TY - JOUR AB - <p><span style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">The objective of this study was to examine the effects of a Zn-methionine complex in diet on milk yield, milk component yields, SCC, and milk Zn concentration of Holstein cows around peak lactation. After matching for parity and days in milk (DIM), 12 lactating Holstein cows (67 ± 2.5 DIM; 1385 ± 43 kg BW) were assigned to one of two dietary treatments: 1) control (<b style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">CTL</b>, n = 6), a TMR diet with 74 mg/kg added Zn in the form of zinc sulfate, n = 6) or 2) CTL supplemented with Zn-methionine complex (<b style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">Zn-Met</b>, n =6) providing additional 20 mg of Zn/kg (512 mg/head/d). Dry matter intake (<b style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">DMI</b>) was lower by 0.8 kg/d for Zn-Met than CTL throughout the study (<i style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">P</i> =0.05). Milk yield of Zn-Met decreased compared to CTL (40 vs 42 kg/d, <i style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">P</i> = 0.01) during the first 35 d but had similar milk yield during the last 35 d of the study. Milk protein and fat percentages, and fat yield were not different between treatments. Milk protein yield was similar between treatments during the first 35 d but tended to increase for Zn-Met (1.41 vs. 1.33 kg/d, <i style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">P</i>= 0.10) during rest of the study. Cows receiving Zn-methionine complex tended to have lower SCC (126 vs 328 ×10<sup style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">3</sup> cells/mL, <i style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">P</i> = 0.07) and greater concentration of Zn (4.48 vs 4.06 ppm, <i style="font-size:10.0pt;line-height:107%;font-family:&quot;Times New Roman&quot;,serif;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-US;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">P</i> = 0.05) in milk throughout the study.&nbsp; Overall, the present Zn-methionine complex tended to improve milk protein yield and SCC more prominently as feeding progressed. However, it decreased DMI suggesting a negative impact on palatability of the diet.</span></p> AU - Ranga Appuhamy, Maria Jose Oconitrillo, Janaka Wickramasinghe, Nadiia Stepanchenko, Cori Siberski, James E. Koltes DA - 2021/3// DO - 10.31274/air.11933 IS - 1 VL - 17 PB - Iowa State University Digital Press PY - 2021 TI - The Effects of a Zinc-Methionine Supplementation in High Producing Dairy Cows T2 - Iowa State University Animal Industry Report UR - https://www.iastatedigitalpress.com/air/article/id/11933/ ER -