Betaine and Choline Supplementation to Enhance Mohair Production
- Measure responses to an increased dietary supply of betaine and choline in Angora goats on fiber growth rate, composition, and quality
- Measure responses to an increased supply
of betaine and choline in dairy goats on milk production and
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- Thirty-six Alpine doelings (17 wk of age, 17 ± 1.2 kg BW) consumed ad libitum a completely mixed diet (18% CP, 74% TDN) containing ruminally protected choline RPC at 0, 8, or 16 g/kg dry matter for 90 d.
- average daily gain tended to increase as a result of supplementation (162, 166, and 172 g/d for 0, 8, and 16 g/kg of RPC, respectively).
- Feed efficiency (feed/gain) was also linearly improved in RPC groups (7.24, 7.04, and 6.84 for 0, 8, and 16 g of RPC, respectively)
- Observed improvements in average daily
gain and feed efficiency with dietary choline inclusion suggest
that choline may be limiting in diets for growing Alpine doelings.
These findings are important, they may lead to simple and safe
means of naturally enhancing efficiency of goat production for
improved profitability and sustainability.
Seasonal Manipulations to Improve Cashmere and Meat Returns in Goats
- To quantify the response in fiber growth and breeding cycles of two methods of melatonin treatment applied in April in the U.S. This represents an attempt to improve both meat and cashmere returns from U.S. goats following a single spring melatonin treatment.
- To determine whether shedding, following the cessation of a spring melatonin treatment, can be prevented by the suppression of plasma prolactin concentration. This objective seeks to greatly enhance the magnitude of cashmere response to melatonin treatment, without compromising meat production.
- To determine the effect of chemical
defleecing agents on fiber growth and quality in cashmere goats.
This technology seeks to harvest cashmere with minimal guard hair
contamination while retaining the guard hair fleece on the goat
for protection from cold.
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- To determine if mimosine treatment of goats at the winter solstice (December) induces shedding of cashmere but not guard hair, twelve adult cashmere wethers (45 ± 2 kg) were infused for a 72-h period with mimosine (M;100 mg/kg body weight) or saline (C). On d 8, cashmere had been shed in three of the six mimosine-treated goats In January and February, cashmere growth rate ((i.e., based on length of nonshed fiber) were greater for M vs C goats.
- Mimosine was effective at removing
cashmere in 50% of the goats treated; secondary follicle activity
in cashmere-shedding goats was increased by mimosine, which led to
additional cashmere growth. These findings may lead to a simple,
inexpensive means of harvesting cashmere from goats without
shearing and with little guard hair contamination.
Exogenous Hormone and Nutritional Manipulation to Increase Fiber Production
- Investigate the interactions among growth hormone, insulin-like growth factor I, insulin, and thyroid hormones for mohair growth and skin metabolism
- Define the role of growth hormone on skin
metabolism and mohair growth and determine whether growth hormone
has the potential to improve mohair production and quality
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The Evaluation of Various Feedstuffs for Milk Production in Early Lactating Goats
- Study interactions between levels of ruminally undegradable protein and digestible energy in lactating goat diets
- Evaluate potential use of cotton byproducts in dairy goat diets
- Determine influences on milk fever in
dairy goats of dietary concentrations and ratios of acidogenic and
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- Seventy Alpine does were used, being fed
diets with 0, 4, 8, 12, or 16% whole cottonseed for a 115-d
period. Currently samples are being subjected to laboratory
analyses. Though not complete, results of this project will be of
value to animal scientists and extensionists and livestock
producers in determining practical feeding guidelines for a
regional available byproduct.
Factors Affecting the Quality and Quantity of Fiber Growth in Goats
- Determine influences of amino acids and hormones on metabolism of skin in Angora goats
- Improve the understanding of regulation of
mohair production, to facilitate future improvements in fiber
production by goats
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- Results of one experiment suggest that
insulin regulates skin methionine metabolism via local effects,
whereas triiodothyronine influences amino acid metabolism via
centrally regulated mechanisms. In Angora goats, skin demand for
methionine may be higher than provided by average blood methionine
concentration. Lysine concentration in the blood is sufficient for
optimal fiber growth. Direct skin perfusion with methionine or
peptide bounded methionine increased fiber. These findings are of
value to animal scientists in increasing knowledge of skin
metabolism for future diet formulation to optimize mohair
production, providing the basis for genetic selection of animals
for mohair production, and development of products to regulate
nutrient uptake in the skin. Ultimately, such research will
benefit livestock producers, in leading to development of
technologies to increase profitability of goat fiber production.
Nutritional Management of Breeds and Genders for Efficient Goat Meat Production
- Determine effects of gender, breed, and
dietary level of concentrate or energy intake on protein and fat
deposition and meat quality in growing goats
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- Spanish x Boer kids (intact males, castrates, and females) were used to investigate effects of gender and age on growth performance. Kids started the experiment at an average BW of 16.4 kg and age of 93 d and consumed a corn-based diet during the study.
- intact males and castrates had greater DMI than females
- males had the greatest ADG loin eye area increased linearly with age
- internal fat increased with age
- internal fat comprised 6.9, 7.0, and 5.1% of empty BW for castrates, females and males, respectively.
- These results reflect performance
advantages for intact male meat goats; changes in internal fat
deposition with advancing age may impact increases in lean tissue
accretion by Boer crossbreds. These findings will be of great
importance to meat goat producers and animal extensionists and
scientists in promoting use of management strategies to achieve
most efficient and profitable production.
Environmental and Physiological Control of the Growth and Properties of Mohair
- Investigate effects of and interactions
between environmental and physiological controls of mohair growth
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- An experiment was conducted to describe the seasonal fleece growth cycle in U.S. goats with ambient climatic conditions, and to determine effects of level of feed intake on the cycle. From September 13, 1995 to October 9, 1996, 20 mature,
- nonpregnant Angora does (30.2 ± .9 kg;
2.45 ± .09 kg 6-mo fleece weight) were maintained in .4-ha
paddocks with low available forage mass. In addition, a diet was
offered at .53 (Low) or .68 kg/d of dry matter (High) to maintain
or slowly increase body weight, respectively. Minimum follicle
activity (FA) occurred 1 mo after the winter solstice and averaged
8 ± 3 and 78 ± 4% in primary and seconday follicles, respectively.
Fleece growth rate, fiber diameter, and fleece medullation were
40, 15, and 120% lower, respectively, in the winter than summer.
Fleece growth rate and fiber diameter were maximal 1 mo before the
autumn equinox. The High goats had a 20% greater shorn fleece
weight than did Low goats. Overall, High and Low goats had similar
clean fiber regrowth rates, yield, and diameter. Spring primary FA
was lower for Low compared with High goats, but secondary FA,
follicle medullation, and fleece kemp level were unaffected by
level of feed intake. In conclusion, U.S. Angora goats, with
constant levels of feed intake, exhibit seasonal follicle and
fiber growth cycles, which may impact efficiency of feed use for
mohair growth throughout the year. Level of feed intake can affect
fleece weight and seasonal changes in primary FA. This research is
of great value to animal scientists and extensionists and goat
producers, in that it will facilitate the formulation of
management plans that can be implemented on the farm to increase
income from goat fiber production.
Protein Supplementation to Enhance Mohair Production
- Determine physiological factors influenced
by protein supplementation that enhance mohair growth and(or)
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- Ruminal and plasma amino acid responses to
providing supplemental DL-methionine (Met) in either drinking
water or feed was studied in adult (45 kg) wethers. Goats received
1) the basal diet (40% forage and 14% crude protein) containing
.15% sulfur, 2) the basal diet plus 2.5 g of Met daily in drinking
water for approximately .18% dietary sulfur, or 3) the basal diet
plus 2.5 g of Met daily top-dressed on feed (.18% dietary sulfur).
Methionine supplemented in water or feed increased plasma
concentrations of glutamate, arginine, Met, and of Met as a
percentage of essential and total amino acids (AA). Plasma Met
concentration was higher when top-dressed; Val, Met, and Met
levels as a % of essential and total amino acids were increased by
Met supplementation. Phenylalanine was higher when Met was placed
in drinking water. Concentrations of serine, threonine, alanine,
tyrosine, valine, leucine, total AA, essential AA, and
nonessential AA exhibited quadratic responses over time
post-feeding, peaking at 1 h. Only Met as a % of total AA was
increased linearly by Met supplementation. Ruminal ammonia
decreased when Met was added to the diet. Volatile fatty acid
ratios, protozoal numbers, and pH were not altered by added Met.
In summary, Met supplementation in water or feed increased plasma
Met. Responses to Met in water need to be tested with goats fed a
higher dietary sulfur level to determine if equal responses can be
attributed to organic and inorganic dietary sulfur. These results
are of importance to animal scientists in facilitating further
research with different forms of dietary sulfur, which may lead to
more profitable mohair growth for goat producers.
Enhancing Browse Utilization by Goats
- Investigate the chemical composition and potential nutritive value of browse with emphasis on the tannin content, type, and limitation to digestion
- Explore relationships among supplemental polyethylene glycol, tannin content in forage, and forage utilization by ruminants in order to increase intake of tannin-containing forages
- Determine if once-daily supplementation
with polyethylene glycol will enhance goat control of noxious
brush and weeds
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- One of the primary studies of this project
will begin in the spring of 1998. A preliminary, pilot experiment
was conducted in the fall of 1997. In this experiment, Alpine
wethers were fed leaves of two brush species, Water Oak and
Shining Sumac. Feed intake was measured and samples of feed,
feces, and urine are currently being subjected to laboratory
analyses to determine nutrient digestibilities and nitrogen and
energy balances. Though this project is in its infancy, expected
results hold promise to markedly enhance the ability of goats to
thrive while consuming high-tannin herbage, thereby improving
utilization of normally low-value plants and increasing the
brush-clearing ability of goats for elevated land productivity and
agricultural system sustainability.