Native Grass Hay Research Articles

Recovery of intravenously infused chromium EDTA and lithium sulphate in the urine of cattle and their use as markers to measure urine volume

A series of metabolism experiments investigated the recovery of continuous-, intravenously infused chromium complexed with ethylenediamine tetra-acetic acid (CrEDTA) and lithium sulphate in the urine of cattle with a view to using the markers to estimate urine and metabolite output in grazing cattle. The recovery of Cr in urine from these infusions was similar (90%) in metabolism trials when cattle consumed three very contrasting diets: high-grain formulated pellet, lucerne hay (Medicago sativa) or low-quality native grass hay (predominantly Heteropogon contortus). By contrast, Li recovery in urine averaged 46.3 ± 0.40% and 72.6 ± 0.43% for native pasture and lucerne hays, respectively, but was not constant across days. There was negligible transfer of Cr from CrEDTA in blood serum to the rumen or faeces, whereas appreciable quantities of infused Li were found in both. The ratio of urine volume estimated by spot samples and marker dilution of Cr, to urine volume measured gravimetrically, was 1.05. In grazing studies using rumen-fistulated (RF) steers grazing seven different tropical and temperate grass and legume pastures, the ratio of concentrations of purine derivatives (PD) to Cr in spot samples of urine was shown to vary diurnally in the range of 49% to 157% of the average 24 h value. This finding indicated the need for regular sampling of urine to achieve an accurate average value for the PD : Cr ratio in urine for use in estimating urinary PD excretion and hence microbial protein production in the rumen. It was concluded that continuous, intravenous infusion of CrEDTA resulted in a constant recovery of Cr in the urine of cattle across diets and, provided an intensive sampling regime was followed to account for diurnal variation, it would be suitable as a marker to estimate urine volume and urinary output of PD in grazing cattle.

Influence of level of supplemental whole flaxseed on forage intake and site and extent of digestion in beef heifers consuming native grass hay1,2

The objectives of this study were to evaluate the influence of supplemental whole flaxseed level on intake and site and extent of digestion in beef cattle consuming native grass hay. Nine Angus heifers (303 +/- 6.7 kg of BW) fitted with ruminal and duodenal cannulas were used in a triplicated 3 x 3 Latin square. Cattle were given ad libitum access to chopped native grass hay (9.6% CP and 77.5% NDF, OM basis). All animals were randomly allotted to 1 of 3 experimental treatments of hay plus no supplement (control); 0.91 kg/d whole flaxseed (23.0% CP, 36.3% NDF, and 25.5% total fatty acid, OM basis); or 1.82 kg/d whole flaxseed on a DM basis. Supplemental flaxseed tended to decrease (linear, P = 0.06) forage OM intake. However, total OM intake did not differ (P = 0.29) with increasing levels of flaxseed. Total duodenal OM flow increased (linear, P = 0.05) with additional flaxseed in the diet, and no differences (P = 0.29) were observed for microbial OM flow. True ruminal OM disappearance was not affected (P = 0.14) by supplemental flaxseed. Apparent lower tract OM digestibility increased (linear, P = 0.01) with level of whole flaxseed. Apparent total tract OM digestibility was not different (P = 0.41) among treatments. Nitrogen intake increased (linear, P < 0.001) with supplemental flaxseed. In addition, total duodenal N flow tended (P = 0.08) to increase with additional dietary flaxseed. However, true ruminal N digestibility did not differ (P = 0.11) across treatment. Supplemental whole flaxseed did not influence ruminal (P = 0.13) or total tract (P = 0.23) NDF digestibility. Ruminal molar proportion of propionate responded quadratically (P < 0.001) with increasing levels of whole flaxseed. An increase in the duodenal supply of 18:3n-3 (P < 0.001), total unsaturated fatty acids (P < 0.001), and total fatty acids (P < 0.001) was observed with additional dietary whole flaxseed. Apparent postruminal 18:3n-3 disappearance tended to decrease (P = 0.07) as intake of flaxseed increased. Overall, the inclusion of 1.82 kg/d of flaxseed does not appear to negatively influence nutrient digestibility of a forage-based diet and therefore can be used as an effective supplement to increase intestinal supply of key fatty acids important to human health.

Seasonal variations in the chemical composition and dry matter degradability of exclosure forages in the semi-arid region of northern Ethiopia

The present study was conduced at two sites (Tembien and Wukro) in the semi-arid region of Tigray in northern Ethiopia to investigate the seasonal dynamics in the chemical composition and dry matter digestibility of grass and browse species of exclosures. The browse species studied in Tembien and Wukro had a mean crude protein (CP) value of 166 and 117 g/kg dry matter (DM), respectively. The mean in vitro dry matter digestibility (IVDMD) coefficient and predicted metabolizable energy (ME) density of the browse species were 0.72 and 9.83 MJ/kg DM, respectively at Tembien, 0.62 and 8.38 MJ/kg DM, respectively, at Wukro. Neutral detergent fibre (NDF) and acid detergent fibre (ADF) values of the browse species varied from 192 to 437 and 127 to 391 g/kg DM, respectively. Acid detergent lignin (ADL) values ranged from 36 to 190 g/kg DM. The mean CP of the grass species in Tembien and Wukro during the long rainy season was 76 and 73 g/kg DM, respectively and values declined below a critical maintenance level during the dry and short rain seasons. Mean IVDMD and ME values for the two sites were 0.41 and 0.47, and 5.38 and 6.11 MJ/kg DM, respectively. The NDF, ADF, and lignin values of the grass species were generally above 700, 400, and 70 g/kg DM, respectively. The CP, IVDMD and ME values of the mixed grass samples differed (P<0.05) among harvesting months and values ranged from 20 to 103 g/kg DM, 0.47 to 0.72 MJ/kg DM, and 6.16 to 9.91 MJ/kg DM, respectively. The browse species could be used as useful dry season protein supplements to the N deficient native grass species. Especial emphasis should be given to propagate Maerua angolensis and Cadaba farinosa at community nursery sites. Harvesting in September, rather than the current extended harvest period that took place in October and November, can considerably improve the feeding value of native grass hay for smallholder ruminant production systems.

Growth performance and carcass characteristics of three Ethiopian goat breeds fed grainless diets varying in concentrate to roughage ratios

Growth and carcass characteristics of three Ethiopian goat breeds, the Afar, Central Highland (CHG) and Long-eared Somali (LES) were evaluated using three grainless diets varying in concentrate:roughage ratios (diet 1 was 50:50, diet 2, 65:35 and diet 3, 80:20) under feedlot conditions. The roughage was native grass hay and the concentrate consisted of wheat bran and noug cake (Guizotia abyssinica). Seventy-two eight-month old intact male goats (24 per breed) were randomly allotted to the dietary treatments, fed for 126 days and slaughtered at an age of approximately 12 months. The LES had higher average daily gain (ADG), heavier slaughter, empty body (EBW) and carcass weights than Afar and CHG goats. Diet significantly affected ADG, but was similar on carcass traits except for dressing percentage (DP) on an EBW basis and some non-carcass components. The DP on an EBW basis was the highest on diet 1. Breed affected the DP, which ranged from 42.5 - 44.6% and 54.3 - 55.8% on slaughter weight and EBW basis, respectively. The LES had a greater buttock circumference and carcass compactness. The pH24 varied between 5.61 - 5.67 and chilling losses were between 2.5 and 3.1%. The physical carcass composition (8-10th rib-cut) ranged from 72 - 73, 6.9 - 10.9 and 17.1 - 20.2% for lean, fat and bone, respectively, and the fat content of the meat ranged from 10.3 - 14.0%. Breed affected the weights of internal fat depots. The findings indicate that breed affected the carcass characteristics of the three Ethiopian goat breeds. Keywords: Indigenous goats; carcass yield; carcass composition; primal cuts; non-carcass components South African Journal of Animal Science Vol. 37 (4) 2007: pp.221-232

Hormonal patterns in normal and hyperleptinemic mares in response to three common feeding-housing regimens1

We previously reported that a rise in plasma leptin concentrations followed the rise in insulin and glucose in meal-fed horses, whereas horses maintained on pasture had little fluctuations in hormonal patterns. We have also described a hyperleptinemic-hyperinsulinemic condition that occurs in about 30% of our light horse mares of high body condition maintained on pasture. The present experiment was designed to 1) study the effect of 3 common feeding-housing regimens on leptin and other metabolic hormones in mares and 2) determine whether the hyperleptinemic condition interacted with these regimens. Six light horse mares with high body condition (average score = 7) were assigned to 2 simultaneous 3 x 3 Latin squares, 1 with normal mares (leptin = 0.1 to 6 ng/mL) and 1 with mares displaying hyperleptinemia (>10 ng/mL). Three feeding-housing regimens were compared: ad libitum pasture, ad libitum native grass hay in an outdoor paddock, and single morning feedings of a pelleted concentrate and hay at 0700 in a barn. Five days of acclimation to the feeding regimens were followed by a 36-h period of hourly blood collection to characterize the hormonal characteristics. Leptin concentrations were elevated (P < 0.001) in mares predetermined to be hyperleptinemic compared with normal mares, regardless of the feeding regimen. Leptin was greatest (P < 0.01) in mares on pasture and least in mares fed hay. Variations over time (P < 0.01) were present for all hormones and metabolites studied. Glucose and insulin concentrations were greatest (P < 0.01) in mares on pasture, with meal-fed mares exhibiting an immediate rise in plasma concentrations of both after feeding. Mares on hay had low and constant concentrations of glucose, insulin, and leptin, with no apparent fluctuations. Cortisol, prolactin, and IGF-I did not differ with leptin status, whereas GH differed due to feeding-housing regimen (P < 0.02); there was also an interaction of leptin status and feeding-housing regimen for GH concentrations (P = 0.094). It was concluded that 1) estimates of hormonal secretion in horses based on frequent sampling, depending upon the hormone in question, can be profoundly affected by the feeding-housing regimens, and 2) the hyperleptinemic condition persists under differing conditions of feeding-housing.

Consumo y digestibilidad de gramíneas tropicales conservadas y el efecto de la suplementación con residuos fermentados de pescadería.

Se llevaron a cabo tres ensayos con carneros adultos con el objetivo de evaluar el consumo voluntario y digestibilidad in vivo de nutrientes, materia seca (MS), proteína bruta (PB) y fibra detergente neutro (FDN) de heno de gramíneas tropicales naturalizadas (HGTN) y ensilaje de sorgo (ES) con o sin suplementacion de residuos fermentados de la producción de filete de tilapia (RFPT) y lodos fermentados de la industria atunera (LFIA). En el primer ensayo metabólico se compararon dietas de los dos forrajes sin suplementación. Cuatro carneros criollos adultos se distribuyeron a los tratamientos según un diseño completamente aleatorizado (DCA). Se observó un mayor consumo voluntario (P &lt; 0.05) por parte de los animales alimentados con HGTN. La digestibilidad aparente también fue mayor para HGTN que para ES, pero estas diferencias no alcanzaron significación estadísticas. En el segundo y tercer ensayo metabólico se evaluó el efecto de la adición de RFPT y LFIA, respectivamente, como suplementos a dietas básales de heno de GTN y ES. El RFPT y LFIA se aplicaron a niveles de 30% del consumo de MS esperado a base del peso vivo. En ambos experimentos, se utilizaron ocho carneros adultos distribuidos según un DCA. Al añadir RFPT y LFIA a la dieta de los carneros aumentó (P &lt; 0.05) el consumo voluntario de MS y PB en relación al consumo obtenido con el forraje solo, pero se alcanzaron mayores consumos de MS (P &lt; 0.05) con HGTN que con ES. En las dietas basadas en ES la suplementacion con ambos residuos fermentados de pescadería tendió a aumentar la digestibilidad aparente de la MS, PB y FDN. En las dietas basadas en HGTN, ambos residuos aumentaron la digestibilidad aparente de la PB, mientras el LFIA aumentó la digestibilidad aparente de la MS. El único efecto negativo observado en esta dieta fue la disminución en la digestibilidad aparente de FDN cuando se suplemento con LFIA.

Acceptability and growth of lambs fed with different forms and levels of tagasaste (Chamaecytisus palmensis)

Sun-drying improved the acceptability of tagasaste and increased the voluntary dry matter intake by lambs. Supplementation of native grass hay by up to 40% of sun-dried tagasaste increased the dry matter and protein intake, the body weight gain and feed conversion efficiency. Copyright © 2005 Whurr Publishers Ltd.

Effects of Different Levels of Dry-Rolled Corn or Barley on the Utilization of Medium Quality Meadow Hay with Steers and Performance with Heifers

In Trial 1, five Angus-Gelbvieh crossbred steers (BW = 295 ± 3kg) fitted with rumen cannulas were used in a 5 × 5 Latin square design to determine intake and digestibility of medium-quality native grass hay (9.5% CP) when supplemented with 0.25% BW dry-rolled corn (low corn; LC), 0.50% BW dry-rolled corn (high corn; HC), 0.25% BW dry-rolled barley (low barley; LB), 0.50% dry-rolled barley (high barley; HB), or when receiving no supplement (NS). Forage DMI decreased with increasing level of corn (P<0.001) and with increasing level of barley (P=0.018) in the supplement (2.27, 2.06, 1.76, 2.11, and 1.95 ± 0.08% BW for NS, LC, HC< LB, and HB, respectively). Organic matter, NDF, and ADF digestibility were not altered (P<0.53) by supplemental treatment. Ruminal fluid pH was significantly changed by supplementation, but pH remained well above 6.2. In Trial 2, 40 weaned, Angus × Gelbvieh heifers (BW = 302 ± 8kg) were used to evaluate measure weight gain of animals fed diets similar to Trial 1. Supplemental treatments were NS, 0.68kg of rolled corn (LC), 1.36kg of rolled corn (HC), 0.68kg of rolled barley (LB); and 1.36kg of rolled barley (HB). Weight gain during the 77-d period was greater (P= 0.002) for all heifers receiving supplements (35, 48, 47, 45, and 55 ± 3kg for NS, LC, HC, LB, and HB, respectively). Both corn and barley supplementation had a linear effect (P<0.04) on weight gains. Neither condition score (5.1, 5.2, 5.2, 5.4, and 5.4 for NS, LC, HC, LB, and HB, respectively) nor condition score change was affected (P<0.37) by treatment. Supplementation with either corn or barley had a quadratic effect on forage and total DMI. These data suggest that with a medium quality meadow hay, either corn or barley can be fed up to 0.5% of BW without affecting total DMI or dietary DM and fiber digestibility, although supplements did decrease forage DMI.

Suitability of tagasaste ( Chamaecytisus palmensis L.) as a source of protein supplement to a tropical grass hay fed to lambs

The diets of lambs in the tropical regions of Africa are severely deficient in protein and leguminous trees provide a potential source to offset this deficit. The present study was carried out to determine the suitability of the herbage from tagasaste (C hamaecytisus palmensis), a leguminous shrub abundant in the central highlands of Ethiopia, as a protein supplement for lambs. The first experiment was designed to determine the acceptability of the tagasaste fodder by lambs when fed at fresh, slightly wilted, highly wilted, and sun-dried states. The results showed that drying significantly increased the palatability of the fodder and intake increased from 139.6 g DM per day in the fresh to 347.6 g DM per day of the sun-dried state. The second experiment was to find out the level of sun-dried tagasaste supplementation for optimal performance of lambs fed a basal diet of native grass hay. The lambs consumed tagasaste supplement at average daily rates of 0, 57.3, 114.4, 178, and 230 g DM per day. Total DM intake significantly increased with supplementation ranging from 425.3 g per day in control diet to 612.7 g per day, when 230 g tagasaste was fed. Intake of CP also increased correspondingly from 20.5 to 73.4 g per day. The supplementary diet resulted in a significant increase in weight gain in lambs from 11.2 g per day in no tagasaste to 52.0 g per day when 178 g per day tagasaste was fed. Tagasaste supplementation did not result in substitution of grass hay intake. In a third trial, the grass hay basal diet was supplemented with 0, 68, 128, 188, and 238 g DM per day of tagasaste. Tagasaste supplementation significantly increased the intake of DM, OM, CP, and ADL and apparent digestibility of total feed DM, OM, NDF and ADL. Digestibility coefficients of total DM, OM, NDF and ADL increased from 0.59, 0.60, 0.57 and 0.035 in the control to 0.71, 0.73, 0.69 and 0.52, respectively, at 188 g DM per day tagasaste consumption. The results indicated that sun-dried tagasaste herbage could be used to supplement a basal diet of native grass hay for feeding lambs.

Effect of nutrient restriction on calpain and calpastatin content of skeletal muscle from cows and fetuses.

Calpains are crucial for the degradation of myofibrillar proteins in muscle. Calpastatin is a specific inhibitor of calpains. The objective of this study was to elucidate the effect of nutrient restriction on the activity of calpains and calpastatin in the skeletal muscle of both cows and fetuses. Beginning 30 d after conception, 20 cows were fed either a control diet consisting of native grass hay fortified with vitamins and minerals at recommendations for a mature cow to gain 0.72 kg/d or half the vitamins and minerals and millet straw at 68.1% of NEm requirements. Cows were slaughtered on d 125 of gestation, and the LM was sampled at the 12th rib for calpain and calpastatin measurement. When comparing the muscle samples from nutrient-restricted and control cows, no difference in the activity of calpain I and II was observed; however, there was a significant difference (P < 0.05) in calpastatin activity. Muscle samples from control cows had greater calpastatin content than those of nutrient-restricted cows (P < 0.05); in contrast, the calpastatin content of fetal muscle was greater in fetuses gestated by nutrient-restricted cows than those of control cows (P < 0.05). Further, there were three calpastatin isoforms of 125, 110, and 70 kD detected in fetal muscle, whereas only the110-kD isoform was detected for cow muscle. These results indicate that the activity of the calpain system in skeletal muscle is mainly controlled through the expression of calpastatin. Alternating the calpastatin content in muscle and thereby modulating calpain activity may provide a mechanism for the maintenance of fetal muscle growth during nutrient restriction, whereas skeletal muscle loss in cows is upregulated.

Feeding value and cost of native spear grass hay in Western Australia

Spear grass hay was harvested from 4 sites on Kanandah Station, Western Australia. In the lead up to harvesting, seasonal conditions were among the best on record. Feeding trials involving steers and wethers were undertaken to evaluate animal performance when fed spear grass hay, with or without access to supplements. The findings indicate that, occasionally, brief opportunities may appear when spear grass range on the Nullarbor Plain can be successfully harvested and made into reasonable quality hay, but the harvesting window of opportunity is short and choosing the best harvesting time is essential. Yields of spear grass hay compared favourably with those of other native grass pastures reported by Queensland researchers. Animals readily consumed the spear grass hay, although both the sheep and cattle lost weight when fed only spear grass hay. However, providing a small amount of supplement (100-200 g/d for wethers; 1 kg/d for steers) maintained livestock. On-station spear grass hay production on the Nullarbor was a cheaper option than importing hay. Based on our findings, if the highest estimated cost of on-station production is used ($153/t), feeding costs are $1.15/hd/d for cattle and $0.15/hd/d for sheep. Alternatively, if the lowest estimated cost of production is used ($64/t), feeding costs are $0.48/hd/d for cattle and $0.06/hd/d for sheep.

Effect of complete feed block on nutrient utilisation and rumen fermentation in Barbari goats

Fifteen Barbari goats (average BW 13 kg) were randomly divided into three groups of five animals each. All animals were fed complete diets consisting of natural grass hay and concentrate mixture in the ratio of 60:40 on the DM basis. In the concentrate mixture, 15% (T 2) or 30% (T 3) CP of mustard cake was replaced with Leucaena leaf meal (LLM). The diet of the control group (T 1) was offered as such, whereas T 2 and T 3 diets were offered in the form of blocks. The bulk density of the complete feed block was 550–600 kg/m 3. Densification of complete diets increased the bulk density 3.2–3.9 times. Total VFA concentration in the rumen was similar in the three groups. Ammonia N concentration was significantly ( P<0.05) higher in the mash-fed goats (T 1) than in the block-fed animals (T 2 and T 3). The rumen anaerobic fungal population was slightly higher in T 2 and T 3 than in T 1 as a result of the proportionate intake of roughage and concentrate from the block form of the diet. The total protozoa population ranged from 7.47×10 4 to 8.65×10 4 ml −1 of strained rumen liquor (SRL). Voluntary feed intake was similar in T 1 (431 g per day), T 2 (409 g per day) and T 3 (415 g per day). Digestibility coefficients (%) of DM, OM, CP, CF and NFE among treatment groups did not differ significantly. Inclusion of Leucaena leaf meal by replacing mustard cake did not affect the N balance in Barbari goats. DCP and TDN intake were sufficient for maintenance. Blood glucose, protein and urea-N were within normal physiological ranges in all groups. It was concluded that Leucaena leaf meal can be incorporated by replacing mustard cake safely and inexpensively without affecting nutrient utilisation in Barbari goats. Further, the process of block making from low bulk density roughage resources substantially reduces the storage space and transportation cost.

Effects of varying levels of phytase supplementation on dry matter and phosphorus digestibility in horses fed a common textured ration

This study examines the effect of phytase supplementation on dry matter and phosphorus digestibility in mature horses. Four mature sedentary quarter horse geldings were used in a 4 × 4 Latin square design experiment. Horses were fed at 2% of the group's average body weight. The experimental diets consisted of textured concentrate of rolled corn, oats, and soybean meal fed in a 50:50 ratio with native prairie grass hay. The treatments were as follows: (1) control (0) with no phytase added to the basal ration, (2) 300 FTU/kg added to the basal ration, (3) 600 FTU/kg added to the basal ration, and (4) 900 FTU/kg added to the basal ration. During the 72-hour collections, total urine and feces were collected. Feed samples were also collect randomly throughout the trial. Feed and fecal sample were analyzed for dry matter, phosphorus, calcium, and magnesium. Urine samples were analyzed for phosphorus, calcium, and magnesium. There was no significance difference in dry matter intake, fecal output, dry matter digestibility, and urinary output across all diets ( P > .05). Phosphorus digestibility was not improved with the addition of supplemental phytase ( P > .05). The failure to observe an improvement in phosphorus digestibility may be because of the high levels of phosphorus in the diets. Further research needs to be conducted using diets with lower levels of phosphorus.

Response of Yearling Quarter Horses to Varying Concentrations of Dietary Calcium

Fifteen yearling Quarter Horses were used in a split-plot designed experiment to determine the effects of three concentrations of Ca on mineral metabolism, bone density, and parameters of growth. Horses were blocked by sex and BW and randomly assigned to one of three dietary treatments that were formulated to contain 115, 100, and 85% of NRC (10) requirements for Ca. Diets consisted of ground corn, soybean meal, and cottonseed hulls fed at a 70:30 with native prairie grass hay at 2.5% BW. The 25-wk trial consisted of three 72-h collection periods at d 0 (Period 1), d 90 (Period 2), and d 180 (Period 3) during which complete urine and fecal collections were taken. Additionally, radiographs of the left front cannon were taken 1 wk prior to each collection for determination of bone density. Data were analyzed with horse and treatment as main effects. Results from this study demonstrated an increased Ca retention with increased intake during all three periods. There was, however, no radiographic evidence of treatment effect on bone density.

Evaluation of non-conventional agro-industrial by-products as supplementary feeds for ruminants: in vitro and metabolism study with sheep

In vitro and in vivo evaluation of non-conventional feed resources was carried out in the International Livestock Research Institute (ILRI), Debre Zeit Station, Ethiopia, using sheep. Ten non-conventional feed types commonly used by urban and peri-urban livestock farmers were obtained from the farming system and evaluated in vitro following standard procedures. Following in vitro studies, five non-conventional feed types were selected for in vivo studies based on the in vitro result, availability, and wide use by farmers. Thirty indigenous rams weighing 22.6±0.97 (mean±SD) kg initially were stratified into weight groups and assigned randomly to treatments. Treatments included Tela atella (traditional brewery residue), Katicala atella (traditional liquor residue), lentil ( Lens culinaris) hull, rough pea ( Lathyrus sativa) hull, and field peas ( Pisum sativum) hull based on the basal diet of native grass hay (control). In vitro study indicated that Tela and K. atella had higher organic matter (97–98%), crude protein (CP) (21%), and gross energy (GE) (21–22 MJ/kg DM) and lower fiber fractions (neutral detergent fiber, NDF=41–60%; acid detergent fiber, ADF=11–21%). Pulse hulls (lentil, rough pea and field pea hulls) had medium to high CP (8–16%), lower GE (17–19.5 MJ/kg DM), and higher fiber fractions (NDF=49–71%; ADF=49–62%). Among the pulse hulls considered, lentil hull had the highest CP (16%), and lowest NDF (49.4%) and ADF (48.6%). Poultry litter and orange peel had the highest CP (30%) and GE (28 MJ/kg DM), respectively. Results of the in vivo study indicated that both atella and pulse hulls improved total dry matter, organic matter, nitrogen, energy and NDF intakes. The improvement was higher for atella compared to pulse hull groups. Basal diet intake was reduced when pulse hulls were fed. T. atella, K. atella and lentil hull had higher nitrogen and energy digestibility compared to pulse hulls and the control. Supplementation improved nitrogen retention, with T. atella, K. atella and lentil hull. Therefore, given the increasing competition with monogastric animals and increasing price of conventional by-products coupled with the deteriorating quality of tropical forages, T. atella, K. atella, and lentil hull have potentials to be used as a protein and energy (except lentil hull) supplements on low quality based diet under small holder livestock production systems. Further research is warranted to lower the concentration of tannins and fiber in pulse hulls and improve the feeding system to enhance the utilization of atella.

Effects of supplementation with high linoleic or oleic cracked safflower seeds on postpartum reproduction and calf performance of primiparous beef heifers.

Primiparous Angus x Gelbvieh (n = 36) rotationally crossed beef cows (initial BW = 487.9 +/- 10.5 kg, body condition score = 5.5 +/- 0.02) were utilized to determine effects of supplemental safflower seeds high in linoleic (76% 18:2) or oleic (72% 18:1) acid on cow BW change, body condition score, milk production and composition, calf weight gain, cow serum metabolites, and metabolic hormones. On d 3 postpartum, cows were randomly assigned to one of three isonitrogenous dietary supplements with equal total quantity of TDN: corn-soybean control supplement (n = 12); high-linoleate safflower seeds (n = 12); or high-oleate safflower seeds (n = 12). Safflower-seed supplements were formulated to provide 5% DMI as fat. Supplements were individually fed from d 3 postpartum through 90 d postpartum. Cows had ad libitum access to native grass hay (7.8% CP), trace-mineralized salt, and water. Date of parturition was evenly distributed across treatments with all cows calving within 14 +/- 0.8 d. There were no differences (P = 0.65) in total OM intake among treatments. Although cow BW change did not differ (P = 0.33) by treatment, supplementation influenced cow body condition score (P = 0.02) with linoleate-supple-mented cows in higher (P = 0.005) condition overall than oleate-supplemented cows (5.1 +/- 0.06 vs 4.9 +/- 0.06). Twenty-four-hour milk production did not differ (P = 0.68) among treatments. Percentage milk fat was not different at d 30; however, at d 60 and d 90 percentage milk fat was greater (P ( 0.05) in control and oleate-supplemented cows than in linoleate-supplemented cows. Calf BW gains (P = 0.27) and adjusted 205-d weights (P = 0.48) were not affected by supplement treatment. Supplementation did not influence serum concentrations of glucose (P = 0.38), NEFA (P = 0.61), GH (P = 0.29), IGF-I (P = 0.81), insulin (P = 0.26), or IGF-I binding proteins (P > or = 0.11). Days to conception did not differ (P = 0.40) among treatments. Although overall productivity of the primiparous cows and their calves was not altered by safflower-seed supplementation, differential effects were noted between supplements. Oleate supplementation increased percentage milk fat at d 60, and cow body condition score was lower than in linoleate-supplemented cows. Linoleate-supplemented cows had greater body condition scores by 90 d postpartum than either corn-soybean- or oleatesupplemented cows.

Copper balance in mature geldings fed supplemental molybdenum

Four mature sedentary geldings were used in a 4×4 Latin square designed experiment to evaluate the effects of supplemental molybdenum (Mo) on copper (Cu) balance. Four diets were formulated to contain 0 (control), 5, 10 and 20 ppm of supplemental Mo and were fed for a 21-day adjustment period followed by a 72-hour fecal and urine collection. Diets consisted of a pelleted concentrate based on corn, soybean meal and cotton seed hulls fed in a 50:50 ratio of concentrate to native prairie grass hay. All diets were formulated to be isonitrogenous and isocaloric with similar concentrations of Cu. Urine was collected every four hours for 72 hours and multiple fecal grab samples were taken every two hours post feeding. On the third collection day, blood samples were drawn at the time of feeding, each hour for five hours post feeding, and eight hours post feeding for serum Cu analysis. Balance data were analyzed using a general linear model procedure with horse, period and treatment as main effects. Serum Cu data were analyzed using the general linear model procedure with horse, treatment and period as main effects and time as the repeated variable. The intake of Cu was similar among all diets fed. There was no difference (p>.05) in serum Cu concentrations over time or between treatments due to supplemental Mo. Urinary and fecal excretion of Cu did not differ (p>.05) between diets. Consequently, the balance of Cu was similar among diets consumed. Excretion of Mo in the urine was higher (p<.05) in horses fed the 20 ppm Mo diet versus the 0, 5 and 10 ppm Mo diet. As Mo intake increased, fecal excretion increased (p<.05) across all diets. Additionally, Mo balance was higher (p<.05) on the 20 ppm Mo diet than all other diets. In conclusion, supplemental Mo appeared to have no adverse effect on the absorption and retention of Cu when fed to mature geldings.

Time-dependent transition probabilities and the assessment of seasonal effects on within-day variations in chewing behaviour of housed sheep

State transitions in the chewing behaviour of six half-breed (Île de France×Texel) yearling female sheep ( Ovis aries L.) were studied by using jaw movements recorded continuously over 5 days at the end of a number of experimental periods from 21 September 1992 to 4 April 1993. The sheep were housed in individual pens. Each of them received the same diet, that is, 250 g/day of concentrate mix (15.5% crude protein (CP), 36.5% neutral detergent fibre (NDF)) fed at 0900 h and natural grass hay (6.7% CP, 69.1% NDF) fed ad libitum at 0915 and 1600 h. Mineral salt blocks and water were continuously available. The main objective was to assess seasonal effects on within-day variations in the chewing behaviour of sheep, at small to large time scales within a day. We therefore focused on two experimental periods characterised by contrasting conditions of daylength and temperature (i.e., ‘Period 1’: 610 min daylight, mean temperature of 10.9°C, and ‘Period 4’: 550 min daylight, mean temperature of 7.2°C). In particular, differences between periods in the nycterohemeral pattern of chewing behaviour and the quality of forecasts of chewing states were tested. We submitted our data to a new method of analysis that we developed: the method of time-dependent transition probabilities, and compared the results to those obtained using other methods that were available in the literature. Overall, the sheep spent more time eating in Period 1 than in Period 4. Specifically, a secondary peak in eating activity, which was observed in the early afternoon in Period 1, was absent in Period 4. The nycterohemeral pattern of eating activity showed significant differences between periods, at the main rhythmic component of 24 h and at short components around 2 h. Such differences were not observed for ruminating and idling activities. The quality of forecasts of chewing states decreased from Periods 1 to 4, in terms of accuracy (based on R 2) and lead of reliable forecasts (i.e., |forecast−observation|<0.1). The most (least) accurate forecasts were obtained for the ruminating (eating) state in both periods. We have attributed the differences that we found between periods to daylength instead of temperature because the sheep were mostly within the thermoneutral zone in our study. By comparison, using mean hourly times of eating activity, significant differences between periods were detected for the 24-h rhythmic component and the 4-h component, instead of the 2-h component, probably because of aliasing (i.e., when the sampling time interval used is longer than suited; the minute was found to be a suitable interval length in the calculation of time-dependent transition probabilities). Using the age-dependent model of Rook and Penning, minor differences between periods were detected. On that basis, the method of time-dependent transition probabilities may be brought forward as a complement of value to existing methods of behavioural data analysis.

The chemical composition of Phyllanthus discoideus and its effect on the ruminal ammonia and volatile fatty acid concentration when fed to west african dwarf sheep

The feeding value of Phyllanthus discoideus (also called Margaritaria discoidea) leaves was evaluated using eight two‐year‐old West African Dwarf sheep fed natural grass hay. Four of the animals were fistulated ruminally and used for ammonia and volatile fatty acid determination in the fluid. Dried leaves of Phyllanthus discoideus were offered at two levels (25% and 50% of DMI, diets D25% and D50%, respectively) as supplements to the basal hay diet. The CP content of the control, D25% and D50% diets were 11.5, 12.6 and 13.6%, respectively, and their digestible energy amounted to 58.2, 61.1 and 56.9%, respectively. Rumen liquor was sampled one hour before and one, three and five hours after the morning feeding. Sheep fed the control diet had a higher ruminai ammonia concentration than those fed diet D25%. Similarly, ruminai ammonia concentration was higher in sheep fed the control diet than those fed the diet D50%. Five hours after feeding the ruminai ammonia concentration was significantly lower than one hour after feeding. The VFA concentrations in rumen fluid of sheep fed the control diet was inferior to those fed diets D25% and D50%. Sheep fed diet D50% showed significantly higher VFA concentrations than those fed diet D25%. Digestibility of organic matter and digestible energy did not show any significant difference. However, a marginal increase in organic matter digestibility of 3.5% was observed in diet D25% compared with the control diet. There was no significant difference in the N‐digestibility in sheep fed the control, D25% and D50% diets. Nevertheless, a marginal improvement in N‐digestibility (1.5%) and N‐retention (2.7%) was observed with the highest level of Phyllanthus discoideus (D50%). In conclusion, Phyllanthus discoideus appears as a particularly valuable feedstuff because it contains low levels of condensed tannins (12.8 g/kg), high CP content (156 g/kg) and a relatively high GE content (19.3 kJ/gDM). Although the improvement in N‐digestibility and N‐retention were only marginal the feeding of Phyllanthus discoideus could be justified under extreme shortage of feed resources during dry season. It should also be mentioned that a much more pronounced effect by supplementation with Phyllanthus discoideus could be expected when poor quality grass hay prevalent in West Africa during the dry season is fed. Phyllanthus discoideus could serve as a supplement to poor quality grass at 25% to 50% of supplementation.

Effects of supplemental protein type on productivity of primiparous beef cows.

Effects of supplemental degradable (DIP) and undegradable (UIP) intake protein on forage intake, BW change, body condition score (BCS), postpartum interval to first estrus, conception rate, milk production and composition, serum metabolites and metabolic hormones, and calf gain were determined using 36 primiparous Gelbvieh x Angus rotationally crossed beef cows. On d 3 postpartum, cows (average initial BW = 495 +/- 10 kg and BCS = 5.5 +/- 0.1) were randomly assigned to one of three dietary supplements (12 cows/treatment). Date of parturition was evenly distributed across treatment (average span of calving date among treatments = 2.4 +/- 2.5 d). Individually fed (d 3 through 120 postpartum) dietary supplements were 0.82 kg of corn and 0.23 kg of soybean meal per day (DIP), the DIP + 0.12 kg of blood meal and 0.13 kg of corn gluten meal per day (DIP + UIP), and 0.82 kg of corn, 0.07 kg of blood meal, and 0.08 kg of corn gluten meal per day in an isonitrogenous replacement of soybean meal (UIP IsoN). Cows had ad libitum access to native grass hay (8.5% CP) and trace-mineralized salt. Total OM intake was greater (P = 0.06) for DIP + UIP than UIP IsoN cows. At 30 d postpartum, DIP + UIP cows produced more milk than UIP IsoN, with DIP being intermediate; however, at 60 d postpartum, DIP + UIP and DIP cows were not different, but both had greater milk production than UIP IsoN (treatment x day interaction; P = 0.08). A treatment x day interaction (P = 0.06) for BCS resulted from DIP + UIP cows having the greatest BCS at 60, 90, and 120 d d postpartum and DIP having greater BCS than UIP IsoN cows only on d 60 postpartum. Serum insulin concentrations were highest (treatment x day interaction; P = 0.09) for DIP + UIP cows at 30 d postpartum but did not differ among treatment thereafter. Serum insulin-like growth factor-binding protein (IGFBP)-2 (34 kDa) and -3 (40 and 44 kDa) were greatest (P < 0.0003) for DIP cows. Serum urea-N concentrations were greater (P < 0.01) in DIP + UIP cows than in either DIP or UIP IsoN cows. However, postpartum interval to first estrus, conception rate, and calf weaning weights were unaffected (P = 0.35, 0.42, and 0.64, respectively) by treatment. Although UIP in addition to or in replacement of DIP affected milk production and blood metabolites, the productivity of these primiparous beef cows was not altered. Thus, the type of supplemental protein does not seem to influence productivity of primiparous beef cows in production systems with conditions similar to our experimental conditions.