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פותח על ידי קלירמאש פתרונות בע"מ -
Comparison of lactational responses of dairy cows in Georgia and Israel to heat load and photoperiod
Year:
2003
Source of publication :
Animal Science
Authors :
אהרוני, יואב
;
.
Volume :
75
Co-Authors:
Aharoni, Y., Department of Beef Cattle, Agricultural Research Organization, Newe Yaar Research Center, PO Box 1021, Ramat Yishay 30095, Israel
Ravagnolo, O., Animal and Dairy Science Department, University of Georgia, Athens, GA 30605, United States
Misztal, I., Animal and Dairy Science Department, University of Georgia, Athens, GA 30605, United States
Facilitators :
From page:
469
To page:
476
(
Total pages:
8
)
Abstract:
The seasonal effects of heat load and photoperiod on yield and composition of milk from primiparous cows in the course of lactation were studied using test day records from 8968 primiparous cows on 76 farms in Georgia, collected from 1990 through 1997. The effect of prepartum photoperiod on milk production in the subsequent lactation of these cows was also evaluated. These estimated seasonal effects were compared with those estimated for 4728 primiparous cows on 13 farms, and for 1538 multiparous cows on three farms during consecutive lactations in Israel from 1994 through 1996. During lactation, the day length had a positive effect on milk yield and negative effects on fat and protein concentrations in the milk, but the daily change in day length had positive effects on milk yield and fat concentration, and a smaller positive effect on protein concentration. The day length during the pre-partum period had negative effects on milk yield and fat and protein concentrations. The heat load during lactation had negative effects on milk yield and fat and protein concentrations. Most of the effects were highly (P < 0.001) significant. There was a very good match between the results obtained for primiparous cows in Georgia and Israel, for the combined effects of heat load and photoperiod during lactation on milk yield and protein and fat concentrations. The match between primiparous and multiparous cows in Israel was better for milk yield and protein concentration than for fat concentration. The estimated effects of pre-partum photoperiod were higher for multiparous cows in Israel than for primiparous cows in either country.
Note:
Related Files :
Bos taurus
Dairy cows
Heat adaptation
Milk composition
milk yield
Photoperiod
עוד תגיות
תוכן קשור
More details
DOI :
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
23851
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:03
Scientific Publication
Comparison of lactational responses of dairy cows in Georgia and Israel to heat load and photoperiod
75
Aharoni, Y., Department of Beef Cattle, Agricultural Research Organization, Newe Yaar Research Center, PO Box 1021, Ramat Yishay 30095, Israel
Ravagnolo, O., Animal and Dairy Science Department, University of Georgia, Athens, GA 30605, United States
Misztal, I., Animal and Dairy Science Department, University of Georgia, Athens, GA 30605, United States
Comparison of lactational responses of dairy cows in Georgia and Israel to heat load and photoperiod
The seasonal effects of heat load and photoperiod on yield and composition of milk from primiparous cows in the course of lactation were studied using test day records from 8968 primiparous cows on 76 farms in Georgia, collected from 1990 through 1997. The effect of prepartum photoperiod on milk production in the subsequent lactation of these cows was also evaluated. These estimated seasonal effects were compared with those estimated for 4728 primiparous cows on 13 farms, and for 1538 multiparous cows on three farms during consecutive lactations in Israel from 1994 through 1996. During lactation, the day length had a positive effect on milk yield and negative effects on fat and protein concentrations in the milk, but the daily change in day length had positive effects on milk yield and fat concentration, and a smaller positive effect on protein concentration. The day length during the pre-partum period had negative effects on milk yield and fat and protein concentrations. The heat load during lactation had negative effects on milk yield and fat and protein concentrations. Most of the effects were highly (P < 0.001) significant. There was a very good match between the results obtained for primiparous cows in Georgia and Israel, for the combined effects of heat load and photoperiod during lactation on milk yield and protein and fat concentrations. The match between primiparous and multiparous cows in Israel was better for milk yield and protein concentration than for fat concentration. The estimated effects of pre-partum photoperiod were higher for multiparous cows in Israel than for primiparous cows in either country.
Scientific Publication
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