Submitted to: Midwestern Section of the American Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 11/16/2004
Publication Date: 3/22/2005
Citation: Freetly, H.C., Ferrell, C.L., Jenkins, T.G. 2005. Moderately altering weight gain patterns of second parity cows through nutrition changes the time that feed resources are offered without any differences in production [abstract]. Journal of Animal Science 83(Suppl. 2):90-91.
Technical Abstract: We hypothesized that feed resources could be deferred from mid-gestation to either late gestation or early lactation without a decrease in fertility or weight of calf produced in second parity cows. One-hundred and one MARC III composite cows (1/4 Hereford, 1/4 Angus, 1/4 Red Poll, and 1/4 Pinzgauer) were divided into three treatments that consisted of three different feed presentation: M-M-M-M (n = 32), L-H-M-M (n = 33), and L-L-L-H (n = 36). Feed levels resulted in cows losing maternal BW (L), maintain maternal BW (M), or rapidly gain maternal BW (H) during four periods (Period 1: 112 to 201 d of gestation, Period 2: 202 d of gestation to parturition, Period 3: parturition through 27 d of lactation, Period 4: 28 d to ~64 d of lactation). As bred and lactating heifers these cows had the same treatment designations except heifers were fed for Low (L), Medium (M), and High (H) rates of gain during four periods (Period 1: 94 to 186 d of gestation, Period 2: 187 d of gestation to parturition, Period 3: parturition through 27 d of lactation, Period 4: 28 d to ~63 d of lactation). Total feed intake of L-H-M-M and M-M-M-M second parity cows did not differ (P > 0.59), but L-L-L-H cows ate less (P < 0.002). At parturition, body condition score (BCS; scale 1-9) did not differ between M-M-M-M (4.6 +/- 0.1) and L-H-M-M (4.4 +/- 0.1) cows, but both treatments had higher BCS than the L-L-L-H (3.8 +/- 0.1; P < 0.001) cows. The percentage of calves weaned (88 +/- 3%; P = 0.77), weight of calf weaned (167 +/- 5 kg; P = 0.63), BCS at breeding (4.5 +/- 0.1; P = 0.20), or the percentage of cows expressing a corpus luteum at the start of next breeding season (80 +/- 4; P = 0.21) did not differ among treatments. Our findings suggest that timing nutrient availability to second parity cows can be used to change the time that feed resources are used.