Sheep & Goat Research Journal. Volume 26, 2011
Growth and Carcass Characteristics of Conventionally Raised Lambs Versus Naturally Raised Lambs
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This study compared growth and carcass quality of conventionally and naturally raised lambs. The hypothesis tested was conventionally raised lambs would have increased growth, but conventional management would not affect carcass characteristics. Two hundred eighty-eight Rambouillet x blackface (Suffolk and Hampshire) lambs (34.1 kg ± 0.13 kg) were randomly assigned to conventional (CONV) or naturally raised (NAT) treatments (6 pens/treatment; 24 lambs/pen) and fed ad libitum via self feeders for 112 d. The NAT lamb diet was 80 percent corn and 20 percent commercial supplement (DM basis; 87.9 percent TDN and 15.8 percent CP) with decoquinate. The NAT lambs were not given antibiotics or growth promoting implants. Conventionally raised lambs were fed a similar diet, with decoquinate, chlortetracycline, and lasalocid included, and were implanted with 36 mg zeranol on d 28. Lambs were weighed and feed refusals collected every 28 d. Lambs were harvested and carcass data collected 24 h post chill. Overall, CONV lambs had increased ADG (0.35 kg vs 0.33 kg ± 0.006 kg; P = 0.03) and final BW (73.3 kg vs. 71.3 kg ± 0.71 kg; P = 0.07) compared to NAT lambs, but DMI (1.64 kg/d vs 1.58 kg/d ± 0.04 kg/d; P = 0.55) and G:F (0.22 vs 0.21 ± 0.004; P = 0.32) were not different between treatments. Naturally raised lambs had greater rib eye area (P = 0.03), decreased body wall thickness (P = 0.05), and increased percentage boneless, closely trimmed retail cuts (P = 0.05). More CONV lambs prolapsed (8.3 percent vs 0 percent; P = 0.001) which increased mortality (2.8 percent vs 0 percent; P = 0.01). In the current trial, naturally raised lambs had decreased growth, marginal increases in carcass quality, and were less susceptible to prolapse and mortality than conventionally raised lambs.
Key Words: Antibiotic, Carcass Traits, Feedlot Performance, Lamb, Naturally Raised, Zeranol
Effects of Rumen-Protected Arginine Supplementation on Ewe Serum-Amino-Acid Concentration...
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The objectives of this research were to determine if rumen-protected arginine supplemented to ewes on d 8 to d 13 of the estrous cycle affected serum-aminoacid concentration, ovarian blood flow, and circulating progesterone. Nineteen multiparous Dorset ewes (63.8 kg ± 1.1 kg initial BW) were individually housed and randomly allocated to one of four rumen-protected arginine treatments: 0 (CON; n = 5), 90 mg/kg BW supplemental arginine (90 ARG; n = 4), 180 mg/kg BW supplemental arginine (180 ARG; n = 5), or 360 mg/kg BW supplemental arginine (360 ARG; n = 5). Following estrous synchronization, ewes were individually fed rumen-protected arginine blended into 150 g ground corn, which was immediately followed with 650 g of a pelleted diet (2.40 Mcal ME/kg and 12.9 percent CP; DM basis) on d 8 to d 12 of the estrous cycle. Ewes fed 360 ARG generally had greater serum- arginine concentrations than CON, 90 ARG, and 180 ARG on d 11 (P ≤ 0.07) and d 12 (P ≤ 0.03). On d 11, arginine as a percent of total amino acid concentration was greater in 360 ARG compared with CON and 90 ARG (P ≤ 0.05). Total essential amino-acid concentration was elevated in 360 ARG compared with 90 ARG and 180 ARG (P ≤ 0.03) on d 12. Arginine supplementation increased peak systolic velocity in the corpus luteum (CL) for 360 ARG and 90 ARG compared to CON (P ≤ 0.04). Flow time (milliseconds) in the ovarian hilus was increased and CL was generally increased in 360 ARG compared to all other treatments (P ≤ 0.04 and P ≤ 0.09, respectively). Supplemental rumen-protected arginine had no effect on serum concentration of progesterone (P > 0.50). Results indicate that rumen-protected arginine supplemented to ewes at the rate of 360 mg/kg BW may increase circulating serum arginine concentration, in addition to increasing ovarian blood flow.
Key Words: Arginine, Ovarian Hemodynamics, Sheep
Sulfur Intake, Excretion, and Ruminal Hydrogen Sulfide Concentrations in Lambs Fed Increasing ...
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The objective of this research was to evaluate the effects of increasing dietary concentration of DDGS on S intake, excretion, and ruminal H2S gas concentrations in lambs. Sixteen wether lambs (36.7 kg ± 2.3 kg) were utilized in a completely randomized design. Treatments were based on increasing concentrations of DDGS in the final finishing diet and included: 1) 0 percent DDGS, 2) 20 percent DDGS, 3) 40 percent DDGS, and 4) 60 percent DDGS. Ruminal H2S concentrations were measured weekly via rumen puncture as lambs were adapted to their respective finishing diets. Feed, water, feces, and urine were collected over a 10 d collection period. Hydrogen sulfide gas concentrations did not differ (P ≥ 0.24) until d 7 when lambs fed increasing concentrations of DDGS had a linear increase (P = 0.009) in ruminal H2S concentrations. Linear increases (P < 0.001) in ruminal H2S concentrations were also observed on d 14, d 28, and d 35 in lambs fed increasing concentrations of DDGS. Dietary DDGS inclusion did not affect DMI (1.37 ± 0.07 kg·hd-1·d-1; P = 0.25). Sulfur intake from feed and water, as well as S excretion in feces and urine increased linearly (P ≤ 0.009) with increasing DDGS inclusion. Sulfur retention increased linearly (P = 0.02) with increasing inclusion of DDGS, although this does not reflect losses due to H2S. Increasing concentration of DDGS in the diet did not result in the occurrence of PEM. This research suggests that lambs excrete substantial amounts of S from DDGS and that water intake and urinary output increase with increasing S intake.
Key Words: Distillers Dried Grains with Solubles, Lambs, Polioencephalomalacia, Sulfur, Water Intake
Effects of Season of Kidding on Doe Performance in Commercial Boer Cross Does
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Little information is available on the impact of season of kidding on doe performance in goats. However, many producers in the southeastern United States kid in the late fall and winter because of seasonal market trends. Weather conditions during this time tend to require higher labor and nutritional supplementation. Because of this, a study was designed to evaluate doe performance by comparing total birth, 60 d and 90 d kid weight, doe efficiency ratio, conception rate, and kid survival to weaning in two alternative kidding seasons. One hundred and twenty commercial, meat-type does were randomly assigned to either a fall (October - December) or spring (March - May) kidding season. Data collected included birth weight, birth type, sex, 60 d weight, and 90 d weight on the kids. Doe weight and body condition score were taken at weaning (90 d), and the efficiency ratio was calculated by dividing the total weight of kids at 90 d by the doe weight taken at weaning. Kidding season had an effect (P < .01) on doe weight at weaning, total weight at 90 d, and conception rate. Season of birth did not affect total birth weight (P = .21) or total 60 d weight (P = .38). Doe weight and total 90 d weight were higher for fall than spring kidding; however, conception rate was higher for spring kidding does. This research indicates that kidding season has an influence on total weaning weight per doe. However, differences in conception rate may decrease profitability of fall and early winter kidding herds.
Key Words: Meat Goat, Season of Birth, Doe Efficiency Ratio
Mixed Grazing Goats With Cattle on Reclaimed Coal Mined Lands in the Appalachian Region: Effects on Forage Standing Biomass,
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Reclaimed coal-mined lands in Appalachia of the United States can be successfully utilized for beef cattle but the proliferation of invasive-plant species, such as autumn olive (Elaeagnus umbellata Thunb.) can limit this option. An experiment was conducted in 2006, 2007, and 2008 near Wise, Va. to determine the effects of cattle-alone grazing and mixed grazing of goats with cattle on forage standing biomass, forage botanical composition, and autumn olive. After the first sampling, forage standing biomass remained higher in cattle-alone grazing (P ≤ 0.002). Weed content was lower at the end of the grazing season in mixed grazing in all years (P < 0.03). Total autumn olive branch length was reduced by goat browsing in the mixed grazing treatment by the end of the experiment (P < 0.02). Total autumn olive shrub height was not affect by either treatment at the end of the study (P = 0.33). Goats grazing with cattle consumed plant species not preferred by cattle. Mixed grazing goats with cattle is a viable option for reclaimed coal-mined lands in Appalachia.
Keywords: Autumn Olive, Browse Species, Cattle, Goat, Grazing, Land Reclamation