Lower Feed Intake Research Articles

7 Environmental sustainability of livestock systems in the southeastern U.S.: Opportunities and research gaps

Abstract According to the Environmental Protection Agency (EPA), enteric methane (CH4) was the second largest source of greenhouse gas emissions from agriculture in 2021 behind nitrous oxide emissions from soil management. Cattle production in the southeastern U.S. represent a significant source of enteric CH4. In 2021, 31.5% of all cattle derived enteric CH4 arose from the southeastern U.S., representing 43.3% of cow-calf, 27.4% of stocker, 23.1% of feedlot, and 12.1% of dairy derived enteric CH4, according to the EPA. Previous work has demonstrated that reducing CH4 emissions represents the most promising means to limit climate change in the short-term, due to the short atmospheric lifespan of CH4. As such, developing enteric CH4 mitigation strategies for southeastern cattle producers is imperative. Enteric CH4 mitigation strategies can be grouped into diet formulations (e.g., lipid additions; feeding more grains; protein source and inclusion), feed management (e.g., grain and forage processing; grazing management; forage species), rumen manipulations [e.g., feed additives (ionophores or inhibitors); secondary plant compounds (tannins, essential oils, saponins)], and breeding strategies (e.g., selecting for low CH4 emitters; selecting for low residual feed intake). Of these options, the direct CH4 inhibitors appear to be the most promising. The largest source of enteric CH4 from the southeastern U.S. is from cow-calf production, representing 71.6% of the total. Furthermore, a 13.6% reduction in enteric CH4 from the southeastern cow-calf herd would offset more emissions than a 100% reduction in the southeastern dairy, stocker, or feedlot sectors. Despite the large gains in emission reductions that could be achieved by focusing on enteric CH4 mitigation strategies from southeastern pastoral systems, there has been relatively little research efforts in this area. For example, there has yet to be any investigation into the mitigation potential of CH4 inhibitors when fed to grazing cattle. This is especially important, because the mitigation potential of inhibitors is likely much greater for grazing than for confined fed cattle. Additionally, there are limited and aging research into grazing management strategies effects on enteric CH4 emissions. There also exists a gap-in-knowledge of how common (e.g., supplementation) or changes in management (e.g., selecting for smaller mature cow sizes) practices could potentially influence enteric CH4 emissions. Future research is still needed to further develop enteric CH4 mitigation strategies, with efforts needed in grazing systems, especially for the southeastern U.S.

Animal growth models as a tool to estimate resilience indicators in Bos indicus and Bos taurus heifers: Selection effects and genetics parameters

The aim of the study is to analyze different growth models for the estimation of resilience indicators and to assess the impacts of selection for yearling weight and breed on the resilience capacity of Nelore, Guzerá and Caracu heifers. Weight records of females (n = 38,937) from birth to the measurement of weight adjusted to 550 days of age (W550) were used to fit growth curves. Next, three resilience indicators were calculated based on weight deviations (residuals): natural logarithm of residual variance (LnVar), lag-one autocorrelation (rauto), and skewness of deviations. The means of the resilience indicators were compared between Nelore selection lines (NeC: selected based on the mean of the contemporary groups for W550; NeS: selected based on the highest selection differential for W550; and NeT: selected based on an index considering highest selection differential for W550 and lower residual feed intake) and breeds (Nelore, Guzerá, and Caracu). Additionally, the heritabilities of the resilience indicators were estimated, as well as the genetic correlations between these indicators and productive traits using blupf90+ program. The results indicated that selection for yearling weight had an impact on the resilience capacity of the animals, with NeS and NeT heifers exhibiting greater weight variability (mean LnVar: 6.09 ± 0.02 and 6.12 ± 0.02, respectively) but also the highest recovery rate (rauto: 0.04 ± 0.01 and 0.04 ± 0.01, respectively). Nelore heifers were the most resilient, with a fast recovery rate (rauto: 0.01 ± 0.05) and there was little influence of the environment on performance (skewness: 0.00 ± 0.01). Caracu was the breed most affected by environmental disturbances (LnVar: 6.46 ± 0.02), with inverse subsequent weight deviations (rauto: -0.12 ± 0.05). The heritabilities of the resilience indicators were low and moderate, with the highest estimates being observed for LnVar in the three breeds (0.05 ± 0.05 to 0.38 ± 0.07). LnVar and skewness showed moderate positive genetic correlations with W550 (0.29 ± 0.18 to 0.55 ± 0.12), while the genetic correlations of rauto with W550 were weak and negative (-0.19 ± 0.17 to -0.28 ± 0.20). Selection for yearling weight influenced the resilience capability to environmental challenges in heifers during the growth phase. The results reinforce the greater adaptation capacity of zebuine breeds (Bos indicus) to tropical environments when compared to taurine breeds (Bos taurus). LnVar showed enough genetic variability to be included in breeding programs for zebu breeds aiming selection for more resilient animals.

Ileal phosphorus digestibility of soybean meal for broiler chickens remains consistent across institutions in a collaborative study regardless of non-phytate phosphorus concentration in the pre-experimental starter diet

The same experimental protocol was used in 4 institutions to evaluate the impact of non-phytate phosphorus (nPP) concentration in the starter diet on regression method-derived ileal P digestibility of soybean meal (SBM) during the subsequent grower phase. A total of 1,536 Ross 308 male broiler chickens on d 0 post hatching were allotted to 2 pre-experimental starter diets that contained 3.5 or 4.5 g nPP/kg (96 replicate cages per diet, 8 birds per cage) for 18 d. Subsequently, 576 birds from each starter diet were selected and allocated to 3 experimental semi-purified grower diets containing 400, 510, or 620 g SBM/kg (32 replicate cages per diet, 6 birds per cage) for 3 d until collection of ileal digesta. Statistical analysis was conducted as a randomized complete block design with the starter period as whole plot and the grower period as split-plot. The only significant 2-way interaction was between grower diet and experimental institution (P < 0.05) on BW gain and gain to feed ratio. The main effect of institution and grower diet impacted (P < 0.05) feed intake, the digestibility of DM, P, and calcium, and disappearance of inositol hexakisphosphate (InsP6) in the grower diets. Birds fed the 3.5 g nPP/kg starter diet had lower (P < 0.05) BW gain and feed intake during the grower period, but presented higher (P < 0.05) digestibility of P and disappearance of InsP6 compared with the birds that were fed the 4.5 g nPP/kg starter diet. Regression method-derived ileal P digestibility of SBM was determined to be 46 or 42% for the respective 3.5 or 4.5 g nPP/kg pre-experimental starter diet and was not affected by the nPP concentration or by the institution. In conclusion, the experimental protocol used in the current study resulted in similar estimates across multiple institutions and is thus endorsed for future application in studies that aim to expand the database of digestible P content in plant source feed ingredients.

Effect of in ovo injection of epigallocatechin-3 gallate and oleuropein on hatching, productive and physiological aspects of broiler chicks exposed to short heat stress

This study was aimed to investigate the influence of in ovo injection (IO) into air cell (AC) or yolk sac (YS) of epigallocatechin-3 gallate (EG) and oleuropein (OL) as antioxidants on hatching, physiological and productive performance of heat-stressed chicks. 840 fertile eggs were chosen for IO on 12th day of incubation. Eggs were divided into 7 groups within 4 replications each as follows: negative control (NC) without IO and other groups involved IO of 100 μl distilled water and 5 mg each of EG and OL in both AC and YS sites of egg. After hatching, chicks were exposed to heat stress for 24 h and raised for 42 d. Compared with NC, the results revealed that main effect of IO with EG and OL increased (p≤0.05) hatchability and decreased deformed chicks and serum levels of glucose, cholesterol, aspartate aminotransferase, corticosterone and heat shock protein 70 with enhancing feed efficiency, superoxide dismutase, glutathione peroxidase and thyroxine in serum or liver. High chick length and relative chick weight with low serum protein carbonyl and feed intake were recorded (p≤0.05) by EG. Low rectal temperature and heterophil to lymphocyte ratio with high body weight were recordered (p≤0.05) by OL. No mainly altered effects between both IO sites on most variables measured. However, there were significant influences among interactive treatments which related to in ovo injected substance in an injection site-dependent manner. It is concluded that improved hatchability, physiological and productive characteristics of heat-stressed chicks were achieved by IO of EG and OL.

Comparing the effect of phytobiotic, coccidiostat, toltrazuril, and vaccine on the prevention and treatment of coccidiosis in broilers

This study compared 2 herbal anticoccidiosis drugs (water-soluble and feed-additive drugs) with monensin coccidiostat, toltrazuril (TTZ, anticoccidiosis drug), and Livacox Q (anticoccidiosis vaccine) in terms of their effects on the prevention and treatment of coccidiosis in broilers. In this study, 280 Ross 308 broiler chickens (a mix of both genders) were used in a completely randomized design with 7 treatments and 5 replications each including 8 chickens per replicate. On d 21 of rearing, all experimental groups, except for the negative control group (NC), were challenged with a mixed suspension of common strains of Eimeria, and the intended indices were assessed, including performance indices, number of oocysts per gram (OPG) of feces, intestinal injuries, and the total number of intestinal bacteria. In addition, the NC and the group receiving the monensin had greater body weight gain (BWG) (P < 0.05). At the end of week 6, the monensin group had the highest feed intake (FI), while the water soluble medicine treatment resulted in the lowest feed intake (P < 0.05). Regarding the lesion scores on day 28, the highest and lowest rates of jejunal injuries were observed in the positive control group (PC), the monensin and vaccine group respectively. The rate of oocysts excretion (oocysts per gram of feces = OPG) on different days was higher in the PC group, and the use of monensin could further reduce excretion compared to the other groups (P > 0.05). Based on a comparison of the population of lactic acid bacteria between the NC and both medicinal plant treated groups, the use of these products could increase the population of these types of bacteria. Moreover, the population of Escherichia coli was less considerable in the NC and herbal powder groups (P < 0.05). Overall, similar to commercial medicines, the herbal medicines used in this project can be effective in the prevention and treatment of coccidiosis and can improve profitability in broiler rearing centers by improving intestinal health.

LUMPY SKIN DISEASE: AN ENCROACHING RISK IN CATTLE FARMING

Lumpy skin disease (LSD) is a vector-borne disease of cattle and water buffalo caused by the lumpy skin disease virus (LSDV) of the Capripoxvirus genus. LSD mainly affects the skin and the lymphatics of animals, and manifests as firm skin nodules, low feed intake, and a drop in milk production. Animal-to-animal contact, blood-feeding insects, animal products, stable flies, and mosquitoes can facilitate the transmission of LSD across herds and borders. The first case of LSD was reported in 1929 in Zambia. It was endemic to Africa until 1985 and later spread to Eastern Europe and Asia. The latest outbreak of LSD was reported in the Asia-Pacific region. At present, biosafety measures (control of animal movement, vectors, and animal products) are being devised by authorities to tackle LSD. Vaccines are also being developed for LSDV in recent decades. Live attenuated vaccines of both homologous and heterologous (of the Capripoxvirus genus) virus strains were utilized. A few side effects of the live vaccines were observed, such as skin nodules, low feed intake, and a drop in milk production. Inactivated LSDV vaccines were produced, showing a higher safety profile than live vaccines, yet offering only partial protection and lacks cross-protection. Recombinant LSDV vaccines are also under development; however, challenges remain in terms of the best vaccine delivery methods and antigen selection from the large poxvirus genome. Overall, mass vaccination with an effective vaccine may play a central role in the control of LSDV.

Microbe-derived Antioxidants Enhance Lipid Synthesis by Regulating the Hepatic AMPKα–SREBP1c Pathway in Weanling Piglets

BackgroundWeaning usually causes low feed intake and weight loss in piglets, which mobilizes lipid to energize. The microbe-derived antioxidants (MAs) exhibit great potential in antioxidation, anti-inflammation, and metabolic regulation. ObjectivesWe aimed to investigate the changes of lipid metabolism postweaning and effects of MA on growth performance and hepatic lipid metabolism in weanling piglets. MethodsIn the first experiment, piglets weaned at 21 d of age were slaughtered on weaning day (d0), 4 (d4), and 14 (d14) postweaning (6 piglets per day). In the second experiment, piglets were divided into 2 groups, receiving MA (MA) and saline gavage (CON), respectively. All piglets were weaned at 21 d of age and 6 piglets from each group were slaughtered at 25 d of age. ResultsIn experiment 1, the serum triglyceride, total cholesterol (TC), and LDL cholesterol on d4 and d14 declined significantly compared with d0 (P < 0.05). The serum leptin on d0 was higher than that on d4 and d14 (P < 0.05). The serum ghrelin kept increasing from d0 to d14 (P < 0.05). The hepatic hormone-sensitive lipase and adipose triglyceride lipase first increased from d0 to d4 and then decreased from d4 to d14 (P < 0.05). In experiment 2, the average daily gain and average daily feed intake from 21 to 25 d of age increased in the MA group compared with the CON group (P < 0.05). The serum TC, hepatic TC, and glucose of MA group showed a significant increase than that of the CON group (P < 0.05). The expression of SCD1, ACAT2, and PPARγ were upregulated in the MA group (P < 0.05). Contrary to the decreased expression of phosphorylation of adenosine 5′-monophosphate-activated protein kinase alfa subunit (Thr172), the nuclear sterol regulatory element–binding protein 1c, fatty acid synthase, and peroxisome proliferator-activated receptor gamma of MA group increased than that of CON group (P < 0.05). ConclusionsWeaning promoted hepatic lipolysis and MA could enhance lipid synthesis by regulating adenosine 5′-monophosphate-activated protein kinase alfa subunit–sterol regulatory element–binding protein 1c pathway, thus improving growth performance of weanling piglets.

Partially replacing plant protein sources with torula yeast in rainbow trout (Oncorhynchus mykiss) feed increases growth and factors related to immune status

AbstractIn this study, the impact of adding 10% or 20% torula yeast (PB TY10 and PB TY20) to a fishmeal‐free diet on digestibility and growth of juvenile rainbow trout was assessed. The yeast diets were compared with a plant‐only diet (PB) and a diet containing 20% fishmeal (FM). The apparent digestibility of dry matter, protein, energy, and ash of yeast in trout (~120 g) were 78.6%, 93.8%, 84.8%, and 48.7%, respectively. All PB diets had higher protein digestibility and PB TY20 had higher ash digestibility than the FM diet. To assess growth, trout (~44 g) were divided into triplicate tanks (30 per tank) and fed one of the four experimental diets for 12 weeks. The PB diet resulted in lower growth and daily feed intake (p &lt; 0.05), but adding yeast significantly improved them. Final weight of PB TY10 did not differ significantly from that of FM. Expression of oclna and cldn15 in the proximal intestine increased in trout fed yeast (p &lt; 0.05). Expression of tlr2, mcsfr, and tnfa, as well as the plasma lysozyme concentration, increased with PB TY20 (p &lt; 0.05). In conclusion, torula yeast has the potential to improve the robustness and growth of rainbow trout in the context of fishmeal‐free diets.

Performance, feed efficiency, feeding behavior, and cortisol concentration of lambs ranked for Residual Feed Intake and Residual Intake and Gain.

This study aimed to evaluate the performance, feed efficiency, feeding behavior, and cortisol concentrations of lambs ranked into different groups of Residual Feed Intake (RFI) and Residual Intake and Gain (RIG). Forty Santa Inês lambs with a mean initial age of 120 ± 30 days and mean initial (IBW) and final body weight (FBW) of 28.9 ± 3.2 and 43.7 ± 3.9 kg, respectively, were used. The animals were fed at an automatic feed and water station (Intergado®) for 60 days and classified at the end of the experiment as low-RFI/RIG, medium-RFI/RIG, and high-RFI/RIG according to RFI and RIG. Performance, feed efficiency measures, ingestive behavior, temperament, and cortisol concentrations were measured, and Pearson's correlation analysis was performed to evaluate the relationship between the variables studied. The variables that differed most between RFI groups were dry matter intake, feed conversion, and feed efficiency, with better values in efficient animals (RFI-). Regarding the RGI groups, the average daily gain of animals classified as RIG- was 19.37% lower than that of animals classified as RIG± and 39.28% lower than that of animals classified as RIG+. Only the hourly feeding rate per day (p = 0.04) differed significantly between RFI and RIG classes, while no differences were observed for the ingestive behavior variables or cortisol. The number of visits to the feed bunk (total, with or without intake) showed no correlation with any performance or efficiency measure. Identifying animals ranked into different RFI and RIG classes shows that more efficient animals have a lower feed intake for the same weight gain and spend less time at the feed bunk.

Different levels of single-strain probiotic (Bacillus subtilis) with proteolytic enzyme (serratiopeptidase) can be used as an alternative to antibiotic growth promoters in broiler

In the current study, the proteolytic enzyme (serratiopeptidase) was used to enhance the efficacy of Bacillus subtilis (B. subtilis) probiotic as a growth promotor in broiler chicken. The effects of serratiopeptidase on the efficacy of different levels of B. subtilis as a growth promotor in broiler chicks were evaluated regarding growth performance traits, villus histomorphometric characterization, and intestinal microbiota count. Day-old broiler chicks (n=120) were allocated into four groups having three replicates/group. In the control group (C), the basal diet was kept without supplementation. In treatment groups (P100, P150, and P200), the basal diet was supplemented with 100, 150, and 200 mg probiotics, respectively besides 30mg proteolytic enzyme in the three treated groups for 4 weeks. The performance parameters were significantly affected by the supplementation of serratiopeptidase to the B. subtilis treatment groups. Feed intake (FI), body weight gain (WG), feed conversion ratio (FCR), and dressing percent were significantly improved in the treatment groups as compared to the control group. Significantly, the lowest feed intake was recorded for the P200 group. The highest body weight gain and dressing percent were recorded for the P200 group. Improved FCR was recorded in the P200 group (1.7) as compared to the control group. The different levels of B. subtilis supplemented with serratiopeptidase revealed significant improvements (P<0.05) in the morphology of the intestine by showing increases in villus height and width and crypt depth of the small intestine. The microbial count revealed that E. coli and salmonella colonies were significantly reduced in the P200 group as compared to the control and other treatment groups. In conclusion, the supplementation of B. subtilis with serratiopeptidase as a growth promoter in broiler chicks significantly improved the overall performance, and intestinal health and reduced microbial load contributing to optimizing the performance of broiler chickens. The greatest improvement was observed in the P200 group fed with B. subtilis as a probiotic and serratiopeptidase enzyme (200mg:30mg).

Effects of feeding silage of beet pulp or maize on the growth performance, meat quality, and production economics of broiler ducks

The present study aimed to compare the growth, meat quality, and production economics of Cherry Valley broiler ducks fed with a commercial diet along with silage from beet pulp or maize. In this study, 180 male Cherry Valley ducks were reared for 49 d. The control group (group C) was fed a commercial diet ad libitum. The experimental groups were fed a restricted amount of commercial diet and ad libitum beet pulp silage (group B) or maize silage (group M). For all groups, the growth performance and meat quality were analyzed, and their production costs were estimated. The beneficial effects of feeding maize silage on the growth rate were observed on d 29 to 49 in group M; moreover, both experimental groups showed lower feed intake than group C (P < 0.05). The feed conversion ratio was lower in the first rearing stage and during the entire experimental period in groups B and M than that in group C. Group M showed a higher European Production Efficiency Factor and European Broiler Index than group C (P < 0.05). The relative weight of the liver was higher in group C than that in the experimental groups (P < 0.05). Group M showed a higher L* value of leg muscles than group C (P < 0.05). Water-holding capacity was higher in leg muscles from ducks fed with silages (P < 0.05). The experimental groups had lower costs of commercial diets. Higher costs were observed for maize silage than for beet pulp silage. Carcass sales yielded the highest profit for group M and the lowest one for group C. Compared with the control group, the silage-fed groups showed a higher estimated profit by PLN 7.94 to 10.68 per duck (P < 0.05). Based on the beneficial production results, notably lower feed conversion ratio, no negative effects on carcass characteristics, and lower production costs, especially maize or even beet pulp silage in broiler duck rearing, could be recommended.

Modeling energy partition patterns of growing pigs fed diets with different net energy levels based on machine learning.

The objectives of this study were to evaluate the energy partition patterns of growing pigs fed diets with different net energy (NE) levels based on machine learning methods, and to develop prediction models for the NE requirement of growing pigs. Twenty-four Duroc × Landrace × Yorkshire crossbred barrows with an initial body weight of 24.90 ± 0.46kg were randomly assigned to 3 dietary treatments, including the low NE group (2,325 kcal/kg), the medium NE group (2,475 kcal/kg), and the high NE group (2,625 kcal/kg). The total feces and urine produced from each pig during each period were collected, to calculate the NE intake, NE retained as protein (NEp), and NE retained as lipid (NEl). A total of 240 sets of data on the energy partition patterns of each pig were collected, 75% of the data in the dataset was randomly selected as the training dataset, and the remaining 25% was set as the testing dataset. Prediction models for the NE requirement of growing pigs were developed using algorithms including multiple linear regression (MR), artificial neural networks (ANN), k-nearest neighbor (KNN), and random forest (RF), and the prediction performance of these models was compared on the testing dataset. The results showed pigs in the low NE group showed a lower average daily gain, lower average daily feed intake, lower NE intake, but greater feed conversion ratio compared to pigs in the high NE group in most growth stages. In addition, pigs in the 3 treatment groups did not show a significant difference in NEp in all growth stages, while pigs in the medium and high NE groups showed greater NEl compared to pig in the low NE group in growth stages from 25 to 55kg (P < 0.05). Among the developed prediction models for NE intake, NEp, and NEl, the ANN models demonstrated the most optimal prediction performance with the smallest root mean square error (RMSE) and the largest R2, while the RF models had the worst prediction performance with the largest RMSE and the smallest R2. In conclusion, diets with varied NE concentrations within a certain range did not affect the NEp of growing pigs, and the models developed with the ANN algorithm could accurately achieve the NE requirement prediction in growing pigs.

Size matters: lower body weight pigs have a different response to immune challenge and amino acids supplementation above the estimated requirement compared to heavy pigs.

The immune response varies between pigs, as not all pigs have the same response to a stressor. This variation may exist between individuals due to body weight (BW) or body composition, which may impact the capacity for coping with an immune challenge (IC). Tryptophan (Trp), threonine (Thr), and methionine (Met) requirements might also play a considerable part in supporting immune system activation while reducing variation between pigs; however, the latter has yet to be reported. This exploratory study investigated the effect of initial BW (light vs. heavy-weight) and supplementation of Trp, Thr, and Met above National Research Council (NRC) requirements on feeding behavior and the coping capacity of growing pigs under an IC. Eighty gilts were categorized into 2 groups according to BW: light-weight (LW, 22.5kg) and heavy-weight pigs (HW, 28.5kg). Both BW groups were group-housed for a 28-d trial in a good or poor sanitary condition (SC). Pigs within a poor SC were orally inoculated with 2 × 109 colony units of Salmonella Typhimurium, and fresh manure from a pig farm was spread on the floor. Pigs within good SC were not inoculated, nor was manure spread. Two diets were provided within each SC: control (CN) or supplemented (AA+) with Trp, Thr, and Met at 120% of NRC recommended levels. A principal component analysis was performed in R, and a feeding behavior index was calculated in SAS. Results showed that LW and HW pigs were clustered separately on day 0, where LW pigs had a positive correlation with body lipid percentage (r = 0.83), and HW pigs had a positive correlation with body protein percentage (r = 0.75). After the IC, the cluster configuration changed, with diets influencing LW more than HW pigs within poor SC. On day 14, LW fed AA + diet in poor SC was clustered separately from LW pigs fed CN diet, whereas LW fed AA + and CN diets in good SC were clustered together. For feeding behavior, in both analyzed periods (period 1: days 7 to 14; period 2: days 21 to 28), LW had lower total feed intake and shorter meals than HW pigs (P < 0.10), independent of the SC. Furthermore, LW pigs fed AA + diet had a more regular feed intake pattern than those fed CN diet, while a more irregular pattern was observed for HW pigs fed AA + diet than CN diet at period 2. These findings suggest that supplementing Trp, Thr, and Met above requirements may be a nutritional strategy for LW pigs under IC by improving feed intake regularity and reducing the probability of being susceptible to IC.

Diagnostic survey of analytical methods used to determine bone mineralization in pigs.

Pigs from 64 commercial sites across 14 production systems in the Midwest United States were evaluated for baseline biological measurements used to determine bone mineralization. There were three pigs selected from each commercial site representing: 1) a clinically normal pig (healthy), 2) a pig with evidence of clinical lameness (lame), and 3) a pig from a hospital pen that was assumed to have recent low feed intake (unhealthy). Pigs ranged in age from nursery to market weight, with the three pigs sampled from each site representing the same age or phase of production. Blood, urine, metacarpal, fibula, 2nd rib, and 10th rib were collected and analyzed. Each bone was measured for density and ash (defatted and non-defatted technique). A bone × pig type interaction (P < 0.001) was observed for defatted and non-defatted bone ash and density. For defatted bone ash, there were no differences among pig types for the fibulas, 2nd rib, and 10th rib (P > 0.10), but metacarpals from healthy pigs had greater (P < 0.05) percentage bone ash compared to unhealthy pigs, with the lame pigs intermediate. For non-defatted bone ash, there were no differences among pig types for metacarpals and fibulas (P > 0.10), but unhealthy pigs had greater (P < 0.05) non-defatted percentage bone ash for 2nd and 10th ribs compared to healthy pigs, with lame pigs intermediate. Healthy and lame pigs had greater (P < 0.05) bone density than unhealthy pigs for metacarpals and fibulas, with no difference observed for ribs (P > 0.10). Healthy pigs had greater (P < 0.05) serum Ca and 25(OH)D3 compared to unhealthy pigs, with lame pigs intermediate. Healthy pigs had greater (P < 0.05) serum P compared to unhealthy and lame pigs, with no differences between the unhealthy and lame pigs. Unhealthy pigs excreted significantly more (P < 0.05) P and creatinine in the urine compared to healthy pigs with lame pigs intermediate. In summary, there are differences in serum Ca, P, and vitamin D among healthy, lame, and unhealthy pigs. Differences in bone mineralization among pig types varied depending on the analytical procedure and bone, with a considerable range in values within pig type across the 14 production systems sampled.

Effect of bone and analytical method on assessment of bone mineralization in response to dietary phosphorus, phytase, and vitamin D in finishing pigs.

A total of 882 pigs (PIC TR4 × [Fast LW × PIC L02]; initially 33.2 ± 0.31kg) were used in a 112-d study to evaluate the effects of different bones and analytical methods on the assessment of bone mineralization response to changes in dietary P, phytase, and vitamin D in growing pigs. Pens of pigs (20 pigs per pen) were randomized to one of five dietary treatments with nine pens per treatment. Dietary treatments were designed to create differences in bone mineralization and included: 1) P at 80% of NRC (2012) standardized total tract digestible (STTD) P requirement, 2) NRC STTD P with no phytase, 3) NRC STTD P with phytase providing an assumed release of 0.14% STTD P from 2,000 FYT/kg, 4) high STTD P (128% of the NRC P) using monocalcium phosphate and phytase, and 5) diet 4 with additional vitamin D3 from 25(OH)D3. On day 112, one pig per pen was euthanized for bone, blood, and urine analysis. Additionally, 11 pigs identified as having poor body condition which indicated a history of low feed intake (unhealthy) were sampled. There were no differences between treatments for final body weight, average daily gain, average daily feed intake, gain to feed, or bone ash measurements (treatment × bone interaction) regardless of bone ash method. The response to treatment for bone density and bone mineral content was dependent upon the bone sampled (density interaction, P = 0.053; mineral interaction, P = 0.078). For 10th rib bone density, pigs fed high levels of P had increased (P < 0.05) bone density compared with pigs fed NRC levels with phytase, with pigs fed deficient P, NRC levels of P with no phytase, and high STTD P with extra 25(OH)D3 intermediate, with no differences for metacarpals, fibulas, or 2nd ribs. Pigs fed extra vitamin D from 25(OH)D3 had increased (P < 0.05) 10th rib bone mineral content compared with pigs fed deficient P and NRC levels of P with phytase, with pigs fed industry P and vitamin D, and NRC P with monocalcium intermediate. Healthy pigs had greater (P < 0.05) serum Ca, P, vitamin D concentrations, and defatted bone ash than those unhealthy, with no difference between the two health statuses for non-defatted bone ash. In summary, differences between bone ash procedures were more apparent than differences between diets. Differences in bone density and mineral content in response to dietary P and vitamin D were most apparent with 10th ribs.

Effect of wet feeding on performance, blood plasma indices, intestinal histomorphometry, and economics of broiler chickens under hot climatic conditions.

The study aimed to investigate the impact of wet feeding on broiler chicken performance and intestinal histomorphometry. The research was conducted at the Veterinary College, Udaipur, India, using 144 commercial broiler chicks from day 1 to 6 weeks of age. The chicks were divided randomly into three experimental groups, each with four replicates comprising 48 birds. The control group (G1) was fed dry; while, group 2 (G2) received wet feed supplemented with 1.00 g water per g of feed and group 3 (G3) received wet feed supplemented with 1.20 g water per g of feed. Results revealed that G3 had significantly superior feed conversion ratios, lower feed intake, and increased body weight and weight gain compared to G2 and G1. Among the three treatment groups, there were no variations in blood plasma indicators. In comparison with G1, duodenum and ileum in G2 had higher villus height. The G3 revealed higher net profit margins and 18.89% saving of feed compared to G1, suggesting that it may be a valuable tool for lowering chicken feed costs.

Parâmetros de postura de codornas de corte reprodutoras submetidas a programas de luz na fase de crescimento

ABSTRACT: When applied at growing phase, lighting program aims to obtain quails with body weight and physiological maturity suitable for the beginning of laying. This study evaluated lighting programs at growing phase on performance, sexual maturity and egg quality of meat quail breeders (Coturnixcoturnix) at laying phase. From 7 to 49 days of age, 300 female meat quails were subjected to three lighting programs (natural, intermittent and continuous), with 5 replicates of 20 birds each. At 49 days of age, 240 quails were transferred to a shed, maintaining the same experimental conditions. Meat quails submitted to continuous and intermittent lighting programs had higher weight of reproductive system and lower ages for first egg production and to reach 50% of egg production (P &lt; 0.05). Quails submitted to natural lighting had lower feed intake from 49 to 70 and 71 to 92 days of age and worse feed conversion up to 114 days of age. Continuous and intermittent lighting programs resulted in more precocious quails compared to natural lighting program. Quails submitted to natural lighting at growing phase presented lower egg production during all periods, not differing for birds submitted to continuous and intermittent programs from the second period (71 to 92 days of age). Intermittent and continuous lighting result in better feed conversion of breeding quails up to 114 days and a higher percentage of laying (49 to 136 days), reducing the number of days to produce the first egg and to reach 50% of laying, in relation to natural lighting.

Effect of Lincomycin and Butyrate Glycerides Supplementation on Performance, Blood Biochemical Constituents, Immune Response and Nutrient Absorption Related Gene Expression in Broilers

Abstract Over 35 days feeding trial, the effects of lincomycin (LM) and butyrate glycerides (BG) supplementation on the growth performance, blood biochemical changes, immune response, and nutrient absorption related gene expression in broiler chickens were evaluated. A total of 480 one- day-old broiler chicks (Ross 308) were allotted into 6 groups (8 replicates/group with 10 birds/replicate). Experimental groups were arranged as follows; control group (A) fed the basal diet (BD); B, C, and D groups were fed the BD supplemented with 350, 500 and 1000 g BG/ton of feed respectively. While group E was fed the BD with 350 + 500 + 1000 g BG/ton of feed during starter, grower, and finisher periods, respectively, and finally group F which received lincomycin (LM) antibiotic (100 g/ton) in overall periods. Broilers that received BG in group E (birds supplemented with BG at 350 + 500 + 1000 g/ton feed) and LM (F) supplements both gained more body weight and weight growth (P&lt;0.05). Lower feed intake and improved fcr were observed in all the experimental groups that received either BG or lm compared to control birds (P&lt;0.05). Lower serum total cholesterol, triglycerides, and glutamic oxaloacetic transaminase (GOT) (P&lt;0.05) were recorded in the lm or BG supplemented birds compared to the control. Higher immune response represented by enhanced antibody titer against H9N1, and newcastle disease (ND) and lower hepatic malondialdehyde (MDA) was obtained in groups D, E and F (P&lt;0.05) compared to the other groups. Higher gene expression of GSH-Px, Glut 2, PepT1 and FAS was obtained in groups D, E and F (P&lt;0.05) compared to the control. Supplemental BG or LM increased the unsaturated fatty acids (oleic, linoleic and linolenic acids) while lowered the palmitic acid contents in breast muscle (P&lt;0.05) compared to control. In conclusion, supplementing broilers’ diets with BG or lincomycin improved their growth performance, immune response and muscle fatty acid profile as well as modulatory role in lipid metabolism. Supplementing starter, grower, and finisher broiler diets with BG at 350 + 500 + 1000 g/ton each may be a useful substitute for lincomycin.

Symbiotic can replace zinc bacitracin in diets for layer-type chicks

Context Antibiotics are being prohibited as additives in poultry diets. Therefore, poultry farmers have been searching for other alternatives, such as symbiotics, to include in broilers and laying hens diets. In contrast, symbiotics have not been tested in laying-type chicks, especially symbiotics composed of three groups of bacteria, yeast and two prebiotics. Aim This study examined the effects of replacing zinc bacitracin with symbiotic supplementation on the performance variables, haematology and blood biochemistry variables, and the weight of the immune and digestive systems in layer-type chicks. Methods A total of 1040 female layer-type chicks from 1 to 5 weeks of age were evaluated in a completely randomised design, four treatments and 10 replicates of 26 birds. The treatments consisted of two basal diets (one composed of corn and soybean meal [control diet] and another similar to the first diet, except with the addition of meat and bone meal [MBM]), and two diets based on MBM: one with 0.05% zinc bacitracin (ZnBc) and another with 0.1% symbiotic. Data were subjected to analysis of variance and means were compared by orthogonal contrasts. Key results MBM provided higher mean bodyweight, weight gain and creatinine levels, but lower liver weight, caecum length and gamma-glutamyl transferase levels than in the birds fed the control diet. From 1 to 14 days, ZnBc provided greater bodyweight and weight gain than MBM. From 1 to 28 and 1 to 35 days, ZnBc resulted in higher bodyweight and weight gain, but lower feed intake and feed conversion ratio than birds fed the MBM diet. ZnBc decreased alkaline phosphatase, and increased creatinine levels and gamma-glutamyl transferase. From 1 to 14 and 1 to 21 days, 0.1% symbiotic provided a better feed conversion ratio than in the birds fed the ZnBc diet. The 0.1% symbiotic supplementation resulted in lower liver and fabricius bursa weights, higher mean alkaline phosphatase, and lower globulin, gamma-glutamyl transferase and aspartate transferase levels than ZnBc. Conclusion The symbiotic is effective for female layer type-chicks, fulfilling the purpose of replacing ZnBc. Implications Symbiotics used in chicks’ diets from the first day of life can replace antibiotics to maintain physiological homeostasis and protect them from possible stress situations.

Suplementação dietética de glutamina e ácido glutâmico sobre o desempenho, morfometria intestinal e características de carcaça de codornas de corte

ABSTRACT: This study evaluated the effect of dietary supplementation with glutamine and glutamic acid (Gln+Glu) on performance, intestinal morphometry, and carcass characteristics of broiler quails. Eight hundred birds were used, distributed in an entirely randomized design with 20 birds per experimental unit, and given five treatments (0.0; 0.2; 0.4; 0.6; and 0.8% Gln+Glu supplementation) with eight replicates. At 1-21 days of age, lower (P &lt; 0.05) feed intake at 0.6 and 0.8% Gln+Glu supplementation and lower weight gain at 0.8% Gln+Glu supplementation compared to the control treatment were observed. By regression analysis, excluding the control treatment, there was an increasing linear effect (P &lt; 0.05) for feed intake at 22 to 42 days of age. For intestinal morphometry, Gln+Glu supplementation only favored the villus development of the ileum (P &lt; 0.05), giving it greater height at 0.2, 0.6, and 0.8% supplementation. Carcass characteristics, cuts, and edible viscera of the birds at 42 days were not affected (P &gt; 0.05) by Gln+Glu supplementation levels. Thus, the glutamine and glutamic acid supplementation affected the performance and intestinal morphology of 21-d-old quails, decreasing feed intake and weight gain associated with the improvement of ileum morphology; conversely, performance and carcass characteristics at 42 days were not affected by amino acid supplementation.