Relationship of thermal- humidity indices to milk yield of cross-bred Holstein Friesians

Date

4-2013

Degree

Bachelor of Science in Agriculture

Major Course

Major in Animal Science

College

College of Agriculture and Food Science (CAFS)

Adviser/Committee Chair

Renato SA. Vega

Abstract

Abstract: Milk yield and weather data of cross-bred Holstein Friesians of the dairy farm and the Agro-meteorological Station of the university were collected, respectively from years 2001 to 2009, to assess the relationships of milk yield and thermal humidity index (THI). Seven thermal-humidity indices were used and its regression coefficient to milk yield was determined. All the THIs were found to be negatively related to milk yield of dairy cows throughout the years. THI2 (Bianca, 1962) has the highest regression coefficient (R2=0.25), hence it is recommended to be used in the farm. The lowest and highest THI value was 74 and 79.5 in January and June, respectively. The highest and lowest milk yield was 12 and 8 kg/d/cow in the months of February and August, respectively. There was significant association between THI and milk yield and increasing from year 2001 to 2005. Highest association of THI was found during year 2003 (R2=0.51). The decreasing R2 observed from 2006 to 2009 indicates that the decrease in milk yield was not associated to heat factor. Therefore, the 2.6 kg/d/cow decrease in milk production and the weak association of milk yield to THI from 2006 to 2009 may be due to other factors like management, nutrition, and breed of dairy cows.

Language

English

Location

UPLB College of Veterinary Medicine (CVM)

Call Number

LG 993.5 2013 A3 I73

Document Type

Thesis

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