Table 5.

ADG and reproductive performance of heifers grazing bahiagrass pastures and randomly assigned, in a 2 × 2 factorial arrangement of treatments, to receive concentrate DM supplementation at 1.25% or 1.75% of BW offered either daily (7×) or 3× weekly (3×; Monday, Wednesday, and Friday) from days 0 to 168 (2 yr; 64 heifers/yr; 4 pastures/treatment combination/yr)

	Supplementation amount				Supplementation frequency
Item1	1.25%	1.75%	SEM	P-value 2	3×	7×	SEM	P-value 2
ADG, kg/d
Days 0 to 86	0.72	0.74	0.021	0.42	0.68	0.77	0.020	0.01
Days 86 to 168	0.59	0.66	0.018	0.003	0.61	0.64	0.018	0.28
Days 0 to 168	0.65	0.71	0.015	0.02	0.65	0.71	0.015	0.007
Pubertal heifers 3, % of total
Day 0	0.0	0.0	4.02	0.99	0.0	0.0	4.09	0.85
Day 56	47.2	55.0	4.02	0.18	44.6	57.6	4.09	0.03
Day 89	81.1	92.0	4.02	0.05	80.0	93.0	4.09	0.03
Day 168	90.5	95.1	4.02	0.42	86.3	99.3	4.09	0.03
Pregnant heifers day 213 4, % of total	64.8	83.0	5.25	0.02	72.4	75.3	5.21	0.70
Calving first offspring, % of total	58.6	72.5	5.63	0.05	59.5	71.9	5.59	0.11
Calving date, day of the study	390	382	3.41	0.05	391	382	3.8	0.07

¹Heifers were assigned to an estrus synchronization protocol which consisted of CIDR insertion on day 56, CIDR removal on day 70, PGF_2α injection on day 86, and GnRH injection and timed-AI on day 89. Heifers were exposed to yearling Angus bulls from days 89 to 168. Bulls were rotated among pastures every 14 d.

² P-value for the comparison of treatments within day of the study.

³Blood samples collected on days 0, 7, 49, 56, 82, 89, 160, and 168 to determine serum concentrations of progesterone. Heifers were considered pubertal when plasma progesterone concentrations were ≥1.5 ng/mL in 2 consecutive 7-d apart blood collections (Cooke and Arthington, 2009).

⁴Overall pregnancy percentage (AI + bulls) determined via rectal palpation 45 d after the end of the breeding season.