Evaluation of peri-partum supplementation of methionine hydroxy analog on cow-calf performance

The objective was to evaluate the effects of peripartum supplementation of methionine hydroxy analog (MFP; Novus International, Inc. St. Charles, MO) to nulliparous beef females on dam and progeny performance. Yearling Angus heifers (n = 60) were blocked by expected parturition date, stratified by body weight (BW) and body condition score (BCS), and randomized to 1 of 15 pens (4 females/pen). Pens were randomly assigned to 1 of 3 dietary treatments; a basal diet supplemented with either 1) 0 g ïÿý animal-1 ïÿý d-1 of MFP (M0); 2) 15 g ïÿý animal-1 ïÿý d-1 of MFP (M15); or 3) 30 g ïÿý animal-1 ïÿý d-1 of MFP (M30). The basal diet consisted of ground hay, silage, and distillers grains and was formulated to maintain similar BW across treatments. Diets were fed from 45 ïÿý 13 d prior to average parturition date through 81 ïÿý 13 d postpartum (DPP) when all cow-calf pairs were commingled and managed as a singular group on pasture until weaning (199 ïÿý 13 DPP). Dam BW, BCS, and blood samples were taken at six predetermined timepoints throughout the study. Progeny data collection occurred at birth, two intermediate timepoints, and at weaning. Milk samples were collected for component analysis at 7 ïÿý 2 DPP and at 55 ïÿý 5 DPP. Serial blood samples were analyzed to establish resumption of postpartum cyclicity, and ultrasonography was performed at 55 ïÿý 5 DPP to evaluate ovarian function. Cows were artificially inseminated at 82 ïÿý 13 DPP and turned out with bulls for a 55-d breeding season. Continuous and categorical data were analyzed using the MIXED and GLIMMIX procedures of SAS, respectively. Dam BW and BCS were not different (P ≥ 0.24) across treatments throughout the study. Week 1 milk fat increased (P = 0.05) linearly and total solids tended to increase (P = 0.07) as MFP increased in the diet; however, no other milk components differed (P ≥ 0.16) as a result of treatment. No differences (P ≥ 0.16) in dam reproductive parameters or progeny performance were observed. At breeding (the conclusion of dietary treatments) blood urea nitrogen (BUN) concentrations linearly decreased (P = 0.03) with increased supplementation of MFP and non-esterified fatty acids (NEFA) concentrations were lower (P = 0.04) in MFP-supplemented dams compared to dams receiving no MFP. Concentrations of BUN and NEFA were not different (P ≥ 0.22) at any other remaining timepoint nor were glucose and methionine (Met) concentrations different (P ≥ 0.15) at any point. These data indicate that supplementation of MFP in late gestation and early lactation may increase milk fat components immediately after calving but does not translate to significant changes in progeny growth or dam reproductive performance

Nutrient partitioning in pregnant and lactating beef females

We investigated the impacts of late gestational nutrient restriction in first-parity beef females on prenatal and postnatal nutrient availability to the offspring. During late gestation, nutrient restricted dams lost maternal body weight and body condition and had less circulating metabolites than adequately-fed dams. Despite contralateral placental growth being less in nutrient restricted dams, total uterine blood flow and total placental mass were maintained, and cotyledonary expression of nutrient transporters and an angiogenic factor were upregulated, which collectively allowed for calf size at birth to be spared. Nutrient restricted dams produced less colostrum, yet it was generally more concentrated so that total colostral nutrients and immunoglobulins, except lactose, were similar. When fed to meet nutrient requirements during lactation, previously nutrient restricted dams recovered quickly metabolically and experienced compensatory growth, but still had less body condition at weaning than adequately-fed dams. Nutrient restricted dams had decreased mammary blood flow, lower milk yield, reduced milk protein concentration, and less total milk nutrients available for their calves. Calves born to nutrient restricted dams diverged in body weight by day 42 of age and weighed less at weaning, but metabolic status pre-weaning was not greatly altered. In summary, first-parity beef females experiencing late gestational nutrient restriction prioritized partitioning nutrients to fetal growth and colostrum production over maternal growth. After parturition, previously nutrient restricted dams fed adequately during lactation partitioned nutrients to maternal growth and basal energy reserves over milk production.Includes bibliographical references

Evaluation of peri-partum supplementation of methionine hydroxy analog on cow-calf performance

The objective was to evaluate the effects of peripartum supplementation of methionine hydroxy analog (MFP; Novus International, Inc. St. Charles, MO) to nulliparous beef females on dam and progeny performance. Yearling Angus heifers (n = 60) were blocked by expected parturition date, stratified by body weight (BW) and body condition score (BCS), and randomized to 1 of 15 pens (4 females/pen). Pens were randomly assigned to 1 of 3 dietary treatments; a basal diet supplemented with either 1) 0 g à ¯à ¿à ½ animal-1 à ¯à ¿à ½ d-1 of MFP (M0); 2) 15 g à ¯à ¿à ½ animal-1 à ¯à ¿à ½ d-1 of MFP (M15); or 3) 30 g à ¯à ¿à ½ animal-1 à ¯à ¿à ½ d-1 of MFP (M30). The basal diet consisted of ground hay, silage, and distillers grains and was formulated to maintain similar BW across treatments. Diets were fed from 45 à ¯à ¿à ½ 13 d prior to average parturition date through 81 à ¯à ¿à ½ 13 d postpartum (DPP) when all cow-calf pairs were commingled and managed as a singular group on pasture until weaning (199 à ¯à ¿à ½ 13 DPP). Dam BW, BCS, and blood samples were taken at six predetermined timepoints throughout the study. Progeny data collection occurred at birth, two intermediate timepoints, and at weaning. Milk samples were collected for component analysis at 7 à ¯à ¿à ½ 2 DPP and at 55 à ¯à ¿à ½ 5 DPP. Serial blood samples were analyzed to establish resumption of postpartum cyclicity, and ultrasonography was performed at 55 à ¯à ¿à ½ 5 DPP to evaluate ovarian function. Cows were artificially inseminated at 82 à ¯à ¿à ½ 13 DPP and turned out with bulls for a 55-d breeding season. Continuous and categorical data were analyzed using the MIXED and GLIMMIX procedures of SAS, respectively. Dam BW and BCS were not different (P ≥ 0.24) across treatments throughout the study. Week 1 milk fat increased (P = 0.05) linearly and total solids tended to increase (P = 0.07) as MFP increased in the diet; however, no other milk components differed (P ≥ 0.16) as a result of treatment. No differences (P ≥ 0.16) in dam reproductive parameters or progeny performance were observed. At breeding (the conclusion of dietary treatments) blood urea nitrogen (BUN) concentrations linearly decreased (P = 0.03) with increased supplementation of MFP and non-esterified fatty acids (NEFA) concentrations were lower (P = 0.04) in MFP-supplemented dams compared to dams receiving no MFP. Concentrations of BUN and NEFA were not different (P ≥ 0.22) at any other remaining timepoint nor were glucose and methionine (Met) concentrations different (P ≥ 0.15) at any point. These data indicate that supplementation of MFP in late gestation and early lactation may increase milk fat components immediately after calving but does not translate to significant changes in progeny growth or dam reproductive performance.</p

Evaluation of peripartum supplementation of methionine hydroxy analogue on beef cow–calf performance

The objective was to evaluate the effects of peripartum supplementation of a methionine hydroxy analogue (MHA) to primiparous, spring-calving beef females on dam and progeny performance. Angus heifers (n = 60) were blocked by expected parturition date, stratified by body weight (BW) and body condition score (BCS), and randomized to 1 of 15 pens. Pens were randomly assigned to 1 of 3 dietary treatments: a basal diet supplemented with 0 (M0), 15 (M15), or 30 (M30) g/animal/d of MHA (provided as MFP feed supplement, Novus International Inc., St. Charles, MO). Diets were fed from 45 ± 13 (SD) d pre-calving through 81 ± 13 d postpartum (DPP), after which all cow–calf pairs were managed as a single group on pasture until weaning (199 ± 13 DPP). Dam BW, BCS, and blood samples were taken at 6 predetermined timepoints. Progeny data were collected at birth, 2 intermediate timepoints, and at weaning. Milk samples were collected for composition analysis at 7 ± 2 DPP and at 55 ± 5 DPP. Serial progesterone samples were analyzed to establish resumption of cyclicity, and ultrasonography was performed at 55 ± 5 DPP to evaluate ovarian function. Cows were bred via artificial insemination at 82 ± 13 DPP and subsequently exposed to bulls for a 55-d breeding season. Pen was the experimental unit, and preplanned orthogonal contrasts were tested (linear effect and M0 vs. M15 + M30). Dam BW and BCS were not affected by treatment (P ≥ 0.29) throughout the study. Week 1 milk fat concentration increased linearly (P = 0.05) and total solids tended to increase linearly (P = 0.07) as MHA increased; however, no other milk components were affected (P ≥ 0.16). Treatment did not affect (P ≥ 0.16) dam reproductive parameters or progeny growth from birth until weaning. Post-calving, circulating methionine equivalents tended to linearly increase (P = 0.10) with increasing MHA supplementation. At breeding, plasma urea N linearly decreased (P = 0.03) with increased supplementation of MHA, and plasma non-esterified fatty acids were less (P = 0.04) in MHA-supplemented dams compared with dams receiving no MHA. Maternal circulating glucose, glutathione peroxidase, and thiobarbituric acid-reactive substances were not affected (P ≥ 0.15) by treatment at any point. These data indicate that peripartum supplementation of MHA may increase milk fat composition shortly after calving, but MHA supplementation did not improve progeny growth or dam reproductive performance in the current study.This article is published as Colby A Redifer and others, Evaluation of peripartum supplementation of methionine hydroxy analogue on beef cow–calf performance, Translational Animal Science (2023): txad046, https://doi.org/10.1093/tas/txad046. Posted with permission.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited

Iowa Cow-calf Production - Exploring Different Management Systems

This project was designed to identify costs, environmental impacts, and best practices from Iowa cow-calf operations based on three production systems. Twenty-eight producers from across the state partnered with the Iowa Beef Center at Iowa State University to assess emerging beef cow management technologies, detail benchmarks, and summarize production and environmental data. Ultimately, the goal of the project was to develop decision aids and educational tools to assist Iowa cow-calf producers across all production systems and improve sustainability of the cow-calf segment in Iowa

Iowa Cow-calf Production - Exploring Different Management Systems

This project was designed to identify costs, environmental impacts, and best practices from Iowa cow-calf operations based on three production systems. Twenty-eight producers from across the state partnered with the Iowa Beef Center at Iowa State University to assess emerging beef cow management technologies, detail benchmarks, and summarize production and environmental data. Ultimately, the goal of the project was to develop decision aids and educational tools to assist Iowa cow-calf producers across all production systems and improve sustainability of the cow-calf segment in Iowa.</p