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PubMed2003

Productive performance of broiler chicks fed diets containing irradiated meat-bone meal.

Experiments were carried out to study the changes in the values of feed efficiency (FE), total protein efficiency (TPE) and metabolizable energy efficiency (MEE) of broiler chicks fed during four age periods (14-21, 21-28, 28-35 and 35-42 days). Five experimental diets were similar in composition but different in the irradiation dose (0, 5, 10, 25 or 50 kGy) applied to the meat-bone meal content of each diet. The results indicated that feeding of broiler chicks on irradiated meat-bone meal (5-50 kGy) had no significant (P>0.05) effects on FE, TPE, MEE and body weight gain during the four experimental age periods. The average values of the FE (feed consumption/weight gain), TPE (weight gain/total protein consumption) and MEE (metabolizable energy consumption in MJ/kg gain) were 1.96, 2.59 and 23.13, respectively. The values of FE and MEE increased while TPE decreased significantly (P<0.05) with age. The pooled FE value was 1.60 during the 14-21 days of age and increased to 2.66 from 35-42 days of age. However, the TPE value was 3.01 during the 14-21-day age period and decreased to 1.82 over the 35-42-day age period. The energy consumption value to produce one kg of body weight increased during the 35-42-day period by 7.71-12.72 MJ/kg gain in comparison with that from the other experimental age periods. Weight gain rate decreased significantly (P<0.05) during the 35-42-day period (66 g/week/bird) when compared with the rate observed during the 14 through 35-day age period.

Age Factors↗

PubMed2005

The effect of feeding hemp seed meal to laying hens.

Seed of the hemp cultivar Unika-b was cold-pressed to obtain hemp seed meal (HSM) containing 307 g/kg crude protein and 164 g/kg ether extract (60 g/kg linoleic acid, 120 g/kg alpha-linolenic acid, 160 g/kg oleic acid, lesser amounts of palmitic, stearic, and gamma-linolenic acids). For 4 weeks, 102 43-week-old DeKalb Sigma hens were fed on isonitrogenous and isoenergetic diets containing 0, 50, 100 or 200 g/kg HSM. Eggs were collected for fatty acid analysis during the fourth week of feeding these diets. No significant differences were found between feed treatments for egg production, feed consumption, feed efficiency, body weight change or egg quality. Increasing dietary inclusion of HSM produced eggs with lower concentrations of palmitic acid and higher concentrations of linoleic and alpha-linolenic acids.

Animal Feed↗

PubMed2002

Nitrogen and food production: proteins for human diets.

Nitrogen was the most commonly yield-limiting nutrient in all pre-industrial agricultures. Only the Haber-Bosch synthesis of ammonia broke this barrier. The rising dependence on nitrogenous fertilizers, which represents the largest human interference in the biospheric N cycle, has two different roles. In affluent nations it helps to produce excess of food in general, and of animal foods in particular, and it boosts agricultural exports. But for at least a third of humanity in the world's most populous countries the use of N fertilizers makes the difference between malnutrition and adequate diet. Our understanding of human N (protein) needs has undergone many revisions and although some uncertainties still remain it is clear that average protein intakes are excessive in rich countries and inadequate for hundreds of millions of people in Asia, Africa, and Latin America. More dietary protein will be needed to eliminate these disparities but the future global use of N fertilizers can be moderated not just by better agronomic practices but also by higher feeding efficiencies and by gradual changes of prevailing diets. As a result, it could be possible to supply adequate nutrition to the world's growing population without any massive increases of N inputs.

Agriculture↗

PubMed2004

A dose-response study with the feed enzyme beta-mannanase in broilers provided with corn-soybean meal based diets in the absence of antibiotic growth promoters.

An experiment was designed to assess the effects of graded levels of beta-mannanase on performance and body weight uniformity of male broilers provided with diets based on corn and soybean meal and devoid of antibiotic growth promoters or coccidiostats. Four dietary treatments contained 0, 50, 80, and 110 MU of Hemicell/ ton (where 1 MU = 10(6) enzyme activity units, 100 MU/ton is manufacturer's recommendation). Each treatment contained 15 pens with 40 birds/pen. Individual bird weights were determined on d 0, 21, and 42. From 21 to 42 d of age, feed intake for the 80 MU/ton treatment was significantly greater than the 50 MU/ton treatment. beta-Mannanase inclusion at 80 or 110 MU/ton induced improvements (P < 0.05) in weight gain (3.9 to 4.8%) and feed efficiency (3.5 to 3.8%) over the control, whereas inclusion of 50 MU/ton resulted in no significant benefit. There were no significant differences between 80 or 110 MU/ton. The experiment demonstrated that dietary inclusion of beta-mannanase at approximately 50 MU/ton is not sufficient for maximum response. Inclusion at 80 MU/ ton improved broiler gains and feed conversion and increasing to 110 MU/ton resulted in no significant additional response.

Animal Feed↗

PubMed1983

Performance and digestion by calves from limestone added to milk replacers containing soy protein concentrate.

Sixteen male Holstein calves were fed milk replacers containing milk protein or 50% of the protein from soy protein concentrate for study of limestone as a buffer in the small intestine. Experimental diets were: A) 19% of crude protein as milk protein; B) same as A but containing .8% limestone; C) 19% crude protein, 9.5% milk protein, and 9.5% soy protein; and D) same as C but containing .8% limestone. Milk replacers were reconstituted with water to 14% solids and fed at 8, 9, 10, 11, 12, and 12% body weight from 1 to 6 wk of age. Calves were fed twice daily, and clean fresh water was available at all times. Soy protein concentrate in the replacer resulted in 20% lower weight gains, lower dry matter and protein digestibilities. Apparent crude protein retention also was reduced, but intake of nutrients, feed efficiencies, fecal scores, and rectal temperatures were not different between protein sources. Limestone did not change any of these measurements. Xylose absorption tests at 3 and 6 wk of age showed differences from age but not treatment. Analysis of digesta from different sections of the gut of 6-wk-old calves sacrificed 6 h after feeding revealed that pH throughout the small intestine was above 6 for both proteins, which may explain the ineffectiveness of added limestone. Compared to milk protein, soy protein concentrate produced a lower pH in the large intestine and feces.

Animals↗

PubMed1995

Effects of early immune stress and changes in dietary metabolizable energy on the development of newly hatched turkeys. 1. Growth and nutrient utilization.

Two experiments were conducted to document the effects of an early immunologic stress and changes in dietary ME(n) on growth and nutrient utilization of newly hatched turkeys. Treatments in both experiments consisted of a complete factorial arrangement of two types of injection and four isonitrogenous diets. Turkeys were injected i.p. with saline (SAL) or a solution of lipopolysaccharide (LPS) (100 micrograms LPS/mL SAL) at 1, 3, and 5 d of age. In Experiment 1, two diets were formulated to contain 2,800 kcal ME(n)/kg. One was a corn-soybean meal-based diet (CSBM) and the other contained 8% Solkafloc (SKF). A third diet (3,100 kcal ME(n)/kg) was formulated by substituting 8% sucrose (SUC) for the 8% SKF. The fourth diet included in Experiment 1 was formulated to contain 3,700 kcal ME(n)/kg. The CSBM and SUC diets were also included in Experiment 2. Two additional diets tested in Experiment 2 were the CSBM diet containing 74.5 mg ibuprofen/kg (IBU) and a corn-soybean meal-based diet with a ME(n) value of 3,100 kcal/kg (CS31). Injection with LPS reduced (P < .05) BW of turkeys throughout Experiment 1 and until 9 d of age in Experiment 2, as compared with injection with SAL, irrespective of dietary treatment. The reduction in BW was mainly due to a decrease in feed intake (FI) (P < .05). Turkeys fed diets with 3,100 kcal ME(n)/kg were heavier (P < .05) than those fed diets with 2,800 kcal ME(n)/kg, irrespective of injection. Inclusion of ibuprofen to the CSBM diet from 1 to 14 d improved (P < .05) BW and feed efficiency (P < .01) of turkeys at 14 d of age, compared with turkeys fed the CSBM diet. Determined ME(n) was not affected by LPS injection. Adverse effects of LPS injection on growth of turkey poults were mainly the consequence of a reduced FI and not of altered nutrient utilization. These effects were not fully alleviated by feeding a diet with 3,100 kcal ME(n)/kg.

Animal Feed↗

PubMed2026

A Review on Heat Stress in Broiler Chickens: Mechanisms, Effects and Mitigation Strategies.

BACKGROUND: Heat stress (HS) is a major environmental challenge for broilers, particularly under rising global temperatures and high humidity. Broiler chickens are highly susceptible because of their rapid growth rate, high metabolic heat production, limited thermoregulatory capacity and genetic selection for fast growth. OBJECTIVE: This review aims to synthesise current evidence, evaluate the effectiveness of existing mitigation strategies, identify key knowledge gaps and provide future research directions to improve broiler resilience, welfare and productivity under increasingly HS conditions. METHODS: This review synthesised evidence published between 2010 and 2025 on the physiological, metabolic, intestinal, immunological and productive consequences of HS and evaluated mitigation strategies. RESULTS: The reviewed studies demonstrate that HS reduces feed intake by approximately 10%-30%, suppresses body weight gain and feed efficiency and increases mortality, with severity depending on temperature, humidity and broiler genotype. HS disrupts carbohydrate, protein and lipid metabolism; induces acid-base imbalance and oxidative stress; compromises intestinal barrier integrity; alters gut microbiota; suppresses immune function; and reduces meat quality. Nutritional interventions, including dietary electrolyte balance, antioxidants, vitamins, selenium, zinc, phytogenic compounds, probiotics, betaine and optimised feeding strategies, environmental management and genetic approaches, including naked-neck and frizzle genes, can partially alleviate these adverse effects. However, inconsistencies among studies persist because of differences in broiler strains, environmental conditions, dietary formulations and experimental protocols. CONCLUSION: HS substantially compromises broiler health, welfare, productivity and meat quality. Nutritional, environmental and genetic approaches can partially mitigate its adverse effects; however, further research is needed to improve broiler resilience under increasingly HS conditions.

Animals↗

PubMed1981

Reduced vitamin a levels of chicks fed anaerobically digested sewage sludge.

Diets containing 20% of air-dried anaerobically digested Fort Collins sewage sludge were fed to broiler chicks. The diets were balanced in protein and had the same vitamin and mineral supplement. The sludge diets containing approximately 2,500 ME kcal/kg compared to 3,000 ME kcal/kg in the control feed. Birds gained less body weight on sludge diets and liver vitamin A levels were reduced. Extrusion of cord-sludge mixture prior to diet formulations made the diet much poorer for supporting growth, reduced feed efficiency, and lowered liver vitamin A levels. It was concluded that ingestion of the sewage sludge impaired the utilization of vitamin A from the diet.

Anaerobiosis↗

PubMed2006

Effect of strain of layer and age at photostimulation on egg production, egg quality, and bone strength.

Bone strength in layers is a concern for economic reasons and animal welfare concerns. Bone characteristics were investigated in 3 strains of hens: Babcock B-300, a small-bodied commercial white-egg layer; ISA-Brown, a commercial brown-egg layer; and an unselected Brown Leghorn line (BL). After being reared together in a single pen with 8 h of light per day, hens were caged with 14 h of light per day. Half of the hens were caged at 18 wk of age and the other half at 20 wk of age, resulting in a 2-wk difference in the age at photostimulation. Body weights, egg production, feed efficiency, and egg quality were measured throughout production. At 15, 25, 50, and 74 wk of age, hens were euthanized for sampling of the radius and the humerus. Breaking strength of the radius and humerus was measured, and the area and density of trabecular (largely medullary bone) and cortical bone were measured using quantitative computed tomography. Egg production and feed conversion of ISA-Brown hens was as good as or better than that of Babcock B-300 hens, and both commercial strains had higher production than the BL. Photostimulation late delayed sexual maturity and improved albumen and shell characteristics but had only minor effects on egg production and did not affect the yolk weight. The delayed photostimulation resulting from caging 2 wk later affected the radius by increasing the area of the trabecular space at 50 wk of age and the density of the bone in the trabecular space at 74 wk of age. Breaking strength of the humerus at 25 wk of age was greater for the birds that were photostimulated late but was not different later in the trial. The humerus, but not the radius, of the BL had a greater breaking strength than that of the commercial strains, suggesting that selection has decreased humeral breaking strength.

Aging↗

PubMed1994

Quantifying the vitamin K requirement of juvenile marine shrimp (Penaeus monodon) with menadione.

A feeding trial was conducted to estimate the optimum dietary vitamin K requirement for juvenile marine shrimp, Penaeus monodon. Purified diets with eight levels (0, 5, 10, 20, 50, 80, 160 and 320 mg/kg) of supplemental menadione were fed to P. monodon (mean weight 1.33 +/- 0.05 g) for 12 wk. Each diet was fed to three replicate groups of shrimp. Shrimp fed diets supplemented with vitamin K (5-320 mg/kg) had significantly (P < 0.05) higher weight gain and feed efficiency than those fed the unsupplemented control diet. Shrimp fed diets supplemented with > or = 50 mg/kg vitamin K had higher protein efficiency ratios than shrimp fed the control diet. Calcium deposition in shrimp generally increased as dietary vitamin K supplementation increased. Vitamin K-dependent carboxylase activity was highest in shrimp fed the control diet, followed by shrimp fed 5-160 mg menadione/kg diet, and lowest in those fed 320 mg menadione/kg diet. Vitamin K-dependent protein precursor concentrations were high in shrimp fed 0-10 mg menadione/kg diet, lower in those fed 20 mg/kg, and lowest in shrimp fed > or = 50 mg/kg diet. Protein efficiency ratio and vitamin K-dependent protein precursor concentration analyzed by broken-line regression indicated that the adequate dietary vitamin K concentration in growing P. monodon is 30-40 mg/kg diet.

Animal Feed↗

PubMed1976

Biotin and early poult growth.

Commerical Broad Breasted White male poults were fed either a soybean and milo ration, or similar rations containing 7.5% or 20% animal protein, for a period of 0-8 weeks. Three groups of 48 birds each were fed each of the three rations which were isocaloric (2926 M.E. Cal. /Kg. of ration) but differed slightly in protein content. Other groups were fed identical rations supplemented with biotin at a level of 220 mcg/kg. When the growth data were analyzed by analysis of variance, highly significant differences noted for treatment (P less than or equal to 0.01). Biotin supplementation of the soybean-milo ration gave no response, but supplementation of the rations containing animal protein with biotin gave excellent growth responses. When the data were combined so that the effect of biotin could be evaluated, a highly significant (P less than or equal to 0.005) improvement in growth was obtained by supplementing the rations with biotin. Feed efficiency was found to be closely related to growth rate. Mortality did not appear to be related to diet, with the differences being non-significant statistically.

Animal Feed↗

PubMed1981

The performance of Bobwhite quail fed diets containing Lactobacilli.

Two experiments were conducted each consisting of two trials. Day-old Bobwhite quail were fed a starter diet containing a microbial preparation of Lactobacilli. In both experiments the experimental diets were fed for 5 weeks. No significant differences in growth, feed efficiency, or mortality were found between the control and Lactobacilli supplemented diets. Mortality was higher than normal within all treatments but unaffected by treatment.

Animal Feed↗

PubMed1997

[Production of cassava whole meal (N. esculenta Crantz) to prepare a feed for growing chicks. II. Evaluation of cassava whole meal in growing chicks].

About 50% of the raw materials used for poultry feeds are constituted of sorghum as a energy source. The purpose of this work was to evaluate the nutritional quality of a cassava whole meal (CWF: 61.2% and 38.8% of root and leaf flours, respectively) for growing chicks. The sorghum was partially substituted from a basal diet by 15, 30 and 45% of CWF. Four diets based of sorghum, soybean meal and CWF were formulated. Levels of 0.0, 8.6, 16.4 and 23.7% of CWF were included in the diets. White Vantress chicks (96) were used in the nutritional experiment during 28 days. Each treatment was assayed with 24 chicks. The diet containing 23.7% of CWF showed the lower weight gain and feed efficiency (p < 0.05) as compared with the other diets, and the liver/ bird weight relation increased directly with the increment of CWF.

Amino Acids↗

PubMed2006

Replacement of dietary fish oil for Atlantic salmon parr (Salmo salar L.) with a stearidonic acid containing oil has no effect on omega-3 long-chain polyunsaturated fatty acid concentrations.

The worldwide increase in aquaculture production and the concurrent decrease of wild fish stocks has made the replacement of fish oil in aquafeeds an industry priority. Oil from a plant source Echium plantagineum L., Boraginaceae, has high levels of stearidonic acid (SDA, 18:4omega3, 14%) a biosynthetic precursor of omega-3 long-chain (> or =C(20)) polyunsaturated fatty acids (omega3 LC-PUFA). Atlantic salmon (Salmo salar L.) parr were fed a control fish oil diet (FO) or one of 3 experimental diets with 100% canola oil (CO) 100% SDA oil (SO), and a 1:1 mix of CO and SDA oil (MX) for 42 days. There were no differences in the growth or feed efficiency between the four diets. However, there were significant differences in the fatty acid (FA) profiles of the red and white muscle tissues. Significantly higher amounts of SDA, eicosapentaenoic acid (20:5omega3, EPA), docosahexaenoic acid (22:6omega3, DHA) and total omega3 FA occurred in both red and white muscle tissues of fish fed SO and FO compared with those fed CO. Feeding SO diet resulted in omega3 LC-PUFA amounts in the white and red muscle being comparable to the FO diet. This study shows that absolute concentration (mug/g) of EPA, DHA and total omega3 have been maintained over 6 weeks for Atlantic salmon fed 14% SDA oil. The balance between increased biosynthesis and retention of omega3 LC-PUFA to maintain the concentrations observed in the SO fed fish remains to be conclusively determined, and further studies are needed to ascertain this.

Animals↗

PubMed1990

The effects of energy and amino acid levels on performance and carcass quality of male and female broilers grown separately.

Studies were conducted to evaluate the response of male and female broiler chickens to diets containing different levels of energy and amino acids. Two energy series were compared: 3,080, 3,135, and 3,190 kcal of ME/kg ("low") and 3,190, 3,245, and 3,300 kcal of ME/kg ("high") in pelleted starter, grower, and finisher diets. Diets provided a minimum of 85, 90, 95, 100, 105, and 110% of suggested amino acid recommendations for the broiler male except for Met and TSAA, which were kept at 105%. Modifications were made in feeding periods, recognizing the differences in rate of gain and marketing ages of the two sexes. Feeding periods were 0 to 21, 21 to 42, and 42 to 56 days for males and 0 to 18, 18 to 35, and 35 to 49 days for females. Four floor pen trials utilizing 9,600 male and 9,600 female broilers were conducted. Birds were processed to determine dressing percentage and abdominal fat pad weights. Energy content of the diets had no significant (P greater than .05) effect on body weight or feed efficiency for male or female broilers. Carcass dressing percentage of females, but not males, was significantly (P less than .05) increased on the high energy series. Abdominal fat pad was not influenced by energy for either sex. For both sexes, increasing dietary amino acid levels resulted in significant (P less than or equal to .05) linear improvements in live weights and feed utilization and a reduction in abdominal fat pad weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗

PubMed1991

Effectiveness of zinc bacitracin on production traits and energy metabolism of heat-stressed hens compared with hens kept under moderate temperature.

Two experiments with a total of 100 White Leghorn hens (26 to 59 wk of age) and 120 Rhode Island Red chickens (4 to 12 wk of age) were conducted to study the effect of 100 mg zinc bacitracin (ZBA)/kg of feed on hens and chickens acclimatized to 20 or 34 C environments. Layers were provided ad libitum access to a diet containing 11.12 MJ ME/kg (1 MJ = .239 Mcal) and 174 g CP/kg supplemented with 0 and 100 mg ZBA/kg. Body weight gain, egg number, total egg mass, and feed efficiency of ZBA-treated hens kept at a moderate temperature (20 C) were not significantly improved by 3.5, 2.6, 3.3, and 3.1%, respectively. However ZBA supplementation induced a more pronounced increase in performance in heat-stressed hens. The respective traits were significantly improved by 66.3, 15.4, 16.9, and 5.9%. Additionally, treated hens maintained at 34 C consumed significantly more feed than untreated hens. Eggshell breaking strength of treated hens held under normal conditions was not significantly improved. Feeding ZBA to heat-stressed hens led to a statistically higher breaking strength. Supplementation with ZBA for hens acclimatized to 20 and 34 C reduced fasting heat production by 4.1 and 7.6%, respectively. However, in the 20 C environment the differences were significant at only one of seven ages. The upper critical temperature (UCT) of ZBA-treated hens increased significantly at both temperatures from 34 to 42 wk of age relative to the control group. No significant effects of ZBA on UCT were observed at 24 to 32 wk and 40 to 52 wk of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

"Neonatal adaptation of energy and protein metabolism".

During the last decade, the development of "bedside" investigative methods, including indirect calorimetry, nutritional balance and stable isotope techniques, have given a new insight into energy and protein metabolism in the neonates. Neonates and premature infants especially, create an unusual opportunity to study the metabolic adaptation to extrauterine life because their physical environment can be controlled, their energy intake and energy expenditure can be measured and the link between their protein metabolism and the energetics of their postnatal growth can be assessed with accuracy. Thus, relatively abstract physiological concepts such as the postnatal timecourse of heat production, energy cost of growth, energy cost of physical activity, thermogenic effect of feeding, efficiency of protein gain, metabolic cost of protein gain and protein turnover have been quantified. These results show that energy expenditure and heat production rates increase postnatally from average values of 40 kcal/kgxday during the first week to 60 kcal/kgxday in the third week. This increase parellels nutritional intakes as well as the rate of weight gain. The thermogenic effect of feeding and the physical activity are relatively low and account only for an average of 5% each of the total heat production. The cost of protein turnover is the highest energy demanding process. The fact that nitrogen balance becomes positive within 72 hours after birth places the newborn in a transitional situation of dissociated balance between energy and protein metabolism: dry body mass and fat decrease while there is a gain in protein and increase in supine length. This particular situation ends during the second postnatal week and soon thereafter the rate of weight gain matches the statural growth. The goals of the following review are to summarize recent data on the physiological aspects of energy and protein metabolism directly related to the extrauterine adaptation, to describe experimental approaches which recently were adapted to the newborns in order to get "bedside results" and to discuss how far these results can help everyday's neonatal practice.

Adaptation, Physiological↗

PubMed1993

White sturgeon tissue fatty acid compositions are affected by dietary lipids.

Juvenile white sturgeon (Acipenser transmontanus) were fed eight isonitrogenous and isoenergetic purified diets for 9 wk to study their ability to utilize different dietary lipids. Each diet contained 15% of control oil mixture (corn oil-cold liver oil-lard, 1:1:1), corn oil, cod liver oil, lard, linseed oil, soybean oil, safflower oil or canola oil. No significant (P > 0.05) differences in percentage of body weight increase, feed efficiency or body composition were observed among sturgeon fed the different lipids. Tissue fatty acid compositions most sensitive to dietary lipids were those of muscle and liver, whereas brain fatty acid composition was the least sensitive. Results of this study indicate that it is possible to increase the levels of (n-3) polyunsaturated and highly unsaturated fatty acids in sturgeon muscle by feeding the fish lipids high in these fatty acids for 9 wk.

Animals↗