Effects of supplementing methionine hydroxy analog on beef cow performance, milk production, and reproduction

Mature Simmental × Angus cows (214 cows; 635 ± 7.4 kg) were utilized to determine the effects of late gestation and early postpartum supplementation of methionine hydroxy analog (MFP; Novus International, Inc., St. Charles, MO, USA) on cow BW, BCS, milk production, milk composition, reproduction, and calf performance until weaning in a fall-calving, coolseason grazing system. Cows were confirmed pregnant prior to experiment, stratified by BW, cow age and AI sire, and assigned to one of twelve pastures (17 or 18 cows·pasture-1). Pastures were randomly allotted to one of two treatments: control (0.45 kg·cow-1·d-1 of wheat mid-based pellets, n = 6) or supplement including MFP (0.45 kg·cow-1·d-1 of wheat mid based pellets including 10 g MFP, n = 6). Treatments were fed 23 ± 1 d prior to calving through 72 ± 1 d postpartum. Cows were weighed post-calving, at supplementation end, AI breeding, AI pregnancy check, and the end of trial (192 and 193 ± 1 d postpartum). At 74 d postpartum, a subset of cow-calf pairs were used in a weigh-suckle-weigh to determine milk production and milk samples were taken to determine milk composition (n = 45·treatment-1). A serum P4 assay was utilized to determine cow cyclicity. After supplementation, all cow-calf pairs were managed as a common group until weaning (191 ± 1 d of age). Cows were bred via AI at 97 ± 1 d postpartum and clean-up bulls were turned out 11 d post-AI for a 55 d breeding season. Cow and calf performance were analyzed using MIXED procedure in SAS (SAS Inst. Inc., Cary, NC) and cow reproductive performance and calf health were analyzed using GLIMMIX procedure. Cow BW and BCS were not different (P ≥ 0.10) at any time points between treatments. There was no treatment effect (P ≥ 0.62) on calf birth BW, calf weaning BW (191 ± 1 d of age), or calf ADG. Calculated 24 h milk production did not differ (P = 0.76) nor did milk composition or component production (P ≥ 0.21). There was no difference (P = 0.69) in percentage of cows cycling between treatments. Cow AI conception rate and overall pregnancy rate were not different (P ≥ 0.50) between treatments. No differences (P ≥ 0.61) in calf health were observed. Supplementation of MFP during late gestation through estimated peak lactation did not affect cow performance, cow milk production, or calf performance when fall-calving cows grazed cool-season forages.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Animal Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2016

Author dc:creator

• Clements, Alyssa Robin

Contributors dc:contributor

• Shike, Daniel W.

• cow-calf
• fall-calving
• late gestation supplementation
• methionine hydroxy analog
• milk production
• reproduction

Statement dc:rights

• Copyright 2015 Alyssa Clements

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/89081

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/89081