Progress 10/01/01 to 10/01/06
Outputs
Fermenten is a commercial by-product of lysine production and is utilized as a blended peptide-bound and non-protein supplemental nitrogen source for cattle. The objective of this experiment was to investigate the effects of Fermenten supplementation on growth, blood measurements, forage DMI, and reproductive performance of beef heifers. Sixty heifers (Brahman x British; avg. age = 9 mo) were stratified by initial BW and randomly allocated to 12 bahiagrass (Paspalum notatum) pastures. Two grain-based supplement treatments were randomly allocated to pastures. Supplements were fortified with either Fermenten (FM) or urea (CT) to achieve a final supplement CP concentration of 16%. Heifer shrunk BW was obtained at the beginning (d 0) and at the end of the feeding phase (d 112). Body volume (length x girth x height) was obtained on d 0, 28, 56, 84, and 112, whereas pelvic area and reproductive tract score were assessed on d 0, 56, and 112. Blood samples were collected on d
28, 56, 84, and 112 for determination of glucose, blood urea nitrogen, IGF-I, and progesterone (P4) concentrations. For assessment of puberty, additional blood samples were obtained 10 d after each collection for P4 analysis. On d 56, 2 heifers were randomly selected from each pasture and placed into individual feeding stations for a 26-d period to determine treatment effects on forage DMI. On d 112, heifers were allocated by treatment into 2 pastures and exposed to bulls for 60 d. Compared to FM, CT had greater pregnancy rate (60.0 vs. 93.1%, respectively; P<0.01), and tended to have a greater number of pubertal heifers by d 112 (53.3 vs. 75.8%, respectively; P=0.08). However, treatment differences were not observed for forage DMI, body growth parameters, and blood measurements. In this experiment, supplementation of Fermenten to yearling heifers did not influence heifer growth and development, but decreased reproductive performance.
Impacts
Reproductive efficiency of the cowherd is a critical component of overall profitability of the system. Development of the replacement heifer is a key factor influencing overall herd reproduction. This study provides insight toward the usefulness of alternative sources of supplemental protein for the developing heifer.
Publications
- Galindo-Gonzalez, S., J.D. Arthington, S.W. Coleman, and A. De Vries. 2006. Case Study: Evaluation of milk production and energy partitioning in primiparous Braford heifers calving at two- vs. three-years of age. Prof. Anim. Sci. 22:467-471.
- Vendramini, J.M.B., L.E. Sollenberger, J.C.B. Dubeux, Jr., S.M. Interrante, R.L. Stewart, Jr., and J.D. Arthington. 2006. Concentrate supplementation effects on forage characteristics and performance of early weaned calves grazing rye-ryegrass pastures. Crop Sci. 46:1595-1600.
- Ezenwa, I.V., R.S. Kalmbacher, J.D. Arthington, and F.M. Pate. 2006. Creeping signalgrass versus bahiagrass for cow and calf grazing. Agron. J. 98:1582-1588.
- Arthington, J.D. 2005. Effects of high-level copper supplementation or copper oxide bolus administration on forage utilization and copper status in beef cattle. J. Anim. Sci. 83:2894-2900.
- Kalmbacher R.S., E.V. Ezenwa, J.D. Arthington, and F.G. Martin. 2005. Sulfur fertilization of bahiagrass with varying levels of nitrogen fertilization on a Florida Spodosol. Agron. J. 97: 661-667.
- Hersom, M., G. Hansen, and J.D. Arthington. 2006. Effect of cation-anion difference on measures of acid-base physiology in beef cows. J. Anim. Sci. 84(Suppl. 2):14-15.
- Cooke, R.F., C.R. Staples, G.C. Lamb, and J.D. Arthington. 2006. Effects of supplement type on performance, reproductive and physiological parameters of yearling Brahman-crossbred heifers. J. Anim. Sci. 84(Suppl. 2):8.
- Ezenwa, I.V., J.D. Arthington, R.S. Kalmbacher, and F.M. Pate. 2006. Is creeping signalgrass an alternative to bahiagrass for cow-calf grazing in Florida? Abstract of a presentation to be given at the 2006 Annual meeting of the Southern Branch of the American Society of Agronomy, February 5-7, 2006, Orlando, FL.
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Progress 10/01/04 to 09/30/05
Outputs
Citrus pulp is often an affordable source of supplemental energy for beef cattle. Citrus pulp is typically high in energy (approximately 80% TDN), but low in CP (approximately 6% CP). The objectives of this study were to compare the effect of different sources of dietary N on growth, DMI, and forage utilization in growing steers provided citrus pulp supplements. Two studies were conducted. In Exp. 1, diet DMI and apparent diet digestibility was determined in four Braford steers (254 kg) randomly assigned to one of four sources of supplemental N, including, 1) urea (U), 2) roasted soybean meal (RSBM), 3) soybean meal (SBM), or 4) no supplemental N (CON). Supplements were formulated to provide equivalent amounts of CP (11.9%) and TDN (66%). Each treatment was randomly assigned to steers using a cross-over design containing four, 21-d periods such that each steer received each treatment. Periods were composed of 14 d of acclimation followed by 7 d of total fecal
collection. Supplement and forage DMI was determined daily. Diet DMI (% BW) was least (P < 0.05) for CON compared to all other treatments (1.37, 2.02, 2.15, and 1.81 for CON, RSBM, SBM, and U, respectively; SEM = 0.10). Steers provided the soybean meal treatments experienced greater (P < 0.05) apparent diet digestibility compared to CON, but not U supplemented steers (60.5, 67.9, 66.7, and 63.7 % for CON, RSBM, SBM, and U, respectively; pooled SEM = 1.75). In Exp. 2, 24 individually fed, crossbred steers (Brahman x British; 261 kg) were provided citrus pulp supplements fortified with SBM, U, or CON (8 steers/treatment) for 56 d. Steer BW gain and diet DMI was determined. Diet DMI was greatest (P < 0.05) for steers provided SBM, compared to U and CON (2.11, 2.52, and 2.17 % BW for CON, SBM, and U, respectively; SEM = 0.10). Steer BW gain was greatest (P < 0.05) for SBM, followed by U, which was greater (P < 0.05) than CON (0.12, 0.74, and 0.51 kg/d for CON, SBM, and U, respectively;
SEM = 0.07). These data indicate that supplemental N is important for growing steers provided forage diets supplemented with citrus pulp. Natural protein sources, such as soybean meal, may improve performance and diet digestibility beyond that achieved by NPN sources, such as urea.
Impacts
Feed costs can account for nearly 60% of the annual costs associated with the production of a beef calf. The use of high-quality, commodity by-product supplements is an option for cattle producers that generally provides a lower cost per unit of nutrient purchased. A proper understanding of how to balance byproduct supplements will improve beef cow/calf production efficiency and profitability of the system.
Publications
- Arthington, J.D., and W.F. Brown. 2005. Estimation of feeding value of four tropical forage species at two stages of maturity. J. Anim. Sci. 83:1726-1731.
- Vendramini, J.M.B., L.E. Sollenberger, J.D. Arthington, A. Adegbola, J.C.B. Dubeux, Jr., S.M. Interrante, and R.L. Stewart, Jr. 2005. In situ DM and N disappearance of ryegrass (Lolium multiflorum)-rye (Secale cereale) mixed swards fertilized with different N rates. 83(Suppl. 1):149.
- Vendramini, J.M.B, L.E. Sollenberger, J.D. Arthington, A. Adesogan, J.C.B. Dubeux Jr., S.M. Interrante, and R.L. Stewart Jr. 2005. In situ DM and N disappearance of Tifton 85 bermudagrass fertilized with different N rates. In 2005 annual meeting abstracts [CD-ROM]. ASA, CSSA, SSSA, Madison, WI.
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Progress 10/01/03 to 09/30/04
Outputs
The objective of this study was to investigate the effect of early calf weaning from both primiparous and multiparous cows on measures of cow BW, BCS, and pregnancy rate. Forty-eight crossbred cows (Brahman x British) and their calves were stratified by parity and calving date and randomly allotted to treatment, using a 2 x 2 factorial arrangement, including early- and normal-weaned and multiparous and primiparous cows (n = 12 / treatment). Cows were maintained on bahiagrass pastures for a period of 60 d (3 pastures / treatment; 4 cows / pasture) and provided free-choice access to grass hay and 2.3 kg daily of supplemental liquid molasses (16% CP). An estrus synchronization and timed-AI protocol was applied to all cows 21 d after early weaning (d 0). All cows were exposed to mature Angus bulls for 21 d after the conclusion of the study. Cow BW and BCS were collected at d -21 (date of early weaning), d 0, d 30, and d 60. Hay DMI was 12% less (P < 0.001) for
early-weaned cows, irrespective of parity (6.8 vs. 7.7 kg/d for early- and normal-weaned cows respectively; SEM = 0.31). Throughout the study, multiparous cows were heavier (P < 0.01) with greater (P < 0.01) BCS compared to primiparous cows. On d 0, the BW of early- and normal-weaned cows did not differ; however, by d 60, early-weaned cows had gained more BW than normal-weaned cows, irrespective of parity (P < 0.01; 28 and 2 kg of gain for early- and normal-weaned cows, respectively; SEM = 2.5). Early weaned cows tended (P = 0.15) to have a greater overall pregnancy rate (82% vs. 63%) compared to normal-weaned cows (18 of 22 and 15 of 24 pregnant, respectively). There were no significant weaning x parity treatment interactions for pregnancy rate. These data imply that early-weaned cows, both multiparous and primiparous, have a greater increase in BW and BCS and consume less hay compared to normal-weaned cows.
Impacts
The management of young cows is often the most costly portion of a cow/calf system's feed budget. A better understanding of differences between age of cow and measures of productivity will improve the ability of beef cattle producers to manage this important system. Ultimately, this understanding will lead to improved overall cowherd production and profitability of the system.
Publications
- Arthington, J.D., and G.C. Lamb, and F.M. Pate. 2004. Effects of supplement type on growth and pregnancy rate of yearling Brahman crossbred heifers. Prof. Anim. Sci. 20:282-285.
- Arthington, J.D., 2004. Supplementation of preweaned beef calves. Proc. 8th Annual Curso Novos Enfoques Na Producao E Reproducao De Bovinos. Uberlandia, Minas Gerais, Brazil. p. 179-183.
- Arthington, J.D. 2003. Early weaning. A management alternative for improving heifer and young cow productivity. Proc. 36th Annual Convention of the American Association of Bovine Practitioners. Columbus, OH. pp. 39-43
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Progress 10/01/02 to 10/01/03
Outputs
Beef heifers in Florida are traditionally bred at two-yr of age to calve at three. To improve productivity of young heifers many producers breed heifers as yearlings (13 to 15 mo of age) to calve at two yr of age. The objective of this study was to determine the performance of post-partum, primiparous Braford heifers calving for the first time at two- vs three-yr of age. For comparison purposes, mature, multiparous Braford cows were also included in the study. Four cows and their calves were randomly selected from one of three age groups (n = 12; four pairs/age group), consisting of mature, three-, and two-yr-old cows. All cows averaged 85 d in milk at the beginning of the study. Each pair was randomly allocated to one of 12 individual pens, in a completely randomized design. All pens were fed a daily ration of concentrate and forage (45:55, respectively), according to NRC (1996). Diets were formulated to achieve an ADG of 0.23 kg/d for two- and three-yr-old cows, and
no gain for mature cows. Each calf was fed 1.0 kg of oats 3 times weekly. Body weight, body condition score (BCS), and milk production data were collected from all cows on d 0, 42, and 84. Milk was collected using a single-unit vacuum milking machine. Milk was weighed, and duplicate samples were sent to Southeast Milk, Inc. (Belleview, FL), for determination of milk fat and protein concentration, and somatic cell count (SCC). The uncorrected milk production was converted to 4% fat corrected milk (FCM). Using ultrasound, fat thickness was measured on d 0 and 84 between the 12th and 13th ribs, _ the length ventrally over the longissimus muscle. The calves were weighed on d 7, 42 and 84. At d 0, two-yr-old cows were lighter (P < 0.05) than the other groups. Mature cows lost more BW (P < 0.01) than the other groups (-0.42, 0.04, and 0.17 kg/d for mature, two-, and three-yr-old cows, respectively; SEM = 0.08). Two-yr-old cows had a greater BCS when compared with the other groups (P < 0.05)
on d 42 and when compared to the three-yr-old cows (P < 0.05) on d 84. Production of FCM tended (P < 0.09) to be lesser at d 0 for two-yr-old than mature cows, and by d 42, FCM production of two-yr-old cows was lesser (P < 0.05) than both three-yr-old and mature cows. Averaged over all three collection times, FCM production tended to be 25% lesser for two-yr-old than three-yr-old (P = 0.08) and mature (P = 0.13) cows (5.90, 6.17, and 4.49 kg/d for mature, three-, and two-yr-old cows, respectively; SEM = 0.62). Treatment differences were not detected when comparing fat thickness, however, fat thickness was negatively correlated to FCM production among all cows (P < 0.05; r2 = 0.88). Milk protein content and SCC did not differ (P > 0.10) among the groups. No differences (P > 0.10) were detected in calf BW and ADG. When provided a similar level of nutrition, primiparous Braford heifers calving at two-yr of age tend to have a lesser FCM production than primiparous heifers calving at
three-yr of age. Further studies are needed to examine the economic influence of calving primiparous heifers at two- vs three-yr of age.
Impacts
The management of young cows is often the most costly portion of a cow/calf system's feed budget. A better understanding of differences between age of cow and measures of productivity will improve the ability of beef cattle producers to manage this important system. Ultimately, this understanding will lead to improved overall cowherd production and profitability of the system.
Publications
- Arthington, J.D., W.E. Kunkle, and A.M. Martin. 2002. Citrus pulp for cattle. In: G. Rogers and M. Poore (eds.) The Veterinary Clinics of North America - Food Animal Practice. p. 317. W.B. Saunders Company, Philadelphia, PA.
- Anton, T.E., J.D. Arthington, and F.M. Pate. 2003. The use of stockpiled limpograss as a winter forage supplement for beef cows in south Florida. J. Anim. Sci. 81(Suppl. 2):2.
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Progress 10/01/01 to 10/01/02
Outputs
Forages of central and south Florida are conducive to high yields, but are of limited quality, especially for supporting the reproductive performance of young post-partum cows. The objective of this study was to investigate the effectiveness of early calf weaning for improving the reproductive performance of these females. Forty, post-partum, 3 year-old Braford and Brangus sired heifers were randomly assigned to one of two treatments; early weaned (EW; n=20) and normal weaned (NW; n=20). At the time of early weaning (January 23) cow body condition score (BCS) was low but similar between treatments (3.90 and 3.88 for EW and NW cows, respectively). Calves were similar in age (84 d) and body weight at the time of early weaning (90.7 vs. 87.1 kg for EW and NW calves, respectively). Following EW all cows were returned to bahiagrass pastures with the mature cowherd and provided 2.27 kg of molasses supplement (16% CP) daily. Early -weaned calves were maintained on ryegrass
pastures at a rate of 1.35 calves/ha and were provided supplemental grain (14% CP) at a rate of 1.0% BW daily. Normal-weaned calves remained with their dams in the mature cowherd. Over 112 d of ryegrass grazing, EW calves had a higher (P<0.01) ADG compared to NW calves left with their dams (0.86 and 0.67 kg/day for EW and NW, respectively). Early weaning resulted in heavier (P<0.01) cows that were in better body condition at the time of normal (August 1) weaning (487.1 and 445.4 kg/cow with a body condition score = 6.25 and 4.50 for EW and NW, respectively). This improvement in body condition was associated with a higher (P<0.05) pregnancy rate and lower (P<0.05) calving interval for EW vs. NW cows (89.5 vs. 50.0% pregnant and 391 vs. 412 d calving interval for EW and NW, respectively). These initial data suggests that EW will improve cow body condition resulting in an increased pregnancy rate for low body condition heifers maintained on winter pastures in Florida.
Impacts
Early-weaned calves maintained on winter ryegrass provide Florida cattlemen with the ability to optimize early weaned calf performance, while capitalizing on low cost of gain and favorable spring markets.
Publications
- Arthington, J.D., and R.S. Kalmbacher. 2002. Effect of early calf weaning on cow and calf performance in Florida. J. Anim. Sci. 80(Suppl. 1):101.
- Arthington, J.D. 2001. Early calf weaning improves cowherd productivity. The Florida Cattlemen. 65(12):62.
- Arthington, J.D., and R.S. Kalmbacher. 2001. Developing calf nurseries for an early-weaning system. The Florida Cattlemen. 65(12):62.
- Arthington, J.D. 2002. Early weaning - A management alternative for Florida. Proc. 51st Annual Beef Cattle Short Course. Gainesville, Florida. p. 87.
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Progress 10/01/00 to 10/01/01
Outputs
We have been investigating the establishment of Calf Nurseries for the rearing of early-weaned (EW) calves. Calf Nurseries consist of ryegrass grown on a selected piece of land that slopes from a lower wet area upward to a higher dry area. This provides a dedicated piece of land that should respond favorably to variation in rainfall, whereas the higher land will yield better in wet winters and the lower in dry winters. Each Nursery has a small area (approx. 1/2 acre) of bahiagrass sod were water, feed, and mineral are offered. In our system, calves are born in the fall (October / November) and early weaned in January at an average age of 70-d. `Jumbo' ryegrass is established on cultivated soil in mid-November. We prefer Jumbo because tests have shown it grows later (approx. 30-d) into the spring compared to `Gulf'. Nitrogen is applied at emergence (50 lb / acre) and again on 45-d intervals. We can expect about 100-d of grazing lasting into April. This past year we
examined the effect of early weaning on cow and calf productivity. Early-weaned reared in Calf Nurseries for 112 days, gained 0.41 lb more per day compared to normal-weaned (NW) calves left with their dams (1.89 and 1.48 lb/day for EW and NW, respectively). Once EW calves were moved onto summer limpograss pastures, their performance declined. From May 15 to weaning (August 6), EW calves had an ADG of 0.66 lb/day less than NW calves (1.21 and 1.81 lb/day for EW and NW, respectively). This decline in performance resulted in a higher overall ADG for NW compared to EW calves from January to August. These data would support the marketing of EW calves in late April or early May, once the Calf Nursery stops producing adequate ryegrass. Historically, calf markets are at their highest value this time of year. Cow performance is improved by early weaning. In the current study, early weaning resulted in heavier cows (1074 and 982 lb/cow for EW and NW, respectively) that were in better body
condition at the time of normal weaning (body condition score = 6.25 and 4.50 for EW and NW, respectively). This improvement in body condition was associated with a higher pregnancy rate for EW vs. NW cows (89.5 and 50.0% for EW and NW, respectively).
Impacts
The use of early weaning is an effective management tool for optimizing reproductive performance of young cows. Our initial research indicates that early weaning will improve cow body condition by over 2 points (approx. 100 lb) resulting in a 30% improvement in pregnancy rate. When managing EW calves, the establishment of dedicated Calf Nurseries will provide Florida cattlemen with the ability to optimize early weaned calf performance, while capitalizing on low cost of gain and favorable spring markets.
Publications
- No publications reported this period
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