Table 4.
Itema | Treatmentb | SEM | P-valuec | |||||
---|---|---|---|---|---|---|---|---|
30-d | 60-d | 90-d | Control | S | L | Q | ||
Supplement fed, kg/d | 3.00 | 1.50 | 1.00 | – | ||||
Cow BW, kg, cow BCS and calf BW, kg | ||||||||
Initial BW | 494 | 517 | 503 | 503 | 18.0 | 0.95 | 0.74 | 0.43 |
Initial BCS | 4.66 | 4.65 | 4.54 | 4.87 | 0.20 | 0.28 | 0.65 | 0.85 |
Calving BW | 508 | 515 | 531 | 522 | 6.79 | 0.56 | 0.02 | 0.55 |
Calving BCS | 4.74 | 4.83 | 4.83 | 4.82 | 0.15 | 0.95 | 0.70 | 0.82 |
Calf birth BW | 33.8 | 31.7 | 35.8 | 36.2 | 1.93 | 0.28 | 0.43 | 0.10 |
Cow BW 31 d after calving | 468 | 490 | 482 | 465 | 7.73 | 0.09 | 0.21 | 0.15 |
BW change from parturition to day 31 post-calving | −46.7 | −24.9 | −53.5 | −62.1 | 8.24 | 0.04 | 0.58 | 0.03 |
Breeding season BCS | 5.00 | 5.11 | 4.83 | 5.03 | 0.21 | 0.84 | 0.57 | 0.43 |
Progesterone concentration, ng/dL | ||||||||
21 d after calving | 0.27* | 0.21 | 0.12 | 0.14 | 0.06 | 0.34 | 0.05 | 0.82 |
31 d after calving | 1.24 | 0.70 | 0.69 | 0.14 | 0.37 | 0.08 | 0.29 | 0.55 |
Cow reproductive performance, % | ||||||||
Calving to conception, d | 57.2 | 63.1 | 84.2* | 64.1 | 5.85 | 0.53 | 0.01 | 0.30 |
aBW– body weight; BCS – body condition score; FTAI – fixed time artificial insemination
bTreatments: 30-d – cows received 3.0 kg of concentrate supplement beginning 30 d prior to calving; 60-d – cows received 1.5 kg of concentrate supplement beginning 60 d prior to calving; 90-d – cows received 1.0 kg of concentrate supplement beginning 90 d prior to calving; and control – no concentrate supplement was fed
cS – effect of supplementation, supplemented treatments compared to the control; L and Q – effects of linear and quadratic order of supplement delivery strategy (30, 60 or 90 d). * Means statistically different from the control by Dunnett’s test