Effect of zinc source (zinc oxide vs zinc proteinate) and level on performance, carcass characteristics, and immune response of growing and finishing steers

Abstract

Sixty Angus and Angus x Hereford steers (246 kg initial BW) were used to determine the effects of Zn level and source on performance, immune response, and carcass characteristics of growing and finishing steers. Treatments consisted of 1) control (no supplemental Zn), 2) ZnO, 3) Zn proteinate-A (ZnProt-A, 10% Zn), and 4) ZnProt-B (15% Zn). Treatments 2, 3, and 4 supplied 25 mg of supplemental Zn/kg diet. Steers were individually fed a corn silage-based diet during the 84-d growing phase and a high corn diet during the finishing phase. Cell-mediated and humoral immune response measurements were obtained between d 67 and 74 of the growing phase. Equal number of steers per treatment were slaughtered after receiving the finishing diets for 84 or 112 d. Performance and carcass measurements were similar in steers fed the two ZnProt sources. Zinc supplementation, regardless of source, increased (P < 0.05) ADG during the growing phase. In the finishing phase, ADG (P = 0.10) and gain/feed (P = 0.07) tended to be higher for steers fed ZnProt compared with those supplemented with ZnO. Gain and feed efficiency were similar for control and ZnO-supplemented steers during the finishing phase. Steers fed ZnProt had heavier (P < 0.05) hot carcass weights and slightly higher (P < 0.05) dressing percentages than those in the control or ZnO treatments. Quality grade, yield grade, marbling, and backfat were increased by Zn supplementation, but were not affected by Zn source. In vitro response of lymphocytes to mitogen stimulation and in vivo swelling response following intradermal injection of phytohemagglutinin were not affected by Zn level or source. Humoral immune response following vaccination with infectious bovine rhinotracheitis also was not affected by treatment. Soluble concentrations of Zn in ruminal fluid were higher (P < 0.05) in steers fed ZnProt compared to ZnO steers. Results indicate that ZnProt may improve performance of finishing steers above that observed with inorganic Zn supplementation.

Top-dressing of the different feed additives is effective to prevent lameness and to increase feedlot cattle performance during a short-term period

“…Notice that in the current study the ZnSO 4 was supplied as a topdressing, and this method can, in part, guarantee the consumption of sufficient amounts of Zn. Likewise, Spears and Kegley (2002) reported increased ADG in growing steers when a diet with 33 mg Zn/kg DM was supplemented with 25 mg Zn/kg DM inorganic sources. On the other hand, Froetschel et al (1990) showed that high concentration of Zn affects the number of protozoa, and Zn supplementation decreases ruminal digestion of dietary amino acid, thereby increases CP's reach to small intestine.…”

Effects of zilpaterol hydrochloride and zinc methionine on growth performance and carcass characteristics of beef bulls

“…Carcass characteristics were not affected (P 0.05) by ZM, but interactions (Table 3) indicated that bulls fed ZH plus ZM had the lowest (P B0.01) backfat thickness and IMF. Previous studies evaluated ZM effects on IMF thickness and backfat thickness in steers, but not the interaction ZH )ZM (Greene et al 1988;Malcom-Callis et al 2000;Spears and Kegley 2002). Zinc has a lipogenic effect (Tang and Shay 2001;Park et al 2003;Vardatsikos et al 2013) caused by inhibition of lipolytic substances (May and Contoreggi 1982;Oh and Choi 2004) and by changing expression of transcript factors and genes responsible for triglycerides and lipoproteins synthesis (Oh and Choi 2004).…”

“…Zinc has been related to several mechanisms, such as being a lipogenic compound (Malcom-Callis et al 2000;Oh and Choi 2004), stimulating lipogenesis and inhibiting lipolysis (Coulston and Dandona 1980;May and Contoreggi 1982) through insulin signaling (May and Contoreggi 1982;Saltiel and Kahn 2001;Eom et al 2001;Park et al 2003). Adding Zn to diets favors the deposition of fat and the degree of marbling in meat of feedlot cattle (Greene et al 1988;Spears and Kegley 2002). Adding organic Zn produces better results than inorganic sources (MalcomCallis et al 2000;Spears and Kegley 2002;Nunnery et al 2007).…”

“…Adding Zn to diets favors the deposition of fat and the degree of marbling in meat of feedlot cattle (Greene et al 1988;Spears and Kegley 2002). Adding organic Zn produces better results than inorganic sources (MalcomCallis et al 2000;Spears and Kegley 2002;Nunnery et al 2007). The National Research Council (NRC 1996) recommends 30 mg Zn kg…”

Supplementation of diets for Santa Ines sheep with organic and inorganic zinc sources

“…Among the most common forms of supplementation is the ionic (chlorides, sulfates, oxides, hydroxides, carbonates). However, some of these sources of minerals, especially trace elements, have low absorption in the animal organism or low bioavailability (Spears, 1996).…”