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At least 181 records · Page 10Linked to original sources
PubMed1981

Effects of (DTrp6-Des-Gly10-ProNH29)-luteinizing hormone-releasing hormone ethylamide on the estrous cycle, weight gain, and feed efficiency in feedlot heifers.

Subcutaneous implantation of pelleted (DTrp6-Des Gly10-ProNH29)-luteinizing hormone-releasing hormone in 3 heifers (at a total dose of approx 5 microgram/0.45 kg of body weight) shortly after ovulation did not affect the ongoing luteal phase, but prevented the next expected estrus and ovulation. The effect was reversible and estrus was reestablished 16 and 19 days after pellet removal. The subsequent luteal phase concentrations of plasma progesterone appeared to be below normal concentrations. In a 2nd study, 25 heifers were implanted subcutaneously twice, 56 days apart, at random stages of the cycle. The mean number of estrous episodes over the 112 days of observation was decreased from 5.56 in controls (n = 25) to 1.12 in treated (n = 25) heifers. This suppression of estrus was not associated with change in live weight gain or food intake.

Animal Feed↗
PubMed1987

Feed efficiency, growth rates, body composition, milk production and milk composition of Targhee sheep selected for increased weaning weight.

Lactation and growth of three contemporary lines of grade Targhee sheep developed from the same genetic base were characterized by three experiments performed over a period of 2 yr. Two lines (HW and DH) had been selected for 120-d weaning weights for 24 yr prior to beginning these experiments. A third line (C) was a randomly selected control. Year I experiment contrasted 10 DH with 7 C ram lambs fed to 58 kg. Year II experiments utilized 9 C, 14 DH and 10 HW ram lambs and 11 ewes suckling twins from each line. All Year II ram lambs were born and weaned as twins, then fed to 50 kg. Mature DH and HW ewes were heavier (P less than .05) than C ewes (65.2 and 68.8 vs 54.9 kg), and the DH and HW lambs grew faster than C lambs both before (P less than .05) and after weaning (P less than .05). While both DH and HW lambs drank more milk (2,419 and 2,368 vs 2,059 g X d-1 X pair-1; P less than .10) only HW ewes showed a trend towards greater potential milk production than controls (HW = 2,774 vs C = 2,155 g X d-1 X ewe-1 P less than .12). The HW lambs tended to be leaner than C lambs (P less than .05), but DH lambs did not differ from either line. Lambs from DH and HW lines required less post-weaning feed (121.9 and 129.3 vs 152.0 kg P less than .05) and exhibited 17 and 16% greater weight per day of age at 50 kg than controls (P less than .05). The DH line displayed lower feed: gain ratios than controls in both post-weaning trials (6.68 vs 7.30 to 58 kg; 5.83 vs 6.24 at 50 kg; P = .06).

Animals↗
PubMed1997

Body weight gain, feed efficiency, and fecal scores of dairy calves in response to galactosyl-lactose or antibiotics in milk replacers.

Holstein bull calves (n = 96) were purchased at approximately 7 d of age and were assigned to receive 400, 450, 500, and 550 g/d of milk replacer solids during wk 1 to 4, respectively. Treatments were nonmedicated milk replacer plus dried whey, medicated milk replacer (138 mg/kg of oxytetracycline and 276 mg/kg of neomycin) plus dried whey, or nonmedicated milk replacer plus whey processed with beta-galactosidase to contain 15% galactosyl-lactose. Processed whey was added to provide 1% of dry matter as galactosyl-lactose; an equivalent amount of dried whey was added to the other treatments to provide 6.3% of dry matter daily. Intake of milk replacer and fecal scores were measured daily. No calf starter or hay was fed. Body weights were measured weekly from arrival to 26 d. Serum immunoglobulin G, measured 1 d after arrival, averaged 18.3 g/L. Intake of milk replacer plus additive during the 26-d study was 445 g/d and did not vary with treatment. Body weight and body weight gain were increased by 52 and 72 g/d in response to antibiotics and galactosyl-lactose, respectively. Severity of scours and number of days scouring tended to be reduced when calves were fed milk replacer containing galactosyl-lactose or antibiotics.

Animal Feed↗
PubMed1983

Effect of feeding corn naturally contaminated with aflatoxin on feed efficiency, on physiologic, immunologic, and pathologic changes, and on tissue residues in steers.

Two of 3 groups of Holstein-Friesian steers (groups II and III; n = 5 each) were fed a ration containing corn naturally contaminated with 800 ng of aflatoxin/g. The other group of steers (group I; n = 5) was fed a ration containing noncontaminated corn. The respective rations were fed for 17.5 weeks, except the ration given to group III; the latter's first diet (contaminated with aflatoxin) was changed to a noncontaminated diet after 15 weeks, continuing for the remaining 2.5 weeks. All steers were killed and tissues and fluids were obtained for aflatoxin analysis. Although aflatoxin B1 and M1 could be detected in blood and urine at several sampling times during the experimental period in groups II and III steers (given the diets containing aflatoxin), there appeared to be no effects on body weight gains and immune phenomena, such as lymphoblastogenesis and antibody production, but there was a waning of the delayed cutaneous hypersensitivity in steers given aflatoxin-contaminated diets. In group III animals (diet was changed to noncontaminated ration at 15 weeks), aflatoxin B1 and M1 disappeared from urine before they were slaughtered. All tissues and fluids, except the rumen contents from these group III steers, were void of detectable aflatoxins B1 and M1 at necropsy. The concentrations of aflatoxin B1 in the rumen content of the latter steers were low. All tissues collected at necropsy from the group II steers fed the aflatoxin diet throughout the 17.5 weeks had detectable aflatoxins B1 or M1 present.

Aflatoxin B1↗
PubMed1990

Severity of liver abscesses and efficiency of feed utilization of feedlot cattle.

Relationships of gain, intake, feed efficiency and severity of liver abscesses were evaluated in 12 experiments involving 566 head of individually fed cattle. Concentrate level in the diets ranged from 64 to 95%. In all experiments, livers were scored as unabscessed (0), one or two small abscesses (A-), two to four small active abscesses (A) or one or more large, active abscesses (A+). Based on homogeneity of variances, nine of the experiments were divided into two groups. In one group (four experiments) the incidence of liver abscesses was 32.1% and no significant (P greater than .25) effects of liver abscess severity score on feedlot performance variables were found. In the second group (five experiments), the incidence of liver abscesses was 77.7%. In the second group, liver abscess severity score affected final live weight (P less than .10), hot carcass weight (P less than .0001), dry matter intake (P less than .10), daily gain based on live weight recorded 24 h prior to slaughter (P less than .10), daily gain based on live weight estimated from hot carcass weight with a 62% dressing percentage (P less than .0001), feed efficiency using final live weight estimated from hot carcass weight (P less than .0001) and dressing percentage (P less than .01). In all cases, performance means for cattle with A+ liver scores were the only ones that differed significantly from those of non-abscessed cattle.

Analysis of Variance↗
PubMed2003

Is re-feeding efficiency compromised by prolonged starvation during aestivation in the green striped burrowing frog, Cyclorana alboguttata?

We examined several morphological parameters of the gastrointestinal tract, digesta passage rates, and nutrient assimilation efficiencies of Green-striped Burrowing frogs (Cyclorana alboguttata) following prolonged fasting during three months of aestivation and compared these with frogs that had been continuously fed. Whole animal digesta passage rates were significantly reduced following three months aestivation as a result of a decreased digesta evacuation rate from the stomach. Furthermore, food was selectively retained in the small intestine for an increased time following three months of aestivation. Overall digestibility of food and nitrogen, carbon, and energy extraction efficiencies were not significantly different from control values following three months of aestivation. These findings suggest that C. alboguttata employs reduced digesta passage rates so as to maximize nutrient assimilation efficiency following prolonged food deprivation during aestivation.

Animals↗
PubMed2002

Effects of dietary calcium and phosphorus on mineral retention, growth, feed efficiency and walking ability in growing turkeys.

1. Large White male turkeys from a heavy commercial male-line were fed on 16 diets containing 4 concentrations of calcium (6, 10, 14 and 18 g/kg) and available phosphorus (3, 5, 7, 9 g/kg) in a 4 x 4 factorial experiment with three replicates (pens). Turkeys were weighed and food intakes recorded from 4 to 7, 8 to 10 and 11 to 13 weeks of age. 2. The diets containing 6 g/kg calcium and 5, 7 or 9 g/kg available phosphorus concentrations were associated with lower body weighs at 10 and 13 weeks of age. 3. Fewer than 6% of the turkeys had an abnormal gait at 13 weeks of age. 4. The optimum dietary concentrations were 10 g/kg of calcium and 3 g/kg of available phosphorus. It was concluded that these concentrations should be fed at least to 13 weeks of age. 5. Retentions of dietary calcium and phosphorus averaged 300 g/kg of intake. 6. Utilisation of dietary phytate ranged from 5 to 11 g/kg and it is recommended that organic phosphorus should be ignored in the formulation of diets for growing turkeys unless they are supplemented with a phytase enzyme.

6-Phytase↗
PubMed2000

EAT-20, a novel transmembrane protein with EGF motifs, is required for efficient feeding in Caenorhabditis elegans.

The pharynx of Caenorhabditis elegans is a neuromuscular organ responsible for feeding, concentrating food by its pumping movement. A class of mutants, the eat mutants, are defective in this behavior. We have identified a novel eat gene, eat-20, encoding a unique transmembrane protein with three EGF motifs. Staining with a specific polyclonal antibody reveals that EAT-20 is expressed predominantly in the pharyngeal muscles and a subset of neurons. Some hypodermal cells also express EAT-20. eat-20 mutant animals are starved, have smaller brood sizes, and have prolonged egg-laying periods. The starvation apparently results from pharyngeal pumping defects, including a reduced pumping rate and "slippery pumping," in which the contents of the pharynx sometimes move rostrally. However, electrical activity of eat-20 mutants appears normal by electropharyngeogram.

Amino Acid Sequence↗
PubMed1989

Effects of dietary fiber and protein concentration on growth, feed efficiency, visceral organ weights and large intestine microbial populations of swine.

Finishing barrows (average initial weight 55.5 +/- 2.4 kg) were used to determine the effects of high dietary fiber or protein on performance, visceral organ weights and large intestine microbial populations and to monitor the duration of regression of swine visceral organ mass and microbial populations to control values following transfer from the high fiber or high protein diet to the control diet. Four pigs from each diet were killed on d 17, 34, 48 and 66. From d 34 until slaughter 14 and 32 d later, all remaining pigs were fed the control diet ad libitum. High fiber resulted in significantly higher relative weight of the total gastrointestinal tract after 34 d and higher relative stomach weight up to d 48. Compared with the control diet, the high protein diet resulted in increased relative liver and kidney weights up to d 48. The number of proteolytic and cellulolytic bacteria increased in the colon contents of pigs fed a high protein or high fiber diet, respectively, but declined to below control values within 14 d of transferring pigs from the high protein or high fiber diet to the control diet. The results indicate that diet composition plays a more specific role in visceral organ hypertrophy than can be explained by the normal relative changes in organ size as body weight increases. Thus, high dietary fiber and protein may indirectly increase the animal's maintenance requirement by causing a repartitioning of nutrients from the edible carcass to the visceral organs.

Animals↗