The objective was to assess whether low-protein (LP) diets regulate food intake (FI) and thermogenesis differently during thermoneutral (TN) and heat stress (HS) conditions. Two-hundred-day-old male broiler chicks were weight-matched and assigned to 36 pens with 5–6 chicks/pen. After 2 weeks of acclimation, birds were subjected into four groups (9 pens/group) including (1) a normal-protein diet under TN (ambient temperature), (2) an LP diet under TN, (3) a normal-protein diet under HS (35 °C for 7 h/day), and (4) an LP diet under HS, for 4 weeks. During HS, but not TN, LP tended to decrease FI, which might be associated with a lower mRNA abundance of duodenal ghrelin and higher GIP during HS. The LP group had a higher thermal radiation than NP under TN, but during HS, the LP group had a lower thermal radiation than NP. This was linked with higher a transcript of muscle β1AR and AMPKα1 during TN, but not HS. Further, LP increased the gene expression of COX IV during TN but reduced COX IV and the sirtuin 1 abundance during HS. The dietary protein content differentially impacted plasma metabolome during TN and HS with divergent changes in amino acids such as tyrosine and tryptophan. Compared to NP, LP had increased abundances of p_Tenericutes, c_Mollicutes, c_Mollicutes_RF9, and f_tachnospiraceae under HS. Overall, LP diets may mitigate the negative outcome of heat stress on the survivability of birds by reducing FI and heat production. The differential effect of an LP diet on energy balance during TN and HS is likely regulated by gut and skeletal muscle and alterations in plasma metabolites and cecal microbiota.

Eight broiler weight groups, housed in metabolic chambers, were exposed to 3-5 ambient temperatures (AT) such that AT exposure fell below, near and above the projected thermoneutral (TN) zone. Birds were fed 0, 5, and 10% of body weight (W), or allowed to consume food ad libitum, to vary energy consumption. Energy needs for body weight homeostasis, efficiency of metabolizable energy (ME) use for maintenance and the exponent needed to convert live body weight to metabolic weight was estimated. Energy (Kcal W-1 d-1) and oxygen (l W-1 d-1) needs for body weight homeostasis declined curvilinearly as body weight increased from 0.042 kg to 2.44 kg. Such needs were impacted by AT. The efficiency of ME use to support maintenance energy need varied in a cubic fashion with bird mass. The estimated zone of thermoneutrality, at body weight homeostasis, was inversely related to W (kg), expressed as: TN (ºC) = 31.896 – 0.4625∙W (R2 = 0.99). Under metabolic basal rate (MBR) conditions, the TN zone was curvilinearly related to weight as: TNMBR = 32.6466 − (94.4603∙W) − (0.7660∙W2) (R2 = 0.99). The exponent, to linearize live body weight with heat production (HP) of birds fed to W homeostasis, was determined to be 0.758 with all birds strictly housed at TN. Further, the exponent to linearize HP of birds under MBR (fasted) conditions was estimated to be 0.679. Equations relating chick energy and oxygen consumption need with body weight and AT, metabolizable energy for gain homeostasis (MEmg), metabolizable energy for retained energy homeostasis (MEmr), metabolizable energy for protein homeostasis (MEmp), and metabolizable energy for fat homeostasis (MEmf) are presented.

A study was conducted to investigate the effect of extracted phytase supplementation on growth performance and some carcass characteristics of broiler chicken. A total of 180-day-old Cobb 500 broilers were randomly assigned to four treatment diets in a completely randomized design (CRD) replicated three times with 15 chicks each. The design of the experiment was a completely randomized design (CRD) and the experimental ratio include phytase at the dose rate of 0, 300, 600, and 1200 FTU/kg for 42 days. It was observed that the inclusion of phytase had a significant effect on total feed intake, final body weight, and bodyweight change during starter, finisher, and entire phase among treatments (p<0.05). Higher (P < 0.05) starter phase feed intake, final body weight, and weight change were recorded for T4 and T3 compared to T1 and T2. In addition, better-feed conversion was recorded in the starter phase among treatments with the inclusion of phytase compared with the control group. The highest feed consumption in the finisher phase was attained in T2, followed by the group of birds feeding on the T4 diet, followed by the group of birds feeding on the T1 diet, and the birds fed on the diet T3 attained the lowest feed consumption. However, T2 and T4 are statistically the same (p<0.05). Highest (P < 0.05) final body weight in the finisher phase was recorded in T2, T3, and T4 compared to T1. Also highest (P < 0.05) body weight change was recorded in T2 compared with T3, T4, and T1. The highest (p<0.001) feed intake in the entire phase was recorded in diets containing 300 (T2) and 1200 FTU/kg (T4) compared with T1 and T3. Final body weight and body weight change among treatment with phytase inclusion showed similarly significant effects (p<0.001) compared with the control group. The weight of most carcasses was similar (P>0.05) among treatments except the dressed weight and breast weight were significant effects (p<0.05) compared to the control group. It was concluded that the inclusion of phytase had a considerable impact on feed intake, final body weight, body weight change, and carcass yield characteristics.

The objective of this study was to assess the effects of low protein diets on feed intake (FI), heat production and markers of FI and thermogenesis regulation in broilers under experimentally induced heat stress. Two-hundred-day-old broiler chicks were weight-matched and assigned into 36 pens (5-6 chicks/pen) followed by assigning them into two treatments (18 pens/treatment): 1) thermoneutral (TN), 2) heat stress (HS). Within each treatment, the pens were randomized to receive two diets (9 pens/diet): 1) normal protein (NP), 2) low protein (LP). The study lasted 6 weeks with 2 weeks of acclimation and 4 weeks of data collection. On week 6, birds were euthanized, and blood and tissue samples collected. All data were analyzed with either GLM or mixed procedure (SPSS). The student’s t-test was used to separate means between NP and LP diets within each treatment. There was no difference in average daily gain between NP and LP diets in the TN group, but LP decreased that during HS (P< 0.05). In TN condition, LP tended to increase the average daily feed intake (ADFI) compared to NP (P< 0.1), while during HS, LP was not different from NP in terms of ADFI (P>0.05). In TN condition, LP had a higher thermal radiation than NP, but LP had less thermal radiation than NP during HS (P< 0.05). In support of ADFI data, LP had a greater ghrelin transcript in the duodenum than NP in TN condition (P< 0.05). However, during HS, LP tended to decrease the plasma ghrelin concentration compared with NP (P< 0.1). Unlike TN condition, LP had a decreased muscle sirtuin and cytochrome c oxidase transcript than NP during HS (P< 0.05). Our data provide evidence that low protein diets mitigate the negative outcome of heat stress by reducing feed intake and heat production, which are regulated through genes expressed in the gut and skeletal muscle.

The objective of the current study was to evaluate the color changes and lipid oxidation of ground chicken patties packaged in polyvinyl chloride (PVC) film, high-oxygen (HiOx)–modified atmospheric packaging (MAP; 80% oxygen + 20% carbon dioxide [CO2]), and carbon monoxide (CO)-MAP (0.4% CO + 19.6% CO2 + 80% nitrogen) and stored at 2°C. Surface color was measured using a HunterLab MiniScan spectrophotometer on days 0, 1, 2, and 4. Lipid oxidation, pH, and aerobic plate count were determined on days 0 and 4 of storage. Fatty acid profiles were determined on day 0 to characterize saturated and unsaturated fatty acids. Patties packaged in PVC had greater (P < 0.05) pH than HiOx-MAP and CO-MAP. Gas chromatography analysis indicated that ground chicken has 72.8% unsaturated fatty acids and 27.2% saturated fatty acids (based on total lipids and fatty acid methyl ester). The formation of carboxymyoglobin on ground chicken patty surface was confirmed by peaks at 420 and 570 nm, whereas oxymyoglobin had peaks at 410 and 580 nm. Instrumental color analysis indicated both HiOx-MAP and CO-MAP had greater (P < 0.05) redness (a* values) than PVC on day 4 of storage. Patties packaged in HiOx-MAP had greater (P < 0.05) chroma values than CO-MAP and PVC on day 4 of storage. Visual panelists noted less (P < 0.05) surface discoloration in CO-MAP than PVC and HiOx-MAP on day 4 of storage. Lipid oxidation was greater (P < 0.05) in PVC and HiOx-MAP than CO-MAP. CO inclusion at 0.4% level effectively inhibited lipid oxidation and stabilized surface redness during refrigerated storage of ground chicken.

Coccidiosis is among the major disease challenges facing the worlds poultry industries. Though a variety of diet delivered drugs are available to minimize coccidiosis incidence and severity, birds will normally develop immunity during the production cycle. Immunity development is critical as drugs are usually not fed continuously to processing. Vaccination at hatch speeds immunity. Timing of immunity development can be critical to performance as late growth curve challenges may have extreme costs for birds lacking immunity. To examine the caloric cost of immunity development 2 groups of birds were reared in cocci free environments with one vaccinated at hatch (Coccivac-B) and the other maintained as naive to cocci. Previous work with such groups indicated that unless ration energy is lowered, vaccinated birds trend higher in body lipid content suggesting energy sparing as body protein was similar. In this experiment finisher rations were fed as formulated, or reduced by 70 kcal to test the hypothesis that energy sparing may occur for Coccivac-B vaccinated chicks. Birds were selected from the 2 backgrounds at 35 d of age and placed on finisher rations plus/minus 70 kcal metabolizable energy per kg ration. Though coccidiosis immunity development occurring early in the production cycle, had small energy costs (3 points FCR at 28 d), this impact was eliminated by 42 d. Further, chicks consuming finisher rations with reduced energy had similar body composition to non vaccinated chicks while vaccinated consuming normal energy trended higher in body lipid content. The concept of Coccivac-B vaccinated chicks sparing energy late in the growth curve requires additional consideration. Strategies to optimize metabolizable energy utilization, and lower feed cost, at constant broiler body composition may include early vaccination to spare late growth curve energy wastage and lipogenesis.

Host defense peptides (HDPs) constitute a large group of natural broad-spectrum antimicrobials and an important first line of immunity in virtually all forms of life. Specific augmentation of synthesis of endogenous HDPs may represent a promising antibiotic-alternative approach to disease control. In this study, we tested the hypothesis that exogenous administration of butyrate, a major type of short-chain fatty acids derived from bacterial fermentation of undigested dietary fiber, is capable of inducing HDPs and enhancing disease resistance in chickens. We have found that butyrate is a potent inducer of several, but not all, chicken HDPs in HD11 macrophages as well as in primary monocytes, bone marrow cells, and jejuna and cecal explants. In addition, butyrate treatment enhanced the antibacterial activity of chicken monocytes against Salmonella enteritidis, with a minimum impact on inflammatory cytokine production, phagocytosis, and oxidative burst capacities of the cells. Furthermore, feed supplementation with 0.1% butyrate led to a significant increase in HDP gene expression in the intestinal tract of chickens. More importantly, such a feeding strategy resulted in a nearly 10-fold reduction in the bacterial titer in the cecum following experimental infections with S. enteritidis. Collectively, the results indicated that butyrate-induced synthesis of endogenous HDPs is a phylogenetically conserved mechanism of innate host defense shared by mammals and aves, and that dietary supplementation of butyrate has potential for further development as a convenient antibiotic-alternative strategy to enhance host innate immunity and disease resistance.

Beker, A., Gipson, T.A., Puchala, R., Askar, A.R., Tesfai, K., Detweiler, G.D., Asmare, A. and Goetsch. A.L., 2009. Energy expenditure and activity of different types of small ruminants grazing varying pastures in the summer. J. Appl. Anim. Res., 37: 1-14.Objectives were to determine the activity energy cost for different types of goats as well as a breed of sheep and to evaluate methods of prediction. Eight animals each of yearling Angora doeling goats, yearling Boer wet her goats, yearling Spanish wether goats and Rambouillet wether sheep slightly more than 2 yr of age were used. Two animals of each type were randomly allocated to one of the four pastures 9.3, 12.3, 4.6 and 1.2 ha. in area. Forage conditions varied markedly among pastures. The experiment was conducted in the summer with three periods, 30, 26 and 26 d in length. Energy expenditure (EE) was estimated from heart rate (HR) on pasture and EE:HR for each animal determined in a calorimetry system. A leg position/ movement monitoring system and a GPS collar with position and movement sensors were used to estimate distance traveled and time spent grazing/eating, resting while lying, resting while standing and walking without grazing/eating. EE attributable to activity (EEa%), expressed as a percentage of the ME requirement for maintenance plus activity in confinement, was determined based on total EE, BW and ADO. ADG was similar among animal types. Distance traveled was affected by an interaction (P<0.00 between animal type and period (Angora goats: 2.98, 2.33 and 2.47; Boer goals: 3.17, 3.46 and 2.68; Spanish goats: 2.85, 5.28 and 3.30; sheep: 3.04, 3.43 and 2.25 km in periods 1, 2 and 3, respectively (SE = 0.423). Time spent grazing was lowest among animal types (P<0.05) for Angora goats (4.3, 8.4, 7.8 and 6.8 h/day) and time spent walking without grazing was lower (P<0.05) for Angora goats and sheep than, for Boer goats.(1.7, 2.4, 2.1 and 1.2 h/day for Angora goats, Boer goats, Spanish goats and sheep, respectively). Total EE was affected by an interaction (P<0.05) between animal type and period (Angora goats: 5.59, 5.55, and 5.16; Boer goats: 9.63, 10.92 and 8.55; Spanish, goats: 6.73, 8.17 and 7.02; sheep: 12.54, 11.84 and 12.93 MJ/ day in periods 1, 2, and 3, respectively (SE = 0.442). EEa% was affected by an interaction (P<0.05) between animal. type and period (Angora goats: 15.7, 17.4 and 15.1; Boer goats: 59.7, 67.4 and 34.4; Spanish goats: 46.2, 61.7 and 41.6; sheep: 22.3, 11.8 and 21.9% in periods 1, 2 and 3, respectively (SE = 6.07). EEa% of goats was predicted with moderate accuracy (R-2 = 0.40-0.41) and without bias from estimates of 5.7.9 and 5.05%/h spent grazing/eating and grazing/eating plus walking, respectively, determined in a companion experiment.; however, these methods were not suitable for sheep.

J. Anim. Sci. Vol. 88, E-Suppl. 2/J. Dairy Sci. Vol. 93, E-Suppl. 1/Poult. Sci. Vol. 89, E-Suppl. 1 342 Transforming coccidiosis mediated lesion score effects into estimates of performance and calorific costs in the form of ADG, FCR, malabsorption and effective caloric value throughout the broiler growth curve to 48 days of age. R. G. Teeter*1, A. Beker1, C. Brown1, C. Broussard2, F. Fitz-Coy2, J. Radu2, and L. Newman2, 1Oklahoma State University, Stillwater, 2Schering-Plough Animal Health, Summit, NJ.

Sixteen Boer and 16 Spanish multiparous does were used to determine how stocking rate (SR), breed and stage of production influence energy expenditure and behavioral activities on pasture and to develop a simple method of predicting energy used for activity. The experiment began lit late spring at an average of 24 d after kidding. Litter size was two and kids were Boer and Spanish. Two does of each breed resided in eight 0.5-ha grass/forb pastures. There were five periods, 56, 60, 63, 64 and 73 d in length, corresponding to mid-lactation, early post-weaning, the late dry period, early gestation and mid-gestation. During period 1 and the first part of period 2, two additional does with kids of each breed grazed in four High SR pastures, with other pastures designated as Low SR. Because of low available forage mass in period 3, grass hay was offered for ad libitum consumption in periods 3-5 and a concentrate supplement was provided in periods 4 and 5. Energy expenditure (EE) was estimated from heart rate (HR) on pasture and EE:HR for each doe determined in a calorimetry system. A leg position/movement monitoring system and a GPS collar with position and movement sensors were used to estimate distance traveled and time spent grazing/eating, resting while lying, resting while standing and walking without grazing/eating. EE attributable to activity (EEa%), expressed as a percentage of the ME requirement for maintenance plus activity in confinement, was determined based on total EE, estimated milk production and doe B Wand ADG. Forage DM mass in the middle of periods was 696, 246, 125 and 196 kg / ha for the High SR and 1362, 967, 4 79 and 610 kg I ha for the Low SR in periods 1, 2, 3 and 4, respectively. Kid ADG at weaning after 73 d was lower (P<0.05) for the High us. Low SR (87 vs. 112 g). Distance traveled was not influenced by SR or breed but varied among periods (3.54, 3.76, 3.09, 3.08 and 4.10 km / d in periods 1, 2, 3, 4 and 5, respectively; SE = 0.193). Time spent grazing/eating tended (P < 0.07) to be greater for Boer vs. Spanish does (7.9 vs. 6.7 h/d) and differed among periods (8.0, 7.8, 7.6, 5.3 and 8.0 h/day in periods 1, 2, 3, 4 and 5, respectively; SE = 0.72). Total EE was greater (P<0.05) for Boer than for Spanish does (13.4 vs. 11.4 MJ/d) and differed among periods (13.5, 11.6, 11.7, 11.8 and 13.4 MJ/day in periods 1, 2, 3, 4 and 5, respectively; SE = 0.41). Likewise, predicted ME intake was greater (P<0.05) for Boer vs. Spanish does (14.2 vs. 12.2 MJ/d) and varied with period (16.1, 10.6, 12.8, 12.6 and 14.0 MJ/day lit periods 1, 2, 3, 4 and 5, respectively; SE 0.47). EEa% was not influenced by SR, breed or period, averaging 49%. Behavioral activities were not highly related to EEa%, although no-intercept regressions against time spent grazing/eating and grazing/eating plus walking indicated an increase in EEa% of 5.79 and 5.05%/h, respectively. In conclusion, although EEa% was not affected by treatments of this experiment or highly related to behavioral activities monitored, it represents a sizeable cost of energy deserved of further study.

Atmospheric NH3 in poultry facilities has been linked to damaged respiratory tract lining, reduced resistance to respiratory diseases, and increased ascites. Therefore, the effects of graded NH3 concentration (0, 30, 60 ppm) on performance, tracheal lesions, conjuctival lesion, ascites incidence, hematocrit (HCT), blood uric acid (BUR), and blood urea nitrogen (BUN) were investigated using commercial broilers. Final body weight, feed consumption, and body weight gain were not significantly (P > 0.05) affected as NH3 concentration increased from 0 to 60 ppm. In contrast, gain to feed ratio was depressed (P = 0.05) at 60 ppm NH3. Right ventricular weight (RV), HCT, tracheal lesions, and pulmonary lesions increased with age (P < 0.05) to 21 d but was not affected by atmospheric NH3. These data indicate that NH3 in poultry houses lowers performance and may increase disease susceptibility.

The effects of graded atmospheric O2 concentration (12, 14, 16, 18, and 20.6%) on chick performance and propensity to develop ascites were investigated using commercial male broilers. Chicks were housed in calorimetry chambers for 2 wk with incoming air diluted with N to provide the desired O2 concentration at thermoneutral (TN) ambient temperature. Day 14 body weight, weight gain, feed consumption, and gain-to-feed ratio increased (P < 0.01) as O2 concentration incrementally rose from 12 to 20.6%. Body weight was 138 g for the lowest atmospheric O2 level compared to 371 g for 20.6% O2. The greatest treatment difference occurred between the 12 and 14% O2 concentrations. Growth depression appeared related to feed consumption. Ascites heart ratio (AHR), ascites score (AS), right ventricular mass (RVM), and hematocrit (HCT) all increased (P < 0.01) as O2 concentration decreased. Blood HCT appeared to be a more sensitive indicator of physiological change attributable to atmospheric O2 than AHR, AS, or RVM. The data reported herein suggests that 19.6% atmospheric O2 is the minimal allowable level for housing birds within a relatively stress-free, TN environment to avoid cardiac and HCT changes related to ascites.

s of papers 21 As the linear relationships between Tb and the respiratory parameters were unaltered by air movement it is proposed that the beneficial effects of this forced ventilation regime are through direct convective cooling and a reduction in deep body temperature. Convective cooling thus reduces the requirement for respiratory evaporation and therefore improves water conservation in addition to decreasing hyperthermic stress. The air movement induced reduction in thermal polypnea will also avoid excessive acid-base balance disturbances. It is proposed that air movements consistent with those achievable on mechanically ventilated commercial transporters will potentially improve productivity and welfare during journeys undertaken in hot conditions.

Oxygen level, ambient temperature, and bronchodilator (metaproterenol) effects on performance, ascites incidence, and hematology were investigated using commercial broilers. In Experiment 1, two atmospheric oxygen concentrations (17.6, 20.6%) and two ambient temperatures (26.7, 32.2 C) were examined in a factorial arrangement. The low-oxygen (17.6%), ambient temperature combination (26.7 C) reduced (P < .01) weight gain whereas the high-oxygen ambient temperature combination enhanced (P < .05) such performance. Ascites incidence for chicks housed at 32.2 C was higher (P < .01) for birds maintained at 17.6% oxygen but oxygen concentration did not impact ascites incidence at 26.7 C. White blood cell counts were elevated in the low-oxygen (17.6%) group at both 26.7 and 32.2 C, and hematocrit was positively (R = .84; P < .05) correlated with ascites incidence. In Experiment 2, two oxygen levels (17.6, 20.6%) at constant 26.7 C were examined with and without metaproterenol, a bronchodilator. Metaproterenol reduced (P < .01) ascites incidence at 17.6% oxygen and completely prevented ascites at 20.6% oxygen. The data suggest that therapeutic development may be enhanced by using hematocrit as an indices of ascites and further that studies directed at bronchodilation have potential to alleviate ascites.