Jenks, Monica Lynn (2016-01). Effects of Saccharomyces cerevisiae Supplementation During Receiving and Finishing Periods on Growth, Efficiency, Behavioral, and Health Responses in Beef Cattle. Master's Thesis.
Objectives of Study I were to evaluate the effects of live yeast (LY; Saccharomyces cerevisiae boulardii strain I-1079; 0.35 x 10^9 cfu/g ProTernative(TM)) supplementation during the receiving period on growth efficiency, feeding behavior, activity and vaginal temperature in 72 newly weaned beef heifers (initial BW of 203 +- 22 kg). Heifers were shipped stressed before being allotted to 1 of 4 pens each equipped with 3 GrowSafe feed bunks, and assigned to 1 of 2 treatments (n = 36) consisting of standard receiving diet (ME 2.36 Mcal/kg, CP 16.5% DM) without LY, and control diet containing LY (5 g ProTernative/kg diet; Lallemand Animal Nutrition). Temperature sensors (iButton(TM)) were placed intra-vaginally to record temperature, and accelerometer devices (HOBO(TM) ) attached (hind leg) to measure physical activity for the first 14 d (n = 18). LY treatment did not affect morbidity rate (10.4%), vaginal temperature (39.2 +- 0.2 ?C), or frequency (16.6 +- 2.2 events/d) and duration (46 +- 5 min/event) of standing bouts. ADG tended (P ? 0.1) to be greater for LY heifers during the first 28 d (0.625 vs 0.432 +- 0.08 kg/d), but was not affected by LY treatment during the 56-d study. LY heifers consumed more (P < 0.05) meals (16.8 vs 14.6 vs. +- 1.1 events/d) that were shorter (P = 0.08) in length (12.8 vs 14.9 +- 1.2 min/event) and smaller (P < 0.05) in size (0.48 vs 0.55 +- 0.04 kg/event) compared to control heifers. Moreover, heterogeneities of DMI (SD = 0.59 vs 0.92 kg/d) and RFI (SD = 0.48 vs 0.73 kg/d) were less (P < 0.05) in LY than control heifers. Objectives of Study II were to evaluate the effects of LY (Saccharomyces cerevisiae strain CNCM I-1077; 0.35 x 109 cfu/g Levucell(TM)) supplementation during the receiving period on growth efficiency, feeding behavior, activity and ruminal temperature in 72 finishing beef steers (initial BW of 435 +- 27 kg). Steers were allotted to 1 of 6 pens each equipped with GrowSafe feed bunks, and assigned to 1 of 3 treatments (n = 24) consisting of standard finishing diet (ME 1.84 Mcal/kg, CP 12.7% DM) without LY, and control diet containing LY (4.5 g Levucell SC/kg diet; Lallemand Animal Nutrition) or control diet containing LY + extract (4.5 g Levucell SC + extract/kg diet; Lallemand Animal Nutrition). Ruminal temperature sensors (BellaAg) were placed, and accelerometer devices (HOBO(TM) ) attached (hind leg) to measure physical activity 14 d intervals during the 70 d trial (n = 30). LY treatment did not affect ruminal temperature (39.7 +- 0.1 ?C), or frequency (13.9 +- 5.94 events/d) and duration (58.6 +- 1.47 min/event) of standing bouts. LY treatment did not affect performance, growth, or carcass traits in finishing steers. LY steers consumed meals that were longer (P = 0.04) in length (19.81 vs 15.4 and 17 +- 1.2 min/event) and at a slower (P < 0.01) eating rate (79.9 vs 102.1 and 98.8 +- 4.37 g/min) compared to control and LY + extract steers. Supplementation with LY may have favorably affected meal patterns of newly weaned beef heifers and in finishing steers. LY treatment did not affect growth efficiency, health status, internal temperature, or physical activity in newly weaned heifers or in finishing steers.