Factorial Arrangement Of Treatments Research Articles

Effects of porcine somatotropin administration on the responses to dietary lysine and a near-ideal blend of amino acids on the amino acid composition of whole-body protein and amino acid accretion rate in growing pigs.

An experiment was conducted to assess the effects of porcine somatotropin (pST) on the responses to a near-ideal blend of AA on the AA composition of empty, whole empty body (WEB) protein and WEB essential AA accretion rate in pigs from 22 to 60kg BW. Forty Hampshire × Yorkshire gilts were individually penned and assigned to a 4 × 2 factorial arrangement of treatments consisting of 4 diets with and without pST injection. A fortified corn-soybean meal basal diet was formulated to contain 1.50% total Lys with Thr, Met, and Trp added to obtain a near-ideal blend of these AA relative to Lys. In 3 additional diets, Lys was reduced to 1.25, 1.00, and 0.75% by diluting the basal diet with cornstarch, cellulose, and sand such that the diets also contained the same ratios of AA. Pigs that received pST were administered a daily i.m. injection of 2mg of pST. At 60kg BW, the WEB (carcass, head, viscera, blood, nails, and hair) was ground and analyzed for proximate and AA composition. Administration of pST increased (P < 0.001) accretion rates of WEB protein and essential AA. Increasing dietary essential AA increased (quadratic, P < 0.03) accretion rate of WEB protein, His, Leu, Trp, and Val in pST-treated pigs, but not in untreated pigs. Lysine composition in the accreted WEB protein was not affected (P > 0.05) by dietary Lys. The efficiency of Lys utilization for WEB Lys accretion was linearly affected (P < 0.01) by dietary Lys. These results indicated that the dietary Lys needed to achieve maximum WEB Lys accretion is markedly increased by pST administration.

46 Efficacy of a biosynthetic 6-phytase depending on basal diet composition in weaning piglets

Abstract A study was conducted to evaluate the efficacy of biosynthetic 6-phytase depending on basal diet composition on growth performance and bone mineralization in weaned piglets. A total of 192 male weaned piglets with initial body weight (BW) of 8.47 ± 0.70 kg (at 33 d of age), distributed in a randomized block design with a 3 x 2 factorial arrangement of treatments. Three basal diet compositions (BD1: adequate in energy and nutrients with phytic P (PP) = 0.23%; BD2 = BD1 minus 70 kcal NE/kg, 0.15% points similarly in digestible P (dig.P) and calcium (Ca) with PP = 0.23%; and BD3 = BD1 minus 70 kcal NE/kg, 0.15% points similarly in dig.P and Ca with PP = 0.29%) and two phytase inclusion (Rovabio PhyPlus; 0 or 1,000 FTU/kg diet) were used in this experiment. The corn-soybean meal-based diets were fed into 2 phases: post-weaning 1 and 2 from 1 to 14 and 15 to 42 d, respectively. Body weight and feed intake were measured at the end of each phase, and average daily gain (ADG), average daily feed intake (ADFI) and feed to gain ratio (F:G) were calculated for the whole experimental period. At the end of the study, all piglets from 16 pens per treatment (n = 32 piglets/treatment) were euthanized and the metacarpi bones were collected for bone ash and P content determinations. There were significant interactions (P &amp;lt; 0.05) between basal diet composition and phytase inclusion on final BW, ADG, F:G, ash and P contents in metacarpal bones of piglets. Compared with unsupplemented diet, the addition of phytase in both nutrient-reduced diets improved final BW, ADG, F:G, ash and P contents in bones, while no improvements (P &amp;gt; 0.05) were observed on these parameters by phytase supplementation in adequate-nutrient diet. There was no significant interaction (P &amp;gt; 0.05) between basal diet composition and phytase inclusion on ADFI. Reduction in nutrients without (BD2) or with increasing dietary PP level (BD3) decreased (P = 0.004) ADFI, compared with adequate-nutrient diet. However, addition of biosynthetic 6-phytase improved (P = 0.03) ADFI by 5.3% compared with unsupplemented diets. The results of the present study highlight that adding biosynthetic 6-phytase to low energy and nutrient diets was more effective compared with the effects in an adequate-nutrient diet in weaned piglets.

287 The effect of cooling pad and Moringa oleifera on lactating sows under heat stress

Abstract Lactating sows and their litters are particularly vulnerable to heat stress (HS). HS decreases sow fertility, feed intake, milk production, and litter growth. Approaches are needed to mitigate the negative effects of HS on animal welfare and reduce oxidative damage to tissues associated with HS. Recently, electronic cooling pad (ECP) were designed to remove heat through conductive cooling. The objective of this study was to test the efficacy of ECP and feeding an antioxidant, Moringa oleifera (4% of the diet, M), to sows from late gestation to weaning on their welfare and production performance. A study was conducted using a 2 by 2 factorial arrangements of treatments with mixed parity Yorkshire x Landrace sows (n = 48) mated to Duroc sires. The sows were exposed to moderate HS conditions from gestation d 100 to d 21 of lactation (weaning). To achieve moderate HS analogous to a summer day, farrowing room temperature was increased incrementally from 800 to 1100 h to 32º C and slowly decreased to 26 ºC from 1700 to 2000 h. Sows were limit-fed their specific diets during gestation (1.36 kg 2X/d) and fed for ad-libitum feed intake post farrowing. Treatments included HS+control corn-soy meal diet (CS), HS+M, ECP+CS, ECP+M (n = 12/treatment). Sow RR and RT were measured four times daily (0600, 1300, 1600, 1900 h) and sow feed intake during lactation was measured along with body weight (BW) change from farrowing to weaning. Birth litter size was determined, and growth of standardized litters (n = 13 piglets/sow) was measured. Milk was collected during active farrowing (d 0) and on d 3 and d 14 post-farrowing and analyzed for macronutrient content. The use of ECP decreased lactating sow RR (Lsmeans HS = 66.5 bpm, ECP = 28.2 bpm, P ≤ 0.0001), RT (Lsmeans HS = 39.2 ºC, ECP = 38.8 ºC, P = 0.003), and lactation BW loss (Lsmeans HS = -21.67, ECP = -5.1 kg P = 0.002). ECP by time-of-day interactions (P &amp;lt; 0.01) existed for RR and RT with ECP having a greater impact from 1300 to 1900 h than at 0600 h. ECP increased lactation feed intake (P &amp;lt; 0.02). An ECP by diet interaction (P = 0.0004) indicated ECP increased lactation feed intake for the sows fed the CS diet (6.48 kg/d vs 4.42 kg/d, P = 0.0004) but did not affect feed intake of sows fed the M diet. Treatment did not affect litter weaning weight (P = 0.14). M increased percent fat in milk (Lsmeans M = 12.28, CS = 11.06, P = 0.05) across all days of lactation. The reduction in sow RR and RT combined with increased feed intake and decreased loss of BW during lactation indicate that ECP improved sow wellbeing in the HS environment. Neither cooling nor M affected litter growth, despite increased fat content of milk of M supplemented sows and increased feed intake of ECP-CS sows.

12 Effects of increasing SID lysine (Lys) and metabolizable energy (ME) levels of lactation diets fed to young and multiparous sows

Abstract Providing insufficient lysine to lactating sows can reduce piglet performance and subsequent farrowing performance of sows. Current SID lysine and ME recommendations for lactating sows are approximately 60 g/d and 20 Mcal/d, respectively. Because of variations in feed intake during lactation, a portion of sows do not meet recommended Lys intake levels. There is no clear understanding of the Lys:Calorie ratio when dietary energy is increased in the summer to ensure adequate caloric intake. The objective was to evaluate a potential advantage of feeding diets with SID Lys and energy levels that exceed recommendations to lactating sows. A total of 855 sows were fed during the summer of 2023 in 2×2 factorial arrangement of treatments in a randomized complete block design. Factors included SID lysine [low (0.85%) vs high (1.11%)] and ME [low (3,183 kcal/kg) vs high (3,334 kcal/kg)]. Diets were formulated to deliver 61 g of SID lysine at 0.85% inclusion to sows that consume 7.2 kg of complete feed per day. Primary outcome variables were sow body composition, lactation average daily feed intake (ADFI), average piglet weaning weight, and pre-wean mortality. There were no interactions between treatments (P &amp;gt; 0.05). SID Lys intake was 61.2 and 76.4 g/d for low and high Lys, respectively (P &amp;lt; 0.01). ME intake was 21.9 and 23.4 Mcal/d for low and high energy, respectively (P &amp;lt; 0.01). Contrary to expectations, ADFI did not differ (P = 0.25) between sows fed the low- and high-energy diets, however, sows fed low lysine consumed 0.29 kg more feed (P &amp;lt; 0.01) per day compared with sows fed high lysine. There were no differences (P ≥ 0.70) in the number of piglets born alive for any treatment group. Sows fed high energy had 0.27 fewer (P &amp;lt; 0.01) still-born piglets per litter compared with sows fed low energy. Pre-wean mortality was also reduced (P = 0.05) by 0.76 percentage units in litters of sows fed the high-energy diet compared with litters of sows fed the low energy. Lysine level had no effects on farrowing and litter performance (P &amp;gt; 0.05). Litters from sows fed the high-energy diet gained 1.2 kg more (P = 0.05) body weight during lactation and tended to result in litter-weaned weights that were 1.5 kg heavier (P = 0.06) than litters from sows fed the low-energy diet. Feeding a diet with a greater lysine concentration during lactation reduced feed intake but did not affect litter performance. In contrast, increasing dietary energy immediately before farrowing and during lactation did not affect sow feed intake but reduced pre-wean mortality and resulted in fewer still-born piglets, greater litter gains, and heavier litter weaning weights.

165 Comparing corn earlage to a blend of corn silage and grain when fed at two different inclusions for finishing cattle

Abstract An experiment was conducted to evaluate the effects of feeding earlage as the sole source of roughage and grain in a finishing diet when compared with corn silage plus grain at equal forage NDF inclusions in the diet. Crossbred yearling steers [n = 216; initial body weight (BW) = 471 ± 14.1kg] were fed one of 4 experimental diets in a 2 × 2 factorial treatment arrangement with roughage type and forage inclusion being the 2 factors. Treatment diets were formulated for earlage to provide all the grain the diet (74%) which provided 14.8% forage and was compared with 29.6% corn silage and 44.4% corn as a 50:50 blend of dry rolled corn (DRC) and high moisture corn (HMC). The other two diets were formulated for corn silage to provide a standard roughage inclusion for finishing diets (i.e., corn silage at 15% to supply 7.5% forage in the diet). To match 7.5% roughage with earlage providing all the roughage, another diet included earlage at 37%, with an additional 37% corn included as the 50:50 blend of HMC and DRC. All diets included 20% wet distiller’s grains (WDGS) and 6% supplement. The two inclusions of forage were either 7.5 or 14.8% forage as either earlage or corn silage. Earlage was assumed to provide 20% forage and corn silage to provide 50% forage, on a DM basis. Cattle were stratified into 3 BW blocks, then assigned randomly assigned to pens within block, and treatment assigned randomly to pens. A total of 24 pens containing 9 steers in each were used with pen as the experimental unit. Feeding performance, carcass characteristics and liver abscess prevalence were evaluated using the MIXED procedure of SAS with BW block and treatment being fixed effects. No interactions between roughage type or forage inclusion were observed for performance or carcass traits (P &amp;gt; 0.13) except for marbling or liver abscesses (P &amp;lt; 0.09). When cattle were fed a diet with corn silage as the roughage source, greater dry matter intakes (DMI) and average daily gain (ADG) were observed (P ≤ 0.01), but feed efficiency was not significantly different (P = 0.35). However, when evaluating effects of NDF inclusion, cattle fed 7.5% forage in the diet were 6.8% more efficient than cattle fed 14.8% forage and tended to have greater gain (P = 0.10), but no significant differences were observed for intake (P = 0.11). These data suggest that cattle fed earlage will eat and gain less than cattle fed a blend of corn silage and grain when estimated forage is equivalent, and when earlage is fed as the sole source of grain, cattle will be less efficient than when conventional roughage inclusions are fed.

160 Awardee Talk: Impact of indigestible protein on coccidiosis and meat and bone meal autoclaving time-related reduction in amino acid digestibility for broiler chickens and growing pigs

Abstract Meat and bone meal (MBM) is a byproduct of the processing of livestock in the rendering industry. Because of its highly digestible protein and balanced amino acid profile, MBM is a valuable protein source in swine and poultry diets. Rendering may reduce amino acid digestibility of MBM because of heat damage to MBM, and the effect of heat damage on amino acid digestibility in MBM may be different between broiler chickens and growing pigs. For this reason, the objective of this study was to determine the effect of autoclaving on standardized ileal digestibility (SID) of amino acid in MBM fed to broiler chickens and growing pigs. Meat and bone meal from the same batch was autoclaved at 134°C for 0, 30, 60, 90, 120, 150, or 180 min, generating 7 samples. Eight experimental diets consisted of 7 diets containing each MBM sample as a sole source of nitrogen and a nitrogen-free diet. In Exp. 1, male broiler chickens [n = 656; initial body weight (BW) = 777 ± 69 g] at d 18 post hatching were assigned to the 8 diets in a randomized complete block design with BW as a blocking factor. On d 23, birds were euthanized by CO2 asphyxiation and dissected for the collection of ileal digesta. In Exp. 2, barrows (n = 16; initial BW = 25.7 ± 1.0 kg) surgically fitted with T-cannulas at the distal ileum were allotted to duplicate 8 × 4 incomplete Latin square design with the 8 diets and 4 periods. Each experimental period consisted of 5-d adaptation and 2-d ileal digesta collection periods. Data for Exp. 1 and 2 were pooled as a 2 × 7 factorial treatment arrangement with the effects of species (i.e., broiler chickens or pigs) and autoclaving time (i.e., 0 to 180 min). The basal endogenous losses of most AA in growing pigs were greater (P &amp;lt; 0.05) compared with broiler chickens. The SID of nitrogen and tryptophan in MBM linearly decreased (P &amp;lt; 0.05) in both species with increasing autoclaving time. An interaction between species and quadratic effect of autoclaving time was observed (P &amp;lt; 0.05) in SID of arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, and valine in MBM. Specifically, the SID of lysine both linearly and quadratically decreased (P &amp;lt; 0.05) in broiler chickens (85.0 to 56.0%), whereas the SID of lysine only linearly decreased (P &amp;lt; 0.05) in growing pigs (79.5 to 46.7%) as autoclaving time increased. In conclusion, given the species differences in amino acid digestibility response to the severity of heat damage, target species should be considered when using amino acid digestibility value of MBM in diet formulation.

PSVI-1 Backgrounding and finishing systems for cattle fed corn silages and corn grains differing in amylase expression

Abstract Amylase is a key enzyme involved in the hydrolysis of starch, which typically constitutes the predominant source of energy in feedlot cattle diets. Performance of cattle during the backgrounding phase can influence performance during the subsequent finishing phase. Our objective was to assess growth performance of backgrounding steers fed diets that contained combinations of corn silage (S) and steam-flaked corn (G) from hybrids with high amylase expression (Enogen corn; E; Syngenta Seeds, LLC) or common corn hybrid (C), as well as subsequent finishing performance, carcass characteristics, and liver abscess incidence when fed G produced from the same hybrids. Crossbred steers (n = 911; 306 ± 8 kg initial body weight) were assigned randomly to one of four backgrounding treatments with 12 replicates in a randomized complete block experiment using a factorial treatment arrangement. Factor 1 consisted of two corn silage hybrids (ES or CS), and factor 2 consisted of two SFC hybrids (EG or CG). In the subsequent finishing phase, animals were assigned to one of two treatments consisting of two grain hybrids (EG or CG) with 24 replicates per treatment. Backgrounding diets (dry basis) contained 20.1% flaked corn and 41.6% corn silage, and finishing diets contained 81.5% flaked corn with triticale silage as a common roughage source. There was no three-way interaction for measures of interest, and no differences among treatment combinations with respect to average daily gain (ADG) or incidence of abscessed livers (P &amp;gt; 0.10). Steers fed CG during the backgrounding phase ate more than steers fed EG (P = 0.04), thus leading to improved overall efficiency of steers fed EG in the backgrounding phase compared with their counterparts fed CG (P &amp;lt; 0.01; Table 1). Overall efficiency tended to be greater for cattle fed CG during the finishing phase (P = 0.06) compared with cattle fed EG during the finishing phase. There was a tendency for interaction between G fed in the backgrounding and G fed in the finishing phase for hot carcass weight (P = 0.07), such that steers fed the same hybrid in both phases had greater carcass weight compared with those fed different hybrids in the backgrounding and finishing phases. Type of grain fed in the backgrounding and finishing phases, but not silage, impacted overall system efficiency.

87 Evaluating the effects of an amino acid-formulated diet on ruminal fermentation in vitro

Abstract The objective was to determine the effect of an amino acid-formulated diet on ruminal fermentation in vitro. While most amino acid-formulated diets focus on improving the amino acid composition of rumen undegradable protein, additional benefits to microbial fermentation within the rumen are unknown. The experiment was a completely randomized design with a factorial treatment arrangement (2 donor diets and 2 substrates). Four ruminally cannulated steers were fed one of two donor diets: control (CON; 55% dry rolled corn, 20% corn silage, 15% dry distiller’s grain, and 10% supplement) and amino acid-formulated (AAF; 51% dry rolled corn, 15% corn silage, 14% dry distillers grain, 10% heat-treated soybean meal, and 10% supplement). After a 30-d diet adaptation period, rumen fluid was collected and pooled by donor diet for the in vitro fermentation. Additionally, two different substrates were used to represent each donor diet. Flasks contained 2.5 g dry matter (DM) of substrate and 150 mL of rumen fluid mixture (2 McDougall’s buffer:1 rumen fluid). Treatments were evaluated in triplicate flasks in two replicated runs for a total of six observations per treatment. Four sealed Ankom F57 bags were filled with 0.25 g DM of substrate each to facilitate measuring in vitro DM disappearance (IVDMD). Flasks were incubated at 39°C with sample aliquots collected at h 0, 4, 8, 12, and 24 to determine pH, ammonia, and volatile fatty acids (VFA). Data were analyzed using the MIXED procedure of SAS 9.4 with a repeated measures analysis. Ammonia, pH, and VFA were analyzed with effects of donor diet, substrate, time, and all interactions. A treatment by hour interaction was detected (P &amp;lt; 0.01) for pH; fluid from steers fed CON was greater than AAF at h 4, 8, 12, and 24. A treatment by hour interaction was also detected (P = 0.02) for ammonia; fluid from steers fed CON was greater than AAF at h 24, but was not different at other time points. Total VFA was affected by hour (P &amp;lt; 0.01) as it increased over time, but substrate did not have an effect (P = 0.21). A treatment by hour interaction (P = 0.06) tended to be observed for molar proportions of acetate as AAF and CON were similar at h 0 but AAF was increasing greater than CON over time. A treatment by hour interaction was observed (P = 0.01) for molar proportions of propionate; at h 4 at 8, CON was greater than AAF. No effect (P ≥ 0.32) of donor diet, substrate or their interaction were observed on IVDMD. Overall, an amino acid-formulated diet for cannulated steers did impact ruminal fermentation in vitro, mostly altering molar proportions of volatile fatty acids and ammonia release from protein degradation.

Effect of combining the methanogenesis inhibitor 3-nitrooxypropanol and cottonseeds on methane emissions, feed intake, and milk production of grazing dairy cows

No single enteric CH4 mitigating strategy has been consistently effective or is readily applicable to ruminants in grassland systems. When CH4 mitigating strategies are effective under grazing conditions, mitigation is mild to moderate at best. A study was conducted to evaluate the potential of combining two CH4 mitigation strategies deemed feasible to apply in grazing dairy cows, the methanogenesis inhibitor 3-nitrooxypropanol additive (3-NOP) and cottonseed supplementation (CTS), seeking to enhance their individual CH4 mitigating potential. Forty-eight dairy cows were evaluated in a continuous grazing study and supplemented with either a starch-based concentrate (STA) or one that contained cottonseeds (1.75 kg DM/d; CTS), and with either 19 g/d of 10% 3-NOP (Bovaer®) or the additive’s carrier (placebo; PBO), in a 2×2 factorial arrangement of treatments. Treatments were supplied mixed with a concentrate supplement (5 kg/d as fed) offered in two equal rations at milking. Methane emissions were measured on week 4 and 8 using the sulphur hexafluoride tracer gas technique over a 5-d period. The 3-NOP and CTS treatments tended to interact on absolute CH4 such that 3-NOP decreased CH4 by 13.4% with STA, but there was no mitigation with 3-NOP and CTS. Treatment interactions were also obtained for CH4 yield, where 3-NOP tended to decrease CH4 when supplied with STA, and tended to increase it with CTS. The increase in CH4 yield with the CTS diet was driven by a numerical decrease in DM intake. Methane intensity was not affected by the 3-NOP or CTS treatments. Total volatile fatty acids in ruminal fluid were not affected by 3-NOP supplementation, but a reduction in acetate and increase in propionate proportion occurred, resulting in decreased acetate: propionate. The 3-NOP additive decreased grass intake, however, energy corrected milk yield and milk composition were largely unaffected. Milk urea increased with 3-NOP supplementation. Combining twice daily supplementation of 3-NOP and CTS did not enhance their CH4 mitigation potential when fed to grazing dairy cows. The relatively low inhibition of CH4 production by 3-NOP compared to studies with total mixed rations may result from the mode of delivery (pulse dosed twice daily) and time gap caused by experimental handling and moving of animals to pasture after 3-NOP supplementation in the milking parlour, which could have impaired the synchrony between the additive presence in the rumen and grass intake in paddocks.

Effects of 3-nitrooxypropanol (3-NOP, Bovaer®10) and whole cottonseed on milk production and enteric methane emissions from dairy cows under Swiss management conditions

The objective of this study was to determine the potential effect and interaction of 3- nitrooxypropanol (3-NOP; Bovaer®) and whole cottonseed (WCS) on lactational performance, and enteric methane (CH4) emission of dairy cows. A total of 16 multiparous cows, including 8 Holstein Friesian (HF) and 8 Brown Swiss (BS) [224 ± 36 d in milk, 26 ± 3.7 kg milk yield], were used in a split-plot design, where the main plot was the breed of cows. Within each subplot, cows were randomly assigned to a treatment sequence in a replicated 4 × 4 Latin Square design with 2 × 2 factorial arrangements of treatments with 4, 24-d periods. The experimental treatments were: 1) Control (basal TMR), 2) 3-NOP (60 mg/kg TMR DM), 3) WCS (5% TMR DM), and 4) 3-NOP + WCS. The treatment diets were balanced for ether extract, crude protein, and NDF contents (4%, 16%, and 43% of TMR DM, respectively). The basal diets were fed twice daily at 0800 and 1800 h. Dry matter intake (DMI) and milk yield were measured daily, and enteric gas emissions were measured (using the GreenFeed system) during the last 3 d of each 24-d experimental period when animals were housed in tie stalls. There was no difference in DMI on treatment level, whereas the WCS treatment increased ECM yield and milk fat yield. There was no interaction of 3-NOP and WCS for any of the enteric gas emission parameters, but 3-NOP decreased CH4 production (g/d), CH4 yield (g/kg DMI), and CH4 intensity (g/kg ECM) by 13, 14 and 13%, respectively. Further, an unexpected interaction of breed by 3-NOP was observed for different enteric CH4 emission metrics: HF cows had a greater CH4 mitigation effect compared with BS cows for CH4 production (g/d; 18 vs. 8%), CH4 intensity (g/kg MY; 19% vs. 3%) and CH4 intensity (g/kg ECM; 19 vs. 4%). Hydrogen production was increased by 2.85 folds in HF and 1.53 folds in BS cows receiving 3-NOP. Further, there was a 3-NOP ' Time interaction for both breeds. In BS cows, 3-NOP tended to reduce CH4 production by 18% at around 4 h after morning feeding but no effect was observed at other time points. In HF cows, the greatest mitigation effect of 3-NOP (29.6%) was observed immediately after morning feeding and it persisted at around 23% to 26% for 10 h until the second feed provision, and 3 h thereafter, in the evening. In conclusion, supplementing 3-NOP at 60 mg/kg DM to a high fiber diet resulted in 18 to 19% reduction in enteric CH4 emission in Swiss Holstein Friesian cows. The lower response to 3-NOP by BS cows was unexpected and has not been observed in other studies. These results should be interpreted with caution due to low number of cows per breed. Lastly, supplementing WCS at 5% of DM improved ECM and milk fat yield but did not enhance CH4 inhibition effect of 3-NOP of dairy cows.

Gastrointestinal response to the early administration of antimicrobial agents in growing turkeys infected with Escherichia coli

This study investigated the effects of the early administration of enrofloxacin (E) or doxycycline (D) for the first 5 consecutive days of life, or the continuous administration of the coccidiostat monensin (M) throughout the rearing period on gastrointestinal function in turkeys infected with avian pathogenic Escherichia coli (APEC) in an early or later stage of rearing. Experiment 1 lasted 21 d, and turkeys in groups E, D, and M were infected with APEC on d 15. Experiment 2 lasted 56 d, and it had a factorial arrangement of treatments where birds in groups E, D, and M were infected with APEC on d 15 or d 50. In both experiments, control groups (C) consisted of infected and uninfected birds without antibiotic or coccidiostat administration. On d 21 (Experiment 1) and d 56 (Experiment 2), 8 birds from each subgroup were killed, and the ileal and cecal digesta were sampled to analyze the activity of bacterial enzymes and the concentrations of short-chain fatty acids (SCFA). The experimental treatments did not affect the final body weight or body weight gain of birds. Both experiments demonstrated that APEC contributed to an increase in ammonia levels of the cecal digesta (means from 2 experiments: 0.311 vs. 0.225 mg/g in uninfected birds) and ileal pH (6.79 vs. 6.00) and viscosity (2.43 vs. 1.83 mPa⋅s). Moreover, the E. coli challenge enhanced the extracellular activity of several cecal bacterial enzymes, especially in older turkeys infected with APEC in a later stage of life. The continuous administration of monensin throughout the rearing period resulted in a weaker gastrointestinal response in older birds, compared with the other 2 antibiotics administered for the first 5 d of life. The results of the study are inconclusive as both desirable and undesirable effects of preventive early short-term antibiotic therapy were observed in turkeys, including normalization of ileal viscosity and cecal ammonia concentration (positive effect), and disruption in cecal SCFA production (negative effect).

Effect of irrigation interval on water consumption, water use efficiency, growth and yield of rice in two area of Sulaymani governorate

The different of locations (which has different in soil and water quality) and irrigation interval has an important influence on water use efficiency and rice crop yield to determine the effects of different irrigation water management on yield and water use efficiency of rice (Oryza sativa L.) in two different locations soils and water quality, the two-field experiments were conducted on silty clay loam and silty clay soil, in earthen and western Suleimani province of Kurdistan-Iraq The experiment was a complete randomized design with a factorial arrangement of treatments with three replications. The main treatment was Irrigation interval (full irrigation (D1), one day (D2), two days (D3), and three-day irrigation (D4)) The depth irrigation were 939, 811, 726 and 681 mm, respectively for qaragol, while for chalax the depth irrigation were 980, 821, 749 and 722 mm respectively. The sub- treatment was, Qaragol (L1) and chalax (L2) locations respectively, the results showed that the effects of irrigation interval and locations and their interaction on rice grain yield and water use efficiency were significant at 5%. The highest grain yield (6263 Kg ha-1) belonged to the (L2) location and the lowest grain yield (5823.3 Kg ha-1) belonged to (L1) in Qaragol location. And the highest water use efficiency 8.547 in Qaragol location belongs to the (D4) and the lowest water use efficiency 6.387 increasing of water use efficiency (D1 vs. D4) caused a 29.5% improvement in water use efficiency. The irrigation schedule can be planned to save water without considerable reduction of crop yield

Influence of low-level tannin supplementation on comparative growth performance of Holstein and Angus × Holstein cross calf-fed concentrate-based finishing diets for 328 d.

The objective of the current study was to evaluate the effects of tannin and monensin supplementation in feedlot diets and breed (Holstein vs. Angus × Holstein) on growth performance, energetic efficiency, and carcass characteristics. Eighty purebred Holstein calves (HOL; initial body weight (BW) = 130 ± 5kg) and 80 Angus × Holstein calves (AXH; initial BW = 129 ± 6kg) were blocked by initial BW and randomly assigned to 40 pens. Dietary treatments consisted of a steam-flaked corn-based diet supplemented with (1) no feed additive (CON); (2) 30mg of monensin/kg of dry matter (DM; MON; Rumensin 90, Elanco, Greenfield, IN); (3) 1.5g tannin)/kg of DM (TAN; ByPro, 70% condensed tannin, SilvaFeed, Indunor, S.A., Buenos Aires, Argentina); (4) M + T, the combination of MON plus TAN dietary treatments. Data were analyzed as a randomized complete block in a 2 × 4 factorial arrangement of treatments, using pens as experimental units. There were no interactions (P > 0.05) between feed additives and breed. Supplemental MON increased (P ≤ 0.04) initial 112-d BW and gain efficiency. However, there were no dietary treatment effects (P > 0.10) on overall growth performance. Monensin supplementation decreased (P = 0.04) minimum daily ruminal temperature compared with other dietary treatments during July, but TAN did not affect ruminal temperature. Holstein steers had greater (P = 0.04) overall DM intake compared with AXH, with no difference (P = 0.19) in overall ADG, leading to increased (P < 0.01) gain efficiency for AXH compared with HOL. Dietary net energy for maintenance and gain, based on growth performance, were greater (P ≤ 0.01) for AXH vs HOL. Compared with HOL, AXH steers had greater (P ≤ 0.01) carcass weight, dressing percentage, kidney, pelvic, and heart fat, 12th rib fat thickness, longissimus area, and preliminary yield grade. Holstein steers had lower (P ≤ 0.04) minimum average ruminal temperature during June compared with AXH, with no differences (P ≥ 0.14) between breeds during July or August. Results indicate that feed additives did not appreciably affect steer growth performance and carcass characteristics, but crossbred AXH steers had greater growth performance, efficiency of dietary energy utilization, and carcass quality measures compared with HOL. This study observed a reduction (4.7%) in maintenance energy expenditure in AXH compared with HOL, implying in maintenance energy coefficient of 0.086 vs 0.082 for HOL and AXH, respectively.

Feeding strategy and prebiotic supplementation: Effects on immune responses and gut health in the early life stage of broiler chickens

This study aimed to investigate the effects of early or late feeding strategies and prebiotic, on immune responses and gut health during the early life stage of broiler chickens. A total of 240 day-old male broiler chicks were used in a 2 × 3 factorial arrangement of treatments that comprised 2 feeding strategies (early or late) and 3 levels of prebiotic (0, recommended dosage or three times the recommended dosage) in a completely randomized design with 4 pen replicates and 10 broilers per each. Compared to broiler chickens that had early access to feed, delayed access to feed resulted in an increased population of Escherichia coli and a decreased population of Lactobacillus spp. and Bifidobacterium spp. in the ileum (P < 0.05). Additionally, delayed access to feed led to a decrease in villus height, crypt depth, villus height: villus width ratio, goblet cell density, and mucin 2 gene expression in the ileum (P < 0.05). The supplementation of prebiotics in both the late and early feeding strategy groups resulted in increased villus height, crypt depth, goblet cell density, mucin 2 gene expression, and antibodies against Infectious Bursal Disease (IBD). Additionally, it led to an improvement in the foot web thickness index (P < 0.05). Furthermore, it resulted in a significant decrease in the population of Escherichia coli, while the populations of Lactobacillus spp. and Bifidobacterium spp. in the ileum were significantly increased (P < 0.05). Therefore, this study suggests that incorporating prebiotics in the starter diet can effectively enhance immune responses and promote gut health, regardless of the feeding strategy (early or late). In conclusion, this study demonstrates the potential benefits of incorporating prebiotics into poultry diets to alleviate the detrimental effects of delayed access to feed and improve gut health during the early life stage of broiler chickens.

Age-dependent development trends (models) of intestinal significant microbiota species and Eimeria oocysts in coccidia-challenged broiler chickens as affected by dietary encapsulated organic acids and anticoccidial drugs

ABSTRACT The study was conducted to investigate the effect of dietary encapsulated organic acids (EOAs) and anticoccidials on the age-dependent development trend of intestinal Lactobacillus, E. coli, coliforms, and Eimeria in Eimeria spp.-infected broiler chickens from reused litter. In total, 525 mixed-sex 1-day-old broiler chickens were used in an uninfected/un-supplemented control plus a 2 (no EOA or 0.1% EOA) × 3 (no anticoccidial, 0.05% maduramicin, and 0.02% diclazuril) factorial arrangement of treatments as a completely randomized design with five replicates of 15 chickens. Results indicated that the cubic model is the best model for explaining the development trends of the intestinal microbial population in uninfected and infected chickens (affected by the EOAs and anticoccidials). Based on the cubic models, the microbial populations had development trends with a decreasing slope from 1-day-old until the early or middle finisher period. EOAs and anticoccidials, especially their simultaneous usage, improved (P < 0.05) the linear and cubic models’ slope (affected negatively by Eimeria infection). A polynomial model (order = 6) was determined as the best model for explaining the EOAs and anticoccidial effects on the trend of intestinal Eimeria oocysts in infected chickens. The infection peak (which happened at 25 days) was reduced by EOAs and anticoccidials, especially their simultaneous usage. In conclusion, cubic and polynomial (order = 6) regressions are the best models fitted for explaining the microbiota and Eimeria oocysts trends, respectively. EOAs and anticoccidials, especially their simultaneous usage, had beneficial effects on the microbiota and Eimeria development trends and gastrointestinal health in coccidia-infected broiler chickens.‏ RESEARCH HIGHLIGHTS Cubic regression is the best model for explaining intestinal microbiota development. Polynomial regression is the best model for intestinal Eimeria oocysts development. Age-development trends are affected by dietary encapsulated organic acids and anticoccidials.

144 Utilizing invasive pigweed (Amaranthus Spinosus) as a novel methane mitigation strategy in beef cattle feed: A sustainable approach

Abstract By 2050, the US beef industry must produce an extra 40 million tons of beef to satisfy the global demand, while reducing methane (CH4) emissions. This surplus of cattle will be provided mostly by cow-calf operations, which rely primarily on grazing. Those pastures are often infested with weeds such as pigweed (Amaranthus spinosus), one of the most invasive in the US, known for its increased polyphenols concentration. Despite the known effect of polyphenols on CH4 reduction, few studies have explored pigweed as a feed additive. Our objective was to evaluate the effect of in vitro addition of pigweed on ruminal fermentation, digestibility, and CH4 production. We collected ruminal fluid from three American Aberdeen steers (374 ± 21 kg) receiving a backgrounding diet (80:20% corn silage:cotton gin trash, as fed). We incubated (24 h, 39°C) diet (0.7 g) plus the inclusion of 0, 2.5, 5, or 10% (of diet DM) of roots, stems, leaves, seeds, or the whole pigweed plant (WHO). Volatile fatty acids (VFA), CH4 (mmol g-1 organic matter), ammonia, pH, gas, in vitro dry matter, and organic matter digestibility (IVDMD and IVOMD) were determined. Using the MIXED procedure of SAS, data were analyzed as a randomized complete block design with a 5 × 4 factorial arrangement of treatments with plant part (n = 5) and inclusion level (n = 4) as fixed main factors. Incubation and bottle within incubation were random effects. Polynomial orthogonal contrasts were used to determine linear, quadratic, and cubic effects of inclusion level. Plant × level interactions were detected in acetate, propionate, and butyric molar proportion, total VFA, CH4 production, and IVDMD (P &amp;lt; 0.01). Increasing levels of stems increased acetate concentration (P = 0.03), while those from WHO led to a linear reduction of acetate (P &amp;lt; 0.01). The inclusion of 2.5% of leaves, seeds, and WHO increased propionate concentration (P = 0.05), but greater levels decreased it (P &amp;lt; 0.01). Increasing levels of all parts decreased acetate:propionate proportion (P &amp;lt; 0.001). Increasing levels of WHO resulted in a linear reduction of CH4 production (P &amp;lt; 0.05), while increasing inclusion of roots and stems increased CH4 production (P &amp;lt; 0.01). Quadratic reductions in CH4 production were observed after increasing the addition of leaves, seeds, and WHO (P &amp;lt; 0.001). Increasing levels of leaves and roots decreased ammonia concentration (P &amp;lt; 0.01) while stems increased it (P = 0.01). Except for stems and roots, there was a linear decrease in IVDMD with increasing levels of all parts (P &amp;lt; 0.001). The inclusion of low levels of seeds, leaves, and WHO promoted ruminal changes leading to a reduction of CH4 production without significantly compromising the digestibility.

Effect of red osier dogwood extract on in vitro gas production, dry matter digestibility, and fermentation characteristics of forage-based diet or grain-based diet

This in vitro batch culture study investigated the effects of red osier dogwood (ROD) extract supplementation on gas production (GP), dry matter disappearance (DMD), and fermentation characteristics in high forage (HF) and high grain (HG) diets with varying media pH level. The experiment was a factorial arrangement of treatments in a completely randomized design with 2 media pH (5.8 and 6.5) × 4 dose rates of ROD extract (0, 1, 3, and 5% of DM substrate). An additional treatment of monensin was added as a positive control for each pH level. The HF substrate consisted of 400 and 600 g/kg DM barley-based concentrate and barley silage, respectively, while the HG substrate contained 100 and 900 g/kg DM barley silage and barley-based concentrate, respectively. Treatments were incubated for 24 h with GP, DMD and fermentation parameters determined. No interaction was detected between the media pH level and ROD extract dose rate on GP, DMD and most of the fermentation parameters. The GP, DMD, and total volatile fatty acid (VFA) concentration were greater (P = 0.01) with media pH of 6.5 in both HF and HG diets. The GP were not affected by increasing ROD dose rate, except that GP linearly decreased in the HF (P = 0.04) and HG (P = 0.01) diets at 24 h; the DMD tended to linearly decrease at pH 6.5 (P = 0.06) for both HF and HG diets and at pH 5.8 (P = 0.02) for the HG diet. Adding ROD extract to the HF and HG diets linearly (P = 0.01) increased the acetate molar proportion at high or low media pH and consequently, the acetate to propionate (A:P) ratio linearly (P ≤ 0.04) increased. Supplementation of ROD extract to the HF diet linearly (P = 0.04) decreased the molar proportion of propionate at pH 6.5 (interaction between pH and ROD extract; P = 0.05), but had no effect on propionate proportion when added to the HG diet. Moreover, the proportion of branched-chain fatty acids linearly (P = 0.03) decreased with ROD extract supplementation at low pH (interaction, P < 0.05) for HF diet and linearly decreased (P = 0.05) at pH 6.5 for HG diet (interaction, P < 0.05). The NH3–N concentration was not affected by ROD supplementation in the HF diet but it linearly (P = 0.01) decreased with increasing dose rate in the HG diet. Methane concentration tended to linearly (P = 0.06) increase with ROD extract supplementation at high pH for HF diet and linearly increased at pH 5.8 (P = 0.06) and pH 6.5 (P = 0.02) for HG diet. These results indicate that the decreased DMD and increased A:P ratio observed with addition of ROD extract may be beneficial to HG-fed cattle to reduce the risk of rumen acidosis without negatively impacting fiber digestion.

Effects of protein concentration and beta-adrenergic agonists on ruminal bacterial communities in finishing beef heifers.

To improve animal performance and modify growth by increasing lean tissue accretion, beef cattle production has relied on use of growth promoting technologies such as beta-adrenergic agonists. These synthetic catecholamines, combined with the variable inclusion of rumen degradable (RDP) and undegradable protein (RUP), improve feed efficiency and rate of gain in finishing beef cattle. However, research regarding the impact of beta-adrenergic agonists, protein level, and source on the ruminal microbiome is limited. The objective of this study was to determine the effect of different protein concentrations and beta-adrenergic agonist (ractopamine hydrochloride; RAC) on ruminal bacterial communities in finishing beef heifers. Heifers (n = 140) were ranked according to body weight and assigned to pens in a generalized complete block design with a 3 × 2 factorial arrangement of treatments of 6 different treatment combinations, containing 3 protein treatments (Control: 13.9% CP, 8.9% RDP, and 5.0% RUP; High RDP: 20.9% CP, 14.4% RDP, 6.5% RUP; or High RUP: 20.9% CP, 9.7% RDP, 11.2% RUP) and 2 RAC treatments (0 and 400 mg/day). Rumen samples were collected via orogastric tubing 7 days before harvest. DNA from rumen samples were sequenced to identify bacteria based on the V1-V3 hypervariable regions of the 16S rRNA gene. Reads from treatments were analyzed using the packages 'phyloseq' and 'dada2' within the R environment. Beta diversity was analyzed based on Bray-Curtis distances and was significantly different among protein and RAC treatments (P < 0.05). Alpha diversity metrics, such as Chao1 and Shannon diversity indices, were not significantly different (P > 0.05). Bacterial differences among treatments after analyses using PROC MIXED in SAS 9 were identified for the main effects of protein concentration (P < 0.05), rather than their interaction. These results suggest possible effects on microbial communities with different concentrations of protein but limited impact with RAC. However, both may potentially act synergistically to improve performance in finishing beef cattle.

Chemical treatments in maize seeds to improve germination in acidic soils

Objective: To evaluate the effect of different germination promoters on three maize genotypes grown in Dystric Cambisol soils, since germination problems are linked to latency and restrict agronomic management.&#x0D; Design/Methodology/Approach: We conducted an experiment at the Instituto Tecnológico Superior de Juan Rodríguez Clara using a split-plot design with a factorial treatment arrangement. The large plot contained genotypes (GEN) G1 = MS-405, G2 = Arlequin, and G3 = MS-404; while the small one comprised promoter (PROMO) HS = humic substance, CI = citrulline, and SA = salicylic acid. We evaluated the following variables: germination speed (GS), emergence percentage (EMERG), stem and leaf volume (S&amp;LV), root volume (RV), chlorophyll (CHL), secondary roots (SECR), stem diameter (DMT), number of leaves (NL), foliar area (FA), root length (RL), and plant height (PH). Then, we conducted a variance analysis and Tukey’s tests (α£0.05).&#x0D; Results: For each promoter, we observed main effects in EMERG, CHL, and PH for CI; S&amp;LV, NL, FA, and PH for HS; and RL for SA. In genotypes G2 and G3, variables GS, EMERG, NL, and PH were statistically equivalent, DMT varied only in G2, and there were no statistical differences for S&amp;LV, RV, CHL, SECR, FA, and RL. We observed some simple effects in combinations with CI: GS and PH varied in G3, EMERG in G2 and G3, CHL in G1 and G3, DMT in G1 and G2, and S&amp;LV in G2.&#x0D; Study limitations/Implications: Soaking corn for one hour in the solution and weighing the correct amount properly are required, since weighing too much may inhibit germination.&#x0D; Findings/Conclusions: Promoter CI at a dose of 1,000 ppm accelerates the emergence speed of genotypes G2 and G3 in acidic soils.

Growth and yield models for black beans under magnetization and pH variation in a greenhouse

Objective: To estimate growth and yield variations in common beans (Phaseolus vulgaris L.) treated with a magnetized nutrient solution considering two factors: magnet exposure time and pH level. The significance of this crop lies in its nutritional and economic value.&#x0D; Design/Methodology/Approach: We used a hydroponic system with magnetized Steiner nutrient solution. The design was completely randomized, with a 4 x 6 factorial treatment arrangement and three replications. Factor A comprised exposure times (0.333 hours, 2 hours, chronic, and without magnetization), while Factor B covered solutions with different pH levels (3, 4, 5, 6, 7, and 8). We then applied a multiple regression analysis using the SAS software.&#x0D; &#x0D; Results: Models for vegetative growth variables (plant height, root length, root dry weight, and foliar biomass) and seed yield components (number of pods, number of grains per pod) were statistically significant (p&lt;0.0001). Coefficients of determination ranged from 59.7 % to 82 %, percentages considered appropriate to explain the observed variability.&#x0D; Study limitations/Implications: While the models showed acceptable coefficients of determination, it is essential to consider other factors that were not assessed in this study: exposure to sunlight, insect influence, and diseases that could impact the responses of the bean crop.&#x0D; Findings/Conclusions: Appropriate models to describe vegetative growth and seed yield of the common bean, concerning magnetization time and nutrient solution acidity, include variables such as plant height, root length, root dry weight, foliar biomass, total biomass, number of pods, and number of grains per pod.