John A. Paterson

Effects of increasing field pea (Pisum sativum) level in high-concentrate diets on growth performance and carcass traits in finishing steers and heifers.

Three experiments were conducted to determine the effect of increasing field pea level in high-concentrate finishing cattle diets on ADG, DMI, G:F, and carcass traits, and to estimate the NE of field pea. In Exp. 1, 118 yearling heifers (417.9 +/- 2.4 kg initial BW) were blocked by initial BW and assigned randomly to 1 of 4 treatments (0, 10, 20, or 30% dry-rolled field pea, DM basis; 4 pens/treatment). In Exp. 2, 143 beef steers (433 +/- 19 kg initial BW) were blocked by BW and assigned randomly to 1 of 4 treatments (0, 10, 20, or 30% dry-rolled field pea, DM basis; 6 pens/treatment). In Exp. 3, 80 beef steers (372.4 +/- 0.4 kg initial BW) were assigned randomly to 1 of 4 treatments (0, 18, 27, or 36% cracked field pea, DM basis; 4 pens/treatment). Field pea replaced a portion of the grain (dry-rolled and high moisture corn, dry-rolled corn, and barley and barley sprouts; Exp. 1, 2, and 3, respectively) and protein supplement. In Exp. 1, field pea inclusion decreased DMI linearly (P = 0.03), whereas ADG and G:F were not affected by treatment (P > or = 0.17); however, dietary NE(g) increased quadratically with increasing field pea level (P = 0.04). Fat thickness responded quadratically (P = 0.008) where heifers fed 20% field pea had greatest fat thickness and 30% field pea inclusion the least. Marbling tended (P < or = 0.09) to respond quadratically as field pea increased. No differences (P > or = 0.17) were observed for HCW, LM area, or KPH. In Exp. 2, DMI, ADG, G:F, dietary NE(g), HCW, marbling, LM area, 12th-rib fat, and USDA yield grade (YG) were unaffected by dietary field pea inclusion (P > or = 0.12). In Exp. 3, marbling score increased linearly (P = 0.05), fat thickness increased quadratically (P = 0.01), and YG tended to increase (P = 0.07) quadratically as field pea increased. Field pea inclusion did not affect (P > or = 0.38) DMI, ADG, G:F, dietary NE(g), HCW, or LM area. These results indicate that field pea can be included successfully into rations at levels up to 36% of DM without negatively affecting growth performance and most carcass characteristics of finishing beef cattle; however, effects on marbling score were variable. These data also indicate the energy content of field peas is similar to cereal grains, such as corn and barley, when included in high-concentrate finishing diets.

Effects of Body Condition, Initial Weight, and Implant on Feedlot and Carcass Characteristics of Cull Cows

Abstract Feeding cull cows an energy-dense diet can increase amount and quality of marketable product. Furthermore, implanting cull cows with steroid implants may improve BW gain, feed efficiency, carcass traits, and overall eating quality. Therefore, objectives of this study were to determine effects of implant, initial BW, and body condition score (BCS) at the beginning of the study, on feedlot performance and final live animal and carcass weights, and carcass characteristics of cull cows fed a high-concentrate diet for approximately 90 d. One-half (68) of the cows were allotted to implant treatment (Synovex-Plus®) by initial BW and BCS. Cows were fed a warm-up diet (50 to 60% concentrate, DM basis) for 14 d and then fed a finishing (80 to 85% concentrate, DM basis) diet for the remainder of the study. Variations in initial BW of cows were associated positively (P 0.10) ADG, final BW, or other carcass traits. Implant influenced (P 2 larger longissimus area, 27 units (100 units per marbling score) less marbling and 0.24 units less yield grade. Initial BW, BCS, and implanting influence feedlot performance and carcass characteristics of cull cows.

Effects of Beef Cattle Age and Barley Grain Processing Method on Rate and Efficiency of Gain and Nutrient Digestibilities1,2

Abstract Several experiments were conducted to test the effects of animal age (cows vs. calves) and barley processing method (whole vs. rolled) on rate and efficiency of gain and diet digestibility when barley was fed as a supplement at approximately 0.5% of BW with medium-quality grass hay. No age × processing interactions (P > 0.05) were detected for OM, N, ADF, or NDF digestibilities. Organic matter and N digestibilities were greater (P 0.05) rates and efficiencies of BW gain as those fed diets supplemented with barley. Barley processing had no effect (P > 0.05) on rate or efficiency of gain for cows or calves. There was no economic advantage to rolling light test-weight barley when fed at 0.5% of BW. Similar to Exp. 1, no differences were measured for digestibility of OM, N, ADF, or NDF due to animal age or grain processing method. Unlike Exp. 1, starch digestibility was not influenced by processing method. Results suggested that processing of barley was of greater value for mature cows compared to younger calves.

Readability of Thirteen Different Radio Frequency Identification Ear Tags by Three Different Multi-Panel Reader Systems for Use in Beef Cattle

ABSTRACT The objectives of these experiments were to compare the readability of 13 different commercially available brands of radio frequency identification (RFID) ear tags scanned by 3 different multi-antenna RFID panel readers using Angus heifers. The readability of the tags and flow rates of the heifers were measured through either of the following: 1) an Allflex Single-Lane Multi-Panel Reader (SINGLE), 2) an Allflex Dual-Lane Multi-Panel Reader (DUAL), or 3) a Boontech Alley Master Multi-Panel Multi-Animal Alley Reader (MULTIPLE). Three of the RFID tag brands compared were half-duplex (HDX) technology manufactured by Allflex, Dalton, or Leader. The remaining 10 RFID brands were full-duplex (FDX) technology manufactured by Allflex, Animal Profiling Inc., Dalton, Digital Angel (Destron), Leader, Verilogic, Y-Tex, or Z-Tag. A total of 5,570 observations were collected through the SINGLE system, 3,280 through the DUAL system, and 3,280 through the MULTIPLE system. Because of the differing alley dimensions, cattle moved through the 3 systems at different ( P P = 0.175). Readability did not differ ( P > 0.10) for the SINGLE (99.4%), DUAL (99.5%) or MULTIPLE (99.7%) systems. All flow rates met the National Animal Identification System (NAIS) standards (1 m/s) and readers met USDA 95% readability standards. Results indicate that it was possible to achieve read rates that follow standards proposed by the NAIS.

The Use of an Experimental Vaccine in Gestating Beef Cows to Reduce the Shedding of Escherichia coli O157:H7 in the Newborn Calf1

Beef cows in the last trimester of pregnancy were used to determine if vaccinating against Escherichia coli O157:H7 would increase antibody titers in the serum and also result in the transfer of these antibodies to the neonatal calf. Seventy-one cows were vaccinated 30 d before parturition with an experimental vaccine and then commingled with 66 nonvaccinated cows. Cow fecal and venous blood samples were collected at trial initiation and again about 14 d after parturition. Calf feces and serum were collected at about 14 d after parturition and 60 d later. The serum was analyzed for antibody titers to E. coli O157:H7, and the prevalence of E. coli O157:H7 in feces was determined by the Barkocy-Gallagher procedure. Initial cow antibody titers to E. coli O157:H7 were not different (P = 0.50) between treatments, but by parturition, the antibody titers for E.coli O157:H7 in vaccinated cows were 11 times higher (P < 0.001) than for control cows (917 vs. 83). The serum titers for calves suckling vaccinated cows were higher (P < 0.001) than control calves (1,485 vs.135) at about 14 d after calving. By 60 d, titer levels were still higher (P < 0.001) for calves suckling vaccinated cows. Initial fecal E. coli O157:H7 concentrations for cows were negative for both treatments and remained low. There were no differences in fecal E. coli O157:H7 at 60 d postpartum among calves; less than 5% of calves were shedding. Results suggest that vaccinating gestating cows for E. coli O157:H7 resulted in elevated antibody titers cows, and these antibodies transferred to the calf.

The effect of season on supplemental mineral intake and behavior by grazing steers

An experiment was conducted to compare individual, free-choice loose mineral intake and feeding behavior by steers grazing pasture during late spring to summer (SS) and fall (FS). Each season was divided into 4 periods of 8 to 9 d. Two 1.5-ha paddocks were equipped with a feeder that measured individual mineral consumption. Forage availabilities in both seasons were maintained above 2,000 kg of DM/ha. No differences were observed (P > 0.05) for average mineral intakes (g/d) between seasons (96.3 vs. 85.4 g/d for SS and FS, respectively). Differences among animals and days within each period were observed (P 0.05) was detected. Expressing intake as grams per day is confounded due to differences in animal weight, but when expressed on a metabolic weight basis (MBW), daily mineral intakes differed (P 0.05) were detected between mineral intakes (expressed as either g/d or g/kg of MBW) and available forage nutritional composition or IVDMD of clipped forage. In addition, no significant correlations (P > 0.05) were detected between steer ADG, temperature, or rainfall and mineral consumption. Steer attendance at the mineral feeder appeared to be related to intensity of daylight and daily temperatures according to differences in feeder attendance patterns between SS and FS. Results indicate higher mineral supplement intakes and lower CV during SS when expressed on a MBW basis when forage availability was maintained above 2,000 kg/ha.

CASE STUDY: Retention and readability of radio frequency identification transponders in beef cows over a 5-year period 1

ABSTRACT The objective of this study was to evaluate failure (loss or inability to read) of radio frequency identification (RFID) ear tags in beef cows over a 2- to 5-yr period under ranch conditions. One of 5 types of RFID tags (Allflex HDX, Allflex FDX, Y-Tex FDX, Z-Tag FDX, and Destron FDX) was applied in the ear of a total of 4,316 cows on 4 separate locations (ranches). Tags were evaluated at approximately yearly intervals for either 2 (ranch 1), 3 (ranch 2 and 3), or 5 yr. Percentages of tags that were lost or that failed to read were 1.4, 1.6, 3.7, 5.1, and 5.0 for the 5 consecutive annual evaluations, respectively, when averaged across ranches and RFID tag type. Cumulative losses of 3.0, 6.0, and 19.8% were observed when averaged over all tag types after 2 (all 4 ranches), 3 (3 ranches), and 5 yr (1 ranch). A ranch by tag type interaction was evident for failure of the 2 types of tags evaluated on all 4 ranches; a greater proportion of Allflex HDX tags were lost than Allflex FDX tags at ranch 4 (36 vs. 4%) but not at other ranches (4.7 vs. 5.1% cumulative loss–fail rate for HDX and FDX). This interaction may be due to differences in tag placement. Tags were placed in the top of the ear at ranch 4 but were attached between the second and third ribs of the ear at ranch 1, 2, and 3. Results indicate that loss of RFID tags increases with time after application and may exceed 5% after 3 yr.

CASE STUDY: Searching for the Ultimate Cow: The Economic Value of Residual Feed Intake at Bull Sales

Cow-calf producers seek to reduce costs and increase profits by selecting bulls that produce more efficient offspring. Organizers of formal bull auctions usually produce catalogs for potential buyers that advertise bull performance measures

Comparison of methionine hydroxy analogue chelated versus sulfate forms of copper, zinc, and manganese on growth performance and pregnancy rates in yearling beef replacement heifers

Our objectives were to compare growth performance and pregnancy rates of heifers supplemented with Cu, Zn, and Mn as either methionine hydroxy analog chelate (provided as MINTREX) or in the SO4 form. The experiment used 3 ranches, each having 2 replicate pens per treatment. Performance data were analyzed by ANOVA as a randomized complete block design using pen as the experimental unit. Pregnancy diagnosis data were analyzed using Chi-squared analysis. Heifers (n = 2,480) were fed diets for 181 d (ranch A), 149 d (ranch B), and 151 d (ranch C) before breeding. Heifers were weighed (shrunk) at trial initiation, end of feeding, breeding, and at pregnancy diagnosis. Ranch A heifers were bred by AI followed by natural service (45-d breeding), ranch B heifers were bred by natural service (50-d breeding), and ranch C heifers were bred by AI once at estrus detection only. No ranch × treatment interactions were detected for any measurements, and no differences were detected between treatments for gain, ADG, and G:F. Ranch effects were significant for gain, ADG, G:F, and overall pregnancy rate but not for conception in the first 21 d of breeding. Pregnancies conceived during the first 21 d of breeding did not differ between treatments. Overall pregnancy rate was increased by 2% for heifers supplemented with methionine hydroxy analog chelate versus SO4 form. Under the conditions of this experiment, methionine hydroxy analog chelate contributed to increased pregnancy rates compared with a readily available inorganic form of trace mineral.