J. Anim. Sci. 2006. 84:171-177
© 2006 American Society of Animal Science
The effects of high levels of supplemental copper on the serum lipid profile, carcass traits, and carcass composition of goat kids
S. G. Solaiman*,1,
C. E. Shoemaker*,2,
W. R. Jones
and
C. R. Kerth
* Department of Agricultural and Environmental Sciences, Tuskegee University, Tuskegee, AL 36088; and
and
Department of Animal Sciences, Auburn University, AL 36849
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Abstract
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This experiment was conducted to determine the effect of high levels of supplemental Cu (as CuSO4·5H2O) on the serum lipid profile and carcass traits of goat kids. Fifteen Boer x Spanish wether goat kids (BW = 21.3 ± 0.7 kg) were housed in individual pens and were assigned randomly to 1 of 3 treatments. Treatments consisted of 1) control (no additional supplemental Cu), 2) 100 mg of Cu/d, and 3) 200 mg of Cu/d. Copper sulfate was placed in gelatin capsules and inserted into the esophagus via a balling gun before the morning feeding. Animals were fed a high-concentrate (70:30 grain:hay) diet for 112 d. Serum lipid profile was determined on d 14 and 112, and BW was recorded after 4-h withdrawals from feed and water. After 112 d, animals were slaughtered, and carcass traits were measured. The left half of 12 carcasses and 9th to 11th rib sections from the right side of 15 carcasses were dissected into separable soft tissue and bone portions. The soft tissue portion was analyzed for moisture, ether extract, CP, and ash. Average daily feed intake decreased (linear; P = 0.05), and G:F increased (quadratic; P = 0.02) in the 100 mg of Cu/d group. Serum cholesterol and triglycerides did not change (P > 0.10); however, NEFA decreased (linear; P = 0.01) as supplemental Cu increased. No differences were observed (P > 0.10) in HCW, chilled carcass weight, or kidney and pelvic fat; however, 12th rib fat (linear; P = 0.01) and adjusted fat thickness (linear; P = 0.03) decreased as Cu supplementation increased. No differences (P > 0.10) in LM area were observed; however, percentage of boneless closely trimmed retail cuts increased (linear; P = 0.04) as Cu supplementation increased. The moisture (%) of the 9th to 11th rib sections increased (linear; P = 0.03), ether extract (%) decreased (linear; P = 0.02), and CP and ash (%) tended to increase (linear; P = 0.09 and 0.06, respectively) as Cu supplementation increased. Carcass composition measured using the left half of the carcass confirmed the values obtained through the 9th to 11th rib sections. Results of this study indicate that supplemental Cu can alter the serum lipid profile, carcass characteristics, and carcass composition of goat kids.
Key Words: carcass composition • copper • goat kid • serum lipid profile
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INTRODUCTION
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Feeding high levels of supplemental Cu has altered lipid and cholesterol metabolism in nonruminants such as broilers (Pesti and Bakalli, 1996
) and finishing pigs (Amer and Elliot, 1973). Limited research suggests that dietary Cu at physiological concentrations may affect lipid metabolism in ruminants. Supplementing Cu to Cu-deficient sheep led to increased adipose cell volume and increased in vitro lipolytic rates of adipose tissue (Sinnett-Smith and Woolliams, 1987). Ward and Spears (1997) reported that long-term Cu supplementation to diets marginal in Cu decreased fat depth and tended to increase LM area in steers. Engle et al. (2000a) reported that Cu supplementation at 20 or 40 mg Cu/kg of DM to a high-concentrate diet decreased fat depth and serum cholesterol and increased muscle PUFA in Angus and Angus x Hereford steers. Engle and Spears (2000) demonstrated that feeding as little as 10 or 20 mg of Cu/kg of DM with a high-concentrate (>90% ground corn and soybean meal) diet containing 4.9 mg of Cu/kg of DM decreased total serum cholesterol and fat depth in Angus steers; however, 10 or 40 mg of Cu/kg of DM given to Simmental steers fed a corn silage-soybean meal-based diet had no effect on performance, carcass characteristics, and lipid or cholesterol metabolism (Engle and Spears, 2001).
Malan (2000) reported that 60% of the red meat consumed in the world is goat meat. Introduction of the Boer goat has stimulated a significant interest in raising goats for meat in the United States. Data related to the effect of Cu on carcass characteristics and lipid metabolism in goats are limited. Therefore, the objective of the current study was to investigate the effect of high levels of supplemental Cu on the serum lipid profile, selection grade, carcass characteristics, and carcass composition of goat kids.
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MATERIALS AND METHODS
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Fifteen Boer x Spanish wether goat kids (approximately 5 mo of age; 21.3 ± 0.7 kg of initial BW) were used for this experiment. The Tuskegee University Animal Care and Use Committee approved the animal care, handling, and sampling procedures. Goats were purchased at a goat auction in north Alabama and were transported to the Tuskegee University Small Ruminant Research Unit. On arrival, animals were weighed, vaccinated s.c. with Clostridium perfringens type C & D-Tetani Bacterin-Toxoid (Bayer Animal Health, Shawnee Mission, KS) at 2 mL/animal, dewormed with moxidectin (Cydectin; Fort Dodge Animal Health, Fort Dodge, IA), and dusted along the loin area and neck using CoRal 1% dust (Dale Alley Co., St. Joseph, MO). Animals were surgically castrated followed by a s.c. injection of Liquamycin LA-200 (Pfizer Animal Health, Exton, PA) at a rate of 2 mL/goat as recommended by a veterinarian to prevent the occurrence of infection. Goats were housed individually in 1.8- x 2.1-m pens and were quarantined for a period of 30 d, during which the diet was gradually adjusted to a 70:30 grain:hay on a DM basis.
All animals were offered a high-concentrate diet of 70% commercial grain mix (GMX, Nutrena Feed Division, Minneapolis, MN) and 30% bahiagrass hay on a DM basis. The basal diet contained 13.8 mg of Cu/kg of DM, 50 mg of Zn/kg of DM, and <0.01 mg of Mo/kg of DM (Table 1). The basal diet was formulated to meet or exceed all nutrient requirements of growing goat kids according to the NRC (1981). Feed was offered twice daily (0900 and 1700) in quantities sufficient to allow ad libitum access to feed. Fresh water was provided daily. Goats were weighed for 2 consecutive days, stratified by BW, and assigned randomly to 1 of 3 experimental treatments (n = 5 goats per treatment): 1) control (no supplemental Cu), 2) 100 mg of Cu/d, and 3) 200 mg of Cu/d. Copper was supplemented in the form of CuSO4·5H2O placed in porcine gelatin capsules (Torpac #13; Torpac Inc., Fairfield, NJ) and inserted into the esophagus with a balling gun before the morning feeding. Control animals received empty capsules. Level of Cu supplementation was determined according to the previous research reported by Solaiman et al. (2001). Jugular vein blood samples were collected in nonheparinized Vacutainer tubes (Becton Dickenson, Franklin Lakes, NJ) on d 14 and 112 for serum cholesterol and lipid profile determinations.
At the end of the study (112 d), goats were graded by a certified USDA grader; final BW were measured on 2 consecutive days; and they were transported approximately 40 km to Auburn University Lambert Meat Abattoir. Goats were slaughtered according to USDA-approved methods after an overnight period of feed withdrawal. The Institutional Meat Purchase Specifications for Fresh Goat, Series 11 (IMPS; USDA, 2001) was used by a certified USDA grader to report live animal and carcass selection criteria in this study. According to the IMPS, selection criteria range from No. 1 to No. 3. Selection No. 1 designates the greatest proportion of meat:bone, and selection No. 3 designates the least meat:bone evaluated on a carcass. Selection criteria for live animal ranges from No. 1, superior meat type conformation and thickly muscled throughout the body, to No. 3, inferior meat type conformation, narrow in width and very angular in appearance. This is a 2-step grading procedure conducted on live animals or carcasses. First, a live animal or carcass is assigned a selection criteria number of 1, 2, or 3. Then, a percent value (>0.0 and <100 as a decimal) is assigned to the selection criteria. This value will determine how well (as a percent) the animal or carcass fits a particular selection criteria number. Hot carcass weight was determined on the day of slaughter and was used to determine dressing percent (HCW/live BW). Carcass selection grade (according to IMPS), chilled carcass weight, carcass shrink weight, fat depth over the LM (between the 12th and 13th ribs), body wall fat (BWF), adjusted fat thickness (ADFT), estimated percentage of kidney and pelvic fat (expressed as a percentage of HCW), and LM cross-sectional area were determined by a certified USDA grader 48 h after slaughter. Carcasses were split at the midline using a band saw, and the 9th to 11th rib sections from the right side and all the left side of the carcass were used to determine carcass composition. The soft tissue and bone were separated from the left side of the carcass and the 9th to 11th rib sections of the right side of the carcass (Hankins and Howe, 1946). Percent boneless, closely trimmed retail cuts (BCTRC %) were estimated according to the lamb formulation with metric unit conversions added (D. B. Griffin, Texas A & M University, personal communication):
Soft tissue samples were placed in plastic bags and stored at –20°C for later analysis.
Analytical Procedures.
Feed samples were analyzed for DM and Kjeldahl-N according to AOAC (1998). Neutral detergent fiber, ADF, and ADL were determined according to Van Soest et al. (1991) and modified (Komarek, 1993) for use in an Ankom fiber apparatus (Ankom Technology Corp., Fairport, NY). Copper, Zn, and Fe concentrations were determined using dry ashing methods as described by Hue and Evans (1986). Concentration of Mo in the feed was determined by ashing samples in a muffle furnace followed by digestion using a microwave digestion system (MDS 2100) procedure described by Gengelbach et al. (1994).
Ashed liver samples (AOAC, 1998) collected from the right liver lobe and serum samples (diluted 1:4 in deionized H2O) were used to determine Cu by flame atomic absorption spectrophotometer (GBC 908AA, Perkin-Elmer, Wellesley, MA). Serum samples were also analyzed for total cholesterol concentration according to the method described by Sigma (1995). Triglyceride concentrations (Sigma, 1990) and NEFA concentrations were determined via enzymatic, colorimetric methods (Wako Chemicals, 1995).
Soft tissue from the 9th to 11th rib sections and from the left half of the carcass were thawed at 4°C overnight and ground twice with a Hobart (Hobart Corporation, Troy, OH) meat grinder (Model 4822) using a 9.5-mm grinding plate (C. D. Triump; No. 22). Samples were ground 2 additional times with a KitchenAid Mixer/Grinder (Model K5SS, KitchenAid, Inc., St. Joseph, MI) using a 5-mm grinding plate. Half-carcass samples were thoroughly mixed and subsampled. The soft-tissue samples were analyzed for moisture by drying 5 g samples at 100°C for 48 h. Ash content was determined on dried samples by ashing samples in a muffle furnace at 600°C overnight. Ether extract (EE) was determined on wet samples using the Soxtec Avanti System (Foss Tecator, Model 2055, Foss North America, Eden Prairie, MN), and results were calculated on a wet basis (AOAC, 1995). Nitrogen was determined by the combustion method (AOAC, 1998) using the Leco FP-2000 (Leco Corp., St. Joseph, MI), and CP was calculated as N x 6.25 and expressed on a wet basis.
Statistical Analyses.
The serum data collected on d 14 and 112 and the carcass data were analyzed by the GLM procedure of SAS (SAS Inst., Inc, Cary, NC). The Cu level effects were tested by a polynomial regression using orthogonal contrast for equally spaced treatments (Steel et al., 1997) estimated by the GLM procedure of SAS. The F-test-protected least squares means procedure of SAS was used to separate treatment means. Differences were declared significant at P < 0.05.
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RESULTS AND DISCUSSION
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Performance data and Cu status of goat kids fed high supplemental Cu are in Table 2. Although ADFI of goats decreased (linear; P = 0.05) as Cu supplementation increased, gain efficiency improved (quadratic; P = 0.02) in the 100 mg of Cu group, which is similar to results reported by Solaiman et al. (2001) for Nubian doe goats fed 100 to 150 mg of additional Cu/d. Gengelbach (1994) also observed decreased intake and increased G:F in Angus steers when 10 mg of Cu/kg of DM was supplemented to a corn silage diet containing 5.3 mg of Cu/kg of DM. Our results contrast those reported by Ward and Spears (1997) for a study with growing Angus steers, in which supplementation of 5 mg of Cu/kg of DM to a corn silage diet containing 5.2 mg of Cu/kg of DM increased intake but did not affect gain or G:F. Several factors, such as initial Cu status of the animals, Cu content of basal diet, and concentration of Cu antagonists (Fe, S, and Mo), may affect responses of cattle to supplemental Cu. Serum and liver Cu concentrations were within the reported normal ranges (Beck, 1956) for goats on control and 100 mg of Cu/d; however, liver Cu increased (linear; P = 0.0001) as Cu supplementation increased.
This study is the first to investigate the effects of dietary Cu on serum lipid profile and carcass characteristics in goats. Data are compared with those reported for cattle and other species where appropriate. Serum cholesterol concentrations at d 14 or 112 were not affected (P > 0.10) by dietary treatment (Table 3). Our results agree with findings in steers, in which the addition of 20 or 40 mg of Cu/kg of DM, regardless of Cu source, did not affect serum cholesterol during a 56-d growing phase; however, serum cholesterol decreased by d 84 of the finishing phase (Engle et al., 2000a). In contrast, Engle et al. (2001) reported increased serum cholesterol for lactating Holstein cows fed a 60:40 concentrate:forage (corn silage and alfalfa silage) diet supplemented with 40 mg of Cu/kg of DM. In other studies, however, supplemental Cu decreased serum cholesterol; Angus steers fed high-concentrate finishing diets with 10 or 20 mg of Cu/kg of DM (Engle and Spears, 2000) or Angus and Hereford x Angus steers fed 10 or 40 mg of Cu/kg of DM (Engle et al., 2000b). The discrepancy in the effect of dietary Cu on cholesterol metabolism between studies may be explained partially by the differences in Cu status of the animals and diets used. Control goat kids in our study had liver Cu concentrations of 206 ± 59.0 mg/kg of DM, whereas Holstein cows had liver Cu of 372.4 ± 58.4 mg/kg of DM in the control group (Engle et al., 2001). In contrast, Angus and Angus x Hereford steers in control group reported by Engle et al. (2000a) had final liver Cu of 63.2 ± 22.2 mg/kg of DM, and Angus and Hereford x Angus steers in another study had final liver Cu of 68.2 ± 12.7 mg/kg of DM in the control group (Engle et al., 2000b). Thus, there was a clearly lower Cu status of the animals in the Engle et al. (2000a, b) studies. It seems that, when feeding Cu, low liver Cu was associated with decreased serum cholesterol; however, high liver Cu (perhaps increased lipid metabolism—lipolysis) increased serum cholesterol. Our animals were somewhere in between the cattle used in Engle et al. (2000a,b; 2001). Another discrepancy was the differences in the Cu concentration of basal diets used in these experiments. In our study, the Cu concentration of the basal diet was 13.8 mg of Cu/kg of DM. The basal diet used in the Engle et al. (2001) experiment with Holstein cows was 8.9 mg of Cu/kg of DM. The basal finishing diets used for their 2 other experiments (Engle et al., 2000a,b) had 4.9 mg of Cu/kg of DM. The clear difference in Cu concentration of these basal diets might have contributed to the Cu status of the animals and, in combination with other factors such as species, breed, and gender differences, might have resulted in differences in findings.
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Table 3. Effects of high levels of supplemental copper on mean serum cholesterol, triglycerides, and NEFA in goat kids
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Supplemental Cu did not affect serum triglycerides at d 14 or d 112 (Table 3
); however, NEFA decreased at d 112 (linear; P = 0.01) as supplemental Cu increased. Our results agree with the findings of Engle et al. (2000a, b) and Lee et al. (2002), in which triglycerides were unaffected by Cu supplementation in steers; however, in findings of Bakalli et al. (1995), plasma triglycerides were decreased in broilers fed 250 mg of Cu/kg of DM. Findings on the effects of Cu supplementation on cholesterol, triglycerides, and NEFA are inconsistent. Animal species, breed, individual animal variability, number of animals tested, diet fed, level of supplemental Cu, or concentration of other minerals such as Zn, Mo, or S in the diet may be contributing factors.
The USDA selection criteria used to evaluate live animals or carcasses were unaffected by Cu treatment (Table 4). Goats receiving 100 mg of Cu/d graded in Selection Criterion No. 1 by 76% (100% would be a perfect selection No. 1) for live animals, followed by the control group (graded in Selection Criterion No. 1 by 36%) and those receiving 200 mg Cu/d (graded in Selection Criterion No. 2 by 4%). The carcasses of the control group graded in Selection Criterion No. 1 by 64% were very similar to the 100 mg of Cu/d supplemented group, which graded in Selection Criterion No. 1 by 58%. The carcasses of the 200 mg of Cu/d supplemented group graded in Selection Criterion No. 2 by 18%, following closely the live selection grades. These are the first data reported on selection criteria for goats, and no comparisons can be cited. This selection grade system is specific to goats and limited to the subjectivity of the USDA grader; therefore, the selection criteria cannot be compared with yield measurements in goats.
This study is the first to investigate the effects of dietary Cu on carcass characteristics in goats. Hot carcass weight, chilled carcass weight, carcass shrink, kidney and pelvic fat, and LM area were not affected by dietary Cu treatment (Table 4). Dressing percent (linear; P = 0.08) and BWF tended to decrease (linear; P = 0.08) with increased Cu supplementation. Body fat (linear; P = 0.01) and ADFT (linear; P = 0.03) decreased, and BCTRC % increased (linear; P = 0.04) as Cu supplementation increased (Table 4). Dressing percent, 12th rib fat thickness, and LM area in our study were in accord with values reported by Oman et al. (1999, 2000) for Boer x Spanish kids similar in age and fed concentrate-based diets.
The decrease in fat depth observed in goat kids receiving supplemental Cu is similar to that observed previously in Angus and Angus x Hereford steers fed 20 or 40 mg of Cu/kg of DM (Ward and Spears, 1997; Engle and Spears, 2000; Engle et al., 2000a,b). Engle and Spears (2001) reported that 10 or 40 mg of Cu/kg of DM fed to Simmental steers had minimal effects on lipid metabolism. Decreased fat thickness can be partially explained in the study reported by Sinnett-Smith and Woolliams (1987), in which Cu supplementation increased basal and norepinephrine-stimulated lipolytic rates in lamb adipose tissue. Acetyl CoA carboxylase (ACC) is the rate-limiting enzyme of fatty acid synthesis, which is allosterically controlled and responds to both hormonal and metabolite stimuli in all species (Munday et al., 1991). The products of ACC provide substrates for fatty acid synthesis via fatty acid synthase (FAS). Reduction in ACC may limit fatty acid synthesis through FAS. In an attempt to determine the effect of supplemental Cu on lipogenic gene expression in steers, Lee et al. (2002) reported that dietary Cu (10 or 20 mg of Cu/kg of DM) did not influence the level of s.c. adipose tissue ACC mRNA. They concluded that in their study, the amount of supplemental Cu might have been too low to induce expression of the genes involved in lipid metabolism; however, in chicks, a high concentration of dietary Cu (180 mg/kg of dietary DM) decreased FAS activity in the liver (Konjufca et al., 1997). Moreover, in rats, Cu deficiency increased hepatic FAS mRNA (Wilson et al., 1997). Acetyl CoA carboxylase and FAS activities were not measured in the current study; however, a decrease in ACC or FAS enzyme activities could explain the decreased 12th rib fat thickness observed. In addition, it has been shown that different breeds of cattle have different fat deposition patterns (Smith et al., 1976; Koch et al., 1976) and Cu metabolism (Gooneratne et al., 1994; Ward et al., 1995). Experiments examining breed, species differences in lipid metabolism, and Cu metabolism and any potential interactions need to be conducted to better understand the effect of Cu on lipid metabolism in cattle and goats.
Reports of body composition as they relate to mineral supplementation are limited in goats, and direct comparisons could not be made. Tahir et al. (1994) reported that measurement of the 9th to 11th rib section was considered the acceptable part of the carcass to predict total protein, fat, and bone in the carcass of sheep and cattle. Chemical composition of the 9th to 11th rib sections and one-half the carcasses of the experimental goats are shown in Table 5. The percent moisture of the 9th to 11th rib sections increased (linear; P = 0.03), and percent EE decreased (linear; P = 0.02) as Cu supplementation increased. Mahgoub et al. (2000) reported an increase in level of fat and a decrease in water in carcasses of Omani sheep fed a high-energy diet. Water content in an animal’s body tends to decrease as live weight increases, and fat deposition increases during late growth when the moisture in the animal’s body decreases (Naude and Hofmeyer, 1981). Evidently, Cu supplementation changed this trend in our study. The percent protein and ash in the 9th to 11th rib sections tended to increase (linear; P = 0.09, and linear; P = 0.06, respectively) with increased Cu supplementation. The trend in increased protein and ash in the carcass along with increased moisture could partially explain these changes.
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Table 5. Effects of high levels of supplemental Cu on whole carcass based on 9th to 11th rib section and half-carcass composition of goat kids
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Chemical composition of the left half of the carcass was measured to confirm the values for 9th to 11th rib sections (Table 5). Although moisture was underestimated (6 to 8 percentage units) and EE was overestimated (6 to 9 percentage units) in 9th to 11th rib sections, percentages of protein and ash were similar to those reported for the left half of the carcass. Cameron et al. (2001) reported similar moisture (56.1%), fat (18.6%), and greater protein (20.3%) and ash (8.87%) in carcasses of Boer x Spanish goats at 212 d of age fed a concentrate-based diet containing 25% CP. Marinova et al. (2001) reported carcass composition in Bulgarian White male goats that were 4 to 5 mo of age and were fed a 39:61 grain:hay diet containing 15% CP. In their study, one-half of carcass moisture was numerically greater (69.9%), and fat was numerically less (10.3%) than in our study; however, CP (18.9%) and ash (0.89%) were similar to our values. The difference in moisture and fat can be explained by the difference in the age, gender, and diet. In our study, animals were 8 to 9 mo of age at the time of slaughter and were castrated males fed 70:30 grain:hay diets.
In summary, Cu supplementation at 100 mg/d improved gain efficiency, altered serum lipid profile, decreased carcass fat depth over the LM, and improved carcass BCTRC in goat kids fed a high-concentrate diet. Decreasing deposited fat on the carcass may have health benefits for humans and ultimately decrease the waste per carcass. Measurements of 9th to 11th rib sections may be used to determine carcass composition; however, more data are needed to validate this procedure. Further research is needed to determine the role of Cu on lipid and cholesterol metabolism in goats.
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Footnotes
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2 Present address: Dept. of Anim. Sci., Auburn University. 
1 Corresponding author: ssolaim{at}tuskegee.edu
Received for publication April 7, 2005.
Accepted for publication August 28, 2005.
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LITERATURE CITED
|
|---|
Amer, A. M., and J. I. Elliot. 1973. Effects of level of copper supplement and removal of supplemental copper from the diet on the physical and chemical characteristics of porcine depot fat. Can. J. Anim. Sci. 53:139–145.
AOAC. 1995. Official Methods of Analysis. 16th ed. Assoc. Offic. Anal. Chem., Arlington, VA.
AOAC. 1998. International Official Methods of Analysis. 16th rev. ed. Assoc. Offic. Anal. Chem., Gaithersburg, MD.
Bakalli, R. I., G. M. Pesti, W. L. Ragland, and V. Konjufca. 1995. Dietary copper in excess of nutritional requirements reduces plasma and breast muscle cholesterol of chickens. Poult. Sci. 74:360–365.[Medline]
Beck, A. B. 1956. The copper content of the liver and blood of some vertebrates. Aust. J. Zool. 4:1–18.
Cameron, M. R., J. Luo, T. Sahlu, S. P. Hart, S. W. Coleman, and A. L. Goetsch. 2001. Growth and slaughter traits of Boer x Spanish, Boer x Angora, and Spanish goats consuming a concentrate-based diet. J. Anim. Sci. 79:1423–1430.[Abstract/Free Full Text]
Engle, T. E., V. Fellner, and J. W. Spears. 2001. Copper status, serum cholesterol, and milk fatty acid profile in Holstein cows fed varying concentrations of copper. J. Dairy Sci. 84:2308–2313.[Abstract]
Engle, T. E., and J. W. Spears. 2000. Dietary copper effects on lipid metabolism, performance, and ruminal fermentation in finishing steers. J. Anim. Sci. 78:2452–2458.[Abstract/Free Full Text]
Engle, T. E., and J. W. Spears. 2001. Performance, carcass characteristics, and lipid metabolism in growing and finishing Simmental steers fed varying concentrations of copper. J. Anim. Sci. 79:2920–2925.[Abstract/Free Full Text]
Engle, T. E., J. W. Spears, T. A. Armstrong, C. L. Wright, and J. Odle. 2000a. Effects of dietary copper source and concentration on carcass characteristics and lipid and cholesterol metabolism in growing and finishing steers. J. Anim. Sci. 78:1053–1059.[Abstract/Free Full Text]
Engle, T. E., J. W. Spears, L. Xi, and F. W. Edens. 2000b. Dietary copper effects on lipid metabolism and circulating catecholamine concentrations in finishing steers. J. Anim. Sci. 78:2737–2744.[Abstract/Free Full Text]
Gengelbach, G. P. 1994. Effects of copper deficiency on cellular immunity in cattle. Ph.D. Diss., North Carolina State Univ., Raleigh.
Gengelbach, G. P., J. D. Ward, and J. W. Spears. 1994. Effect of dietary copper, iron, and molybdenum on growth and copper status of beef cows and calves. J. Anim. Sci. 72:2722–2727.[Abstract]
Gooneratne, S. R., H. W. Symonds, J. B. Bailey, and D. A. Christensen. 1994. Effects of dietary copper, molybdenum, and sulfur on biliary copper and zinc excretion in Simmental and Angus cattle. Can. J. Anim. Sci. 74:315–325.
Hankins, O. G., and P. E. Howe. 1946. Estimation of composition of beef carcasses and cuts. USDA Tech. Bull. 926. Washington, DC.
Hue, N. V., and C. E. Evans. 1986. Procedures used for soil and plant analysis by the Auburn University Soil Testing Laboratory. Alabama Agric. Exp. Stn., Dep. of Agron. and Soils, Dep. Series 106.
Koch, R. M., M. E. Dikeman, D. M. Allen, M. May, J. D. Crouse, and D. R. Campion. 1976. Characterization of biological types of cattle III. Carcass composition, quality and palatability. J. Anim. Sci. 43:48–62.[Abstract/Free Full Text]
Komarek, A. R. 1993. An improved filtering technique for the analysis of neutral detergent fiber and acid detergent fiber utilizing the filter bag technique. J. Anim. Sci. 71:824–829.
Konjufca, V. H., G. M. Pesti, and R. I. Bakalli. 1997. Modulation of cholesterol levels in broiler meat by dietary garlic and copper. Poult. Sci. 76:1264–1271.[Abstract/Free Full Text]
Lee, S. H., T. E. Engle, and K. L. Hossner. 2002. Effects of dietary copper on the expression of lipogenic genes and metabolic hormones in steers. J. Anim. Sci. 80:1999–2005.[Abstract/Free Full Text]
Mahgoub, O., C. D. Lu, and R. J. Early. 2000. Effects of dietary energy on feed intake, body weight gain and carcass chemical composition of Omani growing lambs. Small Rumin. Res. 37:35–42.[Medline]
Malan, S. W. 2000. The improved Boer goat. Small Rumin. Res. 36:165–170.[Medline]
Marinova, P., V. Banskalieva, S. Alexandrov, V. Tzvetkova, and H. Stanchev. 2001. Carcass composition and meat quality of kids fed sunflower oil supplemented diet. Small Rumin. Res. 42:217–225.
Munday, M. R., M. R. Milic, S. Takhar, M. M. Holness, and M. C. Sugden. 1991. The short term regulation of hepatic acetyl-CoA carboxylase during starvation and refeeding in the rat. Biochem. J. 280:733–739.[Medline]
Naude, R. T. and H. S. Hofmeyer. 1981. Meat Production. Pages 285–307 in Goat Production. C. Gall ed. Academic Press, New York, NY.
NRC. 1981. Pages 10–12 in Nutrient Requirements of Goats. Natl. Acad. Press, Washington, DC.
Oman, J. S., D. F. Waldron, D. B. Griffin, and J. W. Savell. 1999. Effect of breed-type and feeding regimen on goat carcass traits. J. Anim. Sci. 77:3215–3218.[Abstract/Free Full Text]
Oman, J. S., D. F. Waldron, D. B. Griffin, and J. W. Savell. 2000. Carcass traits and retail display-life of chops from different goat breed types. J. Anim. Sci. 78:1262–1266.[Abstract/Free Full Text]
Pesti, M. G., and R. I. Bakalli. 1996. Studies on the feeding of cupric sulfate pentahydrate and cupric citrate to broiler chickens. Poult. Sci. 75:1086–1091.[Medline]
Sigma. 1990. Triglycerides: Quantitative, enzymatic determination in serum or plasma at 500 nm. Tech. Bull. No. 336. rev. ed. Sigma Chemical Co., St. Louis, MO.
Sigma. 1995. Total cholesterol: Quantitative, enzymatic determination in serum or plasma at 500 nm. Tech. Bull. No. 352. Sigma Chemical Co., St. Louis, MO.
Sinnett-Smith, P. A., and J. A. Woolliams. 1987. Adipose tissue metabolism and cell size: Variation between subcutaneous sites and the effect of copper supplementation. Anim. Prod. 45:75–80.
Smith, G. M., D. B. Laster, L. V. Cundiff, and K. E. Gregory. 1976. Characterization of biological types of cattle II. Postweaning growth and feed efficiency of steers. J. Anim. Sci. 43:37–47.[Abstract/Free Full Text]
Solaiman, S. G., M. A. Maloney, M. A. Qureshi, G. Davis, and G. D’Andrea. 2001. Effects of high copper supplements on performance, health, plasma copper, and enzymes in goats. Small Rumin. Res. 41:127–139.[Medline]
Steel, R. G. D., J. H. Torrie, and D. A. Dickey. 1997. Principles and Procedures of Statistics: A Biometrical Approach. 3rd ed. McGraw-Hill Book Co., New York, NY.
Tahir, M. A., A. F. Al-Jassim, and A. H. H. Abdulla. 1994. Influence of live weight and castration on distribution of meat, fat and bone in the carcass of goats. Small Rumin. Res. 14:219–223.
USDA. 2001. Institutional Meat Purchased Specifications for Fresh Goat. Series 11. USDA/MRP/AMF, Livestock and Seed Program, Meat Grading Certification Branch, Washington, DC.
Van Soest, P. J., J. B. Robertson, and B. A. Lewis. 1991. Methods for dietary fiber, neutral detergent fiber, and non starch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74:3583–3597.[Abstract]
Wako Chemicals. 1995. Enzymatic colorimetric methods for quantification of non-esterified fatty acid in serum. Procedure No. 994-75409E. Nissanstr, Germany.
Ward, J. D., and J. W. Spears. 1997. Long-term effects of consumption of low-copper diets with or without supplemental molybdenum on copper status, performance, and carcass characteristics of cattle. J. Anim. Sci. 75:3057–3065.[Abstract/Free Full Text]
Ward, J. D., J. W. Spears, and G. P. Gengelbach. 1995. Differences in copper status and copper metabolism among Angus, Simmental, and Charolais cattle. J. Anim. Sci. 73:571–577.[Abstract]
Wilson, J., S. Kim, K. G. Allen, R. Baillie, and S. D. Clarke. 1997. Hepatic fatty acid synthase gene transcription is induced by a dietary copper deficiency. Am. J. Physiol. 272:E1124–E1129.[Medline]
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Abstract
INTRODUCTION
