Effect of Maternal Nutrition on Performance of Nellore Cows and Pre-Weaning Growth of Their Progeny

The majority of developmental programming studies with beef cows have been conducted with Bos taurus. Little is known about developmental programming in Bos indicus particularly the Nellore breed, which is the predominant beef breed in Brazil. The aim of the present study was to determine the effect of maternal nutrition on cow performance as well as the development of the calves until weaning. Ninety-two multiparous Nellore cows (initial BW 387 ± 9.0) were allotted to a completely randomized design with two treatments. Cows were inseminated with male semen from the same bull at two different time-points. Forty-six cows were fed only mineral (control) and the other 46 were fed a protein supplement (33%CP, 1%BW) from day 125 of gestation until calving. Cows were grazed on Brachiaria brizanta cv Marandupastures (8.2% CP and 68.5% NDF). At calving, cow-calf pairs were commingled and grazed on the same pasture until weaning. Least squares means for all data were computed using PROC MIXED procedures of SAS. Cow BW and body condition score did not differ at any time point during the study (P≥0.25); however, cows that were supplemented with protein gained more BW (P=0.03) and body condition (P=0.05) during gestation. As a result, pregnancy rate in the subsequent breeding season tended (P=0.10) to be greater for cows supplemented with protein. On the other hand, BW gain during lactation was greater for cows from the control group (P=0.05). Calves from cows supplemented with protein had greater birth BW compared to calves from cows not supplemented (P=0.05). Calf BW at 119 d or at weaning did not differ, nor did calf BW gain from birth to weaning (P≥0.77). In conclusion, supplementation of pregnant Nellore cows with protein during the dry season improves calf birth BW, cow BW gain and body condition during gestation, and can help cows recover from calving sooner.

Table 1. Performance of cow and calf until weaning

Item	Control	Supple	SE	P
Cow weight, kg
Day 0	390.2	384.6	9.03	0.69
Pre-calving	468.7	479.9	8.29	0.34
Post-calving	424.1	436.6	8.30	0.28
Weaning	479.0	465.6	15.53	0.54
Weight gain - gestation	79.2	95.3	5.27	0.03
Weight gain - lactation	59.1	26.4	11.78	0.05
Day 0 BCS	5.23	5.02	0.12	0.25
Pre-calving BCS	5.24	5.39	0.12	0.36
Change in BCS	0.01	0.36	0.13	0.04
Pregnancy rate %	62.1	78.6	-	0.09
Calf weight
Birth	33.7	35.8	0.78	0.05
Weaning	205.5	207.3	4.42	0.77