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Improving Milk Production through Evening Feeding of Dairy Cows
The objective of this experiment was to establish milk production effects of evening instead of morning feeding in once-daily fed high-producing lactating dairy cows. Eight multiparous (664 ± 62 kg body weight; 80 ± 40 days in milk; mean ± SD) lactating Holstein cows were studied in a cross-over design experiment with two 21-d periods. Cows were kept under thermoneutral conditions and fed a total mixed ration (TMR) based on barley and corn grains, corn silage, and alfalfa hay at either 0800 h or 2000 h. The forage to concentrate ratio on a dry matter basis was 50:50 fed for 5-10% daily orts. Feed intake and milk production were monitored continuously for the entire experiment and subjected to data analysis for the third week of both periods. Statistical data analysis was conducted with Mixed Models Procedures of SAS program. Feed intake was similar between morning-fed (21.2 kg) and evening-fed (21.4 kg) cows (P>0.15). Milk yield was also similar, but milk fat content was higher in evening-fed vs. morning-fed cows (3.5% of 35.0 kg vs. 3.2% of 34.7 kg, P<0.05). As a result, milk fat production was increased by evening instead of morning feeding (1.23 vs. 1.11 kg/d, P<0.05). Milk protein content was not different between morning-fed (3.0%) and evening-fed cows (3.1%). Results demonstrated that timing of feeding is an external modulator of dairy cow physiology and metabolism and contributes significantly to peripheral supply of metabolites, thus, determining milk fat content and yield. Improved milk fat production despite the unaltered total daily feed intake demonstrates improved feed efficiency and economics.
Keywords: Evening feeding, Milk production, Dairy cow