Factorial Arrangement Of Treatments Research Articles

Interactions of dietary wheat cultivars and NSP-degrading enzyme on productive performance and egg quality traits.

The nutritional value of enzyme-supplemented wheat-contained diets can be influenced by interactions between wheat cultivar and exogenous enzyme, which in turn cause various effects on the performance of poultry. The effects of diets including various wheat cultivars with or without enzyme on productive performance and egg quality characteristics were evaluated. A total of 270 58-week-old Lohmann LSL-Lite were allocated to 9 experimental dietary groups with 5 replicate cages and 6 birds per each cage. Based on a 4×2 factorial arrangement of treatment, nine iso-caloric and iso-nitrogenous experimental diets, including four wheat cultivars (Sardari, Azar 2, Pishgam and Sirvan) with and without enzymes plus a corn-based control diet, were tested in a completely randomized design during an 8-week trial period. From weeks 58 to 63 and 63 to 67 of age, the hens fed with Sardari-included diet showed the lowest feed intake compared to other groups (p<0.05). Egg production (EP), feed conversion ratio (FCR) and egg mass (EM) were not influenced by the experimental diets. At the age of 62 weeks, the effect of adding enzyme on egg shape index was significant. Moreover, in sampling week 67, increased eggshell weight (%) was detected in enzyme-supplemented diets compared to diets with no enzyme (10.03 vs. 9.37, respectively). Besides, the shell thickness was the highest in the group fed with Azar 2, and the lowest in the group fed with Sirvan at the age of 67 weeks (p<0.05). Albumen weights (%) were also significant in some cases. The highest albumen weight was observed in Sirvan-included diet without enzyme on week 62. Reduced yolk weight was detected in enzyme-supplemented Pishgam-included diet on 62 weeks of age (p<0.05). The inclusion of the diets of laying hens with the four tested Iranian wheat cultivars has no negative impact on most productive performance and egg quality indices. Moreover, supplementing the wheat-included diets with non-starch polysaccharidase enzyme (beta-endopower) improved eggshell weight on week 67.

Effects of stimbiotic supplementation on gut health, immune response, and intestinal microbiota in weaned piglets challenged with E. coli.

In order to make piglet diets more effective, it is necessary to investigate effective methods for breaking down xylan in cereal. The objective of this study was to determine the effects of dietary stimbiotic (STB) supplementation on growth performance, intestinal morphology, immune response and intestinal microbiota in weaned piglets. A total of 24 (Duroc × Yorkshire × Landrace) weaned pigs (initial body weight of 8.01 ± 0.38 kg and 28 ± 3 d old), were assigned to 4 treatments with 6 replicates per treatment. Pigs were housed in individual pens for 17 days, including 5 days adaption period and 12 days after the first Escherichia coli (E. coli) challenge. The experiment was conducted in a 2 × 2 factorial arrangement of treatments consisting of two levels of challenge (challenge and non-challenge) and two levels of STB (0 and 0.5 g/kg diet). Supplementations of STB 0.5 g/kg improved the gain to feed ratio (G:F) (P < 0.05) in piglets challenged with shiga toxigenic E. coli (STEC). STB supplementation decreased (P < 0.05) white blood cells, neutrophils, lymphocytes, and expression levels of tumor necrosis factor-alpha and interleukin-6. Supplementation of STB improved (P < 0.05) the lymphocytes and neutrophils in piglets challenged with STEC on 12 dpi. Supplementation of STB also improved (P < 0.05) the villus height to-crypt depth ratio of ileum in piglets challenged with STEC. Supplementation of STB increased (P < 0.05) the expression levels of claudin-1 of ileum. In genus level, supplementation of STB increased (P < 0.001) the abundance of Prevotella compared to non-supplementation of STB groups in pre-inoculation period. Also, supplementation of STB decreased (P < 0.05) the abundance of Faecalibacterium and Eubacterium_coprostanoligenes_group compared to non-supplementation of STB groups in post-inoculation period. In phylum level, supplementation of STB increased (P < 0.05) the abundance of Desulfobacterota and Fibrobacterota in pre-inoculation period. E. coli challenge increased the abundance of Fibrobacterota compared to non-challenged group in post-inoculation period. In conclusion, these findings indicated that STB supplementation could alleviate a decrease of the performance, immune response, and inflammatory response in piglets induced by the STEC challenge.

Comparative growth performance, gizzard weight, ceca digesta short chain fatty acids and nutrient utilization in broiler chickens and turkey poults in response to cereal grain type, fiber level, and multienzyme supplement fed from hatch to 28 days of life

Growth performance, gizzard weight, ceca digesta short-chain fatty acids (SCFA), and apparent retention (AR) of components were investigated in broilers and turkeys in response to cereal grain type, fiber level, and multienzyme supplement (MES) fed from hatch to 28 d of life. 480-day-old male broiler chicks and equal number of turkeys were placed separately in metabolism cages (10 birds/cage) and allocated to 8 diets. The species-specific diets were a corn or wheat-based basal diet without (LF) or with 10% corn DDGS or wheat middlings (HF) and fed without or with MES. This effectively created a 2 (grain types)×2 (fiber levels)×2 (MES) factorial arrangement of treatments. The diets had TiO2 as an indigestible marker. Body weight, feed intake, and mortalities were recorded to calculate body weight gain (BWG) and feed conversion ratio (FCR). Excreta samples were collected on d 25 to 27 for AR, and all birds were necropsied for gizzard weight and ceca digesta on d 28. The interaction between grain and MES in broilers was such that wheat diets with MES had the lowest (P=0.005) FCR. In broilers, LF diets had better (P=0.010) FCR than HF diets. The wheat diets had the highest (P=0.006) concentration of butyric acid in broilers. Broilers fed HF and corn diets had heavier gizzard than broilers-fed LF and wheat diets. The MES improved (P < 0.05) AMEn in HF, corn, and wheat diets in broilers. The turkeys fed wheat diets had the lowest (P=0.019) FCR. Turkeys fed HF wheat diets had the heaviest (P < 0.001) gizzard. In turkeys, the MES improved AMEn in HF and LF corn diets, and only in LF wheat diets compared to respective controls. Treatments had no effect on turkeys cecal SCFA. In conclusion, grain type, fiber, and MES did not affect growth in both species. However, species exhibited differing FCR, gizzard, and energy utilization to fiber and MES.

Sodium butyrate alleviates deoxynivalenol-induced porcine intestinal barrier disruption by promoting mitochondrial homeostasis via PCK2 signaling

Deoxynivalenol (DON) is one of the most plentiful trichothecenes occurring in food and feed, which brings severe health hazards to both animals and humans. This study aims to investigate whether sodium butyrate (NaB) can protect the porcine intestinal barrier from DON exposure through promoting mitochondrial homeostasis. In a 4-week feeding experiment, 28 male piglets were allocated according to a 2 by 2 factorial arrangement of treatments with the main factors including supplementation of DON (< 0.8 vs. 4.0 mg/kg) and NaB (0.0 vs. 2 g/kg) in a corn/soybean-based diet. Dietary NaB supplementation mitigated the damaged mitochondrial morphology within the jejunal mucosa and the disrupted gut epithelial tight junctions irritated by DON. In IPEC-J2 cells, we found efficient recovery of the intestinal epithelial barrier occurred following NaB administration. This intestinal barrier reparation was facilitated by NaB-induced PCK2-mediated glyceroneogenesis and restoration of mitochondrial structure and function. In conclusion, we elucidated a mechanism of PCK2-mediated improvement of mitochondrial function by NaB to repair porcine intestinal barrier disruption during chronic DON exposure. Our findings highlight the promise of NaB for use in protecting against DON-induced gut epithelial tight junction disruption in piglets.

Effect of coated urea and monensin on rumen metabolism of Nellore cows fed low-quality forage-based diet

ABSTRACT This study investigated the effect of coated urea supplementation associated with monensin on rumen metabolism and fermentation, in cattle consuming a low-quality forage-based diet. Eight ruminally cannulated Nellore cows consuming Brachiaria brizantha cv. Marandu hay were randomly assessed to two 4 × 4 Latin square design, in a 2 × 4 factorial arrangement, with a factorial treatment arrangement with the factors: (i) urea source: (CON) no urea, (URE) common urea, (PCU) polymer-coated urea and (LCU) lipid-coated urea; (ii) monensin: (MON) addition of monensin in the diet; and (NM) no addition of monensin in the diet. Ruminal NH3-N concentration was affected by urea source and there was an interaction between time and the urea source. Rumen acetate molar concentration was lower, while rumen propionate was greater for URE compared to coated urea. The total tract apparent digestibility of crude protein (CP) and non-protein nitrogen (NPN) were greater for URE compared to coated urea treatments and for LCU compared to PCU. Animals fed URE had greater urea excretion compared to coated urea. In conclusion, coated urea generates a lower ammonia peak; however, both coated urea did not promote total nitrogen release. No synergy was observed with the combination of urea and monensin.

Effects of corn grain processing and protein source on calf performance, rumen fermentation, and blood metabolites

The objective of this study was to investigate the effects of the interaction between corn grain processing and protein source on feed intake, growth performance, rumen fermentation, and blood metabolites of dairy calves. Seventy-two 3-day-old Holstein calves with an initial weight of 39.1 ± 3.24 kg were randomly assigned (n = 12 calves (6 male and 6 female) per treatment) to a 2 × 3 factorial arrangement of treatments with the factors of physical form of the corn grain [coarsely ground (CG) and steam-flaked (SF)] and protein type [canola meal (CAN), canola meal + soybean meal (CASY), and soybean meal (SOY)] were assigned. The study showed a significant correlation between corn grain processing method and protein source on calf performance, including starter feed intake, total dry matter intake (DMI), body weight, average daily gain (ADG), and feed efficiency (FE). The CG-CAN and SF-SOY treatments resulted in the highest feed intake and DMI in the post-weaning and total period, respectively. Interestingly, corn processing did not affect feed intake, ADG, and FE, but the highest ADG was observed at SF-SOY and CG-CAN. In addition, the interaction between corn processing method and protein source improved FE in calves fed CG-CAN and SF-SOY during the preweaning period and throughout the period. Although skeletal growth parameters were unchanged, calves fed SOY and CASY had greater body length and withers height than calves fed CAN during the preweaning period. Rumen fermentation parameters were also not affected by the treatments, except that calves fed CAN had a higher molar proportion of acetate than calves fed SOY and CASY. Corn grain processing and protein source did not affect glucose, blood urea nitrogen (BUN), or β-hydroxybutyrate (BHB) concentrations, except for the highest blood glucose level observed in the CAN treatment and the highest BUN level observed in the preweaned calves fed SOY. However, a two-way interaction was observed for BHB concentration, suggesting that ground corn grain resulted in higher BHB concentration during the preweaning and postweaning periods than steam-flaked corn. In summary, it is recommended to incorporate canola meal with ground corn or soybean meal with steam-flaked corn in calf starters to enhance calf growth.

Effect of Planting Geometry on Growth, Water Productivity, and Fruit Quality of Tomatoes under Different Soil Moisture Regimes

The present study investigated the impact of planting spacing on tomato crop growth, water productivity, and fruit quality under different water regimes. Thus, a field experiment was conducted using a randomized complete block design in a factorial arrangement of treatments. The tomato plants were grown at three planting spacing patterns: 30 cm row-to-row planting spacing, 60 cm row-to-row planting spacing, and 90 cm row-to-row planting spacing, which were marked as (G1), (G2), and (G3), respectively. For each planting spacing pattern, irrigation regimes, namely (I1), (I2), and (I3), were established by setting the soil moisture content to 50%, 100%, and 150% of the reference evapotranspiration. The I3 × G2 combination resulted in the maximum values of plant height (68.2 cm), stem diameter (12.1 mm), and yield (41,269.9 kg/hm2), providing the highest contents of protein (1.93 mg/kg), fat (0.81%), fiber (3.94%), and lycopene (4.00 mg/kg) of the fresh fruit. Conversely, the I1 × G1 led to the minimum values of plant height (37.3 cm), stem diameter (5.65 mm), and yield (7814.7 kg/hm2), providing the lowest contents of protein (1.15 mg/kg), fat (0.50%), fiber (2.39%), and lycopene (2.15 mg/kg) of the fresh fruit. The I1 × G1 had the highest water productivity (25.06 kg/m3) value, while the lowest WP (10.23 kg/m3) value was achieved by I3 × G3. While the I1 × G3 treatment minimized the uniformity coefficient and distribution uniformity, the I3 × G3 treatment maximized their values, indicating more uniform water distribution. Our findings indicate that the I3 × G2 combination can increase tomato productivity, growth, and fruit quality. However, the I1 × G1 performed better in terms of water productivity. The results of this study can positively contribute to improving tomato production systems’ sustainability, productivity, and quality under the increasing problem of climate change.

Polymorphism at the CSN1S1 Locus and Energy Intake Level Affect Milk Traits and Casein Profiles in Rossa Mediterranea Goats.

A total of twenty-seven Rossa Mediterranea lactating goats, consisting of nine homozygous for strong alleles (AA), twelve heterozygous (AF) and six homozygous for weak alleles (FF) at the CSN1S1 locus, were used to evaluate the effect of genotype, diet and genotype × diet interaction on goat milk traits and casein profile. The goats were used in a 3 × 3 factorial arrangement of treatments, with three genotypes (AA, AF and FF) and three different energy intake levels: high (H), medium (M) and low (L). The diets supplied a complete pelleted feed containing 65% of alfalfa hay, respectively, at 150%, 100% and 70% of the total energy requirements. Milk yield was significantly affected by the genotype and diet: Lower levels were found in FF goats than in AA and AF genotypes (673.7 vs. 934.5 and 879.8 d/g, respectively; p = 0.002) as well as in goats fed with the L diet (651.5 vs. 1041 and 852.9 g/d for H and M diet, respectively, p < 0.001). The genotype influenced the casein profile. Specifically, AA goat milk exhibited higher concentrations of total casein and αs1-casein compared to AF and FF genotypes (for total casein and αs1-casein, respectively: 24.9 vs. 20.4 and 19.8 g/kg, p = 0.001; 7.2 vs. 3.7 and 0.7 g/kg, p < 0.001), while the FF genotype showed higher values for αs2-casein concentrations compared to homozygous AA and heterozygous AF goats (3.1 vs. 2.4 and 2.5 g/kg, respectively, p < 0.001). A significant genotype x diet interaction occurred for αs2-casein levels (g/kg) (p = 0.034) and αs1-casein yields (p = 0.027): The αs2-casein level was not affected by the diet in AA goats, whereas it increased with energy intake in AF and FF genotypes. Conversely, the αs1-casein yield gradually increased with energy intake in AA and AF groups, whereas the diet in FF goats did not modify it. The results demonstrated that high energy input, as well as the strong allele at the CSN1S1 locus, enhanced milk production and casein concentrations. Furthermore, they confirmed the existence of an interaction between αs1-casein polymorphism and diets, influencing the milk casein composition and yield.

Yeast polysaccharide mitigated oxidative injury in broilers induced by mixed mycotoxins via regulating intestinal mucosal oxidative stress and hepatic metabolic enzymes

This study was aimed to investigate the effects of yeast polysaccharides (YPS) on growth performance, intestinal health, and aflatoxin metabolism in livers of broilers fed diets naturally contaminated with mixed mycotoxins (MYCO). A total of 480 one-day-old Arbor Acre male broilers were randomly allocated into a 2×3 factorial arrangement of treatments (8 replicates with 10 birds per replicate) for 6 wk to assess the effects of 3 levels of YPS (0, 1, or 2 g/kg) on the broilers fed diets contaminated with or without MYCO (95 μg/kg aflatoxin B1, 1.5 mg/kg deoxynivalenol, and 490 μg/kg zearalenone). Results showed that mycotoxins contaminated diets led to significant increments in serum malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, mRNA expressions of TLR4 and 4EBP1 associated with oxidative stress, mRNA expressions of CYP1A1, CYP1A2, CYP2A6, and CYP3A4 associated with hepatic phase Ⅰ metabolizing enzymes, mRNA expressions of p53 associated with hepatic mitochondrial apoptosis, and AFB1 residues in the liver (P < 0.05); meanwhile dietary MYCO decreased the jejunal villus height (VH), villus height/crypt depth (VH/CD), the activity of serum total antioxidant capacity (T-AOC), mRNA expressions of jejunal HIF-1α, HMOX, and XDH associated with oxidative stress, mRNA expressions of jejunal CLDN1, ZO1, and ZO2, and mRNA expression of GST associated with hepatic phase Ⅱ metabolizing enzymes of broilers (P < 0.05). Notably, the adverse effects induced by MYCO on broilers were mitigated by supplementation with YPS. Dietary YPS supplementation reduced the concentrations of serum MDA and 8-OHdG, jejunal CD, mRNA expression of jejunal TLR2, and 4EBP1, hepatic CYP1A2, and p53, and the AFB1 residues in the liver (P < 0.05), and elevated the serum T-AOC and SOD, jejunal VH, and VH/CD, and mRNA expression of jejunal XDH, hepatic GST of broilers (P < 0.05). There were significant interactions between MYCO and YPS levels on the growth performance (BW, ADFI, ADG, and F/G) at d 1 to 21, d 22 to 42, and d 1 to 42, serum GSH-Px activity, and mRNA expression of jejunal CLDN2 and hepatic ras of broilers (P < 0.05). In contrast with MYCO group, the addition of YPS increased BW, ADFI, and ADG, the serum GSH-Px activity (14.31%-46.92%), mRNA levels of jejunal CLDN2 (94.39%-103.02%), decreased F/G, and mRNA levels of hepatic ras (57.83%-63.62%) of broilers (P < 0.05). In conclusion, dietary supplements with YPS protected broilers from mixed mycotoxins toxicities meanwhile keeping normal performance of broilers, presumably via reducing intestinal oxidative stress, protecting intestinal structural integrity, and improving hepatic metabolic enzymes to minimize the AFB1 residue in the liver and enhance the performance of broilers.

Dietary calcium and nonphosphate phosphorus interaction influences tibiotarsus development and related gene expression of broilers from 1 to 21 days of age

The dietary needs of calcium (Ca) and phosphorus (P) are interdependent, thus accurate evaluation of Ca and P requirements of broilers to support skeleton health and optimal growth is critical. The present study was carried out to investigate the effects of dietary Ca and nonphytate P (NPP) levels and their interactions on growth performance, tibiotarsus characteristics, tibiotarsus metabolism-related enzyme and proteins, and their gene expression of broilers, so as to provide a rational recommendation for Ca and NPP levels in diet. A total of 540 one-day-old Arbor Acres male broilers were randomly allotted to 1 of 15 treatments with 6 replicate cages of 6 birds per cage for each treatment in a completely randomized design involving a 5×3 factorial arrangement of treatments (5 levels of Ca×3 levels of NPP). The birds were fed the corn-soybean meal diet containing 0.60%, 0.70%, 0.80%, 0.90%, or 1.00% Ca and 0.35%, 0.40%, or 0.45% NPP for 21 d. Dietary Ca level affected (P < 0.03) the bone mineral density, bone mineral content (BMC), breaking strength, ash percentage and ash Ca contents in tibia, which showed linear (P < 0.006) responses to dietary Ca levels. Dietary NPP level affected (P < 0.05) tibia BMC, ash percentage, and FGF23 mRNA level. Broilers that received 0.40% and 0.45% NPP had higher (P < 0.04) tibia BMC and ash percentage than those that received 0.35% NPP, but no differences (P > 0.05) were found between 0.40% and 0.45% NPP. Broilers that received 0.40% NPP had higher (P=0.02) tibia FGF23 mRNA level than those that received 0.35% NPP, but no differences (P > 0.05) were detected between 0.40% and 0.45% NPP or 0.45% and 0.35% NPP. The interactions between dietary Ca and NPP affected (P < 0.05) ADG, ALP activity, bone gal protein, FGF23 contents, and the mRNA expression levels ALP and bone gal protein in tibia of broilers. Results from the present study indicate that dietary Ca and NPP interaction influences growth, tibiotarsus development, and related gene expression of broiler chickens. Considering all the criteria, the dietary levels of 0.90% Ca and 0.45% NPP would be optimal for both growth and tibiotarsus development of broilers fed a conventional corn-soybean meal diet from 1 to 21 d of age.

Abomasal infusion of oleic acid and exogenous emulsifier alter fatty acid digestibility and production responses of lactating dairy cows

We evaluated the effects of abomasal infusion of cis-9 C18:1 (oleic acid) and an exogenous emulsifier (polysorbate-C18:1) on fatty acid (FA) digestibility and production responses of dairy cows. Eight rumen-cannulated multiparous cows (96 ± 23 d in milk) were assigned to a 2 × 2 factorial arrangement of treatments in 4 × 4 Latin squares with 18-d periods consisting of 7 d of washout and 11 d of infusion. Treatments were abomasal infusions of water carrier only (CON), 45 g/d oleic acid (OA), 20 g/d polysorbate-C18:1 (T80), or both 45 g/d OA and 20 g/d T80 (OA+T80). The OA treatments were dissolved in ethanol and the T80 treatments in water. To deliver the daily dose for each treatment, the infusate solution was divided into 4 equal infusions per day, occurring every 6 h. Cows were fed the same diet, which contained [% of dry matter (DM)] 30.3% neutral detergent fiber (NDF), 16.3% crude protein, 30% starch, and 3.2% FA (including 1.8% DM from a FA supplement containing 34.4% C16:0 and 47.7% C18:0). Infusion of T80 increased NDF digestibility compared with all other treatments (3.57 percentage units), whereas OA+T80 decreased NDF digestibility compared with CON (3.30 percentage units). Compared with CON, OA (4.90 percentage units) and T80 (3.40 percentage units) increased total FA digestibility, whereas OA+T80 had no effect on total FA digestibility. We did not observe differences between OA and T80 for total FA digestibility. Infusion of OA (3.90 percentage units) and T80 (2.80 percentage units) increased 16-carbon FA digestibility compared with CON. Digestibility of 16-carbon FA did not differ between OA and T80 or between CON and OA+T80. Compared with CON, OA increased (5.60 percentage units) and T80 tended to increase 18-carbon FA digestibility. Digestibility of 18-carbon FA did not differ between OA and T80 or between CON and OA+T80. Compared with CON, all treatments increased or tended to increase the absorption of total and 18-carbon FA. Infusion of OA and T80 increased the yields of milk fat (both increased 0.10 kg/d), 3.5% fat-corrected milk (1.90 and 2.50 kg/d), and energy-corrected milk (1.80 and 2.60 kg/d) compared with CON. We did not observe differences between OA and T80 or between CON and OA+T80 for yields of milk fat, 3.5% fat-corrected milk, or energy-corrected milk. Infusing OA tended to increase plasma insulin concentration compared with CON. Compared with the other treatments, OA+T80 decreased the yield of de novo milk FA (31.3 g/d). Compared with CON, OA tended to increase the yield of de novo milk FA. Compared with OA+T80, CON and OA tended to increase the yield of mixed milk FA, whereas T80 increased it (83 g/d). Compared with CON, all emulsifier treatments increased the yield of preformed milk FA (52.7 g/d). In conclusion, abomasally infusing either 45 g of OA or 20 g of T80 improved digestibility and similarly favored the production parameters of dairy cows. In contrast, providing both (45 g of OA + 20 g of T80) had no additional benefits and moderated the positive responses observed in the individual treatments with OA and T80.

The effects of feeding α-amylase-enhanced corn silage with different dietary starch concentrations to lactating dairy cows on milk production, nutrient digestibility, and blood metabolites

Corn silage is one of the most common ingredients fed to dairy cattle. Advancement of corn silage genetics has improved nutrient digestibility and dairy cow lactation performance in the past. A corn silage hybrid with enhanced endogenous α-amylase activity (Enogen, Syngenta Seeds LLC) may improve milk production efficiency and nutrient digestibility when fed to lactating dairy cows. Furthermore, evaluating how Enogen silage interacts with different dietary starch content is important because the ruminal environment is influenced by the amount of rumen fermentable organic matter consumed. To evaluate the effects of Enogen corn silage and dietary starch content, we conducted an 8-wk randomized complete block experiment (2-wk covariate period, 6-wk experimental period) with a 2 × 2 factorial treatment arrangement using 44 cows (n = 11/treatment; 28 multiparous, 16 primiparous; 151 ± 42 d in milk; 668 ± 63.6 kg of body weight). Treatment factors were Enogen corn silage (ENO) or control (CON) corn silage included at 40% of diet dry matter and 25% (LO) or 30% (HI) dietary starch. Corn silage used in CON treatment was a similar hybrid as in ENO but without enhanced α-amylase activity. The experimental period began 41 d after silage harvest. Feed intake and milk yield data were collected daily, plasma metabolites and fecal pH were measured weekly, and digestibility was measured during the first and final weeks of the experimental period. Data were analyzed using a linear mixed model approach with repeated measures for all variables except for body condition score change and body weight change. Corn silage, starch, week, and their interactions were included as fixed effects; baseline covariates and their interactions with corn silage and starch were also tested. Block and cow served as the random effects. Plasma glucose, insulin, haptoglobin, and serum amyloid A concentrations were unaffected by treatment. Fecal pH was greater for cows fed ENO versus CON. Dry matter, crude protein, neutral detergent fiber, and starch digestibility were all greater for ENO than CON during wk 1, but differences were less by wk 6. The HI treatments depressed neutral detergent fiber digestibility compared with LO. Dry matter intake (DMI) was not affected by corn silage but was affected by the interaction of starch and week; in wk 1, DMI was similar but by wk 6, cows fed HI had 1.8 ± 0.93 kg/d less DMI than LO cows. Milk, energy-corrected milk, and milk protein yields were 1.7 ± 0.94 kg/d, 1.3 ± 0.70 kg/d, and 65 ± 27 g/d greater for HI than LO, respectively. In conclusion, ENO increased digestibility but it did not affect milk yield, component yields, or DMI. Increasing dietary starch content improved milk production and feed efficiency without affecting markers of inflammation or metabolism.

Effects of forage and grain legume-based silages supplemented with faba bean meal or rapeseed expeller on lactational performance, nitrogen utilization, and plasma amino acids in dairy cows

The objective of this experiment was to investigate the effect of forage type [red clover (51%)-grass silage, i.e., RCG; vs. faba bean (66%)-grass silage, i.e., FBG] and concentrate type (faba bean, FB; vs. rapeseed expeller, RE) on lactational performance, milk composition and nitrogen (N) utilization in lactating dairy cows. Eight lactating multiparous Nordic Red cows were used in a replicated 4 × 4 Latin Square experiment, with 21-d periods, in a 2 × 2 factorial arrangement of treatments. The experimental treatments were as follows: (1) RCG with RE, (2) RCG with FB, (3) FBG with RE, and (4) FBG with FB. Inclusion rates of RE and FB were isonitrogenous. Crude protein contents of the experimental diets were 16.3, 15.9, 18.1, and 17.9% of dry matter, respectively. All diets included oats and barley and were fed ad libitum as total mixed rations with forage-to-concentrate ratio of 55:45. Dry matter intake and milk yield were recorded daily, and spot samples of urine, feces, and blood were collected at the end of each experimental period. Dry matter intake did not differ across diets, averaging 26.7 kg/d. Milk yield averaged 35.6 kg/d and was 1.1 kg/d greater for RCG versus FBG, and milk urea N concentration was lower for RCG compared with FBG. Milk yield was 2.2 kg/d and milk protein yield 66 g/d lower for FB versus RE. Nitrogen intake, urinary N, and urinary urea N excretions were lower, and milk N excretion tended to be lower for RCG compared with FBG. The proportion of the dietary N excreted as fecal N was larger in cows fed RCG than for those fed FBG, and the opposite was true for urinary N. We detected an interaction for milk N as percentage of N intake: it increased with RE compared with FB for RCG-based diet, but only a marginal increase was observed for FBG-based diet. Plasma concentration of His and Lys were lower for RCG than for FBG, whereas His tended to be greater and Lys lower for FB compared with RE. Further, plasma Met concentration was around 26% lower for FB than for RE. Of milk fatty acids, saturated fatty acids were decreased by RCG and increased by FB compared with FBG and RE, respectively, whereas monounsaturated fatty acids were increased by RCG versus FBG, and were lower for FB than for RE. In particular, 18:1n-9 concentration was lower for FB compared with RE. Polyunsaturated fatty acids, such as 18:2n-6 and 18:3n-3, were greater for RCG than for FBG, and 18:2n-6 was greater and 18:3n-3 was lower for FB versus RE. In addition, cis-9,trans-11 conjugated linoleic acid was lower for FB compared with RE. Faba bean whole-crop silage and faba bean meal have potential to be used as a part of dairy cow rations, but further research is needed to improve their N efficiency. Red clover-grass silage from a mixed sward, without inorganic N fertilizer input, combined with RE, resulted in the greatest N efficiency in the conditions of this experiment.

Low sanitary housing conditions increase protein fermentation in piglets but do not aggravate the effects of protein fermentation on intestinal health

Protein fermentation has been identified as a risk factor for the occurrence of post-weaning diarrhea. Associations between low protein digestion – provoking protein fermentation - and low sanitary housing conditions suggest that protein fermentation, low sanitary conditions, and post-weaning diarrhea are interlinked.To this end, an experiment (2×2 factorial treatment arrangement) was performed with 160 weaned female piglets (TN70 х Tempo) divided over 5 batches (4 piglets per pen, 2 pens/treatment/batch). The piglets were kept under high (HSC) or low (LSC) sanitary conditions and were fed a diet low (LiP) or high (HiP) in indigestible protein for 14 days. Fecal consistency was scored daily per piglet and after one week, digesta samples were collected to analyze protein digestibility, colonic flow of protein-derived metabolites, and digesta mean retention time in 2 piglets per pen. Furthermore, we measured intestinal permeability for Fluorescein isothiocyanate-dextran (FITC, 4 kDa) and Tetramethylrhodamine isothiocyanate–dextran (TRITC, 40 kDa), and jejunal absorption capacity for lysine, methionine, and glucose, using the everted gut sac technique.Piglets kept under LSC had 9% units lower apparent total tract protein digestibility than piglets kept under HSC (P < 0.001), mainly explained by 7% units lower apparent ileal protein digestibility in LSC piglets (P < 0.001). Since no relevant correlations were observed between digesta mean retention time and ileal N digestibility and jejunal absorption capacity did not differ between treatment groups, these factors were excluded as underlying causes. The colonic flow of protein-derived metabolites was higher for LSC piglets than for HSC piglets (NH3: +31%, BCFA: +40%, P < 0.001), and higher for HiP piglets than for LiP piglets (NH3: +76%, BCFA: +42% for LSC, +25% for HSC, P < 0.001, SC х Diet P < 0.05). Colonic N disappearance was 5.5% units higher for HiP piglets than for LiP piglets (P < 0.01), but was not affected by SC. Fecal consistency scores were reduced for both HiP (−1.5, P < 0.001) and LSC (−0.5, P < 0.001) piglets compared with LiP and HSC, but no SC х diet interaction was observed. Jejunal permeability was slightly increased for HiP piglets (P < 0.05). No negative effects of feeding HiP on colonic permeability were observed.Low sanitary conditions decrease both ileal and fecal protein digestion to a similar extent and stimulate colonic protein fermentation. It is unlikely that digesta transport or jejunal absorption rates are causal to this effect. There are no indications that housing under low sanitary conditions aggravates the effects of protein fermentation on intestinal health.

Hygienic pelleting can decrease Hubbard × Ross 708 apparent ileal amino acid digestibility, broiler performance, and increase digestible amino acid requirement

To reduce pathogenic bacteria such as Salmonella in feed and ensure a high-quality pellet, diets for broilers, turkeys, and breeders may be pelleted using high conditioning temperatures and extended times. However, increased conditioning temperature and time may alter amino acid conformation regarding secondary and tertiary structure, decrease digestibility and subsequent bird performance, and necessitate increased amino acid formulation density. The objective of this study was to evaluate increased conditioning temperature and exposure time within the pelleting process using a hygienizer (hygienic pelleting) in diets that vary in digestible lysine and corresponding amino acid ratio on Hubbard × Ross 708 starter broiler performance, apparent ileal amino acid digestibility (AIAAD), and requirement. A 5 × 2 factorial arrangement of treatments with 5 levels of digestible lysine (−20, −10%, 2019 Ross Broiler Starter Nutrition recommendation, +10, and +20%) and 2 techniques of pelleting (standard and hygienic) was utilized in a randomized complete block design. Standard pelleting utilized 77°C conditioning for 30 s and hygienic pelleting utilized 88°C conditioning for 60 s and 6-min retention time in a hygienizer. Each treatment was fed to 12 replicate pens of 10 male broiler Hubbard × Ross 708 chicks for a 21-day period. Standard pelleting and hygienic pelleting demonstrated a 1.19 and 1.37% digestible Lys requirement, respectively, using the 2 straight line, 1-breakpoint broken-line regression model. Performance data, AIAAD, and the broken-line regression model suggest an approximate 10% increase in digestible Lys and corresponding amino acid ratio relative to 2019 Ross Broiler Starter Nutrition Specifications for Hygienic Pelleting. Nutritionists should be cognizant that nutritional detriment may accompany procedures used to create hygienic pelleted feed.

131 Evaluating Supplementation Programs for Growing Calves Grazing Bermudagrass Pastures

Abstract Due to factors such as, high delivery costs, supplement availability, and labor; producers are interested in supplement delivery alternatives. Our objective was to determine gain in response to hand-fed (HF) or self-fed (SF) summer supplementation programs at the University of Arkansas Livestock and Forestry Research Station, on 20, 0.81-ha common bermudagrass pastures at a stocking rate of 5 growing calves per pasture (BW ± SD = 247 ± 24.6) over three years. This was a 2 x 2 + factorial arrangement of treatments, which included: Control (CON) – only free choice mineral; HF 1.13 kg/d by-product-based supplement offered only late summer (LS) or all summer (AS); SF tub supplement (PVM Cattle Tub, Positive Feed Ltd., Sealy, TX) either LS or AS. The HF supplement in year was a 50:50 blend of soybean hulls and corn gluten feed, in year 2 an extruded dried distillers grains cube (MasterHand Milling, Lexington NE) was used for HF, while in year 3 corn gluten feed was the HF supplement. Data were analyzed as a generalized randomized complete block design using the mixed procedure of SAS (SAS Inst. Inc., Cary, NC). Fixed effects in the model included supplementation treatment, year, and year by treatment interaction. Even though different HF supplements were used each year there was no year X treatment interactions (P ≥ 0.10); therefore, results are presented pooled across years. Early summer ADG was greater for HFAS (P &amp;lt; 0.01) than CON and SFAS, while supplemental efficiency (SE, kg added gain/kg supplement) in early summer was less (P = 0.05) SFAS than HFAS. Late summer ADG was greater for HF than SF and CON; while SE did not differ (P = 0.52) among treatments. Total supplement costs, in US dollars per steer for SF, were $67.50 when fed AS and $49.36 when fed in late summer only. Supplement costs for HF were much lower, $33.54 and $15.72/steer for AS and LS, respectively. Cost of added gain for SF was $28.33 and $16.14/kg for SFAS and SFLS, respectively. When providing supplement by HF, cost of added gain was $3.32 and $1.68/kg for HFAS and HFLS, respectively. With these results, we determined the most cost-effective way to add gain with supplement to growing calves grazing bermudagrass pasture is to hand-feed. When calves were HFAS, total supplement costs were higher, but considering the greater ADG, ending bodyweight, and supplemental efficiency ratio, HF supplements should provide a positive net return. Calves on this experiment did not respond as expected to the SF supplement, likely because the bermudagrass pastures in this experiment averaged over3% CP and were in excess of 10% even in the LS sampling periods.

37 Supplemented with Yucca Schidigera Extract to Feedlot Cattle Consuming Diets with or Without Monensin

Abstract This experiment compared performance and physiological responses of feedlot cattle receiving a saponin containing feed ingredient manufactured from purified extract of Yucca schidigera [Micro-Aid (MA); DPI Global, Porterville, CA] which replaced or was fed in conjunction with feed-grade antimicrobials. Yearling, Angus-influenced steers (n = 20) arrived at the experimental feedlot on d -19 and a shrunk body weight (BW; 309 ± 4 kg) was immediately recorded. Steers were ranked by BW and allocated to 4 groups of 30 steers each. Groups were housed in of 4 drylot pens equipped with GrowSafe automated feeding systems (4 bunks/pen) during the experiment (d -15 to 69). On d 0 groups were randomly assigned to receive a total mixed ration containing: monensin and tylosin (RT; 360 mg/steer daily from Rumensin and 90 mg/steer daily from Tylan; Elanco Animal Health, Greenfield, IN) and/or 4 g/steer daily of MA in a 2 × 2 factorial arrangement of treatments. During the experimental period non-supplemented (CON) steers received a total mixed ration containing no additives. Individual feed intake was recorded daily, and steer BW was recorded every 28 d and before slaughter. Steers were slaughtered according to BW and slaughter groups were balanced by treatments (36 steers on d 120, 36 steers on d 146, and 48 steers on d 174). Carcass traits were recorded upon slaughter. On d 55 eight rumen-cannulated heifers were housed with yearling steers (1 pair/pen). Pairs rotated among groups every 21 d, resulting in a 4 × 4 Latin Square design (n = 8 per treatment) with a 5-day washout between rotations. Rumen fluid was collected from pairs on d 55, 75, 90,110, 125, 145, 160, and 180 (beginning and end of each 21-day rotation) and pH was recorded immediately after collection. No RT × MA treatment interactions were detected (P &amp;gt; 0.10). Feed intake was decreased (P &amp;lt; 0.01) in steers receiving RT, whereas feed efficiency was greater (P = 0.02) in steers receiving RT. Carcass variables including hot carcass weight, backfat thickness, Longissimus muscle area, marbling, yield grade, and percent of carcasses grading choice or better did not differ among treatments (P ≥ 0.17). Rumen fluid pH was greater (P = 0.04) in steers receiving RT. Steers receiving MA had greater (P = 0.03) rumen fluid pH and decreased (P = 0.04) rumen fluid viscosity. Collectively, supplementing feedlot cattle with Yucca schidigera extract improved rumen pH and viscosity, but failed to impact performance or carcass measures in feedlot cattle.

89 Influence of Melatonin Supplementation in Pregnant Cattle Consuming Endophyte-Infected Tall Fescue Seed on Offspring Performance

Abstract The objective was to evaluate growth performance and estimates of body composition in offspring of dams that consumed diets containing tall fescue seed with (E+) or without (E-) the toxic endophyte and with or without melatonin during mid-late gestation. Pregnant heifers (n = 57) artificially inseminated with sex-sorted semen (X chromosome-bearing sperm) from a single Angus sire were administered dietary treatments in a 2 x 2 factorial treatment arrangement (E- without melatonin, E-/NM; E- with melatonin, E-/M; E+ without melatonin, E+/NM; or E+ with melatonin, E+/M; melatonin dose: 100 µg/kg of BW) for a 70-day period between May and July starting at 160±13 d of gestation to mimic ergot alkaloid concentrations in a grazing scenario. All diets contained corn gluten and molasses and were fed using SmartFeed Pro (C-Lock Inc.) controlled feeding units between 0900 and2 1200 h daily. Cattle were removed from dietary treatments 39 ± 19 d before calving. Two replicates were housed separately in an open-air barn, each with a 1.2-ha paddock. Prior to and following the 70-d treatment period, all cattle were maintained as a single group free from toxic fescue. Calves were weaned at 226 ± 19 d of age. Gestation length, calf birth weight, 205-day adjusted weaning weight (205-d WW), carcass ultrasonography measures (ribeye area, REA; REA/CWT; percent intramuscular fat, IMF; rib fat thickness, UFAT; rump fat thickness, URUMP), post-weaning weights (recorded every 28 d between weaning and 84 d post-weaning), and post-weaning ADG (between weaning and 84 d post-weaning) were evaluated in offspring (n = 44). Post-weaning calf weights were analyzed using the MIXED procedure of SAS specific for repeated measures with treatment and time as fixed effects and replicate as random. All other variables were analyzed using the MIXED procedure of SAS with treatment as a fixed effect and replicate as random with gestation length as a covariate for birth weight. Gestation length, birth weight, 205-d WW, and post-weaning calf weight were decreased (P &amp;lt; 0.04) in offspring of dams that consumed E+ relative to E- during gestation. Birth weight was increased (P = 0.02) in offspring of dams receiving melatonin relative to those without melatonin during gestation. The 205-d WW and REA were decreased in calves born to E+/NM dams relative to E-/NM, E-/M, and E+/M (P &amp;lt; 0.03). Post-weaning weight tended to be decreased in calves born to E+/NM dams relative to E-/NM, E-/M, and E+/M (P = 0.06). The UFAT tended to be decreased (P = 0.06) in offspring of dams that consumed E+ relative to E- during gestation. There were no other effects of treatment, time or the interaction (P &amp;gt; 0.10). To our knowledge, these preliminary results are the first to evaluate the potential of melatonin as a therapeutic to recover performance losses in offspring born to pregnant cattle consuming toxic fescue.

47 Influence of Melatonin Supplementation in Pregnant Cattle Consuming Endophyte-Infected Tall Fescue Seed on Offspring Performance

Abstract The objective was to evaluate growth performance and estimates of body composition in offspring of dams that consumed diets containing tall fescue seed with (E+) or without (E-) the toxic endophyte and with or without melatonin during mid-late gestation. Pregnant heifers (n = 57) artificially inseminated with sex-sorted semen (X chromosome-bearing sperm) from a single Angus sire were administered dietary treatments in a 2 x 2 factorial treatment arrangement (E- without melatonin, E-/NM; E- with melatonin, E-/M; E+ without melatonin, E+/NM; or E+ with melatonin, E+/M; melatonin dose: 100 µg/kg of BW) for a 70-d period between May and July starting at 160 ± 13 days of gestation to mimic ergot alkaloid concentrations in a grazing scenario. All diets contained corn gluten and molasses and were fed using SmartFeed Pro (C-Lock Inc.) controlled feeding units between 0900 and 1400 h daily. Cattle were removed from dietary treatments 39 ± 19 days before calving. Two replicates were housed separately in an open-air barn, each with a 1.2-ha paddock. before and following the 70-d treatment period, all cattle were maintained as a single group free from toxic fescue. Calves were weaned at 226 ± 19 d of age. Gestation length, calf birth weight, 205-day adjusted weaning weight (205-d WW), carcass ultrasonography measures (ribeye area, REA; REA/CWT; percent intramuscular fat, IMF; rib fat thickness, UFAT; rump fat thickness, URUMP), post-weaning weights (recorded every 28 days between weaning and 84 days post-weaning), and post-weaning ADG (between weaning and 84 days post-weaning) were evaluated in offspring (n = 44). Post-weaning calf weights were analyzed using the MIXED procedure of SAS specific for repeated measures with treatment and time as fixed effects and replicate as random. All other variables were analyzed using the MIXED procedure of SAS with treatment as a fixed effect and replicate as random with gestation length as a covariate for birth weight. Gestation length, birth weight, 205-d WW, and post-weaning calf weight were decreased (P &amp;lt; 0.04) in offspring of dams that consumed E+ relative to E- during gestation. Birth weight was increased (P = 0.02) in offspring of dams receiving melatonin relative to those without melatonin during gestation. The 205-d WW and REA were decreased in calves born to E+/NM dams relative to E-/NM, E-/M, and E+/M (P &amp;lt; 0.03). Post-weaning weight tended to be decreased in calves born to E+/NM dams relative to E-/NM, E-/M, and E+/M (P = 0.06). UFAT tended to be decreased (P = 0.06) in offspring of dams that consumed E+ relative to E- during gestation. There were no other effects of treatment, time or the interaction (P &amp;gt; 0.10). To our knowledge, these preliminary results are the first to evaluate the potential of melatonin as a therapeutic to recover performance losses in offspring born to pregnant cattle consuming toxic fescue.

153 Meat Quality of Barbados Blackbelly and St. Croix Hair Sheep Lambs Rendered Short Scrotum or Castrated at Weaning

Abstract This study evaluated meat quality parameters of short scrotum and castrated Barbados Blackbelly (BB; n = 16) and St. Croix (STX; n = 15) hair sheep ram lambs. Ram lambs born in April (n = 21) and December (n = 10) were rendered short scrotum (SS; n = 17) or castrated (CA; n = 14) using elastrator bands at weaning (63 days of age). Following a transition period of 2 months in a dry lot, ram lambs co-grazed with ewe lambs in a rotational pasture system and were provided soy hull at 3% BW daily. At target weights of app. 40 kg lambs were slaughtered and loin cuts from individual carcasses were collected for meat quality analysis. Data from the two lambing groups were pooled and analyzed as a completely randomized design with a 2 x 2 factorial treatment arrangement for breed (BB or STX) and sex class (SS or CA). The CIE L* (lightness), a* (redness), and b* (yellowness) values of loin cuts were not significantly influenced by breed or sex class. The longissimus muscle (LM) in loin cuts from CA lambs had a greater (P &amp;lt; 0.0001) fat content (3.73 vs 2.55 ± 0.155%) and tended (P = 0.06) to have a decreased moisture content (69.63 vs 70.75 ± 0.413%) than that from SS lambs. Neither breed nor sex class significantly affected the myoglobin content, percent metmyoglobin and thiobarbituric acid reactive substances (TBARS) values of LM from lamb cuts. Cuts from SS lambs had greater (P &amp;lt; 0.0001) shear force values (3.22 vs 2.64 ± 0.093 kg) than those from CA lambs. However, the cooking loss of loin cuts was not significantly influenced by breed or sex class. The fatty acid profiles of LM from experimental lambs were significantly influenced by breed and sex class. Compared with BB, STX had greater (P &amp;lt; 0.05) concentrations of myristic (C14:0;.38 vs.23%), palmitic (C16:0; 20.15 vs8.98%) and oleic (C18:1n9; 45.01 vs 42.81%), but less than (P &amp;lt; 0.05) concentrations of stearic (C18:0;7.29 vs9.33%) and linoleic (C18:2n6; 6.14 vs 7.47%) acids in LM. Furthermore, the LM from SS lambs had greater (P &amp;lt; 0.05) concentrations of C18:2n6 (8.09 vs 5.51%) and arachidonic (C20:4n6, 2.04 vs.40%), but lless than (P &amp;lt; 0.05) concentrations of C16:0 (19.07 vs 20.06%) and C18:1n9 (41.57 vs 46.24%) acids than that from CA lambs. Data suggest that meat quality parameters were more greatly influenced by sex class than breed when landrace hair sheep lambs were slaughtered at a target weight. Loin cuts from SS lambs were leaner, but less tender than those of CA lambs, and also differed in their fatty acid profiles. Hence meat quality will be impacted by the choice of rendering male lambs sterile.