Beef Cattle Research Abstracts
2008-2010
- 2010 -
Beef Symposium: Population data analyses to evaluate trends in animal production systems
A. DiCostanzo
Department of Animal Science, University of Minnesota, St. Paul
The Beef Symposium titled "Population data analyses to evaluate trends in animal production systems" was held at the joint annual meeting of the American Dairy Science Association, American Society of Animal Science, and the Canadian Society of Animal Science in Montreal, Quebec, Canada, July 12 to 16, 2009. The symposium was organized with the following objectives: 1) to familiarize society members of techniques and procedures to gather, analyze, and interpret population data; and 2) to demonstrate several applications of population data analyses which may be useful in various animal science disciplines.
Using alfalfa leaf meal as a supplement in late-gestation beef heifer and nursing beef calf diets
C.M. Zehnder1, T.D. Maddock2, A. DiCostanzo1, L.R. Miller1, J.M. Hall3, and C.G. Lamb2
Two experiments were conducted to investigate using alfalfa leaf meal (ALM; 22% CP, DM basis) in beef cattle diets. In Exp. 1, a total of 24 late-gestation Angus heifers (initial BW 470 ± 9 kg) were blocked by BW, calving date, and BCS to 1 of 4 dietary treatments in a randomized complete block design. All heifers were offered a basal hay diet (7.4% CP and 67.6% NDF, DM basis). Treatments were arranged as a 2 x 2 factorial consisting of CP supplied at 100 or 112.5% of the recommended daily intake using either soybean meal (SBM) or ALM as the supplemental protein source. Treatments were fed for an average of 100 d before calving. Total DMI was unaffected by supplemental protein source, although heifers consumed more (P < 0.001) ALM supplement than SBM supplement at the expense of hay and corn. Feeding 112.5% of recommended CP to heifers increased precalving rate of BW gain (P = 0.004) and DM digestibility (P = 0.003). Protein source did not affect DM digestibility (P = 0.17). Neither supplemental protein source nor protein amount affected changes in BCS or calving traits. In Exp. 2, replicates of treatments were conducted over 2 consecutive years at 2 locations in northern Minnesota to determine the effects of including ALM in creep-fed supplements on nursing calf performance, supplement BW gain efficiency (GF; BW gain over control/ supplement intake), and cow performance. Treatments were control (no supplement), ALM supplement (58% ALM, as-fed basis), or a wheat middling- and soybean hull-based supplement (MIDD). Milk intake (estimated by the weigh-suckle-weigh technique) was similar among treatments. Creep-fed calves had greater (P < 0.001) ADG than control calves, whereas calves offered MIDD tended to have greater ADG (P = 0.05) than those offered ALM (1.38 vs. 1.30 kg/d, respectively). Calves offered MIDD had greater (P < 0.001) creep feed DMI than those offered ALM (2.6 vs. 1.3 kg/d, respectively). A year x treatment interaction was noted for GF (P = 0.02). In yr 1, GF for calves offered ALM was greater (P = 0.006) than GF for calves offered MIDD, but in yr 2, there were no differences. Alfalfa leaf meal may substitute for SBM in beef heifer wintering diets and conventional creep feed ingredients. When included in creep feed diets, ALM can result in slightly less ADG and less DMI, but supplement conversion efficiency may be increased.
1Department of Animal Science, University of Minnesota, St. Paul
2North Florida Research and Education Center, University of Florida, Marianna
3Nancy M. Cumming Research Extension and Education Center, University of Idaho, Carmen
- 2009 -
Body composition and estrous cyclicity responses of heifers of distinct body conditions to energy restriction and repletion
J.M. Cassady1, T.D. Maddock2, A. DiCostanzo1, and G.C. Lamb2
Twenty Simmental x Angus, half-sibling, postpubertal heifers (initial BW of 443 ± 9 kg) were allotted randomly to 2 treatments to evaluate if initial BCS affects how heifers respond to energy restriction and repletion. Dependent variables of interest were changes in BW, BCS, and reproductive status [determined by concentrations of serum progesterone (P4)]. Empty body composition (EBC) was calculated using equations based on BCS. During a preliminary feeding period, diets were formulated so that each heifer in the designated treatment would reach a BCS of 5 (moderate condition; MOD) or a BCS of 7 (heavy condition; FAT). Once each heifer had reached the desired BCS, diets were formulated to supply 30% of NEm requirements until each heifer became anestrous (serum concentrations of P4 < 1 ng/mL; restriction period). After anestrus, heifers were fed a high energy diet (1.43 Mcal/kg of DM) until estrous cycles resumed (serum concentrations of P4 > 1 ng/mL; repletion period). Body weight, BCS, and EBC were determined on d 1 of each period, on d 43 of restriction, and d 44 of repletion, and when heifers were confirmed to have resumed estrous cycles (2 normal estrous cycles determined by P4 > 1 ng/mL). Regression of BCS on BW determined individual BCS at anestrus and estrus. After 43 d of restriction, FAT condition heifers were heavier (P < 0.001), had greater BCS (P < 0.001), and had a greater proportion of empty body fat (P < 0.001). Heifers in FAT condition remained cyclic longer (P < 0.001) than those in MOD condition (148 vs. 61 d). In contrast, at the onset of anestrus, BW (P = 0.15), BCS (P = 0.54), and empty body fat were similar (P = 0.54) between treatments. At 44 d of repletion, BW (P = 0.46), BCS (P = 0.41), and empty body fat (P = 0.41) were similar between treatments. Heifers in both treatments recommenced estrous activity after similar (P = 0.43) number of days (54 d) of energy repletion, but near onset of estrous cycles, heifers in FAT condition were heavier (P = 0.002) and had greater BCS (P = 0.03) and empty body fat (P = 0.01) than those in MOD condition. Initial BCS influenced days to anestrus, but not BCS or EBC at onset of anestrus. Initial BCS had no effect on days to recommencement of estrous cycles, but did influence the degree of fatness required to resume estrous cycles.
1Department of Animal Science, University of Minnesota, St. Paul
2North Florida Research and Education Center, University of Florida, Marianna
Initial body condition score affects hormone and metabolite response to nutritional restriction and repletion in yearling postpubertal beef heifers.
J.M. Cassady1, T.D. Maddock2, A. DiCostanzo1, and G.C. Lamb2
Twenty Simmental x Angus, half-sibling, postpubertal heifers (initial BW of 443 ± 9 kg) were allotted randomly into 2 treatment groups to evaluate if initial BCS affects response of the hypothalamic-pituitary-ovarian axis to metabolic signals elicited by energy restriction and repletion. During a preliminary feeding period, diets were formulated so that each heifer in the designated treatment would reach a BCS of 5 (moderate condition; MOD) or a BCS of 7 (heavy condition; FAT). Once each heifer had reached desired BCS, diets were formulated to supply 30% of NEm requirements until each heifer became anestrous (serum concentrations of progesterone < 1 ng/mL; restriction period). Blood collections took place on d 1 of each period, on d 43 of energy restriction and d 44 of energy repletion, and when heifers were confirmed to recommence estrous cycles. When heifers were cycling, their estrous cycles were synchronized to ensure hormone sampling occurred during late diestrus or early proestrus. Energy restriction resulted in decreased concentrations of LH (FAT, P = 0.02; MOD, P < 0.001), IGF-1 (FAT, P < 0.001; MOD, P = 0.003), and insulin (P < 0.001); in contrast, concentrations of GH (P < 0.001) and plasma urea nitrogen (P < 0.001) increased. During repletion, LH concentration increased (P = 0.03) in MOD condition heifers but was still less (P = 0.002) than d 1 of restriction, whereas LH concentration tended to increase in FAT heifers (P = 0.06) until it was similar (P = 0.40) to d 1 of restriction. Repletion also increased concentrations of IGF-1 (P < 0.001), insulin (P < 0.001), and glucose (P < 0.001), whereas concentrations of GH (P < 0.001), NEFA (P < 0.001), and plasma urea nitrogen (P < 0.001) decreased. For both treatments, concentrations of GH after repletion were similar (FAT, P = 0.88; MOD, P = 0.10) to those on d 1 of restriction. After repletion, FAT condition heifers had decreased concentrations of IGF-1 (P < 0.001), insulin (P < 0.05), and glucose (P < 0.001), but greater concentrations of acetate (P < 0.01) and butyrate (P < 0.05), than MOD heifers. Anestrus or resumption of estrous cycles seems to be activated gradually in response to dietary manipulation, unrelated to certain metabolite changes.
1Department of Animal Science, University of Minnesota, St. Paul
2North Florida Research and Outreach Center, University of Florida, Marianna
Physiological changes in rumen fermentation during acidosis induction and its control using a multivalent polyclonal antibody preparation in heifers
M. Blanch1, S. Calsamiglia1, N. DiLorenzo2, A. DiCostanzo2, S. Muetzel3, and R.J. Wallace3
Physiological changes in rumen fermentation during acidosis induction and its control using a multivalent polyclonal antibody preparation (PAP) were studied in a completely randomized experiment using 12 crossbred heifers (452 ± 20 kg of BW). Treatments were control (CTR) or PAP. The acidosis induction protocol consisted of 3 periods: 3 mo of 100% fescue hay fed for ad libitum intake, 10 d (from d 1 to 10 of the experiment) of adaptation to the treatment (100% forage feeding + 10 mL/d of PAP top-dressed to the treatment group), and 5 d (from d 11 to 15 of the experiment) of transition, which consisted of increasing the concentrate (16.5% CP) 2.5 kg/d up to 12.5 kg/d while maintaining ad libitum intake of fescue and providing 10 mL/d of PAP to the treated heifers. Concentrate feeding of 12.5 kg/d was maintained until heifers developed acidosis (from d 16 to 22 of the experiment). When an animal was considered acidotic, it was changed to a 50:50 forage:concentrate diet, monitored for 4 d, and removed from the experiment. Samples of ruminal fluid were collected before and 6 h after feeding to determine pH, VFA, lactate, protozoa counts, and DNA extraction for quantitative real-time PCR and denaturing gradient gel electrophoresis analyses. Only samples collected during adaptation to the treatment, at 3 and 1 d before acidosis, on the acidosis day, and at 1 and 4 d after acidosis were analyzed. Differences were declared at P < 0.05. Heifers (83% for CTR, and 50% for PAP) entered into acidosis 5.25 ± 0.17 d after the beginning of the transition. The fermentation profile of animals with acidosis was similar between treatments. From 3 d before acidosis to acidosis day, decreases in pH and in acetate-to-propionate ratio and increases in total VFA, butyrate, and entodiniomorph counts were observed. However, the greatest concentrations of Streptococcus bovis and Megasphaera elsdenii (79 ± 54 and 104 ± 73 ng of DNA/mL of ruminal fluid, respectively) and a decrease in DMI (10.6 vs. 6.46 kg, respectively) were recorded 1 d after acidosis. Compared with CTR heifers, heifers fed PAP had greater pH before feeding on d 6 (6.70 vs. 6.11), 8 (6.54 vs. 5.95), and 9 (7.26 vs. 6.59) after the beginning of the feeding challenge. Heifers fed PAP tended to have greater total VFA concentrations than CTR (124 and 114 ± 4.0 mM, respectively). These results indicate that PAP may be effective in controlling acidosis of heifers during a rapid transition to a high-concentrate diet.
1Grup de Recerca en Nutrició, Maneig i Benestar Animal, Departament de Ciència Animal i dels Aliments, Universitat Autònoma de Barcelona, 08193–Bellaterra, Spain
2Department of Animal Science, University of Minnesota, St. Paul
3Rowett Research Institute, Aberdeen AB21 9SB, United Kingdom
- 2008 -
Effects of administration of prostaglandin F2α (PG) 5 or 7
d after receiving human chorionic gonadotropin (hCG) or gonadotropin releasing hormone (GnRH) in replacement beef heifers
G. Marquezini1, C.R. Dahlen2, M. Blason1, S.L. Bird1, J.E. Larson1, B.J.
Lovaas1, S. Lares1, and G.C. Lamb1
We determined whether PG administered 5 or 7 d after receiving an
injection of GnRH or hCG would alter the interval to ovulation or
interval to corpus luteum (CL) regression. Purebred Angus heifers
were stratified by age, cycling status and weight before being assigned
to one of four treatments in a 2×2 factorial: 1) heifers received a 100-μg injection of GnRH on d 0 followed by a 25 mg injection of PG on
d 5. (G5; n=11); 2) same as G5 but PG was administered on d 7 (G7;
n=11); 3) heifers received a 1,000 IU injection of hCG on d 0 followed
by a 25 mg injection of PG on d 5. (H5; n=11); and 4) same as H5 but
PG was administered on d 7 (H7; n=11). Blood samples were collected
3x weekly from d -25 to -4 and -1, 0, 3, 5, 7, 8, 9, 10, 11 to determine
concentrations of progesterone. Transrectal ultrasonography was used
to determine ovarian dynamics on d -1, 0, 3, 5, 7, plus every 4 hr after
each heifer was detected in estrus until disappearance of the ovulatory
follicle. Average interval from PG to ovulation was greater (P<0.05)
in G5 (100.7 hr) and H5 (102.7 hr) treatments than G7 (65.5 hr) and H7
(64.5 hr) treatments. Concentrations of progesterone were similar on d 3
(1.84 ng/mL), 5 (2.50 ng/mL), and 7 (1.29 ng/mL) between GnRH and hCG treated heifers. Concentrations of progesterone tended (P=0.11)
to be greater when heifers received PG on d 5 (3.00 ± 0.57 ng/mL) than
those receiving PG on d 7 (1.76 ± 0.56 ng/mL) after treatment. Follicle
diameter tended (P=0.10) to be larger at ovulation when treated with
PG on d 5 (14.1 ± 0.4 mm) than d 7 (13.1 ± 0.4 mm) after treatment.
Progesterone 48 hr after PG was greater (P<0.05) in hCG (0.57 ± 0.14
ng/mL) than GnRH (0.19 ± 0.15 ng/mL) treated heifers and for those
heifers treated with PG on d 5 (0.60 ± ng/mL) than those treated on d 7
(0.17 ± ng/mL). We conclude that the interval to ovulation after PG was
greater in heifers treated on d 5 rather than d 7 after treatment with hCG
or GnRH and that concentrations of progesterone after PG were altered
by both treatment of hCG or GnRH and the interval to PG.
1North Central Research and Outreach Center, University of Minnesota,
Grand Rapids
2Northwest Research and Outreach Center, University of Minnesota, Crookston
Effects of feeding a polyclonal antibody preparation against Escherichia coli O157:H7 on performance, carcass characteristics and E. coli O157:H7 fecal shedding of feedlot steers
N. DiLorenzo1, C.R. Dahlen2, and A. DiCostanzo1
Oral doses of avian-derived polyclonal antibody preparations (PAP) against Streptococcus bovis or Fusobacterium necrophorum were effective at reducing ruminal counts of target bacteria, and improving feed efficiency of feedlot steers. The objective of this study was to determine the effects of feeding a PAP against E. coli O157:H7 (PAP-Ec) on performance, carcass characteristics and E. coli O157:H7 fecal shedding of feedlot steers. Eighty four Angus and Angus crossbred steers (258 kg initial BW ± 22) were randomly allocated to one of two treatments: PAP-Ec or CTL. Steers received a basal diet (1.39 Mcal NEg/kg DM, 12.5% CP, 0.7% Ca, and 0.35% P) comprised of high-moisture corn and dry ground corn (50:50 mix, DM basis), corn silage, and a supplement containing laidlomycin propionate and were supplemented (PAP-Ec) or not (CTL) with 2.5 mL PAP-Ec/d. Individual fecal samples were collected every 28 d for E. coli O157:H7 analysis. Steers receiving PAP-Ec tended (P=0.06) to have greater feed efficiency (live basis). Carcass-adjusted feed efficiency did not differ (P=0.10) between treatments. Steers receiving PAP-Ec had greater (P<0.05) fat thickness than CTL. No differences (P>0.10) were observed in E. coli O157:H7 fecal shedding at 0, 28, 84 and 165 d on feed. After 56 d on feed, a greater (P<0.05) prevalence of E. coli O157:H7 was observed in steers fed PAP-Ec. Steers fed PAP-Ec had a lower (P<0.05) prevalence of E. coli O157:H7 after 112 d on feed and tended (P=0.06) to have reduced E. coli O157:H7 prevalence after 140 d on feed. The use of an avian-derived polyclonal antibody preparation against E. coli O157:H7 in feedlot diets may be a valid intervention to enhance cattle performance and reduce E. coli O157:H7 fecal shedding.
1Department of Animal Science, University of Minnesota, St. Paul
2Northwest Research and Outreach Center, University of Minnesota, Crookston
Efficacy of a polyclonal antibody preparation against respiratory disease pathogens on cattle morbidity and performance during the step-up period.
C.R. Dahlen1, N. DiLorenzo2, and A. DiCostanzo2
A polyclonal antibody preparation (PAP) against respiratory pathogens including Mycoplasma bovis, Haemophilus, Pasteurella multocida and Mannheimia haemolytica reduced morbidity and mortality during the first 32 d on feed in lightweight, high morbidity (212 kg and 29%, respectively) calves. However, it is not known whether PAP reduces morbidity in heavier, lower risk (>15% morbidity) calves, or its effects on intake and gains during the step-up period. Thus, the current study was designed to determine the efficacy of PAP in heavier, lower risk calves. One hundred thirty six Angus and Angus crossbred steer calves (276 kg) were randomly assigned to one of two treatments (Control or intranasal dosing 1.5 mL PAP/nostril on arrival and 7 d later) on arrival at the NWROC research feedlot. Within treatment, calves were then allocated (9 or 10/pen) to one of each of 12 pens for a 27-d diet step-up period. On arrival, at d 7 and 27, rectal temperatures were measured. Calves were considered morbid if rectal temperature recorded >39.7°C. Body weights, pen and intakes were measured from d 7 to d 27 of the step-up period. Dosing cattle on arrival and 7 d later with PAP reduced (P=0.01) morbidity (5% vs 14%) detected 7 post-arrival. Rectal temperatures did not differ on arrival or at day 27 (38.8 vs 38.9 °C and 38.6 vs 38.7°C for Control and PAP, respectively). At day 7 rectal temperatures were lower (P<0.05) for cattle dosed with PAP (39.0 vs 38.8 °C for control and PAP, respectively). No effects (P>0.10) of PAP dosing were observed on DMI, ADG or feed conversion during the step-up period. A reduction in morbidity of 9 percentage units represents economic savings in medication and labor costs.
1Northwest Research and Outreach Center, University of Minnesota, Crookston
2Department of Animal Science, University of Minnesota, St. Paul
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