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Biomedical subjects

D Hojman

Publications and source records attributed to D Hojman.

At least 19 recordsLinked to original sources
PubMed2005

Association between live body weight and milk urea concentration in Holstein cows.

Use of milk urea (MU) concentration as a parameter for detection of nutritional imbalances requires identification and quantification of nutritional and nonnutritional factors that influence it. The objective of this study was to assess the relationship between live body weight (BW) and MU concentration in Holstein cows. Results for the test-day measurements at 7 dairy farms were obtained from the Israeli Dairy Herd Improvement Center and concomitant cow weights were registered in local computerized weighing systems. A total of 1996 cows and 25,485 records were studied. The overall unadjusted per-cow mean MU nitrogen concentration and BW were 15.3 mg/dL (SD = 3.8) and 593 kg (SD = 84), respectively. The linear association between BW and MU was negative and highly significant and the quadratic component of BW had a highly significant positive association with MU. There was a significant interaction between the association of MU and BW with lactation number. Sampling month, milk yield, milk fat percentage, and somatic cell count accounted for significant variation in MU. Predicted MU concentrations at different BW values were calculated for each parity group, by setting equations that included the estimates of the variables associated with MU and constant values (lactation averages) for the independent variables, with the exception of BW. Plotting of results showed exponential characteristics for the relationship between BW and predicted MU concentrations. At any of the considered BW, predicted MU concentrations were lower for first-parity cows. The trends and interactions found in the present study may contribute to improving accuracy of models designed to calculate urinary nitrogen excretion rates and normative milk urea concentrations.

Animals↗
PubMed2004

Relationships between milk urea and production, nutrition, and fertility traits in Israeli dairy herds.

The objectives of this study were to identify and evaluate production and environmental factors that influence milk urea (MU) in Israeli dairy herds, to analyze the relationships between MU concentration and nutritional variables, and to examine a possible association between MU and pregnancy rate (PR). Production and environmental data were obtained from the Israeli Dairy Herd Improvement (DHI) Center (n = 1,279,600). Programmed total mixed rations (feeds and quantities) on milk-test day were collected from 42 dairy herds. Data on 36,073 cows that were inseminated close to milk-test day and pregnancy diagnosis results were obtained from the DHI data bank. Highly significant positive relationships were found between MU concentration and milk yield and fat percentage; relationships between MU and milk total protein percentage and somatic cell count were negative. Milk urea levels were higher during the summer months and were higher for adult cows. These levels increased as lactation progressed. Milk urea was positively associated with dietary levels of crude protein, ruminal digestible protein, and neutral detergent fiber contents; it was negatively associated with ration energy and nonstructural carbohydrate contents. Significant influences of specific feeds on MU were detected. A significant negative association was found between MU level and PR. Least squares means for PR for cows in the lowest and highest MU quartiles were 38.4 and 36.1%, respectively. Increasing levels of MU were negatively related to reproductive performance of dairy cows, but the risk of nonpregnancy caused by high levels of MU was lower than reported in previous studies.

Animal Feed↗
PubMed2001

The effect of extended calving intervals in high-yielding lactating cows on milk production and profitability.

A field trial was conducted to examine the effect of extended calving interval (CI) on production and profitability of high yielding cows (n = 937). First insemination was performed at 154 and 93 d postpartum (pp), for treatment and control primiparous cows, respectively, and at 124 and 71 d pp for treatment and control multiparous cows, respectively. During the first experimental lactation, average daily value-corrected milk (VCM) yield was 28.5 and 27.7 kg/d of CI for treatment (n = 131) and control (n = 133) primiparous cows, respectively. No significant difference in average daily VCM yield (33.0 and 32.8 kg/d of CI) was found between treatment (n = 271) and control (n = 215) multiparous cows . In the first 150 d of the subsequent lactation, there were significant differences in milk and VCM production in favor of the treatment primiparous cows (41.4 vs. 39.7 kg of VCM/d) but no significant differences in the production of multiparous cows. Primiparous and multiparous cows with extended lactations were more profitable. During the first experimental lactation, there were advantages of $0.19 and $0.12/d of CI in the net returns for primiparous cows and multiparous cows with longer CI, respectively. When the economic analysis included the first experimental lactation plus the first 150 d of the subsequent one, the net return per day of CI was higher for cows with an extended voluntary waiting period: $0.21/d and $0.16/d for primiparous and multiparous cows, respectively. A delay of 60 d with respect to the usual voluntary waiting period in the beginning of inseminations of high yielding cows has economic advantages and allows the farmer an option for decisions regarding individual cows.

Animals↗
PubMed1989

[Experimental acute necrotico-hemorrhagic pancreatitis in dogs. Treatment by intraductal block].

The aim of this experimental study was to demonstrate that the mortality of calcium chlorine induced acute pancreatitis in the dog was decreased by the intraductal injection of solid substances. Seventy-two dogs were used. In the control group (n = 5) the mortality was 100%. Three different drugs were used for the intraductal injection: Ethibloc (n = 37), Tissucol (n = 10) and silicones (n = 10). The mortality rate has been respectively of 13.5, 10 and 10%. In order to define at which level of the pancreatic duct the obstruction had a maximum efficiency, 10 dogs underwent a distal ligation of the pancreatic duct after induction of the pancreatitis. The mortality rate in this group was 100%. It can be therefore concluded that only the complete obstruction of the pancreatic duct decreases the mortality rate in this experimental model.

Acute Disease↗
PubMed1989

Pancreatic duct occlusion in the management of acute necrotizing pancreatitis in a canine model.

Based on results reported by others in using prolamine (Ethibloc; Ethicon Gmb H) to treat patients with chronic pancreatitis, without any observed pancreatic complications, we decided to use pancreatic duct occlusion experimentally in dogs in which we induced acute pancreatitis by the injection of calcium chloride into the pancreatic duct. This injection proved to be 100% lethal in the 5 animals constituting the control group, none of which were treated after the injection. Acute pancreatitis was then induced in 57 animals, also by injection of calcium chloride. These dogs were then treated with one of three substances that share the same physical properties: prolamine; Tissucol (Immuno AG, Vienna), a biologic tissue adhesive; silicone (Xantopren, Bayer Dental D-5090 Leverkusen). Thirty-seven dogs were treated with prolamine, 10 dogs with Tissucol, and 10 with silicone. The mortality rate in the 57 treated animals was 12.2%, compared to the 100% rate in the untreated control group. The mechanical action achieved by blocking the pancreatic duct shows how the evolution of acute pancreatitis at different stages could be modified. This specific treatment limits the pathophysiologic process of acute pancreatitis in dogs. These findings provide us with a promising outlook for the treatment of this severe illness.

Acute Disease↗
PubMed1988

[Gastric dysplasia: its incidence in precancerous conditions, advanced cancer and early cancer].

Dysplasia cancer sequence has not been determined in gastric cancer yet. Dysplastic changes are not frequent. Gastric cancer generally develops in areas of chronic atrophic gastritis. This chronic atrophic gastritis (CAG) is often associated with intestinal metaplasia (IM). IM has been classified in three types, according to morphologic patterns, differentiation and mucins production. We reviewed 55 gastrectomy specimens and 278 endoscopic biopsies. In order to determine an histological high-risk group, we chose cases with preneoplastic conditions (60 CAG, 10 biopsies of gastric remnants, 3 flat adenomas and 55 gastrectomies by cancer or ulcer). We also included 12 hyperplastic polyps because they may contain foci of intestinal metaplasia. Mucin techniques (PAS-ALCIAN BLUE Ph 2.5 and HID-A.B) were used in all cases that showed extensive intestinal metaplasia. In addition, we used immunohistochemistry techniques to detect CEA. Dysplasia was found only in flat adenomas (3 cases), early gastric cancer (1 case) and advanced cancer (3 cases). We considered a preneoplastic lesion only to moderate or severe dysplasia. Hyperplastic regenerative pathology is considered a reversible condition. Therefore, it should be differentiated from dysplasia. We found that IM type III (sulfomucin predominance) is the most related to carcinoma, particularly to the intestinal type. CEA antigen is poorly specific in detecting high-risk lesions because it was seen in regenerative pathology and in gastric cancer too. Relationship of dysplasia and carcinoma, and/or neoplastic polyps was similar to other series. Concerning to follow-up items, we agree with the concepts proposed by the Japanese Research Society for Gastric Cancer.

Humans↗