نتایج جستجو برای: calving season

تعداد نتایج: 59858  

2015
Janez Jenko Tomaž Perpar Milena Kovač

To study the genetic relationship between the lifetime milk production (LMP), first lactation milk yield (MY305), and length of productive life (PL) in the Slovenian Brown cattle population, first lactation records from 14,389 cows and lifetime performance records (LMP and PL) from 12,416 cows were used. Records of LMP and PL were normalised using the square root transformation of the raw value...

Journal: :iranian journal of applied animal science 2011
h.m. khattab a.z. el-basiony s.m. hamdy a.a. marwan

twenty pregnant buffaloes, eight weeks before the expected calving date, were assigned into two homogeneous groups of 10 animals each, according to their season of lactation (2nd to 8th season of lactation); the first group (g1) were fed on a ration consisting of concentrate feed mixture (22% yellow corn, 35% cotton seed meal, 33% wheat bran, 4% rice bran, 3% molasses, 2% limestone and 1% sodiu...

Journal: :Journal of dairy science 2010
B Fuerst-Waltl M K Sørensen

Mortality in dairy cattle is not only relevant with regard to economic losses but also to animal health and welfare. Thus, the aim of this investigation was to explore the genetic background of postnatal mortality in calves and replacement heifers in different age groups until first calving in Danish Holsteins. Records of Danish Holstein heifer calves born in the years 1998 to 2007 were extract...

2011
Daniel Zaborski Wilhelm Grzesiak

In this study, the detection of dairy cows with difficult calvings using artificial neural networks (ANN) and classification functions (CF) is presented. The set of 15 classification variables was used. The dependent variable was the class of calving difficulty: difficult or easy. Perceptrons with one (MLP1) and two (MLP2) hidden layers as well as radial basis function (RBF) networks were analy...

2006
Ill-Hwa Kim Hyun-Gu Kang

Delayed conception is defined as an interval of greater than 90 days postpartum before a cow becomes pregnant again. In this study, the risk factors for delayed conception in Korean dairy herds were determined by evaluating several reproductive factors in individual cows. The following data was recorded from 1,012 pregnancies in eight dairy herds (designated A-H) from July 2001 to June 2006: he...

2004
John F Mee

: Irish dairy herd fertility has been declining since the 1980s. The extent, nature and causes of this decline in fertility and the current status of Irish dairy herd fertility were described. An increase in calving interval of approximately one day per year has been recorded. The principal components of this trend have been an increased incidence of postpartum endocrinopathies, reduced express...

2007
R. R. Maurer

Straightbred and crossbred heifers (165) and cows (241) that were nonpregnant after exposure to fertile bulls for two consecutive breeding periods of 45 to 60 d (repeat breeders) and contemporary cows (102) that had produced a calf in the previous calving season (controls) were placed with bulls and were observed for mating. Repeat-breeder and control females were slaughtered at 2 to 51 d postm...

Journal: :The Onderstepoort journal of veterinary research 2006
J D Skinner H M Dott A Matthee L Hunt

Breeding records of 40 white rhinoceros and 155 Cape buffalo were analysed. Three rhinoceros cows bred in captivity, themselves conceived for the first time at 84, 87 and 95 months of age, respectively. Rhinoceros cows breed throughout the year. There is no evidence of a relationship between calving interval and month of birth. Calving intervals were normally distributed about the mean of 34 mo...

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