treated cows. Milk production data was analyzed using PROC mixed of SAS ver. 9.1 (SAS Institute, Cary NC). The survival of cows with surgery was compared to survival of matched controls using Cox's proportional hazards model (SAS 9.1 Cary North Carolina, USA). Performance was not directly comparable between amputated and arthrodesis groups because cows were not randomly assigned to the two treatment groups. Therefore, each surgical group was evaluated relative to their respective matched control groups. Amputation cows had a significantly higher culling rate and estimated median survival of 68 days compared to 585 days for their control group. Arthrodesis cows had a median survival time of 286 days and their control cows had a median survival time of 246 days. Total milk production for the first 60 days post surgery was significantly lower for both amputation (1533 kg) compared to control (2121 kg) and arthrodesis (1883 kg) compared to control (2250 kg) groups. Septic arthritis of the distal interphalangeal joint was the most common condition treated by surgery accounting for 70.5% of arthrodesis cases and 73.5% for digit amputation. Toe necrosis accounted for 14.3% of amputation cases and retroarticular abscess made up the rest of the digit amputation (12.2%) and 29.5% of arthrodesis cases. [ABSTRACT FROM AUTHOR]

The objectives were to investigate the effect of 3 navel dips on (1) umbilical infection, (2) health events (pneumonia, diarrhea, and arthritis), and (3) average daily gain (ADG) in newborn dairy calves. A secondary aim was to compare the agreement of standardized ultrasonographic examination with clinical examination for the diagnosis of umbilical infection. In a randomized block design, newborn calves were assigned by birth order to 3 treatment groups: Navel Guard (NG; SCGSolutions Inc., McDonough, GA), 7% iodine tincture (SI), and 2% chlorhexidine gluconate (CH). Treatment consisted of a single dip administration of the umbilicus immediately after removal of the newborn from the calving pen with 1 of the 3 navel dips. Weekly clinical examinations were carried out during the first 4 wk of life with special attention being paid to the umbilicus, joints, respiratory tract, and fecal consistency, and included ultrasonographic evaluation of the umbilical structures. Body weight was assessed by using a girth tape at first and last evaluation. Multivariable logistic regression demonstrated no statistical differences in umbilical infection or health events. Multivariable linear regression analysis showed statistical differences in ADG (least squares means ± standard errors) between groups, with 494 ± 29, 571 ± 29, and 516 ± 29 g/d in groups NG, SI, and CH, respectively. Overall mortality during the study period was 9.5% (n = 40). Postmortem examination identified diarrhea (80%) as the main disorder with 19, 4, and 9 calves in groups NG, SI, and CH, respectively. Kappa values yielded fair [0.30 (95% CI: -0.03-0.63)], good [0.61 (95% CI 0.46-0.75)], moderate [0.53 (95% CI 0.31-0.74)], and moderate [0.49 (95% CI 0.19-0.79)] agreement for detection of omphalitis between clinical and ultrasonographic evaluation in wk 1, 2, 3, and 4, respectively. Agreement was very good for detection of omphaloplebitis, with kappa values (95% CI) of 0.91 (0.80-1.00), 0.87 (0.75-0.98), and 0.90 (0.76-1.00) in wk 2, 3, and 4, respectively, when omphalophlebitis was diagnosed. We detected no difference in the effectiveness of the 3 treatments in the prevention of umbilical infection, pneumonia, diarrhea, or arthritis. [ABSTRACT FROM AUTHOR]

The objective was to determine the association between specific foot lesions and culling in dairy cows. Using 5 trained professional hoof trimmers, data from 6,513 cows in 157 herds were recorded for analysis. During the study period, 1,293 cows (19.9%) were culled. Infectious lesions were most frequent in nonculled cows, whereas hoof horn lesions were most common in the culled cows. Median time to culling was 188 d [95% confidence interval (CI): 175-198 d] for cows without a lesion and 157 d (CI: 149-168 d) for cows with a lesion. Time from hoof trimming to culling was used to model the association between foot lesions and culling hazard. The final multivariate Cox proportional hazards model included heifers, infectious lesions, white line lesions, hemorrhages, sole ulcers, other lesions, and free-stall housing as covariates. Results of the final model showed that infectious hoof lesions had no significant association with culling. Yet, the hazard ratios for white line lesions, ulcers, and hemorrhage were 1.72 (CI: 1.39-2.11), 1.26 (CI: 1.05-1.52), and 1.36 (CI: 1.16-1.59), respectively. The association with culling for the grouped variable "other lesions" was time dependent and decreased with time. These results illustrate that there were significant associations with cow productivity for hoof horn lesions found at routine hoof trimming and that emphasis should be placed on proper treatment and earlier detection of these foot lesions. [ABSTRACT FROM AUTHOR]

Worldwide, there is considerable between-herd variation within individual foot lesion prevalence studies. This variation suggests, that herd-level risk factors are important from a prevention perspective. The objective was to determine the effect of selected risk factors on the prevalence of 7 foot lesions in both tie-stall and free-stall housing systems. As part of a cross-sectional foot lesion study 5 hoof trimmers recorded lesions for all cows that were foot trimmed in a herd. In addition, they completed. a risk factor questionnaire for each herd. The impact of specific risk factors was evaluated using separate multi-variable models for both free-stall and tie-stall herds. The lesions evaluated were digital dermatitis, sole ulcer, sole hemorrhage, heel horn erosion, ,white line separations, white line abscess, and interdigital fibroma. Model types were, selected based on herd-level lesion distribution. Detrimental risk factors identified in free-stall housing included increased alley scraping frequency (2.2- to 2.4-fold for sole ulcers) and trimming in summer or fall (-0.2-fold vs. spring and winter for digital dermatitis). Protective risk factors in free stalls included intermediate bedding depth (0.4-fold for 2.5 to 7.5 cm vs. more or less bedding for interdigital fibroma) and trimming heifers before calving (0.1-fold for white line abscess). In tie-stall herds no protective risk factors were identified. Detrimental risk factors for lesions in tie stalls included year-round access to outside areas (2.1-fold increase in digital dermatitis, 3.5-fold for white line separation, and 7.0-fold for interdigital fibroma vs. no or only seasonal exercise access), routine spraying of feet (2.0-fold increase in digital dermatitis), larger herds (3.0-fold increase in interdigital fibroma vs. <41 cow herds), and the use of wood bedding material (6.5-fold vs. straw bedding for interdigital fibroma). The risk factors identified need further evaluation to determine the temporal relation-ships, as well as whether the relationships with foot lesions are causal. [ABSTRACT FROM AUTHOR]

The objectives of this cross-sectional study were to determine herd-level and cow-level prevalence estimates for 11 foot lesions in Ontario dairy cattle. Foot lesions were recorded by 5 hoof trimmers on 13,530 cows in 204 Ontario dairy herds from March 2004 to May 2005. Significant differences existed between free-stall and tie-stall housing. In free-stall housing systems, 46.4% of cows had a foot lesion, compared with 25.7% of cows in tie-stall barns. Digital dermatitis was the most common lesion in tie stalls, occurring in 9.3% of cows and 69.7% of the herds, whereas in free-stall herds, 22.7% of cows and 96.7% of the herds were affected. The most common hoof horn lesions were hemorrhages and ulcers, at 7.7 and 4.7% in tie-stall housing and 11.0 and 9.2% in free-stall housing, respectively. Foot blocks were used to treat 2.2% of cows in free stalls and 0.3% in tie stalls. Intraclass correlation coefficients ranged from 9.5 to 17.3 for hoof horn lesions and 28.0 to 38.7 for infectious lesions. In summary, foot lesions diagnosed at the time of hoof trimming are common in Ontario, and appropriate treatment for hoof horn lesions is low. [ABSTRACT FROM AUTHOR]

The objective of this study was to test the hypothesis that lameness incidence in lactating dairy cows decreases milk production compared with controls and to determine the best method of the 5 combinations of 2 study designs (retrospective cohort and retrospective matched cohort) and 3 repeated measures statistical methods: ANOVA (with binary classification of lameness); ANOVA with a lameness index (LAMIX) as the variable of interest; and analysis of covariance (ANCOVA, controlling for mean milk production for the first 3 wk of lactation and with a binary classification of lameness). Data were from 1 dairy farm located near Ithaca, NY, and from cows that calved between January 1, 2004 and January 1, 2007. The LAMIX was defined as -1, -2, -3, -4, and -5 = 1, 2, 3, 4, and ≥5 mo before lameness was detected, respectively; 1, 2, 3, 4, and 5 = 1, 2, 3, 4, and 5 mo after diagnosis, respectively; and 0 = cows that were never lame. With the binary lameness classification analyzed by repeated measures ANOVA, there was no effect of lameness on milk yield. The model was biased because lame cows had higher milk yields before lameness compared with nonlame cows. When the LAMIX was used, milk production before lameness was greater than after lameness (3.1 ± 0.28 kg/d). Yet, point estimates generated for LAMIX were inaccurate because of the multicollinearity detected between LAMIX and week of lactation and because of the inability of adjusting the least squares means for the interaction of LAMIX and week of lactation. Therefore, the most appropriate models were the ANCOVA models (both for the matched and nonmatched retrospective-cohort designs). The estimated losses associated with lameness were 314 and 424 kg/cow per 305-d lactation, respectively, for the matched and nonmatched designs. Furthermore, high milk yield in the beginning of the lactation was a risk factor for lameness. [ABSTRACT FROM AUTHOR]

An important part of reproductive management programs on dairy farms is identification of nonpregnant cows and early re-insemination to achieve higher pregnancy rates. The objective of this study was to compare the effect on reproductive performance and pregnancy loss of 2 pregnancy diagnosis protocols: (1) pregnancy diagnosis performed 31 ± 3 d after artificial insemination (AI) by ultrasonography (ULTRA), and (2) resynchronization started 31 ± 3 d after AI but with pregnancy diagnosis performed 38 ± 3 d after AI by palpation per rectum (PALP). Cows were randomly allocated into 1 of the 2 management programs. For cows enrolled in ULTRA, the initial pregnancy diagnosis (P1) was performed by transrectal ultrasonography at 31 ± 3 d after AI, and nonpregnant cows were enrolled in the Ovsynch protocol for resynchronization of ovulation to receive timed AI (TAI). For cows enrolled in PALP, the Ovsynch protocol for resynchronization of ovulation to receive TAI was initiated at 31 ± 3 d after AI regardless of pregnancy status, with the initial pregnancy diagnosis (P1) performed by palpation per rectum at 38 ± 3 d after AI. For both groups, reconfirmation of pregnancy was performed by palpation per rectum at 63 ± 3 d after AI (P2). Cows were inseminated after detection of estrus by use of activity monitors at any time during the study. Two levels of activity were used as a reference for cows AI after detection of estrus based on activity: an activity level of ≥2 when a cow was coded in DairyComp 305 (Valley Agricultural Software, Tulare, CA) as open (nonpregnant) and an activity level of ≥3 when the pregnancy status of the cow was unknown. Our findings showed that the odds of pregnancy loss cows in ULTRA was 2 times higher between P1 and P2 compared with that of cows in PALP. Furthermore, pregnancy diagnosis method (ULTRA vs. PALP) did not have a significant effect on the Cox proportional hazard of pregnancy at P2. The occurrence of assisted parturition, metritis, or retained placenta was associated with a reduced hazard of pregnancy at P2. An economic analysis was performed by simulating a 1,000-cow commercial dairy herd using a decision support tool to estimate the net present value (NPV; $/ cow per yr) from using the 2 different pregnancy diagnosis methods. The analysis revealed minor differences in NPV between the programs, depending on the cost to perform ULTRA or PALP. In summary, we observed no difference in the reproductive performance and only a minor and fluctuating economic difference when using either PALP or ULTRA for pregnancy diagnosis of dairy cows. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the association between uterine disease and indicators of neutrophil (PMN) and systemic energy status in dairy cows. Peripheral blood (120mL) was collected weekly from 84 Holstein cows for PMN isolation and plasma collection from calving until 42 d in milk (DIM). The final analysis included 80 cows. Of those, 20 cows were classified as having metritis (fetid uterine discharge and fever), 15 as having subclinical endometritis (SCE; ⩾10% PMN on uterine cytology), and 45 as healthy controls. Plasma haptoglobin concentration was increased only in cows that developed metritis. Neutrophil glycogen content was reduced in cows developing metritis compared with healthy cows on the day of calving and at 7 and 42 DIM. Cows with SCE had lower PMN glycogen content than healthy cows at 7, 28, and 42 DIM. Blood glucose was affected by disease status within parity. Primiparous metritis cows had greater blood glucose concentrations than healthy primiparous cows. Multiparous metritis cows tended to have lower blood glucose concentration than multiparous SCE cows. Cows that developed metritis and SCE had or tended to have greater NEFA and BHBA than healthy cows, mainly around calving. At calving, cows that developed metritis had higher plasma estradiol concentration than healthy cows and greater plasma cortisol than cows that had SCE. Plasma insulin was not affected. Plasma glucagon was increased for SCE cows. Cows that developed uterine disease experienced a greater degree of negative energy balance and had decreased lower intracellular PMN glycogen levels, which could be a major predisposing factor for disease because of decreased availability of oxidative fuels. [ABSTRACT FROM AUTHOR]

The objective was to compare the reproductive efficacy of Ultrasynch, a synchronization program based on functionality of the corpus luteum as determined by ultrasonography, with an Ovsynch protocol. A randomized field trial was conducted on a commercial dairy in Cayuga County, New York, during scheduled weekly pregnancy examinations. Cows (n = 745) determined nonpregnant 28 to 34 d after artificial insemination (AI) were randomly assigned to Ultrasynch or Ovsynch protocols. Cows assigned to the Ultrasynch management program (n = 366) were treated based on corpus luteum (CL) diameter: cows with a CL >23 mm received an injection of PGF2α and were bred via AI following detection of estrus (Ultra-PGF), whereas cows with a CL ≤23 mm received injections and were bred on an Ovsynch protocol. Cows assigned to the Ovsynch management program (n = 379) were placed on an Ovsynch protocol regardless of CL diameter. Pregnancy status was rechecked 28 to 34 d after AI; cows determined nonpregnant after initial enrollment were maintained in their assigned management group and received treatments based on CL diameter if in the Ultrasynch group and Ovsynch treatments if in the Ovsynch group. Hazard of pregnancy was similar between Ultrasynch and Ovsynch (hazard ratio = 1.10, 95% confidence interval = 0.88-1.36). Median days to conception were 98 and 87 for Ultrasynch and Ovsynch, respectively. The detection of estrus rate of cows in the Ultra-PGF group was 49%; better performance of an Ultrasynch management program may be achievable in a herd with a higher rate of estrus detection. [ABSTRACT FROM AUTHOR]

The objectives were to determine the effects of PGF2α treatment on the prevalence of subclinical endometritis (SCE) and fertility of dairy cows. A total of 406 Holstein cows (167 primiparous and 239 multiparous) from 5 herds were used. Uterine lavage for diagnosis of SCE, PGF2α treatment, evaluation of body condition scores (BCS), and collection of blood samples for estrous cyclicity determination were performed at 21, 35, and 49 d in milk (DIM). Polymorphonuclear cells (PMN) were quantified and thresholds for diagnosing SCE were selected by receiver operating characteristics analysis. Cows classified as having SCE at 35 DIM (⩾6.5% PMN) and 49 DIM (⩾4.0% PMN) had increased time to pregnancy; however, cows classified as having SCE at 21 DIM (⩾8.5% PMN) did not. Median days to pregnancy were delayed by 30 (151 vs. 121 d) and 40 (169 vs. 129) d for cows classified as having SCE at 35 and 49 DIM, respectively. Treatment with PGF2α did not affect the prevalence of SCE either at 35 (37.9 vs. 38.4%) or at 49 DIM (34.0 vs. 40.4%). Treatment with PGF2α did not affect time to first insemination (AI; median 76 DIM for cows treated with PGF2α; 79 DIM for control. Nonetheless, PGF2α treatment increased pregnancy to first AI in all the cows (35.5 vs. 24.1%) and hazard ratio (HR) of pregnancy in cows with BCS ⩾2.5 when all of the cows were evaluated (HR = 1.5; 95% confidence interval; CI = 1.1 to 2.0) and when only cows without SCE were evaluated (HR = 1.8; 95% CI = 1.2 to 2.7). Treatment with PGF2α did not affect the hazard of pregnancy in cows with SCE at 49 DIM (HR = 0.9; 95% CI = 0.6 to 1.3). In these farms, treatment with PGF2α did not affect SCE or time to first insemination, but did increase first-service pregnancy per AI and decreased time to pregnancy in cows with low BCS. [ABSTRACT FROM AUTHOR]

Our hypotheses were that cows classified as lame during the first 70 d in milk have more days from calving to conception and a greater hazard of dying or being culled compared with cows that were not classified as lame. Our objective was to estimate the detrimental effects of lameness on calving-to-conception interval and hazard of dying or being culled in lactating Holstein cows. Data were collected from 5 dairy farms located in upstate New York from November 2004 to June 2006. The design was a prospective observational cohort study. Cows were assigned a visual locomotion score (VLS) using a 5-point scale: 1 = normal, 2 = presence of a slightly asymmetric gait, 3 = the cow clearly favored 1 or more limbs (moderately lame), 4 = severely lame, to 5 = extremely lame (nonweight-bearing lame). In total 1,799 cows were enrolled. In 2 alternative categorizations, cows were considered lame if at least 1 VLS was ≥3 during the first 70 d in milk, and if at least 1 VLS was ≥4 for the same period they were considered lame. Lameness (VLS ≥3) was detected at least once in 26.5, 54.2, 33.9, 51.8, and 39.3% of all cows in farms 1 to 5, respectively. The hazard ratio of being detected pregnant was 0.85 for lame cows (VLS ≥3) vs. nonlame cows; hence, lame cows were at a 15% lower risk of pregnancy than nonlame cows. When lameness was redefined as VLS ≥4, the hazard ratio of been detected pregnant was 0.76 for lame cows vs. cows with VLS <4. Lameness increased the hazard ratio of culling/death, 1.45 and 1.74 for VLS ≥3 and VLS ≥4, respectively, vs. cows with VLS <3 and VLS <4, respectively. In summary, lameness significantly decreased the hazard of pregnancy and increased the hazard of culling/death. The detrimental effects were amplified when considering only severely lame and nonweight- bearing cows. [ABSTRACT FROM AUTHOR]