bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of ammonia concentration and microbial population on in vitro degradation of 14C-labelled dietary proteins
Authors: Song M. K. , Kennelly J. J.
Published: March 2010

Rumen fluid from two nonlactating cows fed barley silage and rolled barley grain based concentrates (75:25 on a dry matter basis) was incubated for 0.5, 1, 2, 3, and 4 h with 14C-labelled soybean meal (SBM), fish meal (FM) and corn gluten meal (CGM) to examine the effects of ammonia concentration and protein solubility on rate and extent of protein degradation by total mixed ruminal microorganisms (TMM) or mixed ruminal bacteria (MB). Proteins were labelled by reductive methylation. Ammonia concentration in control ruminal fluid was 4.0 mg dL−1; graded levels of 1 M (NH4)2SO4 were added to achieve ammonia concentrations of 10, 20, and 30 mg dL−1 ruminal fluid. Soluble protein was extracted with borate-phosphate buffer (pH 7.8). Removal of protozoa reduced the extent of protein degradation. However, relative to bacteria, protozoa appeared to play a minor role in protein degradation. Rate and extent of protein degradation was not influenced by ammonia concentration, but was highly correlated with protein solubility. Therefore, it is concluded that ammonia concentration is not the primary factor regulating proteolytic activity of rumen microorganisms, rather their activities may depend upon the solubility and physico-chemical properties of proteins. Key words: In vitro, ammonia concentration, protein degradation, microbial population
The effect of feeding organically bound selenium and α-tocopherol to dairy cows on susceptibility of milk to oxidation
Authors: Nicholson J. W. G. , St-Laurent A.-M. , McQueen R. E. , Charmley E.
Published: March 2010

Twenty-four lactating Holstein cows were used to compare the effect of two sources of supplemental selenium with or without supplemental dl-α-tocopherol acetate, on oxidative stability of their milk. The Se sources were inorganic Se mixed in the concentrate ration or alfalfa sprayed with 20 g Se ha−1 four wk before ensiling. Half of the cows on each treatment received 3000 IU d−1 of dl-α-tocopherol acetate for the first 4 wk (Period 1) and the other half received the tocopherol for the second 4 wk (Period 2). Improvement (P < 0.01) in flavour scores due to α-tocopherol supplementation were apparent only when 0.1 mg Cu kg−1 was added to the milk to catalyze oxidation. Plasma tocopherol content was increased (P < 0.01) when tocopherol was fed regardless of Se treatment Milk tocopherol content increased (P < 0.01) when the cows were fed both supplemental Se and tocopherol; however, the increase was not significant (P > 0.05) when the tocopherol was fed without Se. Plasma and milk Se contents were higher (P < 0.01) for cows fed the Se-fertilized alfalfa than for the control cows or those fed the inorganic Se. In whole blood there were no significant differences in Se content in Period 1 but levels were higher (P < 0.01) for the cows fed Se-fertilized alfalfa in Period 2. Although feeding Se-fertilized alfalfa (802 ± 128 μg Se kg−1 DM) resulted in higher milk Se than feeding either the unsupplemented diet or the inorganic Se (398 ± 44 μg Se kg−1 DM in the concentrate) this had no effect on the oxidative stability of the milk. The results suggest adequate Se improves the transfer of dietary tocopherol to milk. Key words: Oxidized milk, tocopherol, selenium, cows
True absorption of selenium in dairy cows: Stable isotope tracer methodology and effect of dietary copper
Authors: Koenig K. M. , Shelford J. A. , Buckley W. T.
Published: March 2010

True absorption of Se in dairy cows was determined using a method combining balance techniques with isotopic enrichment of body Se pools. Oral and intravenous routes of isotope administration and tracer enrichment in serum and liver were evaluated for determining endogenous fecal Se. The effect of supplemental dietary Cu on Se absorption was also determined. In two trials, five and six nonlactating Holstein cows were supplemented with 0 or 16 mg Cu kg−1 feed dry matter. The basal diet was cubed orchardgrass hay that contained 0.19 mg Se kg−1 (0.18 mg kg−1 as added selenite) and 14 mg Cu kg−1. Each cow received Se-77 orally and Se-82 intravenously on day 1. Feces, urine and serum samples were collected during two 5-d balance periods (days 16–20 and days 21–25). Liver biopsies were taken on day 27. Endogenous fecal Se determined from tracer enrichment in serum and liver with oral isotope administration and from enrichment in serum with intravenous isotope administration were not different (P > 0.05). It was concluded that any one of these approaches could be used to estimate endogenous fecal Se and true Se absorption. There was no effect of Cu on Se absorption (P > 0.05). True absorption of Se was 11 ± 1.5% of the Se intake. Key words: Selenium, copper, stable isotope, endogenous excretion, absorption, dairy cows
Influence of diet composition on weight gain and skeletal development of White Leghorn chicks reared to four weeks of age
Authors: Summers J. D. , Leeson S. , Spratt D.
Published: March 2010

Experiments were carried out with White Leghorn chicks to study the influence of starting diet composition on weight gain and bone growth. Increasing dietary protein level from 15 to 21% had marked influence on weight gain, tibia length and to a lesser extent, tibia weight for chicks reared to 4 and 7 wk of age. Length of tibia plateaued at lower dietary protein levels than did growth suggesting that weight gain, at a young age, is as good if not a better indication of frame size than is a measure of tiba length. While levels of dietary energy ranging from 11.29 to 12.97 MJ kg−1 did reflect changes in weight gain and tibia length, such changes were small in comparison to those noted with changes in dietary protein level. Increasing supplemental methionine level from 0.05 to 0.15% and a 50% increase in the level of calcium and available phosphorus did not enhance weight gain or frame size over the control diet. Body weight gain for the young chick was not enhanced by high dietary levels of methionine and lysine. Thus, the suggestion of rapid feather development increasing the requirement for methionine or rapid weight gain increasing the requirement for lysine at this particular age is not valid. Key words: Chickens, skeletal growth, weight gain
An attempt at sperm-mediated gene transfer in mice and chickens
Authors: Gavora J. S. , Benkel B. , Sasada H. , Cantwell W. J. , Fiser P. , Teather R. M. , Nagai J. , Sabour M. P.
Published: March 2010

Experiments were carried out to transform laboratory mice and domestic chickens by use of sperm incubated with bacterial plasmid DNA. Following demonstration of "uptake" of such DNA by sperm of both species, attempts were made to replicate a previously published procedure (Lavitrano et al. 1989, Cell 57: 717–723) for producing transgenic mice through in vitro fertilization (IVF). Also, female mice and hens were inseminated (AI) with sperm which had been incubated in a DNA solution. Such incubation did not influence the fertility or hatchability of the hens' eggs. However, no transformed progeny were detected among 45 mice produced by IVF or among 69 mice and 470 chickens produced by AI. Key words: Sperm-mediated DNA transfer, mice, chickens
Effects of a parasympathomimetic agent, slaframine, on reticulo-omasal orifice function
Authors: Kelly J. M. , McBride B. W. , Froetschel M. A. , Croom Jr. W. J. , Hagler Jr. W. M.
Published: March 2010

Three nonlactating, nonpregnant, ruminally cannulated Holstein cows (680–732 kg) fed chopped brome hay ad libitum once daily were used to study effects of slaframine (SF) on rumen function in a 3 × 3 Latin square design. Animals were injected intramuscularly with 0, 20 or 40 μg kg BW−1 SF, allowing for 1 d between trials. At 0, 40, 180 and 360 min postinjection rumen contents were partially evacuated. Reticular contraction frequency (RCF) was determined using a balloon placed in the reticulum connected to a pressure transducer and physiograph and reticulo-omasal orifice opening duration (ROOD) was measured using palpation and endoscopy. RCF as a percentage of predose was decreased linearly by SF treatment (P < 0.01). SF affected ROOD, which was higher (P < 0.05) for both SF treatments. This pattern was also linear (P < 0.01). A characteristic change in reticulum pressure was identified that correlated with SF mediated variation in ROOD (r = 0.67; P < 0.01). Previous research has indicated that SF administration increased salivation and shifted site of digestion. The results presented herein are consistent with these observations and indicate that duration of reticulo-omasal orifice opening may be more highly associated with the rate of digesta passage than reticular frequency. Key words: Slaframine, reticulo-omasal orifice, reticulum motility, cattle
Energy-protein intake and its effect on blood metabolites of high-producing dairy cows
Authors: Nachtomi E. , Halevi A. , Bruckental I. , Amir S.
Published: March 2010

Forty-six multiparous Israeli Holstein cows were used to evaluate the effect of three dietary concentrate levels (50, 65 and 80%) and two crude protein (CP) levels (17 and 21%) in dry matter (DM), on blood metabolites. Cows were divided into six dietary treatments in a 2 × 3 factorial design. Rations were fed ad libitum for the first 5 wk of lactation. Milk yield and feed intake were recorded daily, while milk composition and plasma metabolites were determined weekly. Raising the concentrate levels in the diet led to increased net energy (NE) intake (P < 0.01), and decrease milk fat percent (P < 0.0001); Cows tended to gain more weight and the negative energy balance declined (P < 0.0001) in group 80% concentrate relative to the other two groups. High-CP in the diet elevated protein intake (P < 0.001) without affecting the cows' performance. Increasing the energy intake by raising the concentrate level from 50 to 65 and 80% in the diet, lowered (P < 0.05) the plasma nonesterified fatty acid (NEFA) and 3-hydroxybutyrate (3-OHB) levels and raised the glucose level (P < 0.05) in the 80% concentrate group. The high-CP diet raised the level of 3-OHB (P < 0.01), while plasma levels of NEFA, glucose and cholesterol remained unchanged. No difference was found between winter (December–April) and summer (May–November) in overall average of DM and NE intake. However, 4% FCM, milk fat percentage and milk protein yield were higher (P < 0.05) in winter than summer. This elevation was accompanied by a rise in NEFA (P < 0.06) and total α-amino nitrogen (P < 0.05). It was concluded that plasma parameters determined were found to reflect the dietary status of dairy cows in early lactation; winter conditions encourages lypogenesis and supply of metabolites needed for milk production. Key words: Energy-protein, dairy cow, season, blood metabolites
Potential goitrogenic and toxic effects of an indole glucosinolate extract injected into the developing chick embryo
Authors: Darroch C. S. , Bell J. M.
Published: March 2010

Goitrogenic and toxic effects of an indole glucosinolate extract were assessed using a chick-embryo biassay. An indole extract from brussels sprouts was dissolved in saline at 20 and 40 mg mL−1 and 0.1 mL aliquots were then injected into the egg yolk and blood of developing embryos (15 eggs/treatment) on day 10 of incubation. Aliquots (0.1 mL) of thiourea (10 mg mL−1 saline) were also injected into the yolk and blood (15 eggs/treatment) as positive controls. Thiourea injections increased thyroid weights (P < 0.001), decreased serum thyroxine (P < 0.001) and reduced the length of the duodenum (P < 0.01). Indole glucosinolates did not affect thyroid function but increased chick mortality (P < 0.005). More embryos died from intravenous (IV) injections than from injections into the yolk (P < 0.005). Deaths from IV injections occurred mainly on day 10 of incubation while deaths attributed to yolk injections occurred on days 16 – 21 (P < 0.025). Indole glucosinolates in this experiment were not goitrogenic but did increase the incidence of chick embryo mortality. Key words: Indole glucosinolates, goitrogenic, toxic, chick embryo
Heat pretreatment as a means of improving the response to dietary pentosanase in chicks fed rye
Authors: Teitge D. A. , Campbell G. L. , Classen H. L. , Thacker P. A.
Published: March 2010

Three experiments were conducted to study the effect of heat and acid treatment of rye and wheat on the response of broiler chicks to dietary pentosanase. In exp. 1, autoclaving rye greatly potentiated the growth response to dietary pentosanase (P < 0.01) while producing little or no effect without enzyme. Acid treatment (0.2 N HCl) alone, or in conjunction with autoclaving, improved the performance of broilers fed rye but did not enhance the enzyme response. Examination of the pentosan content or viscosity of treated rye indicated no substantial effect of autoclaving, although some breakdown of pentosan was apparent in the presence of acid. A second experiment confirmed the enzyme potentiating effect of autoclaving in broilers fed rye (cv. Musketeer and Kodiak) and wheat. The response to dietary enzyme was greater for rye than wheat. Viscosity determinations of intestinal contents indicated that autoclaving enabled the dietary pentosanase to reduce viscosity to a greater extent than that achievable with enzyme alone. In exp. 3, Musketeer rye subjected to commercial heat-processing procedures gave a similar response to that observed with autoclaving, although differences in effectiveness were seen. Pelleting alone (without enzyme supplementation) resulted in improved weight gain and feed conversion of chicks fed rye. Both pelleting and micronizing, but not steam-flaking, resulted in a greater response (P < 0.10) to dietary pentosanase. Key words: Broiler chicks, rye, pentosanase, heat treatment
Buoyancy separation of ground forage particles and evaluation of ground white clover particles as feed additive for mice
Authors: Lirette A.
Published: March 2010

In order to determine if buoyancy separation of ground forages would yield more nutritious forage particles for monogastrics, the interrelationship between buoyancy, chemical composition, physical dimensions, and nutritive value of various ground forages was studied. Buoyancy trials were performed using samples of ground forages placed on the water surface in a glass cylinder filled with 4 L water. The particles with the greatest buoyancy were relatively shorter, thinner, and contained higher crude protein and lower ADF and lignin contents. Three groups of 12 weanling mice were fed with three different diets during 3 wk. The first diet was a control ration (NRC recommendations), the second and third diets had 5% of either high buoyancy or low buoyancy white clover particles, respectively. The effect of the diet on blood total cholesterol was also measured. Weight gains of the mice were significantly higher (P < 0.01) for the control and lower buoyancy groups than for the higher buoyancy group. The feed consumption was significantly higher (P < 0.05) for the lower buoyancy diet. The blood total cholesterol was significantly (P < 0.05) lower with the diet containing higher buoyancy particles. It appears that the more-nutritious, high buoyancy white clover particles did not yield better feed consumption and weight gain but reduced blood total cholesterol concentration. Key words: Buoyancy, forages, particles, nutritive value, mice
Use of body surface area to set minimum space allowances for confined pigs and cattle
Authors: Hurnik J. F. , Lewis N. J.
Published: March 2010

The necessity to set minimum space allowances for confined animals has become more urgent as economic pressures have forced the use of increasingly intensive housing. This paper proposes that 50% of body surface area be adopted as a minimum space allowance for confined pigs and cattle. Body surface areas by weight classification have been provided in graph form. Key words: Space requirement, density, welfare, swine, cattle
Effects of somatotropin on the concentration of minerals in the heart, liver, kidneys and carcass of steers
Authors: Boila R. J. , McBride B. W. , Early R. J. , Ball R. O.
Published: March 2010

Growing steers were dosed daily with physiological saline (SAL, 10 steers) or 20.6 mg of recombinantly-derived bovine somatotropin (ST, 10 steers) for 112 d. Administration of ST compared to SAL influenced the concentration of minerals: higher (P < 0.05) K and Mn in liver; lower (P < 0.01) Cu in liver; higher (P < 0.01) Mn in kidneys (P < 0.01); and a tendency (P = 0.07) for higher Zn in bone. Key words: Cattle, somatotropin, minerals, tissues, carcass
Halothane genotype by weight interactions on pig meat quality
Authors: Sather A. P. , Jones S. D. M. , Tong A. K. W. , Murray A. C.
Published: March 2010

The effects of slaughter weight on pork quality as influenced by halothane genotype and breed (Lacombe: LAC, NN-genotype; Yorkshire: YRK, NN-genotype) were investigated in 312 carcasses ranging in weight from less than 65 kg to greater than 105 kg. When adjusted to a warm carcass weight of 87 kg, the longissimus of LAC pigs has normal color and structure scores (2.96 and 2.99, respectively), while halothane-sensitive pigs (HSL, nn-genotype) and XBD (HSL × LAC, Nn-genotype) pigs had inferior color (2.69 and 2.83) and structure (2.55 and 2.74) scores on a 5-point scale with 3 being desirable. The results were corroborated with objective measurements of meat quality including expressible juice, drip, protein solubility and muscle color. At lighter carcass weights (65–75 kg), XBD pigs had pork quality characteristics similar to those of LAC pigs, while at heavier carcass weights (95–105 kg) pork quality from these pigs more closely resembled those of the HSL pigs. Subjective pork color and structure scoring of 85-kg YRK and LAC carcasses suggested they were normal and equivalent to each other. However, objective evaluation of pork quality found that YRK carcasses had 15 g kg −1 greater expressible juice, 8 g kg−1 greater drip and 7 g kg−1 less soluble protein than LAC carcasses, indicating meat from YRK carcasses would have lower processing yields than meat from LAC carcasses. LAC carcasses had 6 kg kg−1 greater intramuscular fat on a wet-matter basis than YRK. These results suggest that the dominance of the halothane gene as it affects pork quality may increase with increasing slaughter weight, and LAC pigs produce higher quality pork than YRK pigs. Key words: Meat quality, market weight, genotype, halothane gene, Lacombe, Yorkshire
Effects of a somatotropin challenge on serum IGF-I concentrations and short-term milk production response in dairy cows
Authors: Kerr D. E. , Manns J. G. , Chaplin R. K. , Laarveld B.
Published: March 2010

The correlation between increases in serum insulin-like growth factor-I (IGF-I) concentration and milk production in response to a single injection of bovine somatotropin (bST) was evaluated. Four cows and four doses of bST (0, 45, 112, 280 mU kg−1) were used in a Latin square design in 4 consecutive weeks. Blood samples were collected 60, 30 and 5 min prior to treatment and then at 12-h intervals for 72 h. Serum IGF-I concentrations were determined after acid gel chromatography by RIA using an IGF-I monoclonal antibody. Treatment effects on serum concentrations of insulin and free fatty acids (FFA) were also determined. The mean IGF-I responses to bST, expressed as a percentage of basal concentrations, were 108, 120, 143 and 228% for the four doses of bST, respectively (P < 0.05, SE = 128). Corresponding milk production responses, determined by expressing milk production 24–72 h post-treatment as a percentage of milk production 16–64 h pretreatment, were 99, 103, 106 and 113%, respectively (P < 0.01, SE = 3.0). The equation describing the relationship between these responses was:[Formula: see text]Serum insulin concentrations oscillated in a marked diurnal pattern with area under the curve being unaffected by bST. There was no main effect of treatment on serum FFA concentrations but there was a treatment × time interaction (P < 0.05) reflecting variable changes in FFA levels in response to treatment. The correlation between the IGF-I-response and milk production response to bST suggests that prior knowledge of an animal's IGF-I-response to bST may be important in selecting animals for maximum benefit from bST treatment. Key words: Insulin, free fatty acids, somatotropin, milk production, cows (dairy)
The effect of frequency of feeding and supplementation with sucrose on ruminal fermentation of alfalfa silage given ad libitum or restricted to sheep
Authors: Charmley E. , Veira D. M. , Aroeira L. , Codagnone H. C. V. , Butler G.
Published: March 2010

Eight ruminally cannulated wethers were used in a factorial trial to examine the effect of frequency of feeding alfalfa silage and sucrose supplementation on voluntary intake, digestibility, rumen fermentation and rate and extent of digestion in and passage from the rumen. When diets were fed ad libitum, frequency of feeding had no effect on voluntary intake, apparent digestibility or the postfeeding concentrations of rumen ammonia N, volatile fatty acids (VFA) and pH. Similarly, VFA ratios and fluid kinetics in the rumen were unaffected. Supplementation with sucrose reduced ruminal concentrations of ammonia N at the higher level of feeding but failed to influence any other measured parameters. When intake was restricted (18 g DM kg−1 body weight), increased feeding frequency reduced the post-feeding ruminal ammonia peak and reduced the post-feeding decline in pH; however, sucrose supplementation had no effect. Kinetics of the liquid phase in the rumen, particulate rate of passage and rate of digestion were not affected by feeding frequency or sucrose supplementation. It was concluded that effects observed at a restricted feeding level may not be apparent when feed is available ad libitum and vice versa. Key words: Sucrose, feeding frequency, alfalfa, silage, sheep
The influence of heat and chemical treatment on ruminal disappearance of canola meal
Authors: McKinnon J. J. , Olubobokun J. A. , Christensen D. A. , Cohen R. D. H.
Published: March 2010

The influence of temperature (125 or 145 °C) and duration (10, 20 or 30 min) of heating, or chemical treatment (acetic (AA) or formic (FA) acid) on in vitro insoluble DM (IDM) and insoluble CP (ICP) and 12 h in situ ruminal disappearance of canola meal was examined. Ruminal disappearances of dry matter (DDM) and crude protein (CPD) were expressed as apparent (ADMD and ACPD), insoluble (IDMD and ICPD) and degradable (DDMD and DCPD). Insoluble DM content was reduced by AA and FA (P < 0.01), while ICP was reduced by FA (P < 0.01). Acid treatment had no effect on in situ DMD or CPD. Heating increased IDM and ICP (P < 0.01). Duration of heating increased ICP at 145 °C (P < 0.01). Apparent DMD was influenced by temperature (P < 0.01) but not duration of heating. Mean ADMD and ACPD for control, 125 and 145 °C were 57.8, 59.6; 36.8, 24.1; and 27.4%, 13.7%, respectively, (P < 0.01). Insoluble and degradable DMD and CPD were reduced by heating (P < 0.01) but the influence of temperature or duration of heating was not consistent. The results indicate that heating at 125 or 145 °C for 10 min or more will reduce in situ DM and CP disappearance of canola meal, and increase the post-ruminal supply of DM and CP. Key words: Canola meal, in vitro solubility, in situ digestibility, heat and acid treatment
Live performance, carcass yield, protein and energy retention of broiler chickens fed canola and flax full-fat seeds and the restored mixtures of meal and oil
Authors: Lee Kyu-Ho , Olomu J. M. , Sim Jeong S.
Published: March 2010

Two experiments were conducted to assess the use, in broiler diets, of full-fat canola and flax seed or their restored mixtures of seed meals and oils. The first experiment compared raw and heated full-fat canola and flax seeds, and mixtures of the meals with the corresponding oils or animal tallow (ratios of 6:4, respectively), each added at 10% to the diet. The second experiment evaluated the raw full-fat seeds or mixtures of the meals with canola oil or animal tallow, added at 10 and 20% to the diets. Each experiment lasted 6 wk. Heat treatment did not significantly affect performance (P > 0.05). Dry matter and protein retention, and bird mortality were not influenced by dietary treatments. Diets containing 10 or 20% full-fat canola or canola meal plus oil mixtures resulted in similar body weight, feed conversion and carcass yield as the soybean meal control diet. In the first experiment, the inclusion of full-fat flaxseed depressed body weight, feed conversion and dietary metabolizable energy (ME) while the flax meal plus flax oil containing diets gave responses similar to the canola meal diets. In exp. 2, increasing the level of flax seed or flax meal plus oil mixture to 20% further depressed body weight and feed conversion. The ME and feed conversion efficiency of birds fed the full-fat seed containing diets were less than those obtained from birds fed the meal plus oil diets, but only significantly so for the flax diets. The type of fat fed with the meal had no effects on the responses of the birds. Key words: Chickens, canola, flax, heating, carcass yield, protein retention, metabolizable energy
Effect of rumen degradable protein and lactation on nitrogen metabolism in dairy goats
Authors: Brun-Bellut J. , Kelly J. M. , Mathison G. W. , Christopherson R. J.
Published: March 2010

Nitrogen flow and exchanges in the digestive tract were measured in three goats during a dry stage and a subsequent hormonally induced lactation stage. Two diets, formulated with and without urea to contain either a high or low level of crude protein and rumen-degradable protein (RDP), were tested in a crossover experimental design within each stage. The amount of urea nitrogen (N) recycled to the ruminoreticulum was higher (P < 0.05) during lactation (3.5 g d−1) than in the dry stage (0.9 g d−1), as was plasma urea concentration. However, the mean amount of urea recycled was lower (P < 0.05) when the high-RDP diet was fed (1.4 g N d−1) than when the low-RDP diet was fed (3.0 g N d−1), even though the plasma urea concentration tended to be higher in goats fed the high-RDP diet. Of the estimated ruminally available N, 90–110% was incorporated into microbial cells. The proportion of bacterial N derived from rumen ammonia (0.77–0.89) was not influenced by protein source or lactation. Of the amino acids flowing into the duodenum, 69–75% were apparently absorbed in the small intestine, whereas total digestive tract apparent digestibility ranged from 81 to 83%. No more than 60% of the fecal N was derived from undigested bacteria from the rumen. It was concluded that the amount of urea which is recycled to the rumen is under metabolic control and that there is efficient use of ruminally available N by rumen microorganisms. Key words: Goats, lactation, rumen-degradable protein, 15N, urea recycling, amino acids
Relationships among rate of passage of feed, dry matter intake and chemical components of several diets
Authors: Mir P. S. , Mir Z. , Hall J. W.
Published: March 2010

Relationships among feed dry matter intake (DMI), rate of passage of feed through the rumen (ROP) and content of chemical components of feeds were determined to investigate the possibility of developing prediction equations for DMI and ruminal passage rates of digesta. ROP determined as exponential rate of marker decline in either feces (ROPf) or rumen contents (ROPr), DMI and body weight (BWt) of animals were determined using six mature steers in a 6 × 6 Latin square design experiment. Alfalfa hay (AA), orchard-grass hay (OG), alfalfa silage (AS), corn silage (CS), 70 + 30: cracked corn and OG (70G), and 70 + 30: barley straw and AA (70S) were used in the experiment. Chemical composition of feeds (protein, neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent insoluble nitrogen (ADIN) and lignin) was determined and, along with BWt of the steers, was regressed against DMI, while DMI was also included among the factors regressed against ROPf and ROPr. Even though animal factors, such as DMI and BWt, and feed factors, including the chemical components, were regressed against ROPf and ROPr, only protein and ADIN content in feed were significant factors included for ROPr (r2 = 0.358), while for ROPf, protein, ADIN and lignin content were the three significant factors (r2 = 0.362). However, DMI of the steers was predictable from the equation DMI (kg) = 15.52−0.080 NDF−0.101 ADF + 9.462 ADIN (as % of DM) (R = 0.84; P < 0.0001; residual standard deviation (rsd) = 1.01) with an R2 value of 0.702, but accurate estimation of rate of passage from feed and animal factors requires more research. Key words: Prediction of rate of passage, chromium mordanted neutral detergent fibre, intake, steers, forages
Modulation of plasma and tissue cholesterol and fatty acid composition by feeding flax and canola seeds and oils to rats
Authors: Sim J. , Nwokolo E. , Jiang Z.
Published: March 2010

Intact full-fat oil seeds might be more resistant to oxidation than extracted and refined oils and might therefore be used as sources of dietary fat. The present study was conducted to examine and compare the influence of feeding full-fat flax and canola seeds and oils on the plasma and tissue lipids of the rat. Male weanling Sprague Dawley rats (n = 4) were housed individually in metabolic cages and fed isoenergetic and isonitrogenous diets containing full-fat flax (FFF), flax meal + flax oil (FO), full-fat canola (FFC), canola meal + canola oil (CO), and soybean meal + animal tallow (AT). After 6 wk of feeding, plasma cholesterol levels were significantly (P < 0.05) reduced in rats fed flax diets (FF and FO) but not in those fed canola diets (FFC and CO). Liver cholesterol levels were not affected by dietary treatment. The highest levels of α-linolenic acid (LNA) and eicosapentaenoic acid (EPA) were recorded in the plasma, liver, heart and epididymal fat of rats fed the flax-containing diets. Intermediate levels of LNA and EPA in plasma and tissues were found in rats fed canola-containing diets. Rats fed flax diets had less arachidonic acid (AA) in plasma, liver, and heart tissues than those fed control and canola diets, indicating inhibition of AA synthesis by high dietary LNA provided by full-fat flax seed and flax oil. These results demonstrated that full-fat flax and canola seeds could be used as sources of dietary LNA to modify plasma and tissue lipids. Key words: Flax seed, canola seed, cholesterol, fatty acid, rat
Delaying sexual maturity of pullets by nutrient restriction at the onset of production
Authors: Atkinson J.L. , Summers J.D. , Spratt D.
Published: March 2010

Two experiments were undertaken to study the effect of delayed sexual maturity of pullets on reproductive performance in the laying house. In the first experiment feed was removed from the pullets for 6 days at the onset of egg production. They were then placed on a regular laying diet. In the second experiment pullets were placed on only wheat bran for a 2-week period at the onset of production, before being placed on a regular diet. Birds on both test treatments lost a significant amount of body weight (17% for exp. 1 and 12% for exp. 2). However, when they were placed on the regular laying diet, egg production rose rapidly so that age at peak production was similar to that of the control birds. Feed intake quickly caught up to that of the control birds, as did egg size. Since birds delayed in sexual maturity are really at a different physiological age from control-fed birds, it was of interest to compare the performance of pullets at similar physiological ages. On this basis, egg production (exp. 2) rose very rapidly for the test birds compared with the control-fed birds, with feed intake and egg weight significantly higher than those of the control-fed birds. With the rapid rise to peak production and enhanced egg size, no loss in egg mass output should be experienced over a normal laying year. Key words: Sexual maturity, limit feeding, pullets, egg size
Effects of intramuscular injections of folic acid on folates status and growth performance of weanling pigs
Authors: Letendre Marie , Bernier Jean F. , Girard Christiane L. , Matte J. Jacques
Published: March 2010

In the first of two trials, 24 piglets (2 wk old) were used to measure the dose–response curve of serum folates after intramuscular injections of folic acid (0, 10, 20 or 30 mg). Administration of 10 mg of folic acid was sufficient (P < 0.01) to prevent the decrease of serum folates observed 1 wk after weaning. In the second trial, 72 piglets (2 wk old) were used to study the effect of repeated intramuscular injections of folic acid (0 or 2.5 mg kg−1 of body weight) on hematological status, liver development, and concentrations of serum and hepatic folates, as well as on growth performance up to 10 wk of age. Serum and liver folates were increased (P < 0.01) by repeated injections of folic acid. However, no treatment effects (P > 0.10) were observed on total content of DNA, RNA and protein in the liver. Hemoglobin, hematocrit, total body weight gain, gain: feed ratio and total feed intake were also not influenced (P > 0.10) by the injections of folic acid. Therefore, although a decrease in serum folates is observed during the weaning period, it does not seem to have detrimental effects on the growth performance of weanling piglets. Key words: Folic acid, folates, growth performance, piglets, weaning
Genotypic and environmental differences in rye fed to broiler chicks with dietary pentosanase supplementation
Authors: Campbell G. L. , Teitge D. A. , Classen H. L.
Published: March 2010

The response of broiler chicks fed rye with dietary pentosanase supplementation was examined with respect to rye variety, area of production, and maturity at harvest. There were significant differences among varieties in the absence of enzyme addition and significant differences (variety × enzyme, P < 0.01) in the magnitude of the chick growth response to dietary pentosanase (exp. 1). Kodiak and Cougar rye gave greater enzyme-induced growth response than did Gazelle rye, with Musketeer rye and an unknown sample displaying intermediate values. Experiment 2 gave similar results; both Kodiak and Cougar rye in chick diets gave a larger response to dietary pentosanase than did Musketeer rye (P > 0.05). Determination of soluble carbohydrates, as well as extract viscosity, indicated that Kodiak rye had higher extract viscosity, higher extractable pentosan content, and a lower arabinose-to-xylose ratio; however, these results were not consistent with Cougar rye. Differing production location of a single variety (Musketeer, exp. 3) or maturity at harvest (exp. 4) indicated no significant effect on the nutritive value of rye attributable to location or maturity with or without enzyme supplementation, nor was there an effect on the magnitude of enzyme response. In rye harvested at different stages of maturity there was, however, a nonsignificant linear depression in chick growth with rye harvested at higher moisture levels. Key words: Rye, pentosans, broiler chicks, pentosanase
Influence of performance testing on reproductive performance of beef bulls
Authors: Wilton J. W. , McMorris M. R.
Published: March 2010

The fertility of beef bulls which completed performance test in the Ontario Bull Test Program was measured by classification of success as breeders according to surveys of consignors to test, by classification of satisfaction in surveys of users of tested bulls and by measurement of calf crop percentages and birth dates of progeny relative to herdmates in the Ontario Beef Herd Improvement Program. Consignors classified 3.0% of the 2556 bulls with completed information as unsuccessful breeders. Users rated 61.5% of the 411 bulls with information from the participant survey as very satisfactory and 4.5% as very unsatisfactory. The effects of end of test weight, gain index, backfat and scrotal circumference on calf crop percentage (cows calving relative to cows exposed), percent of calves born in the first 3 wk of the calving season, percent of calves born in the first 12 wk and satisfaction score were generally small and nonsignificant as tested within breed for 122 Angus, 451 Charolais, 632 Hereford, 575 Limousin and 501 Simmental bulls. In general, gain on test and end-of-test measurements were not found to have any association with subsequent fertility of bulls tested. There was no evidence that increased scrotal circumferences were associated with increased measures of productive performance nor that increased fatness, within the range included in the Ontario Bull Test Program, decreased reproductive performance. Key words: Fertility, genetic evaluation, scrotal circumference, backfat
Effect of dietary level of naked oats (Avena nuda) on internal and sensory quality of eggs and on yolk lipid composition
Authors: Cave N. A. , Farnworth E. E. , Poste L. M. , Butler G. , Burrows V. D.
Published: March 2010

The yolk lipid composition was determined and the sensory and internal quality evaluated for eggs obtained from hens at 8 and 15 m of age from two experiments. In exp. 1, in which naked oats replaced corn and soybean meal at levels of 0–800 g kg−1, there was a marked decrease in Roche yolk color at 8 mo, an increase in egg weight, and at 15 mo and a decrease in yolk flavor intensity with increasing level of oats. In exp. 2, there were four diets (0) a corn-soybean meal control, (876) a soybean-free naked oat alfalfa diet, (874) diet 876 supplemented with lysine and methionine and (691) diet 876 supplemented with canola meal. Haugh units were greater and yolk color less for supplemented naked oat diets versus the control diet. The yolk lipid content of sphingomyelin and sterols were higher than for the control diet. A yolk sulfury aroma was noted at 15 mo. At 8 mo, egg Haugh units were lower for the unsupplemented oat diet relative to the corn-soy diet. There were no other detrimental effects of oat diet on egg sensory quality. Other than a corrigible yolk color effect, egg quality traits do not limit the use of naked oats in poultry layer diets. Key words: Oats (naked), canola, egg internal quality, egg sensory quality, egg lipid composition, laying hen
Edible land snail production under natural climatic conditions in Nova Scotia
Authors: Lirette A. , MacPherson M. D. , MacIntyre J. P. , Lewis J. C.
Published: March 2010

One thousand two hundred and fifty land snails were divided randomly among 25, 1.5-m × 0.9-m × 1.5-m cages wrapped in a nylon screen and chicken wire to prevent the snails from escaping and to protect them from predators. The cages were placed in a shaded area on the southeastern edge of a white clover field and randomly divided into five nutritional treatments with each treatment replicated five times. The snails were fed with natural vegetation, lettuce and oyster shells, lettuce alone, oat bran, or white clover in treatments 1, 2, 3, 4, and 5, respectively. A digestibility trial on lettuce and white clover was also carried out. The snails gained significantly (P < 0.05) more weight when fed with the lettuce and lettuce plus oyster shells than the other treatments. The weight gains for the white clover and natural vegetation were intermediate among the diets. The death rate was approximately 5.1 ± 0.3% in each treatment with the exception of the oat bran diet (66 ± 5%). The digestibilities of lettuce and white clover dry matter were 83.1 ± 1.3% and 82.5 ± 1.5%, respectively, and were not significantly different (P > 0.05). It was concluded that edible land snails can be raised outside during the summer under the environmental conditions of Nova Scotia if fed with diets 1, 2, 3, or 5. Key words: Edible land snail, Otala, nutrition, Nova Scotia
Effects of probiotic supplementation of hull-less barley- and corn-based diets on bacterial fermentation in continuous culture of ruminal contents
Authors: Windschitl P. M.
Published: March 2010

A study was conducted using a continuous culture fermentation system to determine effects of probiotic supplementation on ruminal bacterial fermentation of hull-less barley- and corn-based diets. The probiotic contained both a fungal (Aspergillus oryzae) and yeast (Saccharomyces cerevisiae) culture along with several bacterial cultures. Treatments were arranged in a 2 × 2 factorial design with two sources of grain (hull-less barley, B and corn, C) with (+) or without (−) probiotic supplementation. Probiotic was added directly into the fermenter flasks. Diets consisted of (dry matter basis) 46% bromegrass silage, 5% alfalfa meal, and 49% barley- or corn-based concentrate mix. Probiotic supplementation decreased (P < 0.05) dry matter digestibility with the corn diet (C −, 58.6%; C +, 51.4%) but had no significant effect on the barley diet (B −, 48.7%; B +, 51.8%) Dry matter digestibility tended to be higher (P = 0.07) with corn- vs. barley-based diets. Protein degradation and fiber digestibility were not significantly (P > 0.05) affected by probiotic supplementation. Non-fiber carbohydrate digestibility was decreased (P < 0.05) with C + and tended to increase (P = 0.09) with B + compared to C − and B −, respectively (B −, 60.8%; B +, 67.1%; C −, 72.3%; C +, 63.4%). Probiotic supplementation had no significant (P > 0.05) effect on total or individual volatile fatty acids. Although limited, data suggest that type of grain used in the diet can influence the effectiveness of probiotics in altering ruminal metabolism. Key words: Continuous culture, corn, hull-less barley, probiotic, ruminal fermentation
The effects of feeding monensin and lasalocid together in the same diet or in a daily rotation program on performance and carcass characteristics of feedlot cattle
Authors: McKinnon J. J. , Cohen R. D. H. , Kowalenko W. S. , Janzen E. D.
Published: March 2010

Two hundred and seventy-five Charolais cross steers housed in 25 pens were used to study the effects on feedlot performance of feeding monensin and lasalocid combined in the same diet or in a daily rotation program. Five dietary treatments were utilized. Formulated ionophore concentrations were: (1) monensin at 11 ppm for the first 28 d of the trial and 33 ppm for the remainder; (2) monensin at 16 ppm plus lasalocid at 18 ppm; (3) monensin at 16 ppm for the first 28 d of the trial and 25 ppm for the remainder plus lasalocid at 27 ppm; (4) lasalocid at 36 ppm; (5) daily rotation of diets 1 and 4. Feeding monensin and lasalocid together in the same rotation (diets 2 and 3) or in a daily rotation program (diet 5), did not (P > 0.05) improve feedlot performance or carcass characteristics compared to steers continuously fed monensin or lasalocid (diets 1 or 4). Direct comparison of the two control diets demonstrated that lasalocid-fed steers exhibited more efficient gains (P < 0.05) at day 28 of feeding and a higher dressing percentage (P < 0.05) at slaughter. These results indicate that relative to continuous feeding of monensin or lasalocid, feedlot operators would not benefit by combining these two ionophores in the same diet or by incorporating daily ionophore rotation into their feeding programs. Key words: Ionophores, monensin, lasalocid, steers
Effect of vitamin E on incidence of mastitis in dairy cattle
Authors: Batra T. R. , Hidiroglou M. , Smith M. W.
Published: March 2010

Incidence of mastitis was evaluated for 224 cows randomly assigned to one of two treatment groups: vitamin E supplemented and control. Vitamin E supplementation was started at drying-off and continued up to 90 d of next lactation at the rate of 1000 IU per cow per day and was then reduced to 500 IU daily for the remaining lactation period. Data on the concentration of vitamin E in blood plasma and milk, incidence of mastitis, and reproductive traits were analyzed by the least squares procedure. The model included the fixed effects of breed, parity, treatment, breed × parity, breed × treatment, parity × treatment, year, season, and days dry as a covariate. Concentrations of vitamin E in blood plasma and milk were higher (P < 0.05) in supplemented cows than in control cows. Supplementation of diets with vitamin E significantly lowered milk somatic cell count on day 112 of lactation but did not reduce the incidence of clinical mastitis. Vitamin E supplementation had no significant effect on the incidence of retained placenta. Key words: Vitamin E, mastitis, reproduction, cows, dairy
Effect of formaldehyde-treated barley or escape protein on the ruminal environment and digestion in steers
Authors: McAllister T. A. , Rode L. M. , Cheng K.-J. , Buchanan-Smith J. G.
Published: March 2010

Six Holstein steers fitted with ruminal and duodenal cannulae were fed three diets: formaldehyde-treated rolled barley (0.11% wt wt−1) with canola meal (FTB); untreated rolled barley supplemented with corn distillers' grain and fishmeal (EPB); and untreated rolled barley with canola meal (CON). Foam production from ruminal fluid did not differ among diets. Mean viscosity of ruminal fluid from steers fed FTB was lower (P < 0.02) than rumen fluid from steers fed CON. Ruminal fluid pH of steers fed FTB was lower 2 h after feeding than in steers fed the EPB or CON diets. FTB led to lower (P < 0.02) ruminal ammonia concentrations 1 and 2 h after feeding and lower (P < 0.1) plasma urea nitrogen concentrations 4 h after feeding compared to EPB or CON diets. FTB and EPB tended to lower the ruminal concentration of volatile fatty acids (VFA) associated with microbial amino acid metabolism. Intake, ruminal and postruminal digestion of DM, OM, starch and NDF were not influenced by diet. While EPB had no effect on total tract digestion, FTB increased (P < 0.1) total tract digestibility of starch and decreased (P < 0.1) the digestibility of NDF. EPB increased (P < 0.05) the supply of dietary protein and decreased the supply of microbial protein reaching the small intestine. FTB did not increase the amount of total nitrogen or starch reaching the small intestine of steers. Key words: Cattle, escape protein, starch, formaldehyde, barley
Nutritive value of corn, barley, wheat and oats fed with medium quality hay to fattening steers
Authors: Dion S. , Seoane J. R.
Published: March 2010

Thirty-two large-frame crossbred steers (443 ± 5 kg) were used to determine the nutritive value of cracked corn, rolled barley, rolled oats and rolled wheat in finishing diets for beef cattle fed medium-quality grass hay. Diets contained about 54% grains, 40% grass hay and 6% of a supplement of minerals, vitamins and lasalocid. Total daily dry matter (DM) intake ranged from 9.52 to 10.24 kg, average daily gain from 1.09 to 1.17 kg and gain to feed ratio from 0.113 to 0.121, but these values were not statistically different (P > 0.05). Apparent digestibilities of DM and energy of steers receiving the oats diet were lower than those of steers receiving the wheat diet (P < 0.05), the other diets having intermediate values. Apparent digestion coefficient of protein was higher for the oats diet (P < 0.05) than for other diets. Acid detergent fiber digestibility was higher (P < 0.05) and starch digestibility was lower (P < 0.05) in steers receiving corn than in those receiving barley, oats or wheat. The results indicate that nutritive value of all diets was similar. Key words: Grains, fattening steers, digestibility
The composition, intake, and digestibility of timothy silage preserved untreated or treated with formic acid or a cellulase-hemicellulase preparation
Authors: Narasimhalu P. , Halliday L. J. , Sanderson J. B. , Kunelius H. T. , Winter K. A.
Published: March 2010

Timothy was field-wilted and ensiled in plastic-tube silos either untreated or treated with formic acid or a cellulase-hemicellulase preparation (enzyme). This study showed that first-cut timothy, field wilted to 350 g kg−1 DM, can be stored as a medium- to good-quality silage without using formic acid or enzyme as an additive. Key words: Silage composition, intake, digestibility, volatile fatty acids