Data were collected on 476 spring-calving, primiparous cows at six locations in Louisiana over a 2-yr period. Objectives of the study were to evaluate changes in prepartum body condition score (BCS) and BW of heifers when fed varying energy levels and to determine the influences of prepartum BCS and BW changes and BCS at calving on postpartum traits. Heifers were allocated to one of three energy levels from approximately 90 d prepartum to parturition. The diets were formulated to provide low, recommended, and high energy levels based on TDN requirements. After calving, cows were placed on annual ryegrass pasture and managed similarly at each location. Weight and BCS at calving were greater (P < .05) for females with higher BCS at 90 d prepartum (IBCS) and for those assigned to higher energy levels. Calving and calf growth traits were not affected (P > .05) by IBCS, energy level, prepartum changes in BCS and BW, or BCS at calving. Prepartum changes in BCS and BW regulated by varying energy levels had no effect (P > .05) on postpartum reproduction; however, BCS at calving influenced (P < .03) pregnancy rate and days to pregnancy. Cows with BCS 6 and 7 at calving had higher (P < .05) pregnancy rates (87.0 and 90.7%) than those with BCS 4 and 5 (64.9 and 71.4%). Interval to pregnancy for cows with BCS 4 at calving was 10 to 18 d longer (P < .05) than for those with BCS > or = 5.(ABSTRACT TRUNCATED AT 250 WORDS)

An experiment was conducted to evaluate the dietary effects of Cr propionate (CrProp) and metabolizable energy (ME) on growth, carcass traits, and pork quality of growing-finishing pigs. One hundred forty-four Cambrough-22 barrows were allotted to four dietary treatments in a randomized complete block design (six replicates of six pigs per replicate; average initial and final body weight were 27 and 113 kg, respectively). The dietary treatments were: 1) corn-soybean meal basal (B; low ME), 2) B + 200 ppb of Cr (as CrProp), 3) B + 200 kcal ME/kg (4.5% added fat; high ME), or 4) B + 200 kcal ME/kg + 200 ppb of Cr. At trial termination, three pigs per replicate were killed to determine dietary effects on carcass traits and pork quality. Overall average daily gain, average daily feed intake, and gain:feed ratio were not affected (P > 0.10) by diet. During the early growing period, average daily gain was increased in pigs fed the CrProp-low-ME diets, but decreased in pigs fed the CrProp-high ME diets (Cr x ME, P < 0.04). Feed intake was increased (P < 0.05) in pigs fed the high-ME diets during the early growing period. Forty-five min and 24 h pH were not affected (P > 0.10) by diet. The CIE L* tended (P = 0.07) to be increased and shear force tended (P = 0.06) to be decreased in pigs fed high-ME diets. Subjective marbling was increased (P < 0.03) and longissimus muscle percentage moisture and thaw loss were decreased (P < 0.04) in pigs fed CrProp. Chromium propionate had no consistent effect on growth and carcass traits in this experiment; however, CrProp did affect some aspects of pork quality.

beneficial. The recommended rate by the supplier of the Armadillo cultivar in the area of its development Availability of the recently developed cultivar Armadillo provides is at the low end of the above range (Pogue Seed Co., opportunity for use of burr medic (Medicago polymorpha L.) in the south-central USA where the species has become extensively natural-1997). Naturally occurring stands, especially on upland ized. Area of adaptation and effects of seeding rate and P fertilization sites in Louisiana, are not uniform and appear to regenwere identified as insufficiently understood aspects of this cultivar erate primarily where competition is limited and heavy that could potentially determine success of Armadillo burr medic seed crops have been produced. Appropriate seeding plantings within the region. Thus, objectives were to assess adaptation rates could readily differ throughout the south-central of this cultivar to both cooler and more humid locations than the region within the moisture range from humid Louisiana south Texas origin of the cultivar and to evaluate effects of initial conditions to semiarid West Texas. seeding rate and P fertilization. Neither seeding at 11 or 22 kg ha Ϫ1Although soil tests would not necessarily indicate P nor fertilization with 0 or 25 kg P ha Ϫ1 affected forage accumuladeficiency for many soils within the region, P can still be tion, which was greater (P Ͻ 0.05) in the initial year at Alexandria, the most limiting nutrient for medic seedlings. Dahmane LA (3330 kg ha Ϫ1 ) than at Rosepine, LA or Stephenville, TX. Seed production, critical for reseeding, was greatest (P Ͻ 0.05) at Stephen-and Graham (1981) in Australia found that while maxiville, with 344 kg ha Ϫ1 , and increased with P at the high seeding rate mum growth of an associated grass occurred with 10 mg only. Soil seed reserves 11 mo after seed set was 44% of the initial P kg Ϫ1 soil, an annual medic (Medicago sp.) required seed crop at Stephenville and Ͻ20% at the two, more-humid Louisiana 160 mg P kg Ϫ1 soil for maximum growth. Buxton (1989) sites. On the sites represented, yield potential may limit Armadillo noted that legumes in general require higher soil conprimarily to extensively managed systems. Such systems include livecentrations of nonmobile nutrients such as P for maxistock production and wildlife in the drier western extent of the region, mum growth than do grasses. In addition to the need but they primarily involve plantings for wildlife in the eastern portion for high concentrations of soil P by temperate legumes of the region. High seeding rates with P fertilization can contribute in general, responses of seedlings to banded application to seed production and enhanced opportunity for stand regeneration.

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