Effects of using ground redberry juniper and dried distillers grains with solubles in lamb feedlot diets: growth, blood serum, fecal, and wool characteristics.

Effects of using ground redberry juniper and dried distillers grains with solubles (DDGS) in Rambouillet lamb (n = 45) feedlot diets on growth, blood serum, fecal, and wool characteristics were evaluated. In a randomized design study with 2 feeding periods (Period 1 = 64% concentrate diet, 35 d; Period 2 = 85% concentrate diet, 56 d), lambs were individually fed 5 isonitrogenous diets: a control diet (CNTL) that contained oat hay but not DDGS or juniper or DDGS-based diets in which 0 (0JUN), 33 (33JUN), 66 (66JUN), or 100% (100JUN) of the oat hay was replaced by juniper. During Period 1, lambs fed CNTL had greater (P < 0.05) DMI and ADG and tended to have greater (P < 0.10) G:F than lambs fed 0JUN or lambs fed DDGS-based diets. Lamb DMI, ADG, and G:F quadratically increased (P < 0.008) as juniper increased in the DDGS-based diets. During Period 2, lambs fed CNTL had greater (P < 0.05) DMI than lambs fed 0JUN or lambs fed DDGS-based diets, but ADG was similar (P > 0.41). Compared to 0JUN, lambs fed CNTL had similar (P = 0.12) G:F and tended to have less G:F (P = 0.07) than lambs fed DDGS-based diets. Among lambs fed DDGS-based diets, DMI was similar (P > 0.19), ADG increased linearly (P = 0.03), and G:F tended to decrease quadratically (P = 0.06) as juniper increased in the diet. Serum IGF-1, serum urea N (SUN), and fecal N were greater (P < 0.05) and serum Ca and P and fecal P were similar (P > 0.13) for lambs fed CNTL vs. lambs fed DDGS-based diets (CNTL). Within lambs fed DDGS-based diets, SUN increased quadratically (P = 0.01) and fecal N increased linearly (P = 0.004), which can partially be attributed to increased dietary urea and condensed tannin intake. Most wool characteristics were not affected, but wool growth per kilogram of BW decreased quadratically (P = 0.04) as percentage of juniper increased in the DDGS-based diets. When evaluating the entire 91-d feeding trial, results indicated that replacing all of the ground oat hay with ground juniper leaves and stems in lamb growing and finishing diets is not detrimental to animal performance and that DDGS-based diets can reduce total feedlot costs, as compared to sorghum grain and cottonseed meal-based diets. However, compared to using juniper or oat hay as the sole roughage source, using both during the growing period (Period 1) enhanced growth performance and further reduced total feedlot costs.

Redberry juniper as a roughage source in lamb feedlot rations: wool and carcass characteristics, meat fatty acid profiles, and sensory panel traits.

Effects of replacing cottonseed hulls with juniper leaves on end products were investigated in lambs. Lambs were individually fed diets containing cottonseed hulls (CSH), half of the CSH replaced by juniper (CSHJ), or all the CSH replaced by juniper (JUN). Lambs grew the same amount of wool when measured as greasy fleece (P>0.19), clean fleece (P>0.46), and clean wool production per unit of BW (P>0.54). Average fiber diameter quadratically decreased (P=0.04) and became more uniform (P<0.04) as percentage of juniper increased in the diet. Carcass characteristics were not affected (P>0.16) by diet. Myristic, palmitoleic, and arachidic acids, cis-9, trans-11 CLA, and the ∆9 desaturase index linearly increased (P<0.09) and stearic acid linearly decreased (P=0.05) as percentage of juniper increased in the diet. Off-flavor linearly increased (P=0.02) as juniper increased in the diet.

Evaluating percentage of roughage in lamb finishing diets containing 40% dried distillers grains: growth, serum urea nitrogen, nonesterified fatty acids, and insulin growth factor-1 concentrations and wool, carcass, and fatty acid characteristics.

Effects of percentage of roughage on growth, serum urea N, NEFA, and IGF-1 concentrations and wool, carcass, and fatty acid (FA) characteristics were investigated in Rambouillet wether lambs (n = 33). Lambs were individually fed ad libitum pelleted diets for 98 d containing 40% dried distillers grains and other ingredients, with 10% (CSH10), 20% (CSH20), or 30% (CSH30) cottonseed hulls replacing an increasing amount of ground sorghum grain. Results indicated no interaction between diet and day for lamb BW, ADG, or G:F. Percentage of roughage did not affect lamb BW, even though ADG linearly increased (P = 0.005) as cottonseed hulls increased in the diet. Increasing percentage of cottonseed hulls in the diet linearly increased (P < 0.001) daily DMI, which resulted in a linear increase (P = 0.001) in degradable protein intake. All lambs had similar G:F: 0.200, 0.181, and 0.190 for lambs fed CSH10, CSH20, and CSH30 diets, respectively. Diet x day interactions were not observed (P > 0.45) for serum urea N, NEFA, or IGF-1 concentrations. Serum urea N linearly increased (P = 0.005) as percentage of cottonseed hulls increased in the diet. All lambs had similar NEFA concentrations, but serum IGF-1 linearly decreased (P = 0.001) as percentage of cottonseed hulls increased in the diet. Lambs had similar wool fiber characteristics except that average fiber curvature and SD of fiber curvature linearly increased (P = 0.03) as percentage of cottonseed hulls increased in the diet. Carcass characteristics and sensory panel traits were not affected (P > 0.19) by diet, except for body wall thickness (quadratic, P = 0.03) and a linear decrease in sustained tenderness (P = 0.02) as the percentage of cottonseed hulls increased in the diet. As cottonseed hulls increased in the diet, percentages of myristic and palmitoleic (linear, P < 0.05) and arachidic SFA (quadratic, P = 0.03) decreased and cis-9,trans-11 CLA increased (linear, P = 0.007). When sorghum grain and cottonseed hull prices are similar to those reported for this study, lamb feeders are advised to use the CSH30 diet vs. CSH10 or CSH20 diets because even though DMI was greater for lambs consuming CSH30 diet, those lambs had greater ADG and the least cost of feed x kg(-1) of BW gain.

Pharmacokinetic differences in exposure to camphor after intraruminal dosing in selectively bred lines of goats.

A pharmacokinetic dosing study with camphor was used to determine whether selection lines of high-juniper-consuming goats (HJC, n = 12) and low-juniper-consuming goats (LJC, n = 12) differed in their respective disposition kinetics. Postdosing plasma camphor concentrations were used to examine whether a timed single blood sample collected after intraruminal administration of camphor would be a useful screening test to aid in the identification of HJC. Yearling female Boer x Spanish goats (n = 24) received a single intraruminal dose of monoterpene cocktail (0.270 g/kg of BW) containing 4 different monoterpenes that represented their composition previously reported for Ashe juniper (Juniperus ashei). Camphor, the predominant monoterpene in Ashe juniper, was 49.6% of the mix and was the monoterpene analyzed for this study. Blood samples were taken at 15 time points from 0 to 8 h after dosing. Concentrations of camphor were measured in plasma using solid phase extraction and gas chromatography/flame-ionization detection analysis. Maximal plasma concentration of camphor was greater for LJC than HJC (P = 0.01), and area under the curve extrapolated to infinity was greater for LJC than HJC (P < 0.01). Total systemic exposure (area under the curve) to camphor was 5 times less in HJC goats. We conclude that 1) HJC goats possess internal mechanisms to reduce the bioavailability of camphor, and 2) a blood sample taken at 45 min or at 60 min after intraruminal administration of camphor may be useful for identifying HJC individual animals from within large populations of goats.

Heritability of juniper consumption in goats.

Data from goats (n = 505), collected over a 4-yr period, were used to estimate the heritability of juniper consumption. Juniper consumption was determined by near-infrared spectroscopy on fecal samples (n = 1,080) collected from female Boer-cross goats grazing pastures with a variety of plants, including juniper. The animals with records were progeny of 72 sires. Individual goats had from 1 to 4 observations over a 4-yr period. Predicted juniper consumption for individual observations ranged from -5 to +62% of the diet. Data were analyzed with a mixed model that included management group as a fixed effect, BW as a covariate, and permanent environment, animal, and residual as random effects. Management group was a significant source of variation. Least squares means of juniper consumption, as a percentage of the total intake, for management groups varied from 19 to 47%. Heritability of juniper consumption was 13%. Repeatability of juniper consumption was 31%. These results suggest that progress to selection for goats that will consume greater amounts of juniper is obtainable, but is expected to be slow.

Impacts of animal science research on United States sheep production and predictions for the future.

One hundred years ago, there were more than 48 million sheep in the United States. In 1910, they were valued at $4/head, with 43% of income coming from the sale of sheep, lambs, and meat and 57% coming from wool. Over the years, fluctuations in this ratio have challenged the breeder and researcher alike. By 2007, sheep numbers had declined to 6.2 million, with the average sheep shearing 3.4 kg of wool (representing <10% of income), 0.2 kg more than in 1909 but 0.5 kg less than fleeces in 1955. Sheep operations have declined by more than 170,000 in the past 40 yr. A cursory examination of this information might lead one to conclude that animal science research has made little impact on sheep production in the United States. On the contrary, lamb crops in the new millennium (range = 109 to 115%) are greater than those recorded in the 1920s (85 to 89%) and dressed lamb weights increased from 18 to 32 kg from 1940 to the present. In the past century, researchers conducted thousands of investigations, with progress reported in new, existing, and crossbreed evaluations, quantitative and molecular genetics, selection, nutrition, fiber, meat, hides, milk, growth, physiology, reproduction, endocrinology, management, behavior, the environment, disease, pharmacology, toxicology, and range, pasture, and forage utilization such that a vast amount of new information was accrued. Our understanding of sheep has benefited also from research conducted on other species, and vice versa. Many factors that have contributed to the decline in the sheep industry are not influenced easily by academic research (e.g., low per capita consumption of lamb meat, predation, reluctance to adopt new technologies, cost and availability of laborers with sheep-related skills, and fewer young people pursuing careers in agriculture). The size of the US sheep industry is expected to remain stable, with possible slow growth in the foreseeable future. To remain profitable, producers will take advantage of new (or previously unused) technologies, the desire of the public for things natural, domestic niche and international fiber markets, and the ability of the sheep to control noxious weeds and thrive in suboptimal ecosystems.

Effects of breed, sex, and age on the variation and ability of fecal near-infrared reflectance spectra to predict the composition of goat diets.

The effects of breed, sex, and age of goats on fecal near-infrared reflectance spectroscopy-predicted percentage juniper in the diet were investigated, as were spectral differences in feces from goats differing in estimated genetic merit for juniper consumption. Eleven goats from each breed, sex, and age combination, representing 2 breeds (Angora and meat-type), 3 sex classifications (female, intact male, and castrated male), and 2 age categories [adult and kid (less than 12 mo of age)] were fed complete, pelleted rations containing 0 or 14% juniper. After 7 d on the same diet, fecal samples were collected for 3 d, and the spectra from the 3 replicate samples were averaged. Fecal samples were assigned to calibration or validation data sets. In a second experiment, Angora and meat goats with high or low estimated genetic merit for juniper consumption were fed the same diet to determine the effect of consumer group on fecal spectra. Feces were scanned in the 1,100- to 2,500-nm range with a scanning reflectance monochromator. Fecal spectra were analyzed for the difference in spectral characteristics and for differences in predicted juniper in the diet using internal and independent calibration equations. Internal calibration had a high precision (R(2) = 0.94), but the precision of independent validations (r(2) = 0.56) was low. Spectral differences were affected by diet, sex, breed, and age (P < 0.04). However, diet was the largest source of variation in spectral differences. Predicted percentage of juniper in the diet also showed that diet was the largest source of variation, accounting for 95% of the variation in predictions from internal calibrations and 51% of the variation in independent validations. Predictions from independent calibrations readily detected differences (P < 0.001) in the percentage of juniper in the 2 diets, and the predicted differences were similar to the actual differences. Predicted juniper in the diet was also affected by sex. Feces from goats from different juniper consumer groups fed a common diet were spectrally different, and the difference may have resulted from a greater intake by high- compared with low-juniper-consuming goats. Fecal near-infrared reflectance spectroscopy predictions of botanical composition of diets should be considered an interval scale of measurement.

Fiber production and properties in genetically furred and furless rabbits.

The objectives of this study were to describe and compare means and measures of variability of fiber characteristics and fiber production between genetically furred and furless rabbits and among classes of furless rabbits. An F1 generation of rabbits was produced by mating New Zealand White does to a rare, furless Mini Lop buck. All F1 offspring had normal coats of fur. Inter se random matings of the F1 stock (barring full-sibling matings) were made to produce the F2 generation that consisted of approximately 75% furred and 25% furless progeny. Furless animals were further subjectively classified into 3 distinct classes (1 to 3) having increasingly more fur. In yr 1, 17 furred and 20 furless rabbits (age 28 to 49 d) were randomly assigned to growing pens, and in yr 2, 17 additional furless and 9 additional furred rabbits were included to increase the size. After 6 wk, the rabbits were weighed, and a measured area of fur (approximately 20 cm2) was shorn from the left flank of each rabbit. This fiber was weighed and measured for staple length, fiber diameter, prickle factor (% of fibers > 30 microm in diameter), and fiber curvature. Fiber production per unit area of skin was calculated and fiber production per animal was estimated. In yr 2, all of the furless and 2 of the furred rabbits were shorn over their entire bodies to obtain direct measurements of total fur weight. Furless rabbits were 9% heavier (1,941 vs. 1,783 g of BW, P < 0.01) and produced approximately 90% less fiber per unit area of skin than furred rabbits (1.74 vs. 15.83 mg/cm2, P < 0.01). The fibers from furless rabbits were shorter (1.54 vs. 2.56 cm, P < 0.01) and coarser (15.8 vs. 14.5 microm diameter, P < 0.01) than those from furred rabbits and exhibited greater prickle factor (11.3 vs. 3.5%, P < 0.01) and curvature values (47.5 vs. 38.5 deg/mm, P < 0.01). Class 3 furless rabbits were heavier than rabbits of classes 1 and 2 (2,075 vs. 1,817 and 1,981 g of BW, respectively, P < 0.05). Means for actual total fiber production per animal for classes 1 to 3 were 0.64, 2.07, and 8.68 g, respectively, compared with 23.0 g for furred rabbits (P < 0.01). Although some similarities were present, several of the correlations involving fiber properties and BW were substantially different (e.g., BW vs. staple length and fiber diameter vs. weight of fiber per unit area) for furred and furless groups. These results, and those reported elsewhere from a series of experiments, support the potential for production of furless rabbits in arid and tropical environments.

Evaluation of Dorset, Finnsheep, Romanov, Texel, and Montadale breeds of sheep: III. Wool characteristics of F1 ewes.

An experiment was designed to evaluate the effects of five sire breeds (Dorset, Finnsheep, Romanov, Texel, and Montadale), two dam breeds (Composite III [CIII] and northwestern whiteface [WF]), and three shearing seasons (December, February, and April, corresponding to August, October, and December breeding seasons) and their interactions on wool and other characteristics of F1 ewes. Fleeces were collected and characterized from six 2-yr-old F1 ewes representing each of the 90 sire breed x dam breed x shearing season x year (three) subclasses. Characteristics measured objectively were grease and clean fleece weights, clean yield, mean fiber diameter and SD, and mean staple length and SD. Visual assessments of fleece color were also made. Data collected on the F1 ewes were analyzed using a mixed model analysis of variance procedure. The model included fixed effects of year of birth, sire breed, dam breed, shearing season, six two-way interactions, and the three-way interaction of sire breed x dam breed x shearing season. The random effect of individual sire within year of birth x sire breed was also fitted. Texel- and Montadale-sired ewes produced more clean wool (P < 0.05) (approximately 0.24 kg) than Dorset-, Finnsheep-, and Romanov-sired ewes. Texel-sired ewes produced the coarsest wool (28.7 microm) (P < 0.05), whereas Romanov-sired ewes produced the finest (24.9 microm) and longest (9.12 cm) fleeces (P < 0.05). Ewes from WF dams produced more and finer wool (0.15 kg and 2.7 microm) than ewes from CIII dams (P < 0.001). Ewes shorn in December produced more, coarser, and longer wool (P < 0.05) than those shorn in February and April. This trend in wool production is opposite to that in conception rate (reported previously). Romanov-sired ewes produced the lowest percentage of white fleeces (62.6%), whereas Dorset-sired ewes produced the most (P < 0.001) white fleeces (96.3%). Estimates of heritability were calculated for grease and clean fleece weights (0.36), percentage of clean yield (0.31), average fiber diameter and SD (0.86 and 0.42, respectively), and average staple length and SD (0.49 and 0.00, respectively). Although necessary for a thorough evaluation of these 10 types of crossbred ewes, it is estimated that wool income would only constitute a small portion (1 to 5%) of overall income from sheep of this type.

Carcass traits of Rambouillet and Merino × Rambouillet lambs and fatty acid profiles of muscle and subcutaneous adipose tissues as affected by new sheep production system.

Rambouillet and Merino×Rambouillet lambs were assigned to production systems varying in physical environment and diet: RF (raised-floor, open-sided barn/85% oat hay-10% wheat-5% molasses), FL (feedlot/high-concentrate), and P (pasture/grazing plus supplement). Although treatment duration was varied to produce similar final weights, RF lambs were heavier than P lambs, but dressing percentages were similar. Backfat thickness was less with P and for Merino cross lambs. RF feed was higher in saturated fatty acids (SFA) percentage than FL feed and P supplement, but lower compared to pasture plants. For both breed types, muscle tissue from RF was higher in SFA and lower in polyunsaturated fatty acids (PUFA) percentage than that from FL or P. In adipose tissue, SFA and PUFA tended to be higher and monounsaturated fatty acids were lower with RF for Merino cross lambs. Nevertheless, 16:0 or 18:1 percentage differences among P, FL and RF lamb tissue samples were minor vs. large variations among their respective diets.

Effects of sheep production systems on oxidative storage stability of lean lamb patties.

Rambouillet lambs were assigned to three production systems varying in physical environment and diet: RF (a new, raised-floor feeding structure, with animals fed a pelleted mixture of 85% oat hay, 7.5% barley and 7.5% molasses); FL (a feedlot, with animals fed high-concentrate rations); and P (a pasture, with animals given access to the pasture and a high-concentrate supplement). Lengths of time on feed were adjusted to produce similar final shorn weights for each system. Ground meat patties were made with knife-separable lean from hind legs and aerobically refrigerated. Fat content of patties was not significantly different between RF and FL or P, while total unsaturated fatty acid percentage was slightly lower (P<0.05) for RF treatment. Patty color (redness) was most stable for RF. Lipid oxidation in raw patties also was lower (P<0.05) for RF than FL, but oxidation in cooked patties was greater for RF.

Fiber characteristics of qiviut and guard hair from wild muskoxen (Ovibos moschatus).

In response to increasing commercial interest and the high market value of qiviut (the downy underwool of the muskox), we have employed standards and measurements used in the wool and cashmere industries to describe qiviut fiber characteristics. Fleece samples (qiviut with guard hair) were shaved from the midshoulder of 299 wild muskox hides of known sex and age (1, 2, 3, and 4+ yr) during the Banks Island, Canada, muskox harvest in November 1997. Samples were analyzed for fiber diameter distribution of raw fiber and qiviut, scoured and qiviut yields, and lengths of guard hair and qiviut fiber. We found a sex x age interaction for average fiber diameter (AFD) in raw fiber (P= 0.002) and qiviut (P < 0.001) only. Adult males had significantly coarser AFD than females (21.5 microm, males vs 20.1 microm, females and 18.2 microm, males vs 17.5 microm, females) for raw fiber and qiviut, respectively. Qiviut AFD from yearlings was 1.7 microm finer than the AFD of adult qiviut. Fiber diameter distribution (SD) decreased with age in the raw sample (P < 0.003) and qiviut (P < 0.001) and qiviut SD was greater (P < 0.001) in males than in females. Qiviut theoretical yield (% mass of fibers < or = 30 microm) increased (P < 0.001) with age, and females had higher theoretical yields than males (P < 0.001). Scoured yield did not vary between sexes in any age class and averaged 93.3%. Qiviut staple length did not differ with either age or sex. In summary, differences between the sexes were small up to the 3rd yr, and these differences were not likely to be of commercial importance. However, considering that AFD is a primary commercial criterion of value, AFD changes from 16.5 microm in yearlings to 18.2 microm in adults and from 17.5 microm in adult females to 18.2 microm in adult males would be expected to result in significant differences in commercial value.

Prediction of clean mohair, fiber diameter, vegetable matter, and medullated fiber with near-infrared spectroscopy.

Four experiments were conducted in three separate years to test the utility of near-infrared spectroscopy (NIRS) to predict the clean mohair content of Angora goat fleece. Mohair fleece samples were obtained each year from yearling billies at the conclusion of the Angora Goat Performance Test conducted at the Texas A&M University Research Station, Sonora. In Exp. 1 (n = 293) and Exp. 2 (n = 256), fleeces were scanned with a Pacific Scientific (Silver Spring, MD) near-infrared spectrometer fitted with a fiber-optic probe, and calibrations were developed for clean mohair content. In Exp. 3, 59 mohair fleeces collected at the Texas A&M Research Station in San Angelo were sampled four times each. Each sample was scanned with the same spectrometer in reflectance mode fitted with a transport mechanism. This mechanism allowed the instrument to scan a 15-cm2 segment of the fleece sample. Conventional procedures to determine reference values for mohair yield, vegetable matter content, fiber diameter, and percentage of medullated and kemp fibers were conducted. Prediction equations were developed that related NIR spectra to reference values for yield and diameter parameters and were used to predict mohair characteristics for each fleece sample. The predicted and reference values were subjected to a simple analysis of variance to determine variation within and across samples. In Exp. 1, mohair base was related to NIR spectra with R2 = .46 and standard error of calibration (SEC) = 2.84%. In Exp. 2, similar repeatability errors for mohair base could be obtained for both reference- and NIRS-derived values. Fiber diameter and medullated fibers were poorly related to NIR spectra. When samples were scanned using the transport mechanism (Exp. 3), R2 and SEC were .82 and 1.19% for mohair base and .93 and .98 microm for fiber diameter, respectively. The CV for mohair base and diameter were 1.0 and 1.4%, whereas those for predicted mohair base and diameter were 1.4 and 3.4%, respectively. The increased variation within samples for predicted values represents sampling error and lack of fit between NIRS and the laboratory determined values. When the samples from Exp. 1 and 2 were rescanned with the NIRS transport (Exp. 4), R2 and SEC were .79 and 2.03% for mohair base and .52 and 3.49 microm for fiber diameter. The fiber optic probe would facilitate real-time analysis on the shearing floor, but our data indicate that the spectral limitations so far are too severe. A large sample device such as the transport gave excellent results for predicting mohair base and fiber diameter.

Effects of fish meal and sodium bentonite on daily gain, wool growth, carcass characteristics, and ruminal and blood characteristics of lambs fed concentrate diets.

We evaluated the effects of replacing some soybean meal (SBM) protein with fish meal (FM) protein in diets adequate and slightly deficient in CP, with or without .75% sodium bentonite (NaB) on performance and ruminal and blood metabolites of individually fed Suffolk lambs. Diets were based on corn, SBM, and cottonseed hulls. In Exp. 1, five lambs were assigned to each of the three dietary treatments (11% CP with 3% FM, 13% CP with 0 or 3% FM). Lambs fed diets that contained 11% CP with 3% FM or 13% CP with 0% FM had similar DMI and ADG. Gain and feed efficiency were slightly improved (P = .18) by the 13% CP diet with 3% FM. In Exp. 2, 32 lambs were assigned to four dietary treatments (13.5% CP of DM) in a 2 x 2 factorial arrangement (0 or 3% FM, and 0 or .75% NaB on an as-fed basis). The DMI and ADG were increased (P < .05) by FM and NaB supplementation. Interactions (P < .05) revealed that NaB increased DMI, ADG, gain per feed (g/kg of DMI), and plasma urea N concentration in the absence of FM but not in the presence of FM in the diet. Neither FM nor NaB influenced (P = .25) wool growth. Total ruminal VFA were increased (P < .06) by FM and NaB. Differences in mineral content of phalanx bone, liver, and kidney were small and may be related to the mineral content of diets and the effect of NaB on mineral solubilities. Similar DMI and ADG of lambs fed FM and NaB separately and in combination suggest that their beneficial effect is not additive.

Measurement of medullation in wool and mohair using an Optical Fibre Diameter Analyser.

We conducted three experiments to evaluate the Optical Fibre Diameter Analyser (OFDA) for estimating medullation (med [M], kemp [K], and total [T] medullated fiber content) in mohair and wool produced by Angora goats and sheep, respectively. Medullation can be a beneficial characteristic in certain types of wool, but it is highly undesirable in mohair and apparel wools. Current techniques for evaluating medullation in animal fibers are laborious, slow, and expensive. The OFDA had been modified by the manufacturer to measure fiber opacity distribution, a characteristic known to be indicative of medullation in white fibers, and was capable of providing such measurements in a very short time. Measurements made on magnified fiber images produced with a projection microscope (PM) were used as a reference for M, K, and T in fiber samples. An initial experiment with 124 mohair samples (T = .10 to 9.10%) seemed to indicate that OFDA estimates of M, K, and T were only poorly correlated with corresponding PM values (r2 = .5409, .1401, and .5576, respectively). However, a second experiment using wool and mohair samples containing a wider range of medullation (T = .58 to 26.54%) revealed that OFDA estimates of M, K, and T for wool were highly correlated with PM measurements (r2 = .9853, .9307, and .9728, respectively). Evidence was also obtained indicating that the low r2 values associated with mohair relationships were likely due to a combination of factors: 1) high variation among the standard PM measurements and 2) the relatively low M, K, and T contents of the mohair samples compared with wool. In a third experiment, greater accuracy was obtained in the PM measurements by evaluating many more individual fibers per sample (10,000). In this case, OFDA estimates of M, K, and T for mohair were highly correlated with corresponding PM measurements (r2 = .8601, .9939, and .9696, respectively). However, the two sets of linear regression equations obtained for wool and mohair were somewhat different, indicating that separate calculations should be used to estimate PM measurements from OFDA data. In conclusion, it was demonstrated that the OFDA instrument is capable of providing relatively fast, accurate, and potentially less expensive estimates of medullated fiber characteristics in mohair and wool.

Prospects for expanded mohair and cashmere production and processing in the United States of America.

Mohair from Angora goats has been produced in the United States since the introduction of these animals from Turkey in 1849. Cashmere on Texas meat goats was reported in 1973, but domestic interest in commercial production did not occur until the mid-1980s. Since 1982, the average prices of U.S.-produced mohair and cashmere (de-haired) have ranged from $1.81 to $9.48/kg and approximately $55 to $200/kg, respectively. However, return to producers from mohair has been relatively constant, averaging $10.21/kg, due to the federal incentive program. Because this program is scheduled to terminate with final payment in 1996, the future of mohair profitability is questionable. Prospects for expanded mohair and cashmere production and processing in the United States are influenced by numerous interacting factors and potential constraints. These include the prospect that the goat and textile industries may no longer be profitable in the absence of clear government policies. Although selection may have slightly increased fiber production by Angoras (long term) and domestic meat goats (short term), availability of genetic resources may prove to be a constraint to increased fiber production by cashmere goats and improved meat production by both types of goat. Land resources are plentiful unless new government policies prohibit goats from vast tracts of rangeland and forest because of environmental concerns. Future demand is an unknown, but with increasing world population and affluence, prospects for long-term improved demand for luxury fibers seem good. Competition from foreign cashmere growers is expected, whereas, in the short term, mohair production overseas is declining. However, increased processing of cashmere in its country of origin is expected to result in shortages of raw materials for European and U.S. processors. The amount of scouring, worsted, and woolen equipment in the United States is adequate to accommodate major increases in domestic processing of goat fibers. However, the absence of specific processing knowledge and skills may be constraints. Similarly, the absence of acceptable small-scale dehairing equipment for cashmere will limit cashmere processing on a cottage industry scale. Purely practical considerations such as the effects of predation and cost of fencing could become major constraints to expanding the goat fiber industry. Likewise the success (or lack thereof) of industry promotion of fiber and goat meat could be an overriding factor. To emerge from the uncertainty of erratic raw material prices and to better control profitability, domestic goat-fiber producers are encouraged to consider innovative, cooperative, retained ownership business ventures that will permit them to profit-share up to the retail level.

Animal performance and fleece characteristics of Angora goats maintained on western and southern Texas rangeland.

Two hundred castrated male Angora goats (18 mo of age) were divided equally between rangeland sites in the oak savannah of the Edwards Plateau (EP) and the mixed-brush shrublands of the South Texas Plains (STP) for 5 yr to study influence of environment and age on body weight (BW), mohair production, and mohair fiber characteristics. Goats were grazed on rangeland typical of the respective regions and were given typical management that included shearing in February and July or August of each year. Shorn goats were weighed and individual fleeces were measured for grease weight (GFW), clean yield (CMFP), average fiber diameter (AFD), and proportion of medullated fibers, med (MFP) and kemp (KFP). Rainfall and maximum and minimum temperatures were recorded daily at each site. The AFD (P = .01) and its associated SD (P < .001) and kemp levels (P = .03) were all higher at the STP than at the EP site (39.4 vs 37.9 microns, 10.4 vs 11.1 microns, and .80 vs .68%, respectively). Angora goats at EP weighed less (38.1 vs 41.7 kg, P = .03), and sheared less (1.90 vs 2.22 kg, P = .01), finer (36.4 vs 39.3 microns, P < .001), and less kempy (.52 vs .84%, P < .001) mohair at the February shearing than at the August shearing. No seasonal differences in body weight or in mohair production or quality were apparent at STP. The proportions of total variation in grease mohair production (30.6%), CMFP (22.2%), and AFD (15.7%) due to year effects were two to three times greater at STP than at EP. In contrast, year effects were responsible for only a small proportion (2.2 to 4.6%) of the variation in medullated fibers. The effects of rainfall accumulation within specific 6-mo growing periods were positive for BW, GFW, CFW, AFD, SD of AFD and MFP and negative for CMFP and KFP. Only the rainfall effects on SD of AFD and medullated fibers were significant (P < .05). The effects of age were positive for BW (P < .001), CMFP (P = .046), AFD (P < .001), MFP (P = .014), and KFP (P = .084) and negative for GFW (P = .046) and CFW (P = .107). This study documents influence of environment and age of goats on body weight, mohair production, and fiber characteristics.

Performance of hair breeds and prolific wool breeds of sheep in southern Illinois: wool production and fleece quality.

The objective of this study was to compare weight and quality of fleeces of different F1 ewe types produced from breeds with a broad range of fleece types. Weights of 629 fleeces produced during 1988 through 1991 from F1 ewes that were daughters of Suffolk and Targhee dams and Finnsheep, Combo-6, Booroola Merino, St. Croix, and Barbados sires were recorded. Staple length was measured on the mid-side of each ewe present in 1991. Fleeces shorn in 1991 were sent to a wool marketing organization, and staple length, wool grade, and clean fleece yield were subjectively estimated (n = 220). Mid-side fleece samples were collected from no more than two randomly selected ewes from each subclass (breed of dam-breed of sire-age of ewe) in 1991 (n = 78) and sent to a wool laboratory where fiber diameter, yield, and percentage of colored, med, and kemp fibers were objectively determined. Ewes from Targhee dams produced fleeces with greater weight, greater fiber length, smaller fiber diameter, lower yield, and fewer colored fibers than ewes from Suffolk dams (all differences significant, P < .01). Booroola Merino-sired ewes produced heavier (P < .01) fleeces than did Finnsheep- and Combo-6-sired ewes (4.13 and 3.09 kg, respectively), and in turn, Finnsheep- and Combo-6-sired ewes produced heavier (P < .01) fleeces than did ewes sired by hair breed rams (3.09 and 1.70 kg, respectively). Among hair breed-sired ewes, St. Croixsired ewes produced heavier (P < .01) fleeces than did Barbados-sired ewes (1.88 and 1.52 kg, respectively). Fleeces produced by Booroola Merino-sired ewes had smaller (P < .01) fiber diameter than all sire breed groups except Combo-6-sired ewes, and fleeces produced by St. Croix-sired ewes had greater (P < .01) fiber diameter than all other sire breed groups. Lab scoured yield was greater (P < .01) for fleeces from ewes from hair breed than for fleeces from ewes from wool breed sires (74.2 vs 66.1%). Proportions of undesirable fibers (med, kemp, and colored) were 20 to 600 times greater (P < .01) in fleeces of ewes from hair breed sires than in fleeces of ewes from wool breed sires. In general, F1 ewes from Booroola Merino sires produced the heaviest, highest quality fleeces, and ewes from the hair breed sires of St. Croix and Barbados produced the lightest, lowest quality fleeces. Ewes from Finnsheep and Combo-6 sires produced fleeces that were more similar to the fleeces of ewes from Booroola Merino sires than to the fleeces of ewes from the hair breed sires.

Evaluation of the optical fibre diameter analyser (OFDA) for measuring fiber diameter parameters of sheep and goats.

The Optical Fibre Diameter Analyser (OFDA) instrument is based on automatic image analysis technology and was recently introduced to provide a rapid, accurate measurement of average fiber diameter (AFD) and diameter distribution (SD) of textile fibers. Experiments were conducted with wool and mohair in various physical forms (top, core, and staple) to compare results produced by the OFDA with two other methods of determining fiber diameter parameters: the standard projection microscope (PM) method as described by the American Society for Testing and Materials (ASTM) and the Peyer Texlab FDA 200 System (FDA200). The results show that the OFDA fiber diameter measurements were very closely related to PM measurements, and the OFDA partially overcame one shortcoming of the FDA200, overestimation of SD. The results suggest that the OFDA is a promising system for rapid and accurate evaluation of fiber diameter and its distribution.

Effects of supplementation on intake, growth rate, and fleece production by female Angora kid goats grazing rangeland.

Ninety-eight and 88 female Angora kid goats (6 mo of age) were grazed/browsed on Edwards Plateau rangeland in 92- and 88-d trials in 1989 and 1990, respectively. The goats were either not supplemented (negative control, NC) or fed isoenergetic amounts of corn (C), a corn/cottonseed meal/molasses mixture (C/CSM), or a corn/cottonseed meal/fish meal/molasses mixture (C/CSM/FM). The C/CSM and C/CSM/FM supplements provided equal CP but different amounts of ruminally undegraded protein (UDP). The goats were allowed to graze/browse in a common pasture and were separated into treatment groups three times each week for feeding. Intakes of supplement and forage were measured using a dual-marker technique. Forage intake was not increased with supplemental feeding (P = .21), but tended (P = .08) to be greater with high-protein supplements than with C. Total digestible DMI was greater (P < .01) for supplemented goats and was not affected by supplement type. Supplemental feeding increased BW gain (P < .01) and clean fleece weight (CFW; P < .01). High-protein supplements increased BW gain (P < .01), CFW (P = .07), fiber diameter (FD; P < .01), and staple length (P < .01) compared with C. Greater amounts of UDP (C/CSM/FM) did not increase BW gain (P = .99) but tended to increase CFW (P = .12) and FD (P = .15). Supplemental feeding increased total digestible DMI by partial substitution (corn) for forage or addition (high-protein supplements) to forage, and both energy and protein increased BW gain and CFW and influenced mohair traits.