M.A. Froetschel

Reproductive Performance of Beef Heifers Supplemented with Corn Gluten Feed and Rumen-Protected Fat before Breeding

ABSTRACT A rumen-protected fat (Megalac) and corn gluten feed supplement (RPCG) was fed to heifers to determine reproductive effects. Angus (n = 24) and Polled Hereford (n = 17) heifers (initial BW 376.9 ± 29.9; kg average age 14 mo) were randomly assigned 60 d before breeding began to the following treatments: control (n = 20; no supplementation), or RPCG supplement (n = 21; 8% Megalac, 92% corn gluten feed; fed 5 d/wk at 3.45 kg/ heifer daily). Breeding began April 14 using AI (d 1 to 44), and bulls (d 45 to 71). Heifer BW (kg) and ultrasound subcutaneous fat (cm) for control and RPCG, respectively, were as follows: February 11 = 376 and 373, 2.23 and 2.15, SE 6.4 and 0.11; April 11 = 431 and 434, 2.20 and 2.36, SE 6.4 and 0.11; June 18 = 444 and 446, 2.09 and 2.22, SE 3.1 and 0.11; (control vs. RPCG: P > 0.10 for BW and ultrasound subcutaneous fat). Serum cholesterol (mg/dL), high-density lipoprotein (HDL; mg/dL), leptin (ng/mL), on d 60 for control were 139.6, 100.9, and 8.38, respectively, and for RPCG were 162.9, 122.2, and 10.70 (control vs RPCG for cholesterol and HDL, P 0.10).

Influence of Ruminally Undegraded Protein and Zinc Methionine on Milk Production, Hoof Growth and Composition, and Selected Plasma Metabolites of High Producing Dairy Cows

Thirty-six first or later lactation Holstein cows were grouped according to their 305-d mature equivalent milk yield and used in a 240-d 2 × 3 factorial design experiment. Objectives were to determine the effect of supplemental Zn-Met and ruminally undegraded protein (RUP) on milk production, hoof growth and composition, and selected plasma metabolites of high producing dairy cows. During the dry period, cows received rations supplemented with 1) ZnSO4 (DT1) or 2) Zn-Met (DT2). Treatments during lactation were 1) soybean meal (SBM) (LT1), 2) ZnSO4-treated SBM (LT2) (Consolidated Nutrition L. C., Ft. Wayne, IN), and 3) ZnSO4-treated SBM plus supplemental Zn-Met (LT3) (Zinpro Corp., Eden Prairie, MN). All rations were formulated to contain equal amounts of Zn. Cows receiving DT1 had higher 3.5% fat-corrected milk (FCM) and milk fat percentage when compared with those receiving DT2 (P<0.05). Hoof growth was greater during the dry period for cows receiving DT2 (0.22 mm/d) than for those receiving DT1 (0.20 mm/d). The ZnSO4-treated SBM and LT3 had no effect on hoof growth during lactation. Mean hoof CP content was lowest at peak lactation (85.6%) and highest at calving (90.4%). Cows receiving LT3 had the highest hoof Zn content during lactation. Glucose was higher later in lactation and at feeding; whereas, insulin and plasma essential amino acids (AA) were highest at peak lactation. For high producing dairy cows, especially those with hoof problems, supplemental RUP and Zn-Met may provide nutrients needed for hoof growth and increase production by helping maintain hoof health and DMI.

Effect of long-term corn by-product feeding on beef quality, strip loin fatty acid profiles, and shelf life

The objective of this study was to evaluate the meat quality and shelf life of steaks from steers fed dried distillers grains with solubles (DDGS) or dried corn gluten feed (CGF) compared with soybean meal with corn (SBM) as a protein supplement from weaning to slaughter. Angus cross steers (n = 81; BW = 306 ± 26.1 kg) were randomly assigned to pens (n = 9) and fed a stocker diet of corn silage (75% of DM) with DDGS, CGF, or SBM and ground ear corn. After 84 d of stockering, 12 steers (BW = 397 ± 15.3 kg) were randomly selected from each treatment and finished using the same protein supplement at 25% of DM for 100 d. Carcass data were collected (24 h) and the longissimus lumborum was fabricated into steaks at 48 h postmortem. Steaks were assigned to proximate analysis, Warner-Bratzler shear force (7-, 14-, or 21-d aging), and retail display (1, 3, 6, or 9 d). Protein source did not affect carcass yield, quality, or longissimus lumborum composition (P > 0.05). After 7 d of aging, DDGS and CGF steaks were more tender (P < 0.01) than SBM, but were similar (P = 0.30) after 14 and 21 d of aging. Feeding corn by-products did not influence subjective overall color acceptance (P = 0.17) in this study, but acceptance declined over time (P < 0.01). Subjective redness was similar (P > 0.05) among diets except SBM steaks were more red (P < 0.01) than DDGS after 9 d. On d 3 and 6 of retail display, CGF steaks exhibited more discoloration (P < 0.04) than SBM or DDGS steaks. However, after 9 d DDGS steaks were more discolored (P < 0.01) than CGF or SBM. Objective L* was lighter for CGF (P < 0.04) over 9 d of display, and all treatments became darker (P < 0.01) as time increased. Redness (a*) declined (P < 0.01) over time with SBM steaks maintaining more color in the red spectrum than CGF and DDGS after 6 d of display. Protein source did not affect (P > 0.05) the rate of lipid oxidation. Total SFA concentrations were similar (P > 0.05) among treatments; however, total MUFA were less (P < 0.05) and total PUFA concentrations were greater (P < 0.05) in DDGS steaks compared with SBM or CGF steaks. These data show that DDGS or CGF can be fed as a protein supplement at 25% DM from weaning until slaughter while maintaining meat quality when compared with steers fed soybean meal as a protein supplement.

Use of corn gluten feed and dried distillers grains plus solubles as a replacement for soybean meal and corn for supplementation in a corn silage-based stocker system

Corn gluten feed and dried distillers grains plus solubles (DDGS) were evaluated as replacements for soybean meal and ground ear corn when supplemented with corn silage during 2 yr of a beef cattle stockering program. Experiment 1: In YR 1, 104 steers (initial BW = 305 ± 30 kg), and in YR 2, 56 steers and 38 heifers (initial BW = 301 ± 32 kg) were stratified by weight and assigned to 1 of 9 groups. Each group was randomly assigned to 1 of 3 corn silage-based (75% of DM) diets supplemented with: i) corn gluten feed (CGF), ii) DDGS, or iii) soybean meal and ground ear corn (CSBM) at 25% of DM. On d 0, 28, 56, and 84, BW and BCS were recorded. Additionally, ribeye area, 12th rib fat thickness, intramuscular fat, and rump fat thickness were assessed via ultrasound on 9 (YR1) and 4 (YR 2) steers per pen that were randomly assigned as observational units. Average daily gain was greater (P < 0.05) for steers fed DDGS and CSBM compared with CGF (1.08, 1.08, and 0.94 kg/d, respectively). Average DMI (P < 0.05) was less for DDGS compared with CSBM with CGF intermediate (18.1, 18.8, 20.2 g/kg BW, respectively), and the resulting G:F was greatest for DDGS (P = 0.01). Cost per kilogram of BW gain was least for DDGS (P > 0.05). Ultrasound data indicated no differences (P ≥ 0.13) in predicted carcass traits among treatments. Experiment 2: Diets from Exp. 1 were subjected to in vitro digestion for incubation times of 0, 2, 4, 8, 16, 24, 48, and 72 h to estimate DM degradation, gas production kinetics, and CP fractions. The potentially degradable DM fraction was greater (P = 0.01) for CSBM compared with CGF and DDG. Total gas production and rate of gas production was not different among treatments (P > 0.42). Rumen degradable protein was greatest for CSBM and least for DDG (P = 0.001). These data indicate that DDGS can be used to replace soybean meal and corn in silage-based stocker systems to decrease feed costs without compromising animal performance and CGF may decrease animal performance.

Influence of Urea Alone or Combined with Fish Solubles, Fish Meal, or Feather Meal in Liquid Supplement with and Without L-Carnitine on Performance and Ruminal and Metabolic Parameters of Weanling Calves

Using growing calves (n = 368) grazing mature forage in three 84-d experiments, one objective was to compare the effects of feeding molasses-based liquid supplements containing urea (U) alone or combined with fish solubles (FS), fish meal (FM), or feather meal (FE) on performance, and blood metabolites. Another objective was to evaluate the effects on these criteria of adding carnitine to these supplements to provide 1 g·h−1·d−1 L-carnitine. Including FM or FE in the mixture improved (P<0.05) supplement consumption in two experiments and improved growth rate in all experiments. Carnitine improved the growth rate when U was the only protein source, but reduced growth rate when FM was included in the liquid supplement (P<0.05). During the growth phase, plasma ammonia N (PAN) was higher (P<0.05) when U was the only protein source as compared with FM or FE. Carnitine did not influence these metabolic parameters. During the metabolic phase of each experiment, calves similar to those used in the growth phase were dosed via stomach tube with 3 g liquid supplement/kg BW. Ruminal and blood samples were collected at 0, 0.5, 1, 2, and 4 h after dosing. Ruminal ammonia N, PAN, and plasma urea N (PUN) concentrations were higher (P<0.05) when calves were dosed with U or FS supplement than when dosed with FM or FE supplements. Calves dosed with liquid supplement containing carnitine had lower (P<0.05) concentrations of ruminal ammonia N and PAN. Carnitine reduced (P<0.05) PUN in one experiment and increased (P<0.05) PUN in another. Branched-chain volatile fatty acids were increased (P<0.05) by dosing with FS or FM supplements. Including ruminally undegradable protein sources (FM or FE) in liquid supplement improved intake and performance and was related to reduced ruminal ammonia N, PAN, and PUN. Carnitine fed in liquid supplement also reduced ruminal ammonia N and PAN concentrations.

Influence of L-Carnitine on Performance and Ruminal and Blood Metabolites of Grazing Calves and Finishing Lambs12

Three experiments were conducted to study the influence of level and type of L-carnitine (LC) on performance and rumiasl and plasma metabolites of weanling calves and finishing lambs. Weanling calves (84) grazing dormant dallisgrass-bermudagrass forage were fed a 20% CP supplement to provide 0, 0.5, 1, or 2 g of ruminally unprotected (RUP) LC per calf daily in Exp. 1. There was a linear increase (P=0.01) and cubic response (P=0.03) to RUP LC in growth rate and quadratic changes (P=0.01) in plasma ammonia N (PAN) and plasma urea N (PUN). In Exp. 2, 32 lambs were individually fed 14% CP diets containing 0, 50, 100, or 200 ppm RUP LC or ruminally protected (RP) LC in a 2 × 4 arrangement of treatments. Lambs gained BW faster (P=0.03) and more efficiently (P=0.07) as the LC level increased to 100 ppm and then declined at 200 ppm (quadratic response). Longissimus area decreased (P=0.03), and fat cover tended (P=0.15) to decline, at 50 and 100 ppm LC and increased at 200 ppm (linear and quadratic response). Ruminal ammonia N levels were reduced at 50 ppm LC but increased at greater LC levels (linear, quadratic, and cubic response, P=0.02). Plasma carnitine concentrations increased (P=0.01) as the dietary level of LC increased. Protected LC was more effective than RUP LC in increasing growth rate (P=0.06) and reducing PAN (P=0.1). In Exp. 3, 16 wether and 16 ewe lambs were individually fed corn-based or soybean hull-based diets with 0 or 100 ppm RP LC in a 2 × 2 arrangement of treatments. Lambs fed RP LC gained BW faster and more efficiently (P=0.04) than lambs that were not fed LC. Lambs fed corn-based and soybean hull-based diets responded similarly to RP LC; however, performance was greater (P=0.03) for lambs fed the corn-based diet. Gender of lambs did not influence the response to diet or RP LC. Supplementing the diet with 100 ppm RP LC reduced (P=0.01) ruminal pH and ammonia N. Plasma carnitine concentrations were increased (P=0.01), and PAN was decreased (P=0.04) by feeding 100 ppm RP LC. Ruminnaly unprotected and RP LC were effective in improving growth rate in ruminants; the latter appeared to be more effective in finishing lambs. L-carnitine reduced ruminal ammonia N and plasma glucose and, in some cases, PAN and PUN.

Effects of feeding extruded full-fat cottonseed pellets in place of tallow as a fat source for finishing heifers on feedlot performance, carcass characteristics, sensory traits, display color, and fatty acid profiles.

The objective of this study was to examine the effects of supplemental feeding of full-fat extruded cottonseed pellets (FFECS) compared with tallow on carcass characteristics, sensory traits, retail display color, and fatty acid profiles, especially CLA isomers in finishing heifers. Twenty-one Angus heifers (450 ± 5 kg) were assigned randomly to 1 of 3 experimental diets: 1) 100% supplemental fat from tallow at 4.1% of ration DM (TAL), 2) a 50:50 ratio of supplemental fat from a combination of tallow at 2.1% and FFECS at 12.8% of ration DM (TAL/ECS), and 3) 100% supplemental fat from FFECS at 25.6% ration DM (ECS). All rations were formulated to contain 7.5% fat on a DM basis. Heifers were individually fed, ad libitum, for 82 d, and BW, G:F, DMI, ADG, and body composition via ultrasound were collected at 3 to 4 wk intervals. After 82 d on feed heifers were slaughtered under federal inspection, and carcass characteristics were measured (at 24 h). The LM was removed for retail display color (1, 3, 6, 10 d), Warner-Bratzler shear force (1, 3, 7, 14, 21 d postmortem aging), sensory analysis (1, 7, 14, 21 d postmortem aging), and fatty acid profile analysis. Subcutaneous fat, including all layers, was removed from the LM for fatty acid profile analysis, and ground beef patties (80:20) were produced with lean from the brisket and fat from the plate for retail color analysis (1, 2, 4, 7 d). Supplemental fat source did not influence feedlot performance for any of the traits measured (P > 0.12) or any carcass traits related to yield, quality, or LM color at the 12th- to 13th-rib interface (P > 0.15). Supplemental fat source did not affect Warner-Bratzler shear force or any sensory traits (P > 0.20), but LM steaks became more tender as postmortem aging time increased up to 14 d (P < 0.01). During retail display of LM steaks and beef patties, the only difference was LM steaks from ECS were darker (lower L* value) than TAL or TAL/ECS steaks (P < 0.02). As display time increased, LM steak and beef patty objective and subjective color deteriorated (P < 0.01). Although feeding FFECS compared with tallow increased linoleic acid (C18:2(n-6)) in both intramuscular and subcutaneous fat (P < 0.04), this did not lead to an increase in total CLA content (P > 0.90). Full-fat extruded cottonseed pellets are interchangeable with tallow in heifer finishing diets without impacting feeding performance, meat quality, shelf life color, or CLA content of adipose sites.

The effects of zilpaterol hydrochloride supplementation on market dairy cow performance, carcass characteristics, and cutability

ABSTRACT Market dairy cows (n = 34) were used to determine the effects of zilpaterol hydrochloride (ZH) supplementation, in addition to concentrate feeding, on growth performance, carcass characteristics, and carcass yields. Cows were stratified by BW and randomly assigned to 1 of 2 treatments: 1) concentrate fed for 42 d (control) or 2) concentrate fed for 42 d with ZH (8.33 mg/kg) from d 19 to 39. Dietary supplementation of ZH had no effect (P > 0.05) on locomotion score, BCS, BW, ADG, G:F, or DMI over the course of the feeding period. Supplementation with ZH increased (P

Effects of Fish Meal and Sodium Bentonite on Performance, and Ruminal and Blood Characteristics of Kids Fed Concentrate or Forage Diets,

Twenty-four wether and 24 doe crossbred kids were used to evaluate the effect of fish meal (FM) and sodium bentonite (NaB) on growth, and ruminal and blood metabolites. Six treatments were: four isonitrogenous (13.5% CP) diets (0% FM and 0% NaB; 0% FM and 0.75% NaB; 3% FM and 0% NaB; or 3% FM and 0.75% NaB) fed to confined kids, and the 0% FM and 0% NaB or 3% FM and 0% NaB diets fed to grazing kids as supplement. Diets were based on corn, soybean meal, and cottonseed hulls. Data were analyzed as two independent 2 × 2 factorial arrangements. The first analysis compared the four diets fed in confinement. The second analysis compared 0 or 3% FM supplemented diets fed in confinement to the same diets fed as supplements to grazing kids. Grazing kids were allowed 8 h daily grazing time on pasture. After grazing, kids were penned individually and allowed access to their respective supplements for 1 h. A FM × NaB interaction (P<0.02) occurred for average daily gain (ADG) where FM improved ADG in the absence of NaB but not in the presence of NaB. There were similar trends noted for DMI and gain per feed (g/kg DMI). Growth rates of confined and grazed kids were similar and both were improved (P<0.01) by including FM in the supplement. Ruminal pH was increased and total VFA decreased by feeding FM to confined kids (P<0.01). Kids that were supplemented after grazing had higher ruminal pH, acetate, isobutyrate, butyrate, and isovalerate and lower propionate levels than kids in confinement. Dietary FM had no effect on blood metabolites of confined or grazed kids. This research suggests that replacing a portion of dietary soybean meal protein with fish meal protein in the absence of NaB improves the growth rate of kids. Grazing kids that are properly supplemented gain as fast on 40% less feed as kids fed complete diets in confinement.

Nutritional value of ensiled grocery food waste for cattle

Assessment of nutrient variability, feed value, ensiling capability, intake, and digestibility of grocery food waste recycled from large retail stores was conducted in 3 experiments. In Exp. 1, 115 proximate nutrient analyses of grocery byproduct feed (GBP) from stores in the southern United States from April 8, 2011, to November 18, 2012, were evaluated for variation in nutrient concentration. Grocery byproduct feed was characterized as being a readily fermentable, high-moisture energy feed with an average DM content of 17.5 ± 3.7% and TDN of 89.8 ± 7.1%. In Exp. 2 and 3, grocery food waste consisting of fruit, vegetables, and bakery items from large retail stores in the Atlanta, GA, area was used for ensiling and feeding studies. The GBP material for Exp. 2 was processed on farm into homogenous slurry and treated to reduce its moisture content and preserved in experimental silos. Drying treatments included 3 levels of citrus pulp substitution (8, 16, and 24% as-fed basis), or passively removing liquid as seepage after stacking for 24 h, or oven drying (24 h at 80°C). All GBP mixtures effectively ensiled after 28 d, as determined by changes in pH, soluble carbohydrates, and fermentation acids. Ensiled GBP was moderately stable during 72-h aerobic exposure. In Exp. 3, a feeding/digestibility trial, 8 yearling Holstein steers were used in a replicated 4 × 4 Latin Square and fed 4 incremental levels of ensiled GBP in total mixed rations (TMR). Steers were fed 0, 18, 36, and 54% ensiled GBP as part of a TMR containing 68% wheat silage and 32% concentrate on a DM basis. The rations averaged 35.9, 30.7, 26.8, and 23.8% DM with incremental levels of GBP. Steers increased DM intake and digestibility when fed increasing GBP (P < 0.5). Digestible energy and TDN were linearly related to the level of GBP fed (P < 0.01). The TDN content of GBP was 82.7% (DM basis) and similar to predicted TDN values from commercial feed analyses of GBP. The feeding and nutritive value of ensiled GBP indicates it can be priced to be used effectively as an energy supplement in TMR for cattle.