Glycine supplementation to low protein, amino acid-supplemented diets supports optimal performance of broiler chicks

Six experiments were conducted to determine the effects of low CP in diets for broilers and to evaluate limiting essential and nonessential amino acids (AA) in these diets. All experiments were conducted with Ross x Ross broilers in brooder batteries from 0 to 17 or 18 d posthatch. Treatments were replicated with 6 pens of either 5 or 6 broilers each. In Experiment (Exp.) 1, corn-soybean meal diets were formulated to 16.18, 17.68, 19.18, 20.68, or 22.18% CP. The 22.18% CP diet provided 1.23% Lys and 0.89% TSAA, met or exceeded all nutrient requirements of young broilers, and served as the positive control (PC) diet in all experiments. Increasing dietary CP linearly increased final BW, daily gain (ADG), and gain:feed (G:F) (P \u3c 0.005). In Exp. 2, additions of crystalline essential (EAA) or nonessential AA (NEAA) were added to the low CP diet to simulate the AA profile of the PC. Daily gain, final BW, and G:F were decreased (P \u3c 0.01) when CP was reduced, but the addition of the NEAA increased final BW, ADG, and G:F (P \u3c 0.07) to the level of broilers fed the PC. Addition of EAA alone was without effect. In Exp. 3, chicks fed diets with supplemental Glu, Ala, Asp, or Pro had reduced daily feed intake (ADFI), ADG, and final BW (P \u3c 0.05) compared with the PC diet. Addition of Gly or the combination of Gly, Glu, Asp, Ala, and Pro to the low CP diet increased G:F (P \u3c 0.01) compared with chicks fed PC, and ADG was not different from that of broilers fed the PC diet. In Exp. 4, chicks were fed either the PC diet, the low CP diet with Gly + Ser concentrations of 1.23, 1.35, 1.47, 1.59, 1.71, 1.83, 1.95, or 2.07%, or a 10th diet that contained 1.23% Gly + Ser and with Glu to equal the N concentration of the 2.07% Gly + Ser diet. Final BW, ADG, and G:F were increased linearly (P \u3c 0.001) as the concentration of dietary Gly + Ser was increased. Chicks fed the low CP diet with 2.07% Gly + Ser had growth performance that was not different from that of chicks fed the PC. The addition of Glu to the low CP diet was without effect. In Exp. 5, chicks were fed the PC with additions of 0, 0.15, or 0.30% Gly or the low CP diet containing 1.60, 1.72, 1.84, 1.96, 2.08, 2.20, or 2.32% Gly + Ser. Glycine addition to the PC had no effect, but Gly addition to the low CP diet increased G:F linearly (P \u3c 0.001). Growth performance of chicks fed the low CP diet with 2.32% Gly + Ser was equal to that of chicks fed the PC diet. In Exp. 6, chicks were fed the PC or the low CP diet containing 1.80, 1.95, 2.10, 2.25, 2.40, 2.55, 2.70, 2.85, or 3.00% Gly + Ser. Glycine addition to the low CP diet increased G:F linearly (P \u3c 0.001). In summary, low CP diets result in optimal growth of broilers with Gly + Ser levels of 2.44%. ©2006 Poultry Science Association, Inc

Effects of glycine supplementation at varying levels of methionine and cystine on the growth performance of broilers fed reduced crude protein diets

Two experiments were conducted to investigate gly addition to reduced crude protein corn-soybean meal (C-SBM) diets with varying levels of TSAA achieved by varying Met and Cys. The experiments were conducted with female Ross 708 broilers in brooder batteries from 0 to 18 d posthatching. Treatments had 6 replicates with 6 broilers/pen. Diets in all experiments were fed without or with gly supplementation to contain 2.32% total gly + Ser. All diets were C-SBM based and formulated to contained 1.27% standardized ileal digestible Lys supplemented with 0.20% Lys (0.394% Lys·SO4) and to meet or exceed the requirement of all nutrients except Met and Cys where appropriate. Experiment 1 consisted of 8 dietary treatments. Three ratios of Met to Cys (60:40, 50:50, and 40:60) were used on a mole for mole basis to achieve 0.063 mol of TSAA/kg of feed and a positive control with Met:Cys of 50:50 at 0.76 TSAA:Lys. glycine supplementation did not affect ADg or ADFI; however, g:F was increased (P = 0.003) with gly supplementation. An increase in Cys and a decrease in Met resulted in a decrease (P = 0.028) in ADg but had no effect on ADFI or g:F. In experiment 2, Met was kept constant at a marginal level of 0.45% and Cys was increased in 0.05% increments from 0.35 to 0.50%. glycine supplementation had no main effect on ADg, ADFI, or g:F; however, gly increased g:F at the lower levels of Cys but not at the higher levels (gly × Cys, P = 0.031). A linear decrease (P = 0.071) was found in ADFI with increasing Cys supplementation. These data indicate that gly increased g:F in female broilers fed suboptimal levels of Met and Cys but not at Cys levels at or above the requirement. This implies that the synthesis of Cys accounts for a portion of the increased g:F observed from gly supplementation in female broilers fed reduced CP C-SBM diets. © 2011 Poultry Science Association Inc

Effect of protein and energy sources and bulk density of diets on growth performance of chicks

Four completely randomized designed experiments (EXP) were conducted to determine the effect of energy, amino acid (AA) levels, and bulk density of diets on growth performance of chicks fed diets containing corn (C) or cornstarch:dextrose (CD) as energy sources and soybean meal (SBM) or soy protein isolate (SPI) as protein sources. The chicks were fed C-SBM diets 6 to 8 d posthatching before allotment to treatment, and the assay periods ranged from 7 to 14 d. Initial weights were 86, 93, 94, and 71 g in EXP 1 to 4, respectively. Treatments were replicated 6 to 8 times with 4, 5, or 6 chicks per replicate. In EXP 1, the treatments were 1) CSBM (1.26% Lys and 3,200 kcal of ME/kg); 2) CD-SPI (1.26% Lys and 3,460 kcal of ME/kg); 3) CD-SPI (1.36% Lys and 3,460 kcal of ME/kg); and 4) CD-SPI (1.26% Lys and 3,200 kcal of ME/kg). The AA in all diets were increased in proportion to Lys. In EXP 2, chicks were fed C or CD as the energy source and SBM or SPI as the protein source in a 2 x 2 factorial arrangement. In EXP 3, the treatments were 1) C-SBM (1.26% Lys and 3,200 kcal of ME/kg); 2) CD-SPI (1.26% Lys and 3,200 kcal of ME/kg); 3) Diet 1 limit-fed to chicks consuming 90% of Diet 2; 4) Diet 2 limit-fed to chicks consuming 90% of Diet 2. In EXP 4, Diets 1 and 2 were the same as Diets 1 and 2 in EXP 3, but fed in mash or pelleted form. In all EXP, chicks with access ad libitum to diets with SPI had decreased (P \u3c 0.02) average daily gain (ADG) and feed intake (ADFI) compared with those with access ad libitum to diets with SBM. In EXP 2, feeding C- or CD-dextrose as the energy source had no effect (P \u3e 0.05) on ADG, ADFI, or gain:feed. In EXP 3, ADG was decreased in chicks fed the diets with SPI relative to those fed diets with SBM, but the decrease was much greater in chicks that had access ad libitum to feed (protein source x feed intake, P \u3c 0.01) than in those limit-fed to the same feed intake. In EXP 4, ADG, ADFI, and gain:feed were decreased (P \u3c 0.01) in chicks fed diets with SPI as the protein source. Pelleting increased (P \u3c 0.01) ADG, ADFI, and gain:feed regardless of protein source, but the increase was much greater in chicks fed the diets with SPI (protein source x feed form, P \u3c 0.01). Results from these EXP indicate that diets with SPI compared with SBM do not result in maximum growth performance in commercial broilers, and the problem may be due somewhat to nutrient deficiency but more to the physical form of the diet. ©2005 Poultry Science Association, Inc

Effects of body size on estimation of mammalian area requirements.

Accurately quantifying species' area requirements is a prerequisite for effective area-based conservation. This typically involves collecting tracking data on species of interest and then conducting home range analyses. Problematically, autocorrelation in tracking data can result in space needs being severely underestimated. Based on the previous work, we hypothesized the magnitude of underestimation varies with body mass, a relationship that could have serious conservation implications. To evaluate this hypothesis for terrestrial mammals, we estimated home-range areas with global positioning system (GPS) locations from 757 individuals across 61 globally distributed mammalian species with body masses ranging from 0.4 to 4000 kg. We then applied blockcross validation to quantify bias in empirical home range estimates. Area requirements of mammals 1, meaning the scaling of the relationship changedsubstantially at the upper end of the mass spectrum

Moving in the anthropocene: global reductions in terrestrial mammalian movements

Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission

Effects of body size on estimation of mammalian area requirements

Accurately quantifying species’ area requirements is a prerequisite for effective area‐based conservation. This typically involves collecting tracking data on species of interest and then conducting home‐range analyses. Problematically, autocorrelation in tracking data can result in space needs being severely underestimated. Based on previous work, we hypothesized the magnitude of underestimation varies with body mass, a relationship that could have serious conservation implications. To evaluate this hypothesis for terrestrial mammals, we estimated home‐range areas with GPS locations from 757 individuals across 61 globally distributed mammalian species with body masses ranging from 0.4 to 4,000 kg. We then applied block cross‐validation to quantify bias in empirical home‐range estimates. Area requirements of mammals 1, meaning the scaling of the relationship changed substantially at the upper end of the mass spectrum

Spatial patterns of large African cats : a large-scale study on density, home range size, and home range overlap of lions Panthera leo and leopards Panthera pardus

SUPPORTING INFORMATION : APPENDIX S1. Site information. APPENDIX S2. Intuitive explanation of the autocorrelated kernel density estimator. APPENDIX S3. Sources of density data. APPENDIX S4. Mathematical modifications of Jetz et al.’s (2014) overlap equation. APPENDIX S5. Lion pride size data.1. Spatial patterns of and competition for resources by territorial carnivores are typically explained by two hypotheses: 1) the territorial defence hypothesis and 2) the searching efficiency hypothesis. 2. According to the territorial defence hypothesis, when food resources are abundant, carnivore densities will be high and home ranges small. In addition, carnivores can maximise their necessary energy intake with minimal territorial defence. At medium resource levels, larger ranges will be needed, and it will become more economically beneficial to defend resources against a lower density of competitors. At low resource levels, carnivore densities will be low and home ranges large, but resources will be too scarce to make it beneficial to defend such large territories. Thus, home range overlap will be minimal at intermediate carnivore densities. 3. According to the searching efficiency hypothesis, there is a cost to knowing a home range. Larger areas are harder to learn and easier to forget, so carnivores constantly need to keep their cognitive map updated by regularly revisiting parts of their home ranges. Consequently, when resources are scarce, carnivores require larger home ranges to acquire sufficient food. These larger home ranges lead to more overlap among individuals’ ranges, so that overlap in home ranges is largest when food availability is the lowest. Since conspecific density is low when food availability is low, this hypothesis predicts that overlap is largest when densities are the lowest. 4. We measured home range overlap and used a novel method to compare intraspecific home range overlaps for lions Panthera leo (n = 149) and leopards Panthera pardus (n = 111) in Africa. We estimated home range sizes from telemetry location data and gathered carnivore density data from the literature. 5. Our results did not support the territorial defence hypothesis for either species. Lion prides increased their home range overlap at conspecific lower densities whereas leopards did not. Lion pride changes in overlap were primarily due to increases in group size at lower densities. By contrast, the unique dispersal strategies of leopards led to reduced overlap at lower densities. However, when human-caused mortality was higher, leopards increased their home range overlap. Although lions and leopards are territorial, their territorial behaviour was less important than the acquisition of food in determining their space use. Such information is crucial for the future conservation of these two iconic African carnivores.The Natural Sciences and Engineering Research Council of Canada and a Hugh Kelly Fellowship from Rhodes University, Grahamstown, SA.https://onlinelibrary.wiley.com/journal/13652907am2024Centre for Wildlife ManagementMammal Research InstituteZoology and EntomologySDG-15:Life on lan

Ratio of Total Sulfur Amino Acids to Lysine for Finishing Pigs

We conducted two experiments to determine the optimum ratio of total sulfur amino acids (TSAA) to Lys for late finishing pigs. In Exp. 1, 50 barrows and 50 gilts were allotted to treatments with three replicates of three or four pigs per replicate in a randomized complete block (RGB) design within a split-plot arrangement of treatments. Sex was the whole plot and TSAA:Lys ratio was the subplot. Average initial and final BW were 77 and 111 kg. Barrows and gilts were fed diets formulated to contain .55 and .65% Lys, respectively. The ratios of TSAA:Lys were .50 .55, .60, .65, and .70. Diets met or exceeded an ideal amino acid pattern for all indispensable amino acids (except TSAA), and all diets were isonitrogenous and equal in electrolyte balance. In Exp. 2, 60 gilts were allotted to five treatments with four replicates of three gilts each in a RCB design. Average initial and final BW were 74 and 110 kg. Gilts were fed diets formulated to contain .65% Lys The ratios of TSAA:Lys were .35, .425, .50, .575 and .65 In Exp. 1, there were no TSAA:Lys ratio effects (P \u3e .10) for ADG, final BW, percentage muscle, longissimus muscle area, carcass length, percentage fat-free lean (PFFLEAN), lean gain per day (LGD), total tat (TOFAT), percentage TOFAT (PTOFAT) fat gain per day (FGD), lean:fat, retained energy in TOFAT as ether extractable lipid (RE-F), retained energy (RE), or serum urea N (SUN). Feed intake (ADFI) was greater (quadratic, P \u3c .05) for pigs fed .70 TSAA:Lys than for pigs fed any other treatment. Hot carcass weight psoas muscle weight, 10th rib fat thickness dressing percentage, fat-free lean (FFLEAN), and retained energy in FFLEAN as protein (RE-P) responded inconsistently to TSAA:Lys ratio, resulting in cubic (P \u3c .09) effects. In Exp. 2, ADFI (linear, P \u3c .08) TOFAT (linear, P \u3c .05), PTOFAT (linear, P \u3c .07), FGD (linear, P \u3c .05), RE-F (linear, P \u3c .05), RE (linear, P \u3c .05), and SUN (linear, P \u3c .02; quadratic, P \u3c .01) decreased as TSAA:Lys ratio increased. Also, gain:feed (GF) (linear, P \u3c .01; quadratic, P \u3c .04), PFFLEAN (linear, P \u3c .04), and lean:fat (linear, P \u3c .04) increased as TSAA:Lys ratio increased. One-slope, broken-line regression models estimated required ratios of TSAA:Lys of 44 (SUN), .40 (ADG) .47 (ADFI), .45 (GF), .45 (FFLEAN), .44 (LGD) .65 (TOFAT), .65 (FGD), .44 (RE-P), .65 (RE-F) .65 (RE), and .57 (lean:fat). Thus, for growth and muscling traits of late finishing pigs, the optimum ratio of TSAA:Lys is less than the current proposed ratio (.65), but to minimize fat accretion, the ratio is .65

Comparison of dried whey permeate and a carbohydrate product in diets for nursery pigs

Three experiments were conducted to compare dried whey permeate (DWP; 80% lactose) and a carbohydrate product (CHO; 40% lactose, 30% sucrose, and 10% glucose) for nursery pigs. Pigs were fed in a 3-phase feeding program, and diets contained 1.6, 1.4, and 1.2% total Lys for phases 1 (d 0 to 7), 2 (d 7 to 21), and 3 (21 to 28). Dietary treatments included 1) control (no lactose), 2) low level of DWP, 3) high level of DWP, 4) low level of CHO, and 5) high level of CHO. In Exp. 1 (4 reps of 4 pigs per pen; initial BW = 7 kg and 23 d of age), the low and high levels used for each source in each phase were phase 1 (12.5 and 25%), phase 2 (10 and 20%), and phase 3 (6 and 12%). In Exp. 2 (6 reps of 5 pigs per pen; initial BW = 8 kg and 26 d of age) and 3 (4 reps of 4 pigs per pen; initial BW = 6 kg and 21 d of age), the inclusion levels were phase 1 (6 and 12%), phase 2 (3 and 6%), and phase 3 (common diet with no lactose). In Exp. 1, pigs fed diets with DWP or CHO had increased ADG (P = 0.02 and P = 0.01) and ADFI (P = 0.01) compared with pigs fed the control diet during phase 1. Gain:feed was reduced (P = 0.08) for pigs fed diets with CHO. During phases 2, 3, and overall, ADG, ADFI, and G:F were not affected (P \u3e 0.10) by diet. In Exp. 2, pigs fed diets with CHO had increased ADG (P = 0.08 and P = 0.07) and ADFI (P = 0.04 and P = 0.01) compared with pigs fed the control diet during phases 1 and 2. Pigs fed diets with CHO had increased ADFI (P = 0.08 and P = 0.07) in phases 1 and 2 and increased ADG (P = 0.02) in phase 2 compared with pigs fed diets with DWP. Overall, pigs fed diets with DWP and CHO had increased ADFI (P = 0.06 and P = 0.01) compared with pigs fed the control diet, but ADG was increased (P = 0.07) for pigs fed diets with CHO. In Exp. 3, ADG, ADFI, and G:F were not affected (P \u3e 0.10) by DWP or CHO during phase 1. Daily BW gain was increased (P = 0.02 and P = 0.07) for pigs fed diets with DWP or CHO during phase 2 compared with pigs fed the control diet. Overall, ADG was increased (P = 0.05) for pigs fed diets with DWP, but ADFI and G:F were not affected. Results from the combined data of Exp. 2 and 3, indicated that overall ADG (P = 0.05 and P = 0.04) and ADFI (P = 0.04) were increased in pigs fed diets with DWP or CHO compared with pigs fed the control diet. These data suggest that DWP or CHO improve growth performance of weanling pigs. © 2010 American Society of Animal Science