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Öğe Analysis of risk factors for dystocia in a Turkish Holstein herd(2010) Uzmay C.; Kaya I.; Ayyilmaz T.The aim of this study was to investigate the effects of calf birth weight, sex of calf, dam weight, parity of dam, age at first calving, gestation length, season and year of calving on dystocia in a Turkish Holstein herd. The data were collected from the Holstein herd of the research farm of the Agricultural Faculty of Ege University. A total number of 687 calvings (single births) from January 2005 through May 2010 were investigated in the study. The results of the preliminary analysis showed that dystocia was much more prevalent in pnmiparous cows (41.9% dystocia) compared with multiparous cows (5.1 % for second parity and 4.4% for third and greater parity cows). Therefore, the data set was divided into two parts for analyzing dystocia in primiparous (236 first calvings) and multiparous (451 sec and later calvings) cows separately. Binary logistic regression analysis was used to determine the factors affecting dystocia. Variables which had a p-value of ? 0.15 in univariate logistic regression analysis were included in the multivariate analysis. In this stage, backward stepwise logistic regression analysis was carried out and variables which had a p-value of ?0.10 were removed from the model. For primiparous cows, variables in the univariate analyses with a p-value ? 0.15 were sex of calf, birth weight class, dam weight class, ratio of calf birth weight to dam weight class, gestation length class and year of calving. Of these 6 variables included in the multivariate logistic regression analysis, birth weight class, gestation length class and year of calving remained in the model (p<0.05). The risk of dystocia increased with increasing birth weight in first parity cows. Compared to the reference category (birth weight class of ?35 kg), the risk of dystocia for calves with birth weight classes of 35.1-40.0, 40.1-45.0 and ?45.1 kg were 1.96, 4.53 and 5.29 times higher, respectively. Heifers with shorter gestation lengths had a lower risk of dystocia. Heifers with gestation lengths of 271-280 days had a 74% lower risk for dystocia compared to heifers with gestation lengths of ?281 days. For multiparous cows, factors in the univariate analyses with a p-value of ?0.15 were sex of calf and year of calving. None of these factors was found to have a significant effect (p>0.10) on dystocia in multivariate logistic regression analysis for multiparous cows. © Medwell Journals, 2010.Öğe The effects of several cow and herd level factors on lameness in Holstein cows reared in Izmir province of Turkey(2010) Yaylak E.; Akbas Y.; Kaya I.; Uzmay C.This study was carried out to determine the prevalence of lameness and risk factors for lameness. Data of 1078 Holstein cows from 34 farms in Izmir province of Turkey were evaluated. Lameness was determined by using a Lameness Score (LS) scale with 5 levels. Mean prevalence of lameness (LS = 3) was 28.3%. The percent of the cows with LS 1-4 or 5 were found to be 37.9, 33.8, 20.9%, 5.8 and 1.6%, respectively. Cow-level variables were parity, days in milk, body condition score and hygiene score of lower rear legs. There were 18 herd level variables used to explain the variation in the prevalence of lameness among the herds. LS data were analysed using individual and multifactorial binary logistic regression. About 12 of the 22 potential risk factors investigated in the study were found to be significant (p<0.10) in the individual logistic regression analysis. However, only 9 of the 12 factors remained in the final multifactorial logistic regression model. These significant 9 factors on lameness were parity, body condition score, herd size, animal keeper, total area per cow, soil area per cow, frequency of scraping, ratio of concentrate feed to total feed intake and consulting a feeding expert. © Medwell Journals, 2010.Öğe Effects of udder and teat morphology, parity and lactation stage on subclinical mastitis in holstein cows [Siyah alaca i·neklerde meme ve meme başi formu ile laktasyon sirasi ve laktasyon döneminin subklinik mastitis üzerine etkisi](2003) Uzmay C.; Kaya I.; Akbaş Y.; Kaya A.The relationships of udder and teat morphology, parity, and lactation stage with subclinical mastitis were investigated in cows raised in herds registered with the Izmir Holstein Breeders Association. Data from 887 cows in 21 herds were used. The udder and teat morphology of the cows was scored. Detection of subclinical mastitis was performed by a hand-held device measuring the electrical conductivity of the milk. It was found that 55.9% of cows had trough-shaped udders, 25.9% had ball-shaped udders, 11.5% had rear-heavy udders, and 6.7% had pendulous udders. Teats were cylindrical in 73.3%, funnel-shaped in 18.8%, pear-shaped in 3.2%, and long and thick in 4.7% of cows. Teats were located squarely in 54.1% of cows, and rear teats were closer to each other compared with the front teats in 45.9%. In multivariate logistic regression analysis, udder and teat morphology, parity, and herd were found to affect significantly (P < 0.001) the probability of subclinical mastitis. The effects of teat placement and stage of lactation were not significant. Cows with trough-shaped udders had the lowest risk of subclinical mastitis, and cows with pendulous udders had the highest risk. When teat morphology was considered, the risk of subclinical mastitis was highest for cows with long and thick teats. The risk of subclinical mastitis for cows with funnel-shaped teats was found to be lower than for cows with cylindrical teats. The risk of subclinical mastitis was found to increase as parity rose.Öğe The level of inbreeding and its effects on milk yield, age at first calving and calf mortality in Holstein cattle reared on the Agricultural Faculty farm of Ege University [Ege üniversitesi ziraat fakültesi çiftliginde yetiştirilen siyah alaca sigirlarda akrabali yetiştirme düzeyi ve bunun süt verimi, i·lkine buzagilama yaşi ve buzagi ölümleri üzerine etkileri](2003) Uzmay C.; Akbaş Y.In this study, the inbreeding coefficient of 1535 Holstein calves born on the Agricultural Faculty farm of Ege University during the period 1980-2000 was calculated, and the change of inbreeding levels over the years was investigated. Furthermore, the effects of inbreeding on first lactation 305-day milk yield, age at first calving and calf mortality were examined. The mean inbreeding level of calves born in the investigated period was 1.89%. The level of inbreeding in the herd fluctuated from 0% to 4.37% according to the birth years of calves. Furthermore, over the last 3 years of the period (1998-2000) inbreeding steadily increased. Over the years, it was estimated that a linear relationship (R2 = 0.62) existed between the inbreeding level and the percentage of sires bred in the herd. Estimates of inbreeding depression per 1% increase in inbreeding were -16.9 kg for milk yield, and 2.8 days for age at first calving. These levels of depression, however, were not statistically significant. A significant relationship between inbreeding and calf mortality was found. While calf mortality for non-inbred calves was 8.9%, it was 17.8% for calves with an inbreeding level ? 12.5%.Öğe A Research on Rearing Calves with Acidified Whole Milk [Buzagilarin Ekşitilmiş Süt ile Büyütülmesi Üzerine Bir Araştirma](2000) Kaya A.; Uzmay C.; Alçiçek A.; Kaya I.The objective of this study was to investigate the effect of acidified whole milk fed at 10 % of body weight on calf performance, and the incidence of scours. Twenty Holstein calves were assigned to one of two dietary treatments (whole milk or acidified whole milk), each consisting of 10 calves (5 male and 5 female), from d 5 to d 46 of age for a 42-d trial. Calves were fed either warm whole milk (35 to 37°C) or acidified cold whole milk (acidified with formic acid to pH 4.8 and given at 10 to 20°C) from nipple pails twice daily at 10 % of body weight. The amounts of milk given were adjusted weekly according to body weight, and the calves were gradually weaned, starting at d 40 of age. During the experiment the calves were offered pelleted starter, alfalfa hay and water for ad libitum intake. All the calves were housed in individual pens. Body weight was recorded weekly. Fecal consistency scores were recorded daily on a scale of 1 to 4 (1=normal, 2=soft, 3=runny and 4=watery). Intakes of whole milk, starter, and total dry matter from milk and starter were similar between the treatments. Average daily body weight gains (d 5 to 46) for calves fed whole milk, and acidified whole milk were also similar (427.44 and 459.95 g/d, respectively). There was no significant difference in the efficiency of feed conversion between the treatments. Calves fed acidified whole milk exhibited lower fecal consistency scores than did calves fed whole milk (2.04 vs. 2.33 during d 5 to 25 and 1.34 vs. 1.46 during d 26 to 46) even though the differences between treatments were not significant The percentage of calf days with scours was significantly higher for calves fed whole milk than for those fed acidified whole milk for d 5 through 25 (34.28 vs. 18.57 %). In the same period, the percentage of calf days treated for scours was 8.57 % for calves fed whole milk while there was no incidence of scours requiring treatment in calves fed acidified whole milk. The cost of body weight gain was quite high for calves fed whole milk compared with those fed acidified whole milk, due mainly to the costs of veterinary treatment for scours ($ 3.76 vs. $ 2.68 / kg gain).Öğe Research on various testing procedures and different methods of estimating lactation milk yield in dairy cattle [Süt sigirlarinda farkli süt verim denetim uygulamalari ve hesaplama yöntemleri üzerine araştirmalar](2002) Kaya A.; Uzmay C.; Akbai Y.; Kaya Y.; Tümer S.This research was carried out to determine the effect of various milk sampling intervals and different methods on the accuracy of estimation of lactation milk yield in dairy cattle. Individual daily milk weights of 599 Holstein, Simmental and Brown Swiss lactations from the Aegean Agricultural Research Institute were used. It was assumed that test-day milk yields were obtained by regular and irregular intervals of 28 d and 56 d, with the irregular intervals having a standard deviation of 5 d. From test-day milk yields, 305 d milk yields were estimated by the Holland (Lactation yield = mean of test day yields x lactation duration (days)) and Test Interval methods. It was found that the bias of estimation increased significantly (P<0.01) as the length of testing intervals increased. The effect of the calculation method on the bias of estimation was also significant (P<0.01). The Test Interval method estimated actual yield more accurately than the Holland method. The difference between the regular and irregular testing intervals with respect to bias of estimation was insignificant. Rank correlations between actual yields and estimated yields were significant (P<0.01) and very high. Therefore, any of the combinations of calculating milk yield in the study can be used to estimate milk yield for the purpose of ranking cows. However, if the aim is to estimate actual yield most accurately, the testing interval should be 28 d. In this case, the Holland or the Test Interval method can be used. If the testing interval is 56 d, the Test Interval method must be used to estimate actual yield.
