Maternal supply of methionine during late-pregnancy enhances rate of Holstein calf development in utero and postnatal growth to a greater extent than colostrum source

Background: Pregnancy and early life are critical periods of plasticity during which the fetus and neonate may be influenced by environmental factors such as nutrition.Maternal methionine(Met) supply in non-ruminants during pregnancy can affect offspring development and growth.Thus,the objective of this study was to investigate if increasing Met supply during late-pregnancy affects developmental parameters of the calf at birth and if either maternal Met or colostrum from Met-fed cows alters calf growth.Calves born to Holstein cows individually-fed a basal control [CON; 1.47 Mcal/kg dry matter(DM) and 15.3% crude protein] diet with no added Met or CON plus ethylcellulose rumen-protected Met(MET; Mepron? at 0.09% of diet DM; Evonik Nutrition & Care GmbH,Germany)during the last 28 ± 2 d of pregnancy were used.A total of 39 calves were in CON(n = 22 bulls,17 heifers) and 42 in MET(n = 20 bulls,22 heifers).At birth,calves were randomly allocated considering dam treatment and colostrum as fol ows: 1) calves from CON cows and colostrum from CON cows(n = 21); 2) calves from CON cows and colostrum from MET cows(n = 18); 3) calves from MET cows and colostrum from MET cows(n = 22); and 4) calves from MET cows and colostrum from CON cows(n = 20).Al calves were housed,managed,and fed individual y during the first 9 wk of life.Results: Despite greater daily DM intake pre-partum in cows fed MET(15.7 vs.14.4 ± 0.12 kg/d,P < 0.05),colostrum quality and quantity were not affected by maternal diet.At birth,MET calves had greater(P ≤ 0.05) body weight(BW,44.1 vs.42.1 ± 0.70 kg),hip height(HH,81.3 vs.79.6 ± 0.53 cm) and wither height(WH,77.8 vs.75.9 ± 0.47 cm).In contrast,concentrations of His,Lys,and Asn in plasma were lower(P ≤ 0.05) in MET calves.Regardless of colostrum source,the greater BW,HH,and WH in MET calves at birth persisted through 9 wk of age resulting in average responses of + 3.1 kg BW,+ 1.9 cm HH,and + 1.8 cm WH compared with CON.Average daily gain during the 9 wk was(P < 0.05) 0.72 ± 0.02 kg/d in MET compared with 0.67 ± 0.02 kg/d in CON calves.Respiratory scores were normal and did not differ(P > 0.05) due to maternal Met supply or colostrum source.However,fecal scores tended to be lower(P ≤ 0.10) in MET calves regardless of colostrum source.Conclusions: Increasing the maternal supply of MET during late-pregnancy enhanced growth in utero as wel as during the pre-weaning and early post-weaning periods.Although the ～ 1 kg/d greater DM intake during the last 2–3 wk prior to parturition could explain a portion of the 2 kg extra body mass of MET calves at birth,other mechanisms potential y encompassing nutrient assimilation efficiency likely played a role.Assessing the exact mechanisms sensitive to supply of Met or total amino acid supply during the latter stages of growth in utero merit further research.