نتایج جستجو برای: parity number and calving season

تعداد نتایج: 16882918  

Journal: :Theriogenology 2004
David A Dargatz Grant A Dewell Robert G Mortimer

A national sample of cow-calf producers was contacted to participate in a study to describe selected calving management practices on operations throughout the United States. Information was gathered on calving season, frequency of dystocia, frequency of observation, timing of assistance, and calving facilities. Regional and herd size differences existed in all parameters evaluated. Most calves ...

Journal: :Journal of Dairy Science 2021

This study assessed the extent of reproductive losses and associated genetic parameters in dairy cattle, using in-line milk progesterone records for 14 Swedish herds collected by DeLaval's Herd Navigator. A total 330,071 samples were linked to 10,219 inseminations (AI) from 5,238 lactations 1,457 Red 1,847 Holstein cows. Pregnancy loss traits defined as early embryonic (1–24 d after AI), late (...

Journal: :Jurnal Ilmu Produksi dan Teknologi Hasil Peternakan 2023

Empowering smallholder cattle farmers through the Field station of School for Smallholder Community (SL-SPR) Program is one efforts to improve reproductive performance Bali in farmers. This research aims evaluate reared semi-intensively SL-SPR Sungai Lilin, South Sumatra. Data on were collected from observation method direct and interviews with respondents community. The was totally 45 farmers,...

2013
Pete Anderson

Calving difficulty (dystocia) contributes heavily to losses in production in beef cow/calf herds. The obvious losses are due to calves or cows that die at or soon after calving. Less noticeable losses are due to delayed rebreeding, more open females, an extended calving season and increased labor costs. While occasional dystocia is almost unavoidable, through proper management, cattlemen can mi...

Journal: :Journal of animal science 2001
R Ramirez-Valverde I Misztal J K Bertrand

This study compared the accuracy of several models for obtaining genetic evaluations of calving difficulty. The models were univariate threshold animal (TAM), threshold sire-maternal grandsire (TSM), linear animal (LAM), and linear sire-maternal grandsire (LSM) models and bivariate threshold-linear animal (TLAM), threshold-linear sire-maternal grandsire (TLSM), linear-linear animal (LLAM), and ...

حقدوست, علی اکبر, شریفی, حمید,

  Background & Objectives : Management of time-dependent variables is the advantages of survival analysis. This study compares time-dependent and -independent variables in survival analysis in culling of dairy cows.   Methods: In this historical cohort, 7067 dairy cows in the Province of Tehran were recruited. Cows were followed to the next calving or culling. Data on the occurrence of healt...

2015
NATHANIEL D. RAYL

Understanding spatiotemporal variability in prey accessibility is important for disentangling predator-prey interactions and is relevant to management interventions to reduce predation. Recently, caribou (Rangifer tarandus) in Newfoundland declined by 66%, with calf predation by black bears (Ursus americanus) implicated as a major proximate mechanism of the decline. Most predation occurs when c...

Journal: :Journal of dairy science 2007
J M Hickey M G Keane D A Kenny A R Cromie P R Amer R F Veerkamp

Calving difficulty is a trait that greatly affects animal welfare, herd profitability, and the amount of labor required by cattle farmers. It is influenced by direct and maternal genetic components. Selection and breeding strategies can optimize the accuracy of genetic evaluations and correctly emphasize calving difficulty in multiple-trait indices provided there are accurate estimates of genet...

2013
S. McParland B. O’Brien J. McCarthy

Somatic cell count (SCC) is an indicator of both udder health and milk quality and is measured at an animal level through national milk recording schemes. The objective of this study was to assess the animal and herd factors contributing to elevated SCC (i.e. poorer milk quality). Test day records (n = 2,658,928) from 519,456 cow lactations obtained between 2007 and 2011 were included in the an...

Journal: :Acta Veterinaria Scandinavica 2004
JP Valde LG Lawson A Lindberg JF Agger H Saloniemi O Østerås

Data from the national dairy cow recording systems during 1997 were used to calculate lactation-specific cumulative risk of mastitis treatments and cumulative risk of removal from the herds in Denmark, Finland Norway and Sweden. Sweden had the lowest risk of recorded mastitis treatments during 305 days of lactation and Norway had the highest risk. The incidence risk of recorded mastitis treatme...

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