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PubMed1986

Effects of early feed restriction in broilers. I. Growth performance and carcass composition.

The effect of severe nutrient restriction at an early age was investigated in male and female broilers. At day 5 (females) or day 6 (males) post-hatching, chicks on limited intake were provided only enough feed (starter diet) to meet daily maintenance energy requirements only. Restriction was carried out for either 6 or 12 days, after which refeeding was on an ad libitum basis. Ad libitum fed controls were included. Minimal weight gain was noted during the period of restriction. Two weeks following refeeding, weight gains in the treated chicks exceeded that of controls. Final body weights (8 weeks) of 6-day-restricted chicks was slightly greater than controls, whereas 12-day-restricted chicks were significantly lower. Limiting nutrient intake at an early age resulted in better feed efficiency accompanied by less carcass fat and smaller abdominal fat pads. A similar, though not as dramatic effect was observed in female broilers. Results of early feed restriction on broiler growth patterns suggest that significant improvements in feed efficiency can be attained along with a reduction in total body fat.

Adipose Tissue↗

PubMed1977

Effect of ruminal lactic acid-utilizing bacteria on adaptation of cattle to high-energy rations.

Heifers, unadapted to a concentrate ration, were intraruminally inoculated (1 dose) with cultures of ruminal lactic acid-utilizing bacteria or with ruminal fluid from a steer adapted to a concentrate ration. Inoculation with cultures (1 L) of Selenomonas ruminantium or Megasphaera elsdenii did not produce better average daily weight gains or feed efficiency of heifers fed a high-energy ration for 21 days, if these values were compared with the performance of noninoculated heifers. Average daily weight gain and feed efficiency of heifers inoculated with 1 L of Peptococcus asaccharolyticus culture or with 1 L of adapted ruminal fluid and fed a high-energy ration for 21 days were better if these values were compared with the performance of noninoculated heifers.

Animal Feed↗

PubMed2004

Evaluation of microbial phytase in broiler diets.

Two trials were conducted to evaluate the efficacy of a new microbial phytase (Phyzyme XP) for broiler chicks. Trial 1 used 192 8-d-old male broilers in a 14-d trial to assess growth and nutrient utilization. Dietary treatments (221.9 g/kg CP) included a positive control [5.0 g/kg nonphytate P (NPP)], negative control (1.2 g/kg NPP), and negative control plus 500 or 1,000 phytase units/kg of diet. Phytase addition increased weight gain, feed intake, feed efficiency, and tibia and toe ash (linear, P < 0.01) with tibia ash also responding quadratically (P < 0.05). Apparent ileal digestibility of P (linear and quadratic, P < 0.05), tryptophan, and valine (linear, P < 0.05) also increased. Linear and quadratic responses were observed for retention of DM, nitrogen, P, and several amino acids (P < 0.05) with added phytase. Trial 2 utilized 576 1-d-old male broilers over a 42-d period to evaluate growth performance. Diets were formulated for starter (222.7 g/kg CP) and grower (201.5 g/kg CP) phases and included a positive control (starter and grower, 5.0 and 3.8 g/kg NPP, respectively); negative control (starter and grower, 2.4 and 1.8 g/kg NPP, respectively); negative control plus 500, 750, or 1,000 phytase units/kg; and negative control plus 500 phytase units/kg of Natuphos phytase. Phytase increased weight gain and feed intake (starter, grower, overall) as well as feed efficiency during the starter period (linear, P < 0.05). Feed intake was also improved during the grower period and overall (quadratic, P < 0.05). Tibia and toe ash of birds fed for the first 21 d increased (linear, P < 0.05) with tibia ash also increasing quadratically (P < 0.05). Overall, tibia and toe ash were improved due to phytase addition (linear and quadratic, P < 0.05). In conclusion, this microbial phytase, derived from Escherichia coli and expressed in Schizosaccaromyces pombe, elicited improved growth performance, bone mineralization, and P utilization in broiler chicks.

6-Phytase↗

PubMed2002

Studies on the use of Colocasia esculenta (taro cocoyam) in the diets of weaned pigs.

Sixty weanling Large White x Duroc pigs were allocated to five groups of 12 pigs per group and fed on one of five diets. The five diets comprised 0, 50% and 100% unboiled, sun-dried taro cocoyam cormels (Colocasia esculenta) and 50% and 100% boiled, sun-dried taro cocoyam cormels as replacements for maize. The levels of some antinutritional factors were also determined in both boiled and unboiled, sun-dried taro cocoyam. Boiling reduced (p < 0.05) the amounts of the antinutritional factors in the taro cocoyam cormels. There were no significant differences (p > 0.05) in feed intake, weight gain or feed efficiency between the diets containing boiled taro cocoyam cormels. However, for unboiled, sun-dried taro cocoyam cormels, there were significant differences (p < 0.05) in weight gain and feed efficiency, these being depressed at more than 50% replacement of maize. This may be due to the relatively high amounts of antinutritional factors in the unboiled, sun-dried taro cormels. Boiled taro cocoyam cormels were comparable to maize as an energy source in the diets of weanling pigs.

Animal Feed↗

PubMed1985

Effects of dietary sodium and chloride on growth, efficiency of feed utilization, plasma electrolytes and plasma basic amino acids in young pigs.

The metabolic and physiological consequences of three dietary levels of sodium (0.02, 0.11 and 0.18%) and chloride (0.10, 0.22 and 0.33%) were investigated. Corn, soybean meal and corn-gluten meal diets were formulated with varying levels of sodium and chloride. Pigs fed 0.02% sodium gained slower and less efficiently than pigs fed higher levels of sodium. Blood pH was not affected by either dietary sodium or chloride. Linear (P less than 0.01) increases in HCO3, base excess (BE) and plasma sodium were observed when dietary sodium increased. hemoglobin, plasma potassium, urea nitrogen, ornithine, lysine and total basic amino acids decreased linearly as dietary sodium increased. Blood hematocrit decreased curvilinearly (P less than 0.05) with increasing dietary sodium. In addition, increasing dietary chloride linearly increased plasma potassium and decreased blood HCO3 and BE. A curvilinear response to dietary chloride was observed for hemoglobin. Dietary sodium influenced pigs' growth and feed utilization as well as plasma electrolytes and basic amino acids. Although dietary chloride did influence plasma potassium and the buffering capacity of the blood, it had no effect on the rate and efficiency of weight gain of the pigs.

Amino Acids↗

PubMed1989

Mothers' working models of infant feeding: description and influencing factors.

This study examined four aspects of mothers' working models of infant feeding: (1) infant behaviour that cues feeding decisions; (2) infant self-regulative behaviour; (3) importance of infant self-regulative behaviour and maternal effort directed to it; and (4) maternal effort and value given to task-oriented and efficient feeding. The relation of these aspects to maternal experience, age, formal education, family income, and feeding method was also explored. Subjects were 122 mothers of healthy, term infants between 14 and 60 days old. A telephone interview obtained demographic and attribute data and assessed the four aspects with 30 scaled items. Crying before and sleepiness during feeding were relatively compelling cues for maternal action. Most mothers gave only moderate ratings to the importance of infant self-regulative behaviour and to task-oriented and efficient feeding. Parity and feeding method affected response to specific items, with primiparae more concerned about length and regularity of feedings. Mothers who bottle-fed their infants were more concerned about maintaining a feeding once initiated than mothers who breast-fed their infants. Four-factor analysis yielded two item clusters with good internal consistency: Cluster a. Maternal Effort to Accomplish Feeding Goals; and Cluster b. Importance of Infant Self-Regulative Behaviour. Cluster a. and b. were strongly correlated. Feeding method influenced both clusters, and the interaction of parity and feeding method had an effect on Cluster a. Mothers with lower family income had higher scores on Cluster b; multiparae with lower family income on Cluster a. How and when infant self-regulation develops as a goal is a question in need of study.

Adolescent↗

PubMed1988

Effects of ethoxyquin feed preservative and peroxide level on broiler performance.

Rancidity development in feeds and feed ingredients reduces the feeds' nutritive value and produces toxic peroxides. This investigation was conducted to determine the effects of different levels of peroxide on broiler performance and to determine the effectiveness of ethoxyquin in ameliorating the adverse effects of peroxides. Poultry fat was oxidized to contain 0, 50, 100, and 175 meq peroxide/kg and added to diets to provide 0, 2, 4, or 7 meq peroxide/kg feed, respectively. Liquid ethoxyquin was incorporated into the diets at 0, 62.5, and 125 ppm. Each of the 12 diets was fed to 8 replicate pens with 35 males and 35 females/pen. Body weights at 21 and 42 days of age were significantly lower in birds fed diets containing 4 or 7 meq peroxide/kg feed. At 49 days of age, the reduction in body weight was significant only at the 7 meq/kg level. Reductions in feed efficiency showed a similar pattern, but the depression was significant only at the highest peroxide level. Supplementation of 62.5 and 125 ppm ethoxyquin resulted in significantly heavier birds at 49 days of age but had no significant effect on feed efficiency. Beneficial effects of ethoxyquin supplementation were evident at higher peroxide levels. The study showed that at least 4 meq peroxide/kg feed was required to significantly affect bird performance, and that the addition of ethoxyquin could alleviate the deleterious effects of dietary peroxide.

Animal Feed↗

PubMed2001

Proportion of corn silage in diets of feedlot steers fed to achieve stepwise increases in growth.

Two experiments were conducted to investigate the effects of proportion of dietary corn silage during periods of feed restriction on performance of steers. In Exp. 1, Simmental x Angus steer calves (n = 107; initial BW = 273 +/- 3.8 kg) were allotted to 12 pens with eight or nine steers/pen and four pens/treatment. Periods of growth were 273 to 366 kg BW (Period 1), 367 to 501 kg BW (Period 2), and 502 to 564 kg BW (Period 3). In two of the dietary regimens, steers were given ad libitum access to feed throughout the experiment and were fed either a 15% corn silage diet in each period or an 85, 50, and 15% corn silage diet in Periods 1, 2, and 3; respectively. In the third feeding regimen, a programmed intake feeding regimen was used. Steers were fed a 15% corn silage diet in each period. However, feed intake was restricted to achieve a predicted gain of 1.13 kg/d in Period 1 and 1.36 kg/d in Period 2, and feed was offered for ad libitum consumption in Period 3. For the entire experiment, ADG was similar (P = 0.41) among treatments and feed efficiency was lower (P < 0.10) for steers in the corn silage regimen than for steers in the programmed intake and ad libitum regimens. In Exp. 2, Simmental x Angus steer calves (n = 106; initial BW = 233 +/- 2 kg) were allotted by BW to 12 pens (three pens/treatment) and fed in three periods similar to those described in Exp. 1. Four feeding regimens were investigated: 1) AL; steers were offered a 15% corn silage diet for ad libitum consumption in all three periods; 2) PI; DMI was programmed to achieve gains as described in Exp. 1; 3) CS-HLL; programmed intake as described above except diets contained 85, 15, and 15% corn silage in Periods 1, 2, and 3, respectively; and 4) CS-HIL; same feeding regimens as CS-HLL, except diets contained 85, 50, and 15% corn silage in Periods 1, 2, and 3, respectively. Steers were given ad libitum access to feed in Period 3. Overall ADG was lower (P < 0.05) for steers in the CS-HLL and CS-HIL feeding regimens than for steers in the AL and PI regimens; feed efficiency was greatest for steers in the PI regimen. Few effects of feeding regimen on carcass characteristics were observed.

Animal Feed↗

PubMed1988

Influence of Fermacto on the performance of laying hens when fed diets with different levels of methionine.

An experiment was conducted to determine the effect on laying hens of adding Fermacto at a level of 454 g/909 kg diet to diets containing various levels of supplemental methionine. The addition of Fermacto to the basal diet resulted in increased (P less than or equal to .05) production, egg mass, and feed intake while improving feed efficiency. A significant (P less than or equal to .05) main effect for supplemental Fermacto over all levels of added methionine was found for egg production and feed efficiency.

Animal Nutritional Physiological Phenomena↗

PubMed1987

Production performance of White Leghorn layers fed lactobacillus fermentation products.

A series of trials was conducted to determine if adding a Lactobacillus fermentation product (LAC) to the feed of laying hens would improve their production performance. Feeding a liquid, nonviable LAC product to either cage or floor housed laying hens did not improve hen-day egg production, feed efficiency, nor egg size during a 48 week experimental period. Laying hens fed a dried, nonviable LAC product did not show any improvement in hen-day egg production nor feed efficiency compared with laying hens fed no LAC or zinc bacitracin. Addition of a viable LAC product to ratios of differing protein levels did not improve hen-day egg production, livability, or egg size of laying hens.

Animal Feed↗

PubMed1976

Effect of high dietary copper on gizzard integrity of the chick.

Six experiments were conducted with male broiler chicks kept in battery brooders to investigate the effects of feeding diets high in copper on the integrity of the gizzard lining. Conventional and corn starch-soy basal diets were used. Slight improvements in body weight gain and/or feed efficiency were observed when the diets were supplemented with 250 p.p.m. copper as as CuSO4-5HSO, but higher levels (500 to 1000 p.p.m.) depressed growth and decreased feed efficiency. Little or no gizzard erosion was seen in birds fed the practical ration without added copper. Gizzard erosion was observed with 250 p.p.m. copper and the severity of the condition increased with higher levels. With the same level of copper supplementation, severity of gizzard erosion was greater when chicks were fed the corn starch-soy diet than when fed the practical diet. Adding 0.5 p.p.m. selenium to the practical diet containing 1000 p.p.m. copper slightly improved the appearance of the gizzard lining, although the subjective scoring index was significantly (P less than 0.05) lower in only one of two experiments. The addition of zinc, vitamin E, and vitamin B12 did not prevent the gizzard damage caused by high copper levels. Severity of gizzard erosion was significantly reduced by adding 0.35% cholic acid to the semipurified diet with 500 p.p.m. copper, but not to the practical diet with 100 p.p.m. copper. There was no correlation between acidity of the gizzard contents and severity of the erosion.

Animal Feed↗

PubMed2004

The yeast production system in which Escherichia coli phytase is expressed may affect growth performance, bone ash, and nutrient use in broiler chicks.

The efficacy of three Escherichia coli-derived phytase preparations on the performance and nutrient utilization of broiler chicks was evaluated. Two hundred sixteen 7-d-old male broiler chicks were grouped by weight into 6 blocks of 6 cages with 6 birds per cage. Six corn-soybean meal-based diets were randomly assigned to cages within each block. The 6 diets were adequate P, very low P, and low P and contained (g of P/kg of diet) 7.7, 4.0, and 5.1, respectively; and low-P diet plus phytase preparation A, B, or C at 1,000 units/kg of feed. All 3 phytase preparations were produced in different yeast production systems with slightly different glycosylation patterns. Preparation A was produced in Pichia pastoris, B in Schizosaccharomyces pombe, and C in Saccharomyces cerevisiae. The chicks were fed the experimental diets from 8 to 22 d of age. Excreta samples were collected between 17 and 21 d of age. At the end of the study, blood was collected, chicks were killed, and tibiae were removed from 3 birds per cage. Weight gain, feed intake, and feed efficiency among the 3 phytase preparations did not differ, although only phytase A diet outperformed (P < 0.05) the low-P diet in terms of weight gain and feed efficiency. All 3 phytase diets outperformed (P < 0.05) the low-P diet in bone mineral content, density, strength, percentage ash, P retention, and serum P levels. Phytase B diet outperformed the adequate-P diet in bone strength. All 3 preparations increased (P < 0.05) Ca retention with phytase B or C showing a better retention of Ca than phytase A. All 3 phytase preparations showed similar P use as indicated by BW gain and tibia bone characteristics.

6-Phytase↗

PubMed1986

Ahemeral light-dark cycles and intermittent photoperiod effects on laying hens.

To compare the effects of using continuous (C) vs. intermittent (I) photoperiods with normal (24 hr) and a long but decreasing light-dark cycle (LDLDC) on production performance and egg quality, 240 White Leghorn hens of the University of Missouri-Columbia strain were individually caged in light-controlled rooms. Treatments applied at 21 weeks of age were light-dark cycles (LDC) of 25 hr gradually reduced to 23.5 hr with C or I photoperiods, and 24-hr LDC (controls); C or I photoperiods were gradually increased from 13.75 to 16 hr for the 25- to 23.5-hr LDC, and from 13.75 to 15 hr for the 24-hr LDC. Data were obtained on hen-day egg production, egg weight, egg mass, egg specific gravity, Haugh units, feed consumption, and feed efficiency. Hen-day egg production was significantly greater (P less than .01) for the combined C photoperiod treatments, while hens consumed significantly less (P less than .05) feed exposed to the combined I photoperiod treatments. Egg specific gravity was significantly better (P less than .05) for the LDLDC vs. the 24-hr LDC program with the difference being attributed to an increase (P less than .05) in initial egg specific gravity with the use of a 24-hr LDC. Egg weight, egg mass, Haugh units, and feed efficiency were not affected (P greater than .05) by LDC or photoperiod treatments.

Animals↗

PubMedDate not supplied

Leg strength and performance of large white tom turkeys fed various protein and energy levels.

Three floor-pen experiments were conducted to determine the effects of varying protein and energy levels on body weight, feed efficiency, mortality, bone breaking-strength, and bone ash, calcium, and phosphorus in large white male turkeys. Increasing metabolizable energy by 100 kcal/kg diet increased body weight and feed efficiency. Increasing dietary protein during starter or finisher periods by 15% resulted in increased body weights by as much as 12%. Modifying dietary protein and energy levels over these ranges did not affect bone strength of toms at market weight.

Animals↗

PubMed1991

The influence of clenbuterol on growth in rats.

1. The influence was studied of a beta 2-agonist, clenbuterol, on mean gain of body weight, feed efficiency and growth of muscle tissue in female Wistar rats of three different weights (70, 150 and 200 g). 2. Clenbuterol significantly increases mean gain of body weight and feed efficiency in all the studies realised, but much more effectively in animals of greater age/weight (200 g). 3. In addition, it favours protein deposition in muscle, given that it increases significantly (P less than 0.001) the muscle/body weight ratio in all of the experiments.

Animal Nutritional Physiological Phenomena↗

PubMed1993

Estimation of body composition changes during weight cycling by bioelectrical impedance analysis in rats.

The effects of body weight cycling (WC) in rats on body composition (BC) and feeding efficiency were studied. The usefulness of estimating BC by bioelectrical impedance analysis (BIA) was also examined. Female Sprague-Dawley rats were divided into high-fat ad libitum feeding, either noncycling or cycling, or restricted feeding (75% of control feed) cycling groups. Control rats were fed a regular laboratory ad libitum diet and did not cycle. All rats were killed at the end of week 61. A BIA unit was used at each stage of WC to obtain resistance and reactance readings. Final BC was determined by chemical analysis. On the basis of the final chemical analysis and BIA measurements, an equation was established and applied to estimate BC at each stage of WC: fat-free mass (g) = 0.38 x body wt (g) + 13.8 x [length (cm)2/resistance] + 70.9 (r = 0.95, P < 0.001). High-fat ad libitum feeding induced rapid body weight and fat gains as well as an elevated feeding efficiency and an internal fat-to-subcutaneous fat ratio, regardless of whether the rats cycled. This change in fat mass was clearly detected by the BIA. Although rats fed restricted diets had similar body weights as did control rats, they had a significantly higher internal fat-to-subcutaneous fat ratio. Thus, not only the amount of food but also the composition of the diet is important for proper weight management. The BIA method is capable of detecting the body fat mass change during WC.

Adipose Tissue↗

PubMed2002

The effects of split marketing on the physiology, behavior, and performance of finishing swine.

One hundred twenty 8-wk-old barrows (20.3 +/- 2.0 kg BW) were used to examine the effect of split marketing on selected behavioral, physiological and performance parameters. Pigs were assigned by weight in a randomized complete block design to one of three treatments: SM (split-marketed), six pigs/pen (1.83 m2/pig); C (control), six pigs/pen (1.83 m2/pig); or MC (modified control), three pigs/pen (3.66 m2/pig). The heaviest half of SM animals were removed 1 wk prior to marketing penmates. Control and MC animals remained in their respective groups until marketing. Animals were videotaped during the first 72 h of the study (INITIAL), 72 h prior to (PRE), and following the removal (POST) of pigs in the SM treatment to quantify maintenance behaviors and to identify socially dominant, intermediate, and submissive pigs. A blood sample was collected from each animal upon completion of INITIAL, PRE, and POST time periods to determine neutrophil:lymphocyte ratio and plasma haptoglobin, cortisol, and corticosteroid-binding globulin (CBG) levels. Animals were weighed and feed disappearance was calculated biweekly. Tenth-rib backfat and area of the longissimus muscle at marketing were ultrasonically evaluated on all animals. Regardless of treatment, animals were more (P < 0.01) active (eating, standing/walking, fighting) at INITIAL than at PRE or POST times. Frequency and duration of fights per pen were less (P < 0.01) in MC than in C or SM pigs for all periods observed. Neutrophil:lymphocyte ratio, plasma haptoglobin, and CBG levels were greater (P < 0.01) during the INITIAL period than during the PRE or POST periods but did not differ between treatments. No treatment or time differences were detected in plasma cortisol levels. The MC pigs exhibited greater (P < 0.01) ADFI with poorer feed efficiency compared to C or SM pigs up to split marketing. During the POST period, both MC and SM pigs had greater (P < 0.01) ADFI with poorer (P < 0.01) feed efficiency than C pigs. The ADG was not different among animals as a result of treatment. There were no treatment differences for any of the carcass measurements. Significant differences in performance between the treatment groups could not be attributed to any physiological or behavioral measures reported here.

Adipose Tissue↗

PubMed1989

Efficacy of diclazuril in the prevention and cure of intestinal and hepatic coccidiosis in rabbits.

The efficacy of diclazuril against intestinal and hepatic coccidiosis was studied in artificially infected rabbits. Prophylaxis against intestinal coccidiosis was evaluated using a mixed infection of Eimeria intestinalis, Eimeria magna and Eimeria perforans. Continuous medication in the feed at 1 p.p.m. was 100% effective in reducing oocyst output and faecal scores, and weight gain and feed efficiency were normal. Hepatic coccidiosis induced by Eimeria stiedai was prevented at 0.5 and 1 p.p.m. as shown by negative oocyst counts, normal liver weight, absence of liver lesions, and normal body-weight gain and feed efficiency. Medication at 1 p.p.m. for 7 consecutive days during the prepatent phase of hepatic coccidiosis resulted in large reductions in oocyst counts and lesion scores with a normal liver weight and growth performance. Diclazuril at 1 p.p.m. in the feed prevented both intestinal and hepatic coccidiosis in rabbits and can be advocated for safe mass medication.

Animals↗