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

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

Clements, Alyssa Robin ; Shike ; Daniel W.

关键词: cow-calf;    fall-calving;    late gestation supplementation;    methionine hydroxy analog;    milk production;    reproduction;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/89081/CLEMENTS-THESIS-2015.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Mature Simmental × Angus cows (214 cows; 635 ± 7.4 kg) were utilized to determine theeffects 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, coolseasongrazing 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). Pastureswere randomly allotted to one of two treatments: control (0.45 kg·cow-1·d-1 of wheat mid-basedpellets, n = 6) or supplement including MFP (0.45 kg·cow-1·d-1 of wheat mid based pelletsincluding 10 g MFP, n = 6). Treatments were fed 23 ± 1 d prior to calving through 72 ± 1 dpostpartum. Cows were weighed post-calving, at supplementation end, AI breeding, AIpregnancy check, and the end of trial (192 and 193 ± 1 d postpartum). At 74 d postpartum, asubset of cow-calf pairs were used in a weigh-suckle-weigh to determine milk production andmilk samples were taken to determine milk composition (n = 45·treatment-1). A serum P4 assaywas utilized to determine cow cyclicity. After supplementation, all cow-calf pairs were managedas a common group until weaning (191 ± 1 d of age). Cows were bred via AI at 97 ± 1 dpostpartum and clean-up bulls were turned out 11 d post-AI for a 55 d breeding season. Cow andcalf performance were analyzed using MIXED procedure in SAS (SAS Inst. Inc., Cary, NC) andcow reproductive performance and calf health were analyzed using GLIMMIX procedure. CowBW and BCS were not different (P ≥ 0.10) at any time points between treatments. There was notreatment 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.