Levels Of Hay Research Articles

Effect of replacing a commercial concentrate with cassava hay ( Manihot esculenta Crantz) on the performance of growing goats

Twenty male and 20 female goats of the F1 Bachthao × Barbary, or Jamnapary, breed with an initial body weight of 13.6 ± 0.46 kg and 108 ± 7.3 days of age were used to compare cassava hay with a commercial grain and protein meal based concentrate in diets based on guinea grass and dried cassava root. The experimental period was 90 days. Concentrate was replaced by cassava hay at five levels: 0, 250, 500, 750 and 1000 g/kg on a dry matter (DM) basis. Growth rates at the five levels of inclusion were 53, 69, 62, 49 and 39 g/d and feed conversion ratios were 10.2, 7.6, 8.6, 10.2 and 13.0 kg DM/kg body weight gain. Increasing the level of cassava hay reduced DM intake, but the crude protein intake was similar for all treatments. The intake of cassava hay optimal for growth rates, feed conversion ratio and feed cost ranged from 0 to 220 g/kg of total DM intake. Increasing levels of cassava hay in the diets decreased the number of Nematoda eggs and Coccidia oocysts in the faeces, but had no effect on the number of Cestoda eggs.

Effects of supplemental fat on growth performance and quality of beef from steers fed barley-potato product finishing diets: II. Fatty acid composition of muscle and subcutaneous fat1

One hundred sixty-eight crossbred steers (317.1 +/- 1.0 kg) were used to evaluate the effects of supplemental fat in finishing diets on the fatty acid composition, including the 9,11 isomer of conjugated linoleic acid, of beef. Steers were allotted within three weight blocks to a randomized complete block design with a 3 x 2 + 1 factorial arrangement of dietary treatments. Main effects were level of yellow restaurant grease (RG; 0, 3, and 6%), and level of alfalfa hay (AH; 3.5 and 7%) with an added treatment containing 6% tallow (T) and 7% AH in barley-based diets containing 15% potato by-product and 7% supplement (all dietary levels are on a DM basis) fed for an average of 165 d. Fatty acids of the LM and s.c. fat from four randomly selected steers per pen were quantified using GC after methylation with sodium methoxide. Dietary treatment did not (P > 0.10) affect total fatty acid (FA) content of the LM (143 +/- 5.2 mg/g) or fat (958 +/- 7.9 mg/g). Myristic acid increased linearly (P < 0.01) with increasing RG from 3.1 to 3.7 +/- 0.1 g/100 g of FA in muscle. Stearic acid increased linearly (P < 0.05) as RG increased in the diet, from 11.4 to 12.9 +/- 0.4 g/100 g of FA in LM and from 9.9 to 12.2 +/- 0.3 g/100 g of FA in fat. Compared with T, steers fed 6% RG had more (P < 0.05) oleic acid in LM (42.7 vs. 40.3 +/- 0.5 g/100g FA) and in fat (43.0 vs. 40.9 +/- 0.5 g/100g FA). The cis-9, trans-11 conjugated linoleic acid (CLA) increased quadratically (P < 0.01) with increasing dietary RG in LM from 0.45 to 0.64 to 0.62 +/- 0.03 g/100 g of FA and increased in fat from 0.61 to 0.84 to 0.83 +/- 0.04 g/100 g of FA. Moreover, cis-9, trans-11 CLA was higher (P < 0.05) in fat from steers fed RG compared with T (0.81 vs. 0.69 +/- 0.04 g/100 g of FA), and tended to be higher (P = 0.07) in muscle (0.62 vs. 0.54 +/- 0.03 g/100 g of FA. Feeding yellow restaurant grease increased content of cis-9, trans-11 CLA in beef without an increase total FA content.

Effects of supplemental fat on growth performance and quality of beef from steers fed barley-potato product finishing diets: I. Feedlot performance, carcass traits, appearance, water binding, retail storage, and palatability attributes1

To measure the effects of dietary fat on feedlot performance, carcass characteristics, and beef appearance, moisture binding, shelf life, and palatability, 168 crossbred beef steers (317 +/- 1.0 kg) were allotted randomly, within weight blocks, to a randomized complete block design with a 3 x2 + 1 factorial arrangement of dietary treatments. Main effects were level of yellow restaurant grease (RG; 0, 3, or 6%) and level of alfalfa hay (AH; 3.5 or 7%), with the added treatment of 6% tallow and 7% AH in barley-based diets containing 15% potato by-product and 7% supplement fed for 165 d (all dietary levels on a DM basis). Dietary treatment did not (P >0.10) affect DMI, LM area, beef brightness, or beef texture. Level of RG linearly increased (P <0.05) ADG from 1.48 to 1.60 kg/d, diet NE(m) from 2.4 to 2.6 Mcal/kg, diet NE(g) from 1.7 to 1.9 Mcal/kg, and internal fat from 2.1 to 2.4%. Level of RG linearly increased (P <0.05) G:F from 0.184 to 0.202, but decreased (P <0.05) beef firmness score from 3.0 to 2.8 and fat luster score from 3.1 to 2.8. Level of AH did not (P >0.10) affect any of the measurements; however, AH interacted with level of RG on fat thickness and yield grade (linear; P <0.05), as well as marbling score and percentage of carcasses grading USDA Choice (quadratic; P <0.05). Fat thickness and yield grade increased with increasing RG level in 3.5%, but not in 7%, AH diets. In steers fed 3.5% RG, marbling scores and percentage of carcasses grading Choice were greatest when fed with 3.5% AH, and least when fed 7% AH. Steers fed tallow had lower marbling scores (P = 0.01) and percentage of carcasses grading Choice (P = 0.066) than those fed RG. Retail storage attributes, including visual and instrumental color, decreased during storage (P <0.01), but were not (P >0.10) affected by diet. Trained sensory panel scores for initial tenderness increased quadratically (P = 0.07) as dietary RG increased, but diet did not (P >0.10) affect drip loss, cooking loss, or trained sensory panel scores for sustained tenderness, initial and sustained juiciness, and beef flavor. Therefore, RG increased diet energy, improved performance, and increased carcass fatness; however, dietary fat and AH did not affect most measurements of water retention, color stability, or palatability of beef.

Effect of Supplementing Graded Levels of Forage Legumes on Performance of Crossbred Calves Fed Tef (Eragrostis tef) Straw

Ebro, A., Nsahlai, I.V., Yami, A. and Umunna, N.N. 2004. Effect of supplementing graded levels of forage legumes on performance of crossbred calves fed Tef (Eragrostis tef) straw. J. Appl. Anim. Res., 26: 107–112. To examine the effect of feeding graded levels of cowpea (Vigna unguiculata) and lablab hay (Lablab purpureus) on feed intake, weight gain, digestibility and utilization of nutrients, Friesian x Boran (Zebu) crossbred calves were fed ad libitum tef straw alone or supplemented with three levels (0.5, 1 and 1.5% of body weight) of either cowpea or lablab hay. Fifty-six and 28 calves were used for the growth and digestibility studies, respectively. Supplementation increased total dry matter, organic matter, nitrogen, gross energy and digestible energy intakes. Furthermore, increasing levels of supplementation increased average daily gain, nitrogen digestibility and nitrogen retention. Cowpea and lablab did not differ (P<0.05) from each other and thus are equally efficient in improving feed intake, nutrient digestibility and utilization for growth. Supplementation of calves with cowpea or lablab hay at levels lower than 1% of body weight may not substitute for the basal roughage.

Effect of Various Levels of Forage and Form of Diet on Rumen Development and Growth in Calves

The effect of form of starter grain (coarse vs. ground) and inclusion of various levels of hay on body weight gain and rumen development was evaluated. Two experiments were conducted to determine the effect of form of diet and forage inclusion on intake, growth, feed efficiency, and weaning age in dairy calves. Diets consisted of commercial coarse starter (C), ground starter (G), coarse starter with 7.5% bromegrass hay of consistent particle size (8 to 19mm) (H1), and coarse starter with 15% hay (H2). In experiment 1, intake was held constant across treatments until weaning, when feed was offered ad libitum. Calves receiving H1 and H2 were heavier and had greater body weight gain and greater feed efficiency than calves receiving C. There were no differences in intake. Total volatile fatty acid concentrations were higher, and the proportion of acetate was lower for calves fed G vs. C. In experiment 2, calves (n = 56) were offered diets on an ad libitum basis and weaned according to intake. There were no differences in body weight gain, average daily gain, feed efficiency, and age at weaning with respect to treatment. Starter and total dry matter intake tended to be greater in calves fed H1 and H2 vs. C. The addition of controlled particle size hay to diets of young calves appears to favorably alter rumen environment, resulting in increased intake and improved feed efficiency. Forage of a consistent particle size can be successfully utilized in starter rations of young calves.

Consumo, digestibilidade aparente de nutrientes e disponibilidade de minerais em ovinos, em função de diferentes níveis de cama de frango na dieta

Foram confinados 20 ovinos em gaiolas metálicas, durante 15 dias, com o objetivo de determinar os efeitos de diferentes níveis de cama de frango sobre o consumo e a digestibilidade de nutrientes, o balanço de nitrogênio e a disponibilidade aparente dos macrominerais. Os animais foram distribuídos em quatro tratamentos em delineamento em blocos casualizados, com cinco repetições. O volumoso foi composto de feno de capim-tifton 85 (Cynodon spp) e a cama de frango, constituída de sabugo de milho triturado e casca de café, numa relação 1:1. As dietas foram isoprotéicas contendo quatro níveis de feno (80, 60, 40 e 20%), quatro níveis de cama de frango (0, 20, 40 e 60%) e 20% de concentrado, na base da matéria natural. Os consumos de MS, MO, NDT, CHOT, CNE, PB e EE na dieta total não foram afetados pelos tratamentos, enquanto os consumos de FDN e FDA reduziram com o aumento do nível de cama de frango na dieta. Os coeficientes de digestibilidade do CHOT, CNE e EE elevaram de 59,7 para 64,6%, 88,5 para 93,2% e 1,5 para 30,2%, respectivamente, com o aumento do nível de cama de frango (de 0 para 60% da dieta). Os coeficientes de digestibilidade da MS e MO não sofreram efeito, com valores médios de 55,8 e 61,9%, e da FDN e PB diminuíram de 52,0 para 39,4% e 77,5 para 58,0%, respectivamente, com o aumento do nível de cama de frango de 0 para 60% da dieta. O balanço de nitrogênio passou de negativo para ligeiramente positivo, com a inclusão da cama de frango, embora tenha ocorrido alta excreção urinária de nitrogênio em todos os tratamentos. A cama de frango presente em 40 e 60% da dieta apresentou alta participação no suprimento de proteína bruta e magnésio, comparada ao volumoso, além de suprir mais de 100% dos requerimentos de Ca, P, Na e K dos animais. Entretanto, a disponibilidade aparente do Ca foi baixa e do P, negativa.

Effects of forage and sunflower oil levels on ruminal biohydrogenation of fatty acids and conjugated linoleic acid formation in beef steers fed finishing diets.

Six Hereford steers (295 kg) cannulated in the proximal duodenum were used to evaluate the effects of forage and sunflower oil level on ruminal biohydrogenation (BH) and conjugated linoleic acid (CLA) outflow. Steers were fed one of six treatment diets in a 3 x 2 factorial arrangement of treatments (grass hay level: 12, 24, or 36% of DM; and sunflower oil level: 2 or 4% of DM) in a 6 x 6 Latin square design. The remainder of the diet was made up of steam rolled corn and protein/mineral supplement. Duodenal samples were collected for 4 d following 10-d diet adaptation periods. Data were analyzed with animal, period, forage level, sunflower oil level, and two-way interaction between forage and sunflower oil level in the model. Dry matter intake showed a quadratic response (P < 0.04), with an increase in DMI as forage level increased from 12 to 24% followed by a decrease in DMI when 36% forage was fed. Flow of fatty acids at the duodenum was higher (P < 0.03) for 4 vs. 2% sunflower oil diets, and similar among forage levels. Apparent ruminal digestibility of NDF increased in a linear manner (P < 0.04) as dietary forage level increased. Ruminal BH of dietary unsaturated 18-C fatty acids, oleic acid, and linoleic acid increased linearly (P < 0.05) as dietary forage level increased. Linoleic acid BH tended (P < 0.07) to be greater for 4 than 2% sunflower oil level. Duodenal flow of pentadecyclic, stearic, linolenic, and arachidic acids increased linearly (P < 0.05) as dietary forage level increased from 12 to 36%. Duodenal flow of linoleic acid decreased in a linear manner (P < 0.03) with increasing dietary forage level. Flow of trans-10 octadecenoate decreased linearly (P < 0.03) as dietary forage level increased, whereas trans-11 vaccenic acid flow to the duodenum increased (P < 0.01) linearly with increased dietary forage. Dietary forage or sunflower oil levels did not alter the outflow of cis-9, trans-11 CLA. Flows of cis-11, trans-13, and cis-9, cis-11 CLA increased linearly (P < 0.05) with increased dietary forage. Flows of cis-11, cis-13, and trans-11, trans-13 CLA decreased linearly (P < 0.05) with increased dietary forage. Increasing dietary forage levels from 12 to 36% in beef cattle finishing diets increased BH of unsaturated 18-C fatty acid and outflow of trans-11 vaccenic acid to duodenum without altering cis-9, trans-11 CLA outflow.

FIBEX-treated rice straw as a feed ingredient for lactating dairy cows

Treatment of rice straw by the proprietary FIBEX process resulted in increased in vitro digestibility by ruminal microorganisms due to a reduced lag time, increased rate of digestion, increased extent of digestion, and possible removal of inhibitory agents present in untreated rice straw. To determine the value of treated rice straw as a feed ingredient for lactating dairy cows, production parameters and milk composition were determined in a feeding trial with thirteen primparous and six multiparous cows in a switchback design involving two diets and 21 days periods. One diet was a conventional dairy diet that contained alfalfa hay, corn grain, soybean meal (SBM) and several byproduct feeds. The other diet contained these same feed ingredients, but with levels of alfalfa hay, corn grain and SBM that were altered somewhat to provide energy, neutral detergent fiber (35.8%), acid detergent fiber (25.8%) and crude protein (18.0%) levels similar to the treated rice straw added at 7% of dry matter. The diet that contained treated rice straw supported higher neutral detergent fiber intake and milk yield. Milk produced from cows fed the two diets had similar levels of protein, urea nitrogen and lactose. Based on its increased in vitro fermentability at higher fiber content, FIBEX-treated rice straw may be useful as a feed ingredient for lactating dairy cows.

Compost convective airflow under passive aeration.

For composting, passive aeration can save energy costs while being just as efficient as forced or active aeration. Passive aeration requires the proper design of aeration ducts, and thus, the proper prediction of the convective airflow rates created by the temperature differential between the compost and the ambient air. To establish such relationship, the temperature and convective air flow regimes of composts were investigated using three bulking agents (wood shavings, hay and straw), each at three moisture contents (MC-60%, 65% and 70%) spanning the normal values. All bulking agent and aeration treatments were aerated in duplicate under passive and active regimes. Laboratory vessels of 105 L were used for all treatments. Passive aeration treatments produced temperatures above 57 degrees C, as did the treatments actively aerated at 4 mg of air s(-1) kg(-1) of initial dry compost material. Compost MC had an effect only on the peak compost temperature, occurring between day 2 and 6. After 6 days of composting, MC no longer had any effect on temperature regime because of the loss of moisture by each mixture. A relationship was established between the Grasholf number (Gr-ratio of buoyancy to viscous forces) and the convective airflow rates, to size the aeration ducts for passive aeration. In general, convective airflow rates ranged from 1.5 to 0.7 mg of dry air s(-1) kg(-1) of initial compost dry matter, from day 0 to day 20, respectively, and for all compost treatments. This airflow rate sizes the aeration ducts installed under compost piles for passive aeration. As compared to straw where airflow rate dropped over a given level of Gr, wood shavings and hay were found to be more effective as bulking agents, as their airflow rate increased constantly with Gr.

Integration of forage legumes with cereal crops. I. Effects of supplementation with graded levels of lablab hay on voluntary food intake, digestibility, milk yield and milk composition of crossbred cows fed maize–lablab stover or oats–vetch hay ad libitum

This study examined the effect of lablab hay supplementation of crossbred cows fed forages from cereal+forage legume intercropping (maize–lablab (ML) stover or oats–vetch (OV) hay) basal diets on feed intake, apparent digestibility, milk yield and milk composition of crossbred cows. Forty eight multiparous (parity 2–4) cows approximately 60 days prepartum and mean live weight 445 S.D.±57 kg at the beginning of the experiment were used in the study. The experiment lasted 200 days each cow, covering 60 days prepartum and 140 days postpartum. Lablab hay supplementation significantly ( P<0.05) increased total DM intake and DM digestibility as compared with the unsupplemented diets but there was no significant ( P>0.05) difference in total DM intake among the supplemented cows. Cows fed ML stover or OV hay supplemented with lablab hay had improved rumen environment as reflected in the rates of DM, OM, N and NDF degradation greater than 0.03 (i.e. 3%) per h. The degradation parameters; a, b, c and the effective degradability (ED) were higher ( P<0.001) for lablab hay supplemented diets than for ML stover or OV hay basal forages fed alone. ML stover fed alone resulted into significantly ( P<0.001) higher Ca, P, and Mg intake than OV hay fed alone while K intake was significantly ( P<0.05) higher with OV hay. Increasing levels of lablab hay supplementation significantly ( P<0.001) increased Ca, P and Mg intakes but did not significantly ( P>0.05) affect K intake in both ML stover and OV hay diets. OV hay and ML stover basal forages fed to unsupplemented crossbred cows resulted into average milk yields of 6.82 and 8.25 kg/cow per day, respectively, over a lactation period of 140 days after calving. Supplementation with lablab hay significantly ( P<0.001) increased milk yield of crossbred cows fed OV hay but for ML stover based diets, supplementation was only significant ( P<0.05) at the lowest level (0.4% BW) of lablab offer. For ML stover based treatments, the highest daily milk yield (9.5 kg/head) was obtained at 0.4% of body weight (BW) lablab hay supplementation, while for OV hay treatments, the highest milk yield of 9.7 kg/head was obtained at 1.2% BW lablab hay supplementation. Mean concentrations of milk fat, protein and total solids were similar for both ML stover and OV hay diets fed alone but lablab hay supplementation did not significantly affect the concentration of milk components of cows fed both forages. It was concluded that for optimum milk production from crossbred cows fed ML stover and OV hay basal diets, supplementation should be at 0.52 and 0.85% of BW level of lablab hay, respectively. The lack of response to higher levels of lablab hay supplement despite the increased protein intake was interpreted as resulting from a deficit of dietary energy.

Calibrating Fecal NIRS Equations for Predicting Botanical Composition of Diets

The objectives of this study were to investigate the use of near infrared spectroscopy (NIRS) of fecal samples for predicting the percentage of mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana (Rydb) Beetle) in sheep diets and to quantify the limitations of using NIRS of fecal samples to predict diet composition. Fecal material from a sheep feeding trial with known levels of sagebrush and several background forages was used to develop fecal NIRS calibration equations validated with fecal material from 2 other sheep feeding trials with known levels of sagebrush in the diets. The 1996 calibration trial varied the level of sagebrush, alfalfa, and grass hay in the diets. The 1998 trial compared frozen to air-dried sagebrush. The Wyoming trial was a metabolism study using frozen sagebrush. Trials used different levels of sagebrush varying from 0 to 30% of the diet in increments of 4 to 10 percentage points. Internal validation of the 1996 trial with a subset of the samples not used for calibration showed that when predicted samples are from the same population as the calibration samples, this procedure can accurately predict percent sagebrush (R2 = 0.96, SEP = 1.6). However, when predicted samples were from a different population than calibration samples, accuracy was much less, but precision was not affected greatly. Low accuracy was caused by a compression of the range of data in the predicted values compared to the reference values, and the predicted sagebrush levels in the diet should be considered to represent an interval scale of measurement. Modified partial least squares regression resulted in better calibration than stepwise regression, and calibration data sets with only high, low, and no sagebrush resulted in calibrations almost as good as data sets with several intermediate levels of sagebrush. High values of the H statistic were related to low precision but did not affect the accuracy of predictions. We believe the interval scale of measurement will contain sufficient information for the purpose of addressing many questions on rangelands. DOI:10.2458/azu_jrm_v55i4_walker

Productive performance and carcass characteristics of lambs fed finishing ration containing various forage levels

This study was conducted to determine the effect of forage level in the finishing ration on productive performance and carcass characteristics in lambs. Twenty male Pelibuey lambs, weighing 24 kg, were assigned to one of the four groups according to a completely randomized design. Each group received one of the four treatments with hay levels at 0, 10, 20 or 30%. Lambs were individually confined to 1.5 m 2 metabolic cages. Dry matter (DM) intake was 48.9% greater for the 30% hay ration than for ration without hay during the entire 60-day-period, as compared to a 56.6% increase during the first 30 days. However, greater hay levels in the ration were associated with lower weight gain. Period differences were also noted, with an average daily gain of 268 g during the first 30 days, and a much lower ( P<0.01) average daily gain of 149 g during the last 30 days. It appeared that the more days the lambs stayed on feed, the less was their weight gain. Feed efficiency of the lambs during the first 30 days (5.0) was greater than during the last 30 days (10.1). Cold and hot carcass weights (kg) decreased (linear, P<0.05) as the level of hay in the ration increased. Full gastrointestinal tract weight tended to increase with an increase in the hay level of the ration. However, there was no treatment effect on the weight of empty gastrointestinal tracts. Hay level in the ration did not affect marbling score, degree of finishing, external fat or longissimus muscle (ribeye) area. No effect of hay level in the ration was observed on weight of skin, liver, lungs, testicles or blood. First and second yield carcass grade reduced (linear, P<0.001) as the level of hay in the ration increased.

Nutrient intake, digestibility, mastication and ruminal fermentation of lambs fed finishing ration with various forage levels

This study was conducted to determine the effect of hay level in the finishing ration for lambs on intake, digestibility, nitrogen retention, mastication and ruminal parameters. Twenty Pelibuey growing male lambs, weighing an average of 36 kg, were assigned to one of the four treatment groups according to a completely randomized arrangement. Treatments were: 0, 10, 20 and 30% chopped hay. Dry matter (DM) intake increased linearly ( P<0.05) with an increase in hay percentage from 0 to 30% in the ration. There was a 38% difference in DM intake between lambs consuming the ration without hay and that with 30% hay, corresponding with DM intake of 61.1 and 84.8 g/kg 0.75. Rumination time varied from 2.4 h per day in lambs fed the ration without hay to 6.9 h per day in lambs fed the ration with 30% hay. Eating time varied from 1.5 to 2.9 h, and increased as the quantity of hay in the ration increased. DM digestibility was 85.5, 79.9, 67.5 and 66.6% for 0, 10, 20 and 30% hay ration, respectively. Neutral detergent fiber (NDF) digestibility was 59.4, 58.2, 42.5 and 35% for 0, 10, 20 and 30% hay ration, respectively. Digestibility of non-structural carbohydrates (NSCs) decreased linearly from 94.2% for the ration without hay to 86.6% for the ration with 30% hay. Retained N (%) decreased linearly ( P<0.01) as the hay in the ration increased, probably related to less readily available energy. Ruminal pH increased linearly ( P>0.01) as the hay in the ration increased. Concentration and molar percentage of acetate increased linearly ( P<0.01) as hay level in the ration increased, while propionate concentration decreased.

Calibrating fecal NIRS equations for predicting botanical composition of diets

The objectives of this study were to investigate the use of near infrared spectroscopy (NIRS) of fecal samples for predicting the percentage of mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana (Rydb) Beetle) in sheep diets and to quantify the limitations of using NIRS of fecal samples to predict diet composition. Fecal material from a sheep feeding trial with known levels of sagebrush and several background forages was used to develop fecal NIRS calibration equations validated with fecal material from 2 other sheep feeding trials with known levels of sagebrush in the diets. The 1996 calibration trial varied the level of sagebrush, alfalfa, and grass hay in the diets. The 1998 trial compared frozen to air-dried sagebrush. The Wyoming trial was a metabolism study using frozen sagebrush. Trials used different levels of sagebrush varying from 0 to 30% of the diet in increments of 4 to 10 percentage points. Internal validation of the 1996 trial with a subset of the samples not used for calibration showed that when predicted samples are from the same population as the calibration samples, this procedure can accurately predict percent sagebrush (R2 = 0.96, SEP = 1.6). However, when predicted samples were from a different population than calibration samples, accuracy was much less, but precision was not affected greatly. Low accuracy was caused by a compression of the range of data in the predicted values compared to the reference values, and the predicted sagebrush levels in the diet should be considered to represent an interval scale of measurement. Modified partial least squares regression resulted in better calibration than stepwise regression, and calibration data sets with only high, low, and no sagebrush resulted in calibrations almost as good as data sets with several intermediate levels of sagebrush. High values of the H statistic were related to low precision but did not affect the accuracy of predictions. We believe the interval scale of measurement will contain sufficient information for the purpose of addressing many questions on rangelands.

Steam-flaked corn diets containing combinations of wet corn gluten feed and alfalfa hay: effects on diet digestibility and ruminal characteristics (2002)

Twelve ruminally cannulated Jersey steers were used to measure digestibility and ruminal characteristics of steam-flaked corn based diets containing combinations of wet corn gluten feed (WCGF) and alfalfa hay (AH). Starch intake was lower (P<0.05), but neutral detergent fiber intake was higher (P<0.05) as AH and WCGF increased in the diet. Ruminal pH was increased by AH (linear, P<0.05) and tended (P<0.07) to increase with WCGF. Feeding higher levels of WCGF tended to increase passage rate (P=0.17) and decreased (P<0.05) total tract organic matter digestibility. Flaked corn diets containing at least 25% WCGF may contribute enough roughage to allow reduction of alfalfa hay levels.

Níveis de feno de alfafa e forma física da ração no desempenho de cordeiros em creep feeding

Com o objetivo de avaliar o desempenho de cordeiros em creep feeding e confinados, foram realizados dois experimentos. No primeiro, 32 cordeiros ¾ mestiços Suffolk foram criados em creep feeding, desmamados aos 56 dias de idade e, em seguida, confinados. Os cordeiros receberam os seguintes tratamentos: 1. sem suplementação; 2. suplementação com ração à base de milho e soja; 3. ração à base de milho e soja com 15% de feno de alfafa; 4. ração à base de milho e soja com 30% de feno de alfafa. Após o desmame, os cordeiros suplementados foram confinados, recebendo a mesma ração do creep feeding até atingirem de 30 a 32 kg de peso vivo. No segundo experimento, foram utilizados 32 cordeiros ¾ mestiços Suffolk, alimentados em creep feeding, recebendo ração farelada ou peletizada até os pesos de abate: 26 e 28 kg. As dietas eram isoprotéicas (21% PB) e isoenergéticas (2,9 Mcal EM/kg MS). Os animais suplementados na fase de aleitamento obtiveram ganho de peso de 147,4g/dia a mais, quando comparados aos não suplementados. Não houve efeito dos níveis de feno de alfafa na ração sobre o desempenho dos animais. Entretanto, no confinamento, a máxima eficiência de ganho de peso esperada para os machos, conforme a análise de regressão, situou-se em 18,7% de inclusão de feno de alfafa na ração. A ração peletizada propiciou maior desenvolvimento dos animais, quando comparada à ração farelada. Os machos que receberam ração peletizada atingiram os pesos de abate de 26 e 28 kg aos 55 e 60 dias de idade, respectivamente.

The effect of dietary protein content and hay intake level on the true and apparent digestibility of hay

The digestibility of concentrate feeds has been determined by difference using hay as a basal forage in many institutions. The objective of this experiment was to examine the effect of hay intake level and dietary crude protein (CP) content on hay digestibility. Groups of wether lambs (1 year old) were fed three levels (600, 700 and 800 g/day) of hay each at two CP contents (103 and 182 g CP/kg DM), achieved by using a urea solution. An extra group of lambs were fed hay unsupplemented with urea (42 g CP/kg DM) at a level of 800 g/day. The true organic matter digestibility (True OMD, calculated using two methods: True OMD 1 and 2) and apparent OMD of all treatments fed the 182 g CP/kg DM diets were significantly higher ( P<0.05) than treatments fed the 103 g CP/kg DM diet (OMD: 632.8 g/kg vs. 604.2 g/kg; True OMD 1: 720.6 vs. 694.1 g/kg; True OMD 2: 711.8 vs. 681.0 g/kg). Apparent and true digestibility also increased as hay allowance increased and a significant linear effect was observed for GED. For the three groups fed 800 g/day of hay, significant differences in digestibility due to CP content only occurred between the 182 and the 42 g CP/kg DM diets (with the exception of CP digestibility). Although the effect of CP content was significant in some cases, the magnitude of the observed digestibility response is of little consequence for concentrate feed evaluation.

Condensed tannin and saponin content of Vigna unguiculata (L.) Walp, Desmodium uncinatum, Stylosanthes guianensis and Stylosanthes scabra grown in Zimbabwe.

Samples of the tropical forage legumes Vigna unguiculata (L.) Walp (cowpea), Desmodium uncinatum (silverleaf desmodium), Stylosanthes guianensis (oxley fine stem stylo) and Stylosanthes scabra (fitzroy) and of natural pasture (veld) hay were analysed and ranked according to their proanthocyanidin (PA) and saponin content. Silverleaf desmodium and fitzroy leaf and stem samples of different ages were also separately analysed for the PA contents. All the samples analysed contained some PA but no saponins. High levels of PA were detected in silverleaf desmodium and very low levels in veld hay and cowpea. In all samples, more of the tannins were bound to protein or neutral detergent fibre (NDF) than were extractable, most being bound to proteins. The proportion of the unextractable PA was greater in younger than in mature materials.

Performance of beef heifers limit-fed growing diets containing alfalfa hay and wet corn gluten feed (2001)

Three hundred thirty-nine crossbred beef heifers were used in a 99-day growing study to identify optimum combinations of alfalfa hay and wet corn gluten feed (WCGF) in limit-fed growing diets. Diets contained 10, 20, or 30% ground alfalfa hay, and 0, 40, or 68% Sweet Bran WCGF (dry basis) in a 3 × 3 factorial arrangement of treatments. An interaction occurred (P 0.10) to diets containing 20 or 30% alfalfa hay and no WCGF. Feed efficiencies for the 30% alfalfa hay and 40% WCGF diet were better (P<0.05) than the diet containing 30% alfalfa hay and no WCGF. Dry matter intake as measured two hours after feeding increased linearly (P<0.01) with increasing levels of alfalfa hay, and decreased linearly (P<0.01) with increasing levels of WCGF. This study suggests that including WCGF at 40% of the diet (dry basis) can effectively replace steam-flaked corn in limit-fed diets containing 20 or 30% alfalfa hay.

Associative effects of supplementing barley straw diets with alfalfa hay on rumen environment and nutrient intake and digestibility for ewes

The objectives of these experiments were to study the positive associative effects of supplementing barley straw-based diets with different levels of alfalfa hay on nutrient intake, rumen environment, and nutrient digestibility and to evaluate the minimal amount of alfalfa hay needed to produce such an effect in ewes. In experiment one, 15 Awassi ewes (five ruminally fistulated; body weight=54 kg±1.5 ) were fed five barley straw-based diets in a 5×5 Latin square design with 3-week periods. Dietary treatments were as follows: diet 1, barley straw (no supplement), diet 2, barley straw supplemented with 1% urea (dry matter basis), diets 3, 4, and 5 barley straw supplemented with 150, 300, and 450 g of alfalfa hay, respectively. In experiment 2, the same experimental diets were fed to 50 ewes (10 ewes/diet) for 50 days in a complete randomized design. In experiment 1, dry matter intake (DMI) was increased ( P<0.05) by the addition of alfalfa hay compared with diets that had no alfalfa. Metabolizable energy intake (MEI) increased linearly ( P<0.05) with the increasing amounts of alfalfa hay, being highest ( P<0.05) for diet 5. Diets that contained alfalfa hay had greater ( P<0.05) dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), and crude protein (CP) digestibilities. The extent of barley straw NDF digestibility was also increased ( P<0.05) with the alfalfa addition (67 versus 60.5%). Rumen ammonia and VFA concentrations were higher ( P<0.05) in diets that contained alfalfa, however, rumen pH was not affected by the diet (avg. 6.64). In experiment 2, the effect of alfalfa hay addition to barley straw-based diets had similar effects on DMI as observed in experiment 1. Straw intake increased ( P<0.05) with the 150 g addition of alfalfa hay compared with unsupplemented diet (725 versus 650 g −d per day) with no further improvement with the higher amounts of alfalfa. It seems that the minimal amount of alfalfa hay needed to produce the positive associative effect on barley straw is 150 g per day for maintenance diets of ewes.