Abstract #M224
Section: Physiology and Endocrinology
Session: Physiology and Endocrinology: Effects of nutrition and metabolism on ruminant reproduction
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Gatlin Ballroom
Session: Physiology and Endocrinology: Effects of nutrition and metabolism on ruminant reproduction
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Gatlin Ballroom
# M224
Effect of prepartum dam supplementation, creep-feeding and post-weaning diet on age at puberty in Nellore heifers.
Marcos V. C. Ferraz Junior*1, Delci D. Nepomuceno2,1, Marcos V. Biehl2, Alexandre V. Pires2,1, Marcelo H. Santos1, Renan G. Silva1, Vinicius N. Gouvea1, Jose R. S. Gonçalves3, Thiago S. Andrade1, Michael L. Day4, 1University of São Paulo, Pirassununga, São Paulo, Brazil, 2University of São Paulo, Piracicaba, São Paulo, Brazil, 3Experimental Station Hildegard Georgina Von Pritzelwitz, Londrina, Paraná, Brazil, 4The Ohio State University, Columbus, OH.
Key Words: puberty, Nellore, supplemental management
Effect of prepartum dam supplementation, creep-feeding and post-weaning diet on age at puberty in Nellore heifers.
Marcos V. C. Ferraz Junior*1, Delci D. Nepomuceno2,1, Marcos V. Biehl2, Alexandre V. Pires2,1, Marcelo H. Santos1, Renan G. Silva1, Vinicius N. Gouvea1, Jose R. S. Gonçalves3, Thiago S. Andrade1, Michael L. Day4, 1University of São Paulo, Pirassununga, São Paulo, Brazil, 2University of São Paulo, Piracicaba, São Paulo, Brazil, 3Experimental Station Hildegard Georgina Von Pritzelwitz, Londrina, Paraná, Brazil, 4The Ohio State University, Columbus, OH.
The objective of this study was to evaluate the effect of various nutritional strategies on age at puberty in Nellore heifers. Nellore cows (n = 237 / BW 432 ± 50 kg / BCS 2.85 ± 0.4; 1 to 5 scale) were used in randomized design with a 2 × 2 x 2 factorial arrangement of treatments. Factors were as follows: factor 1 = prepartum supplementation with protein (PPS; n = 122; 0.5 kg soybean meal/cow daily) during the last trimester of gestation or no supplementation (NPPS; n = 115); factor 2 = provision of creep-feed to calves for 95 d before weaning (CF; n = 117) or no creep-feeding (NCF; n = 120; 22% CP and 72% TDN); and factor 3 = fed post-weaning from 7 to 14 mo of age in a feedlot (PWF; n = 117; 15% CP and 56% TDN) or no feedlot (NPWF; n = 120; Brachiaria pasture). After 14 mo of age, heifers were maintained in Brachiaria ssp. pastures. Heifers were weighed and reproductive status assessed by ovarian US (detection of presence of CL) monthly from 12 to 30 mo old. The proportion of heifers that had attained puberty by 14, 18, 26 and 30 mo of age, and BW at puberty were assessed using PROC MIXED and GLIMMIX. At weaning (220.1 ± 2.0), cow supplementation did not affect BW of heifer calves (168.2 ± 0.4 vs. 170.5 ± 0.5 kg for PPS and NPPS cows, respectively), but BW at weaning were greater (P = 0.01) in the CF (172.7 ± 1.4) than NCF (165.8 ± 1.4 kg) treatment. At the end of the post weaning period (Factor 3) BW were greater (P < 0.01) in the PWF (234.1 ± 2.2) than NPWF (187.2 ± 2.1) treatment and this difference was maintained through 18 mo of age. Proportions of heifers that attained puberty at 14 (7.1%), 18 (22.3%), 26 (70.0%) and 30 (93.2%) mo of age were not influenced by cow supplementation or creep feed. However, the post-weaning feedlot treatment (PWF) increased the proportion of heifers that reached puberty at 14 (13.7 vs. 0.9%; P < 0.01) and 18 (31.7 vs. 13.3%; P < 0.01) mo of age and tended (P = 0.10) to anticipate puberty at 26 mo of age (73.8 vs. 66.1%; PWS and NPWS, respectively). In conclusion, enhanced nutrition during the post weaning period increased the proportion of heifers that reached puberty between 14 and 26 mo of age and is an effective method to anticipate puberty.
Key Words: puberty, Nellore, supplemental management
