Non-Genetic Factors Affecting Somatic Cell Count, Milk Urea Content, Test-Day Milk Yield and Milk Protein Percent in Dairy Cattle of the Czech Republic Using Individual Test-Day Records

Abstract

This study had two aims. Firstly, to determine the associations of month of recording (MOR) and days in milk (DIM) with somatic cell count (SCC), milk urea concentration (MU) and milk production traits (i.e. test-day milk yield, TDM; milk protein percentage, PP and milk protein yield, PY). Secondly, to evaluate the associations among SCC, MU and milk production traits by analyzing individual monthly test-day records for dairy cows raised in the Czech part of the Czech Republic. A total number of 33,881 individual test-day milk records involving 15,565 dairy cows for a 12-month period between January and December 2001 enrolled in Database Computer Center belonging to Czech Moravian Breeders´ Corporation, Inc., Hiradistko, The Czech Republic were used. Data were analyzed using General Linear Model procedure (GLM) using Statistical Analysis System (SAS, 2004). The MOR and DIM had highly significant (P<0.001) effects on the studied traits. The SCC reached the maximum level in September (504,000) associated to the lowest TDM (19.9 kg) and the lowest SCC in December (320,000) and February (335,000 cell/ml). Least squares means of TDM, categorized by 30-d increments of DIM, paralleled reversible changes in PP and followed a curvilinear shape. SCC reached to the peak in the 2 nd and 3 rd months of lactation then decreased gradually to the end of lactation. MU was lower (30.5 mg/dl) during the first 30 DIM compared with all other DIM categories. The statistical analysis of TDM, PY and SCC by MU showed that as MU increased, TDM, PY increased and SCC decreased. MU, SCC, PP and PY were significantly different among TDM categorized. Each of PP and SCC measures inversely associated with TDM, meanwhile MU paralleled change with TDM. Somatic cell count measures showed a paralleled change with PP. The effects of environmental variables and associations among traits must be taken into consideration when cows are evaluated. Keywords: dairy cattle, days in milk, environmental effects, milk urea nitrogen * MOR=month of recording, DIM=days in milk (day), MUC=milk urea content categories (mg/dl), PPC=protein percentage categories (%), MYC= test-day milk yield categories (kg), SSC=somatic cell score categories, SCC= Somatic cell count (x1000) , SCS= Somatic cell score, TDM= Test-day milk yield (kg), MU= Milk urea content (mg/dl), PP=Protein percentage (%), PY= Protein yield (kg)

Studies on Milk Yield, Milk Composition, Circulating Hormones, Energy Metabolites and Biochemical Parameters during Complete Lactation in Sahiwal Cows

“…Almost similar finding was observed by Kennedy et al, (1982) and Schutz et al, (1990) who reported SCC score high in beginning stages of lactation and contrary report by Kataria and Kataria (2006), Kamboz et al, (2007) and Kumaresen (2013) SCC was observed significant high in late lactation than early and mid lactation stages. Above results are with close agreement with result of Oudah (2009) who reported slightly increased in first four months than declined gradually end of lactation. Ouedraogo et al, (2008) found that the low milk yield was associated to higher somatic cell count.…”

Environmental factors affecting milk composition in Holstein cattle breed

“…This device is a combination instrument consisting of the MilcoScan TM FT+ and the Fossomatic TM FC. To convert MU into MUN, the following conversion formula was used: MUN (mg/dl) = MU (mg/dl) × 0.4667 (Oudah EZM, 2009). The principle of analyzing of raw milk samples is based on the methodology by mid -infrared spectrometry method (ISO 9622 /2013).…”

Evaluation of Urine Nitrogen Excretion as the Measure of the Environmental Load and the Efficiency of Nitrogen Utilization

“…Milk samples were analysed for: the total protein content, fat, lactose, and urea concentration by spectrophotometric tests in the near-infrared region using MilkoScan FT+ and BENTLEY FTS in the Central Analytical Laboratory for milk with accreditation under registration number 096/5878/2015/2. The analysed content of urea in milk (MU) was converted to urea nitrogen in milk (MUN) according to O u d a h [26].…”