Biomedical subjects

M T Kidd

Publications and source records attributed to M T Kidd.

At least 19 recordsLinked to original sources

PubMed2006

Protein expression of pectoralis major muscle in chickens in response to dietary methionine status.

The present study evaluated the effect of dietary methionine on breast-meat accretion and protein expression in skeletal muscle of broiler chickens in vivo. All broilers received a common pre-test diet up to 21 d of age, and were subsequently fed either a methionine-deficient (MD) or -adequate (MA) diet (3.1 v. 4.5 g/kg diet) from age 21 to 42 d. Dietary cystine levels were 3.7 v. 3.6 g/kg diet for the MD and MA diet, respectively. Detrimental effects on carcass yield (P=0.004), abdominal fat percentage (P=0.001), and breast-meat weight (P=0.001), yield (P=0.001), and uniformity (P=0.002) were observed and validated in birds fed MD diets. Via tandem MS, a total of 190 individual proteins were identified from pectoralis major (PM) muscle tissue. From the former composite, peptides from three proteins were observed to be present exclusively in breast muscle from those chickens fed the MD diet (pyruvate kinase, myosin alkali light chain-1, ribosomal-protein-L-29). No proteins were observed to be uniquely expressed in chickens fed MA diets. Research is warranted to further explore the possibility of the proteins pyruate kinase, myosin alkali light chain-1, or ribosomal protein L-29, as potential biological indicators of differences in protein expression of PM of chickens in response to a dietary methionine deficiency.

Animal Nutritional Physiological Phenomena↗

PubMed2006

Valine requirements for immune and growth responses in broilers from 3 to 6 weeks of age.

Four experiments were conducted to evaluate valine (Val) requirements in Ross 508 broilers from 3 to 6 weeks of age. Common diets were fed to broilers until 3 weeks of age. Growth and carcass measurements were taken in all experiments. Immune responsiveness measurements were taken in Experiments 1 and 2. Birds given 7.2 g Val/kg of diet in Experiment 1 had more abdominal fat than birds given 8.2 g Val/kg of diet, but there were no differences in growth or other carcass measurements. Because growth performance was not reduced in birds given 7.2 g Val/kg of diet, Val concentration was reduced to 6.4 g Val/kg of diet in Experiments 2 and 3. Increasing Val from 6.4 to 8.7 g Val/kg of diet resulted in linear increases for BW gain, feed efficiency and Val intake in male birds, and Val intake in female birds. Quadratic responses to increasing dietary Val were not observed in any experiment. There were no effects of Val on innate or adaptive immunity. A nonessential amino acid mixture containing the same nitrogen content as the L-Val additions in Experiment 4 was added and tends to support the idea that the responses to Val were specific and not due to increases in total nitrogen. Dose responses to Val resulted in male, but not female, birds given 7.3 g Val/kg of diet having improved BW gain and feed efficiency compared with birds receiving 6.4 g Val/kg of diet.

Abdominal Fat↗

PubMed2006

Dietary lysine needs of late-developing heavy broilers.

Two studies were conducted to determine the response of late-developing broiler males and females to dietary Lys from 42 to 56 d of age. Hubbard Ultra Yield males and females were placed at separated ends of a floor pen broiler house and raised on common diets. At 42 d of age, broilers were then fed 1 of 7 gradient concentrations of dietary Lys that progressively increased by 0.07% from 0.68 to 1.10% total Lys. Regression analysis was performed to estimate dietary Lys needs in the presence of quadratic responses. Female broilers did not respond to dietary Lys for any variable measured. Gradient additions of Lys improved feed conversion linearly (P < 0.01) for male broilers. Fillet weight, tender weight, and their composite increased linearly (P < 0.05) with Lys supplementation in male broilers. Quadratic responses were exhibited by carcass yield, fillet yield, and total breast meat yield, resulting in total Lys optimization dietary levels of 0.88, 0.93, and 0.93%, respectively, in male broilers. Based on results from this study, high-yield male broilers should be fed a minimum of 0.93% total dietary Lys (0.85% calculated digestible) from 42 to 56 d of age. Lack of response by female broilers suggests that less dietary Lys may be needed for adequate growth and meat yield.

Animal Nutritional Physiological Phenomena↗

PubMed2006

Use of supplementary tryptophan to modify the behavior of pigs.

Three experiments were conducted to investigate the short-term use of supplementary Trp on the behavior of grow/finish pigs. Three levels of dietary Trp were used, representing the standard requirement for growth (control), twice (2x), and 4 times (4x) the control amount. In Exp. 1, pigs were fed the diets for 7 d, during which observations were made of their general behavior (time budget), aggression within the group of familiar pigs, and response to a startling auditory stimulus. Behavior effects were evident during the period of supplementation for both the 2x and 4x diets. During the treatment period, pigs fed supplemental Trp spent more time lying (P = 0.04) and less time eating (P = 0.05) than pigs fed the control diet. Although the response of the animals to the startling stimulus was to become alert and stand, similar behavioral effects caused by supplemental Trp also were evident after the startling stimulus (P < 0.01). Based on these observations, the subsequent studies retained the same dietary levels of Trp and incorporated a 3-d feeding of diets before behavior testing. In Exp. 2, pigs were fed the experimental diets for 3 d before being regrouped with unfamiliar pigs on the same diet. Subsequent aggression was affected by Trp supplementation, in that high levels of dietary Trp decreased the total duration of fighting by approximately 50% (P = 0.03). Supplemental Trp had no effect on the number of fights, and there were no differences between the 2 levels of supplemental Trp on any behavior. In Exp. 3, pigs were exposed to specific handling tests on the farm and meat quality assessments after being fed the experimental diets for 3 d. There were no differences among dietary treatments for any of the meat quality characteristic variables measured. The only behavioral or physiological difference observed among the treatments was a slower movement of pigs fed the 4x Trp treatment than control or 2x Trp-fed pigs in a minimal-forced situation (P = 0.04). Response to confinement on a scale, an electric prod, and movement in general did not differ among treatments. High levels of Trp may result in animals avoiding stressful situations if possible, but they seem to have no effect on responses to stressors that animals may experience in a forced situation.

Aggression↗

PubMed2005

Breeder hen dietary L-carnitine affects progeny carcase traits.

(1) Ross 308 broiler breeder hens were given diets containing 0 or 25 mg L-carnitine/kg from 21 weeks of age. (2) Hens were inseminated with semen from Ross broiler breeder males and subsequent growth performance and carcase traits, of progeny obtained from hatches at 30, 35 and 37 weeks of age, were evaluated. (3) Progeny were hatched in a common facility and separated by gender. Experimental treatments employed for the 30-, 35- and 37-week hatches, respectively, were: hen diet and progeny gender (16 replications with two subplots); hen diet, progeny diet (0 and 50 mg L-carnitine/kg of diet) and progeny gender (16 replications with 4 subplots); and hen diet and progeny diet (high and low density; 16 replications with two subplots). (4) Females had lower growth rate and less breast meat, but greater proportions of carcase fat and breast meat than males. Growth performance measurements of progeny were not affected by hen L-carnitine, but hen L-carnitine decreased abdominal fat in progeny. Increasing diet density in the chick diets increased growth and carcase weights. Hen and progeny dietary L-carnitine interacted to increase male mortality. However, dietary hen L-carnitine decreased carcase fat and increased breast meat in progeny fed on high nutrient density diets. (5) In conclusion, L-carnitine in the diet of hens affected carcase traits of their progeny.

Animal Feed↗

PubMed2005

Dietary tryptophan effects on growth and stress responses of male broiler chicks.

1. Three experiments were conducted to determine growth of broiler chicks fed on test diets formulated to be deficient or adequate in tryptophan (Trp) using gelatin by-product as a means of generating a Trp deficiency. Growth response estimates of broiler chicks to graduations of Trp were determined by dose-response criteria and regression analyses. Experiments were conducted using broiler chicks from 1 to 20 d of age. 2. Broiler chicks fed Trp-deficient diets had poor body weight gain, feed intake and feed conversion. Recommended total Trp needs were 2.0, 2.1 and 2.2 g/kg for feed intake, body weight gain and feed conversion, respectively. 3. Blood plasma Trp exhibited a sigmoidal trend while blood plasma glucose increased in a linear manner to supplemental Trp. Physiological stress variables measured were unaffected by dietary Trp.

Animal Feed↗

PubMed2005

Assessment of dietary amino acid scarcity on growth and blood plasma proteome status of broiler chickens.

Dietary Lys needs for chicks were studied. A titration diet consisting of progressive amounts of dietary Lys from 0.95% up to 1.40% was fed to broiler chicks from 0 to 18 d of age. Optimal dietary Lys level was calculated using regression analysis. Body weight gain and feed conversion were maximized at Lys levels of 1.24% (1.10% digestible) and 1.27% (1.13% digestible) of diet, respectively. Blood samples were then collected from 2 groups: birds fed the lowest Lys level and birds fed dietary Lys nearest the determined requirement level (1.25% Lys). Plasma was analyzed for protein spectra via mass spectrometry and then classified by their functional characteristics. The number of proteins was similar between the 2 samples, but there was a tendency toward increased peptides for specific proteins in plasma from chicks fed adequate Lys levels. Furthermore, after these proteins were classified, more muscle-related proteins were found in plasma samples of birds fed Lys-adequate diets. It would appear that an individual dietary amino acid deficiency does not necessarily translate into decreasing protein synthesis proportionate to body weight, but rather significant changes may be occurring within the types of proteins undergoing anabolism. In conclusion, results herein illustrate the potential for using functional genomics in nutritionally related responses of poultry.

Amino Acids↗

PubMed2005

Broiler responsiveness (Ross x 708) to diets varying in amino acid density.

Sex-separate male and female broilers (2,592 broilers; Ross x 708) were placed in 144 floor pens (12 replications per treatment) and fed diets containing high (H) and moderate (M) amino acid density from 1 to 55 d of age. Diets were formulated using ileal digestible amino acid ratios to Lys. Six dietary treatment combinations (MMMMM, HMMMM, HHMMM, HHHMM, HHHHM, and HHHHH) were implemented in 5 diet phases (1 to 5, 6 to 14, 15 to 35, 36 to 45, and 46 to 55 d of age). Male birds were heavier (P < or = 0.05) and had lower (P < or = 0.05) feed conversion, abdominal fat, and breast yield than female birds. Birds fed H diets in the first 3 phases had optimal (P < or = 0.05) BW and feed conversion (d 35, and 45), but optimal (P < or = 0.05) feed conversion at d 55 warranted H diets in all phases. Breast meat (d 35) and carcass (d 55) relative to BW were highest (P < or = 0.05) in birds fed H diets in the first 3 phases; however, differences in 55 d breast meat yield did not occur. Results indicate that amino acid needs of Ross x 708 broilers are most critical from 1 to 35 d of age. Predicted economic margins were advantageous in birds fed H diets resulting in dollar 0.12 and dollar 0.05/bird more income over feed costs at 35 and 55 d, respectively, in comparison with birds fed M diets.

Abdomen↗

PubMed2004

Dietary isoleucine responses in male broiler chickens.

1. Three experiments were conducted to measure growth and carcase responses of growing and finishing broilers fed on test diets formulated to be deficient in isoleucine (Ile). 2. Dose titration methodology was used to measure growth and carcase responses of growing and finishing broilers to graduations of Ile in three additional experiments. 3. The experiments were conducted from d 18 to 30, 30 to 42, and 42 to 56. 4. Broilers given Ile-deficient test diets had poorer weight gain, feed conversion and carcase responses than broilers fed on Ile test diets containing a surfeit of Ile. Adding supplemental Ile to the test diet resulted in equivalent growth and carcase responses to those of broilers fed on the control diet with equal Ile from intact protein sources. 5. Recommended total Ile needs varied between 6.7 and 7.1 g/kg from d 18 to 30, 6.4 to 6.6 g/kg from d 30 to 42, and 5.5 to 6.6 g/kg from d 42 to 56.

Animal Feed↗

PubMed2004

Isoleucine needs of thirty- to forty-day-old female chickens: immunity.

Broilers fed diets with reduced amino acid levels may be limiting in isoleucine. Because research addressing daily Ile needs for broiler immunity is sparse, Ile responses for immunity in female broilers were evaluated in 2 experiments in broilers from 30 to 42 d of age. Cellular and humoral immunity were evaluated in diets limiting in Ile and diets varying in Ile from deficient to adequate. Pen was the experimental unit in both experiments. Treatments in experiment 1 consisted of 2 levels of Ile (0.42 vs. 0.72% total of diet) and 3 strains of broilers, Arbor Acres+, Ross 508, Ross 708 (6 treatments; 5 pens each). In experiment 1, measurements consisted of: a cutaneous basophil hypersensitivity test to phytohemagglutinin-P (PHA-P) on d 37 and 38; cell quantification of CD4+, CD8+, and BU-1+ lymphocytes at d 41 and 42; and relative immune organ weights at 42 d. No Ile x strain interaction occurred. Feeding an Ile-deficient diet to broilers suppressed the cell mediated response to PHA-P, and reduced thymus weight and the percentage of CD8+ T cells. There were no significant differences between strains. In experiment 2, gradations of Ile (0.42, 0.50, 0.58, 0.66, 0.74, and 0.82% total of diet) were fed to one strain (Ross 508) of female broilers (7 pens per diet). A control diet containing 0.70% Ile (6 pens) was compared with an Ile surfeit concentration. Measurements in experiment 2 consisted of a hypersensitivity test to PHA-P on d 35 and 36; a primary antibody response to SRBC from 35 to 42 d; cell quantification of CD8+ alpha, beta, and T cell receptor (TCR)-1 (delta/gamma) lymphocytes on d 41 and 42; and immune organ weights at 42 d. Immunity measurements in birds fed surfeit Ile in the titration diets were equal to birds fed the control diet. A linear response to increasing Ile was obtained for relative bursa, but no Ile quadratic responses were noted for other measurements in experiment 2. Although feeding broilers a diet deficient in Ile suppressed some immune criteria, it does not appear that a marginal Ile deficiency will compromise immunity in growing female broilers.

Animal Feed↗

PubMed2004

Isoleucine needs of thirty- to forty-two-day-old female chickens: growth and carcass responses.

Two experiments were conducted to evaluate Ile responses in female broilers. In experiment 1, dietary Ile was 0.42 or 0.72% total of diet. Diets were fed to 3 broiler strains: multipurpose Arbor Acres+, high-yield Ross 508, and high-yield Ross 708. In experiment 2, dietary Ile dose responses (0.42 to 0.82% total of diet in 0.08% increments) were evaluated. A corn-soybean meal control (0.70%) diet was used in experiment 2 (6 replications). No Ile x strain interactions occurred. Feeding broilers 0.42% Ile suppressed (P < 0.05) BW gain, feed intake, feed conversion, and breast and thigh yields. Arbor Acres+ strain had a higher BW gain and feed intake (P < 0.05) than the Ross 508 and 708 strains. Differences (P < 0.05) among strains were observed in breast and drumstick yields; Ross 708 broilers had increased breast and drumstick yields in comparison to birds from the Arbor Acres+ and Ross 508 strains. Birds fed surfeit Ile in the titration diets grew as well as (P < 0.05) the birds fed the control diet. Quadratic responses (P < 0.05; 95% of response) were obtained for BW gain (0.67%), feed intake (0.66%), feed conversion (0.68%), and breast meat yield (0.63%). The 30- to 42-d Ile need for female broilers is between 0.63 and 0.68% of total diet (0.59 to 0.64% digestible Ile).

Animal Feed↗

PubMed2004

Immune system and cardiac functions of progeny chicks from dams fed diets differing in zinc and manganese level and source.

This research was conducted to evaluate immunity (experiments 1 to 3), cardiac function, and ascities resistance (experiment 4) of progeny chicks from broiler breeders fed diets differing in trace metal level and source. Broiler breeders received a control diet (75 mg of Zn and 83 mg of Mn added/kg of diet), the control diet supplemented with inorganic Zn (75 mg/kg of diet) and Mn (80 mg/kg of diet), the control diet supplemented with organic Zn (75 mg/kg of diet) and inorganic Mn (80 mg/kg of diet), or the control diet supplemented with organic Zn (75 mg/kg of diet) and Mn (80 mg/kg of diet) in experiments 1, 2, and 3. In experiment 4, the control diet and diet supplemented with organic sources of Zn and Mn were fed to broiler breeders. Immune organ weights, circulating granulocytes vs. agranulocytes, CD4 and CD8 positive T cells, cutaneous basophil hypersensitivity, and antibody titers to SRBC and breeder vaccinations were measured in progeny. Some supplemental mineral treatments increased (P < or = 0.05) cutaneous basophil hypersensitivity and relative bursa weight. All supplemental mineral treatments increased (P < or = 0.05) relative thymus weight. In experiment 4, electrocardiograph, pulse oximetry, heart rate, hematocrits, ventricle weights, and ascites incidence were measured in progeny reared in a cold-stress environment. The supplemental organic minerals increased (P < or = 0.05) left ventricle plus septum and total ventricular weights. Although progeny ascites incidence did not differ between breeder mineral treatments, breeders fed supplemental Zn and Mn sired progeny with improved cardiac functional capacity and some improvements in immunity.

Animal Husbandry↗

PubMed2004

Nutritional modulation of immune function in broilers.

Collaborative research efforts across disciplines typically result in more insight toward the hypothesis being tested due to the omnibus nature of the projects. For example, nutritional experiments evaluating a nutrient response will benefit greatly by incorporating biochemical, physiological, and immunological endpoints for measurement. Clearly, commercial poultry producers do not have the luxury of focusing on specific disciplines when field problems occur. Hence, in practice interplay exists among nutrition, genetics, management, and diseases. Dietary composition impacts immune function of the chicken. As research in the area of nutritional immunology has increased, it is becoming apparent that nutrient needs for immunity do not coincide with those for growth or skeletal tissue accretion. This review is not a comprehensive assessment of nutrient needs for immunity in the chicken. Rather, this review is concerned with nutritional modulation of immunity in broilers that offers insight for nutritionists and researchers to implement nutritional regimens to reduce the severity of disease and to test or validate nutritional regimens that heighten immunity. Nutritional modulation of the hen diet and in ovo nutrient modulation to improve chick immunity and disease resistance are discussed.

Amino Acids↗

PubMed2004

Threonine needs of broiler chickens with different growth rates.

The Thr needs in 3 commercial broiler strains (A, multipurpose; B, high yield; C, high yield) known to differ in terms of feed intake, growth rate, and breast yield were evaluated. Birds were randomized across 96 floor pens (12 birds/pen), received a common diet from d 1 to 20, and were fed graduations of Thr (0.52 to 0.87% total Thr in 0.07% increments) from d 21 to 42. Treatments (3 x 6 factorial) were replicated 5 or 6 times. The corn, soybean meal, and peanut meal test diet contained 0.43 and 0.96% digestible Thr and Lys, respectively. An additional group of strain C birds (6 pens) was maintained on a corn-soybean meal diet containing surfeit Thr (0.73% of diet). Birds fed the corn and soybean meal diet performed similarly (P < or = 0.05) to birds fed peanut meal diets. A feed conversion interaction (P < or = 0.05) occurred indicating that strain C was more sensitive to Thr deficiency than strains A and B. The abdominal fat interaction (P < or = 0.05) indicated that strain A had more relative abdominal fat than strains B and C. All strains differed (P < or = 0.05) in terms of BW gain (A, 78.2; B, 75.1; C, 72.9 g/d). Strain C had the lowest (P < or = 0.05) feed intake, which resulted in the lowest (P < 0.05) Thr intake, but it had the highest (P < or = 0.05) breast meat yield. Most parameters tested yielded quadratic (P < or = 0.05) models whereby Thr estimates could be predicted. Namely, BW gain and breast meat yield resulted in total Thr estimates (95% of maximum response) of 0.74 and 0.71%, respectively, which are in close agreement with the 1994 NRC (0.74%). The plasma Thr sigmoid response verified the former estimates. Analysis of strain intercepts and slopes as affected by Thr differed (P < or = 0.05) in terms of feed intake but not BW gain or breast meat yield. The 21 to 42 d Thr need across strains was estimated as 0.74% total or 0.65% digestible. Because dietary Lys was not in excess of the bird's needs, the former digestibility estimate equated to a Thr/Lys of 0.68.

Abdomen↗

PubMed2004

Dietary glycine needs of broiler chicks.

Dietary Gly might become a limiting factor in all-vegetable diets fed to broiler chicks when low CP is formulated in combination with marginal levels of dietary Thr and Ser. A study was conducted to evaluate dietary Gly needs of broiler chicks. Day-old Ross 508 male chicks were placed in 32 floor pens (15 chicks/pen). Chicks were fed a common prestarter diet from 0 to 7 d of age and then fed a diet that contained progressive amounts of dietary Gly ranging from 0.62 to 1.22% from 7 to 20 d of age. Treatment effects were observed for weight gain and feed conversion. Chicks responded in a quadratic manner to supplementation with dietary Gly. The dietary Gly level necessary to support maximum growth and feed conversion for the chick from 7 to 20 d of age was estimated to be at 0.98 (1.76% Gly + Ser) and 1.02% (1.80% Gly + Ser), respectively. Plasma Thr and Ser were unaffected by Gly supplementation, but plasma free Gly increased linearly. Dietary Gly may need to be considered as a limiting nutrient in early nutrition, especially if CP is low, and only vegetable ingredients are being used.

Animal Nutritional Physiological Phenomena↗

PubMed2004

Isoleucine requirements and ratios in starting (7 to 11 kg) pigs.

Two experiments were conducted to refine the Ile needs in 7- to 11-kg pigs. In Exp. 1, 1,680 pigs were fed a 1.25% digestible Lys diet containing 7.5% spray-dried blood cells (as-fed basis) with supplemental crystalline Ile (0.06% increments) to generate seven levels of apparent digestible Ile (0.47 to 0.83%). There were 12 replicates of each treatment with 20 pigs per pen, and treatments were imposed at an initial BW of 7 kg and continued for 16 d. Responses in ADG, ADFI, G:F, and plasma urea nitrogen (PUN) were quadratic (P < 0.01) over the 16-d period. Data were fitted to both a single-slope broken line and a quadratic fit, and when the quadratic response curve was superimposed on the broken line, the points at which the quadratic curve first intersected the plateau of the broken line occurred at 0.70, 0.73, 0.66, and 0.65% digestible Ile for ADG, ADFI, G:F, and PUN, respectively. Using the ADG and ADFI obtained at this intersection point resulted in an estimate of 9.1 mg of digestible Ile per gram of weight gain. In Exp. 2, 1,840 pigs were fed similarly composed diets, except that digestible Lys was lowered in six diets to 1.10% by decreasing soybean meal. Crystalline Ile was supplemented at 0.09% increments to generate six levels of digestible Ile (0.37 to 0.83%). A seventh diet contained 1.25% digestible Lys by supplementing the 0.83% digestible Ile diet with 0.19% L-Lys HCl to verify that 1.10% digestible Lys was deficient for these pigs. There were 12 replicates of each treatment with 22 pigs per pen, and treatments imposed at an initial BW of 7 kg and continued for 16 d. Supplementation of Lys to the 0.83% digestible Ile diet (1.10 vs. 1.25% digestible Lys) did not affect ADG (260 vs. 264 g/d, P = 0.60) and ADFI (359 vs. 343 g/d, P = 0.20), whereas G:F (725 vs. 774 g/kg, P < 0.01) was improved by increasing dietary Lys. Responses in ADG, ADFI, and G:F to the first six diets were quadratic (P < 0.01) over the 16-d period. The points at which the quadratic curve first intersected the plateau of the broken line occurred at 0.686, 0.638, and 0.684% digestible Ile for ADG, ADFI, and G:F, respectively. Using the ADG and ADFI obtained at this intersection point results in an estimate of 9.9 mg of digestible Ile per gram of weight gain. These results suggest that although the percent digestible Ile requirement and digestible Ile:Lys ratio for starter (7 to 11 kg) pigs may be higher than 1998 NRC recommendations, the requirement may be lower than current recommendations when taking gain and feed intake into account.

Animal Feed↗

PubMed2003

Effect of spray-dried bovine serum on intake, health, and growth of broilers housed in different environments.

Three experiments utilizing broilers were conducted in different environments to evaluate the effects of Innavax (INX; spray-dried serum) administered in drinking water on broiler performance. In Exp. 1 (1 to 42 d), 252 Ross x Cobb male broilers were assigned randomly to one of six treatments consisting of tap water mixed with 0, 0.25, 0.50, 0.75, 1.0, or 1.25% (wt/wt) INX. Broilers (six broilers per pen; seven pens per treatment) were housed in Petersime battery cages (raised wire flooring) in temperature-controlled rooms. Average daily gain, and feed and water intake (as-fed) were not affected (P > 0.05) by experimental treatments. Feed efficiency tended to improve linearly (P = 0.076) from d 0 to 7 with increasing levels of INX, but was unaffected (P > 0.05) during the remaining periods. In Exp. 2 and 3, 800 Ross x Ross 308 male broilers (400 broilers in each trial; 10 broilers per pen; 10 pens per treatment) in two 21-d experiments were assigned randomly to one of four treatments consisting of tap water mixed with 0, 0.45, 0.90, or 1.35% (wt/wt) INX. Broilers were housed in floor pens containing clean (Exp. 2) or used (Exp. 3) litter. In Exp. 2, intake, ADG, and feed efficiency were linearly improved (P < 0.05) during the first week with increasing levels of INX. During the second week (d 8 to 14), ADG, water intake, and feed efficiency were linearly improved (P < 0.05) with increasing levels of INX. In the third week (d 15 to 21), ADG and feed and water intake were not affected (P > 0.10) by level of INX. Overall (d 0 to 21), ADG, intake, and feed efficiency were linearly improved (P < 0.05) with INX. In Exp. 3, ADG, water intake, and feed efficiency were linearly improved (P < 0.05) during each period. Feed intake was not affected (P > 0.05) by experimental treatment during d 0 to 7, but was linearly increased (P < 0.05) from d 8 to 14 and 15 to 21. The greatest growth response of broilers to INX was observed when broilers were housed in floor pens with used litter, followed by floor pens with clean litter and battery pens. Further research on the relationship between the response to INX and housing conditions seems warranted.

Animal Husbandry↗

PubMed2001

Optimum site for in ovo amino acid injection in broiler breeder eggs.

Three experiments were conducted to evaluate the effect of differences in in ovo amino acid (AA) injection sites in broiler breeder eggs on subsequent hatchability and BW of chicks. In Experiment 1, an AA solution was injected into eggs with 13-mm or 19-mm, 27-ga needles. Uninjected eggs served as controls. Hatchability was decreased (P < 0.05) in eggs receiving AA injections with the 19-mm needle in comparison to the control and 13-mm-injected groups. However, BW of chicks increased (P < 0.05) relative to pre-incubational egg weight by AA injection with the 13-mm needle. In order to evaluate the in ovo location of AA injections from Experiment 1, India ink was injected into eggs in Experiment 2 with a 13-or 19-mm needle. Immediately after injection, the air cell end of the egg was windowed in order to observe effects of injection site. Windowing of eggs was accomplished by removing a piece of the eggshell over the air cell and the underlying membrane at Day 7 of incubation. The amount of injected India ink was higher in the extra-embryonic coelom in eggs treated by both needles. However, the occurrence of India ink in the extra embryonic coelom was higher (P < 0.05) in the group injected with AA solution using a 13-mm needle as compared to that after injection using a 19-mm needle. The observation of India ink in the amniotic cavity was higher (P < 0.05) in the group injected with AA solution using a 19-mm needle rather than that using a 13-mm needle. In Experiment 3, treatments consisted of control (uninjected eggs) or windowed eggs. Windowed eggs received AA to the chorioallantoic membrane, the yolk, extra-embryonic coelom, or amniotic cavity at Day 7 of incubation. Hatchability was reduced, but chicks hatched when eggs were windowed and when AA were injected into the yolk sac or extra-embryonic coelom. However, chicks did not hatch when AA were administered to the chorioallantoic membrane or into the amniotic cavity. These results suggest that the best AA injection sites in ovo may be the yolk and extra-embryonic coelom.

Amino Acids↗