Reduced Feed Efficiency Research Articles

Knockdown of the glucosamine-6-phosphate N-acetyltransferase gene by RNA interference enhances the virulence of entomopathogenic fungi against rice leaffolder Cnaphalocrocis medinalis

Insect cuticle acts as a first line of defense and a physical protective barrier against entomopathogens. Chitin biosynthesis pathway plays a crucial role in chitin formation in the cuticle of insects. Glucosamine-6-phosphate N-acetyltransferase (GNA) is a key enzyme in insect chitin biosynthesis that regulate the chitin formation. However, how GNA-mediated cuticle metabolism influences virulence of entomopathogenic fungi is still unknown. In this study, CmGNA gene was cloned and characterized from the rice leaffolder Cnaphalocrocis medinalis. The CmGNA contains an open read frame (ORF) 600 nucleotides, encoding 199 amino acids with an isoelectric point of 8.65 and a molecular weight of 22.30 kDa. The expression profile showed that CmGNA was highly expressed in 4th instar larvae and in the cuticle. Here, we also reported the impact of CmGNA gene and entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana, on expression pattern of chitin biosynthesis genes, feeding behavior, survival rate and average body weight of infected larvae, phenotypic deformities, rate of pupation, and adult emergence. Our results showed that knockdown of CmGNA and application of M. anisopliae and B. bassiana three days after RNA interference (RNAi) significantly decreased the expression of CmGNA and other associated genes, reduced feeding efficiency and survival rate, and caused loss of average body weight, less rate of pupation and adult emergence of infected larvae. Knockdown of CmGNA gene also increased the lethality of larvae caused by M. anisopliae and B. bassiana and resulted in significantly phenotypic deformities of infected larvae. Our findings illustrated that RNAi-mediated CmGNA knockdown disturbed the chitin synthesis genes that led to enhancing the virulence of M. anisopliae and B. bassiana, which can provide us new insights to develop novel biocontrol strategies against C. medinalis.

Physiological responses and microbiota shifts after spermidine administration as a postbiotic on rodents fed a high-fat high-fructose diet.

The consumption of a high-fat high-fructose diet partly resemble the western dietary patterns, which is closely associated with excessive body adiposity and metabolic disorders, such as obesity and type 2 diabetes. Moreover, this unhealthy regime produces unfavourable changes on the faecal microbiota, potentially interfering with microorganisms postbiotic function, such as spermidine, a natural polyamine that has been involved in the control of weight gain. The study aimed to analyse the repercussions of spermidine supplementation on somatic measurements, metabolic markers, and the faecal microbiota profile of rats fed a diet rich in fat and fructose. Indeed, Wistar males with oral administration of spermidine (20mg/kg/day) for 6 weeks were evaluated for food and energy intake, biochemical markers, and faecal microbiota signatures. The daily use of spermidine decreased weight gain ( P < 0.01), reduced feed efficiency ( P < 0.01), and attenuated visceral fat deposition ( P < 0.01), although no effect on energy intake, hepatic weight, triglyceride and glucose index and atherogenic indexes. Similarly, the consumption of spermidine partially restored the presence of microbial species, notably Akkermansia muciniphila. Elevated concentrations of this species were linked to a decrease in triglycerides ( P = 0.04), indicating that the supplementation of spermidine might contribute to managing energy fuel homeostasis in association with an obesogenic diet.

Zinc nutrition at first feeding imprints a programming effect on growth and hepatic lipid metabolism in juvenile rainbow trout

The objective of this study was to determine whether supplementation with deficient zinc (Zn) or/and excess copper (Cu) in the first-feeding diet of rainbow trout fry influenced the growth and physiological regulation of juvenile fish subjected to similar challenge feeds again. The feeding trial lasted for 24 weeks and had three phases. In phase I, rainbow trout fry was treated with one of four different plant-based feeds containing or exempting Zn or Cu supplementation (coded Zn-Cu-, Zn+Cu-, Zn-Cu+, Zn+Cu+) for 6 weeks. Thereafter, all groups were fed a common commercial feed for the next 12 weeks (phase II). In phase III, all groups were fed with the “challenge diet” for another 6 weeks which was the basal diet (Zn-Cu-) except that the vegetable oils were replaced by fish oil. The results demonstrated that fish fed a Zn+ diet at first feeding increased larval growth (phase-I), but it had no effect on growth at the end of phase II when fed commercial feeds. In phase III, when re-introduced to a Zn- challenge diet, the feed intake and growth of juveniles with Zn+ history significantly increased, with reduced feed efficiency. Fish growth was neither influenced by dietary Cu levels or by the dietary Cu history in any of the growth phases, but dietary Cu excess (Cu+) reduced body lipid and energy content in fry. In phase I, lower whole-body Zn concentration was observed in the fry of Zn- group compared to Zn+, while the contrary was observed in the juvenile fish as affected by dietary Zn history (phase III). In addition, Zn- dietary history showed increased levels of PUFA and higher mRNA expression of fatty acid biosynthesis genes in the liver. To conclude, early-stage dietary Zn+ history improved growth of juvenile rainbow trout, while dietary Zn- history exhibited signs of improved fatty acid biosynthesis capacity in the liver.

194 Effects of combining plant and yeast extracts with essential oils or protected betaine on performance and health of weaned piglets

Abstract To raise piglets without antibiotics and high trace elements levels, favoring immune development and maturation is a potentially successful strategy, as long as over-stimulation of immune system does not harm animal performance. A trial was undertaken to evaluate response of piglet to varied blend of plant and yeast extracts selected for renowned effects on immune system. Weanling piglets (n = 400; 21 d of age), females and castrated males, were allocated to 4 dietary treatments across 80 pens: negative control (NC), blend of plant and yeast extracts for immune stimulation added to NC (B1), essential oils with anti-inflammatory properties added to B1 (B2), protected betaine added to B2 (B3). Pre-starter diets were fed from weaning to d 42, followed by starter diets offered until the end of the trial at d 69. On d 49, coughing and sneezing (CS) were counted per pen in both rooms, and individual fecal samples were taken from 20 piglets per diet, selected at weaning, to assay total peroxidase activity (TPO), a marker of gut inflammation. Statistical analyses were performed on pen data to analyze effects of treatment on piglet growth rate (average daily gain; ADG), feed intake (average daily feed intake; ADFI) and feed conversion ratio (FCR). The model included the effect of weaning weight, treatment, and interactions. Linear contrasts were used to compare B1 to NC, B2 to B1, and B3 to B2. A similar model was applied to individual fecal TPO measurements. Sneezing count frequency was analyzed with Chi² statistics and odd ratio (OR) were computed per treatment. Dietary treatment did not affect CS counts. Compared with NC, B1 reduced initial ADG and ADFI (from d 21 to 42) and increased initial FCR (P &amp;lt; 0.05). In the following period, ADG, ADFI and FCR improved with B1 (P &amp;lt; 0.05), resuming body weight (BW; final BW: 26.8, 26.8, 27.3 and 27.5, P &amp;gt; 0.20, for NC, B1, B2 and B3, respectively). Overall FCR slightly decreased (1.66 vs. 1.64, P &amp;lt; 0.05, for NC and B1 respectively). Compared with B1, B2 increased initial ADG and ADFI (ADG21-42: 0.244 vs. 0.258 kg, P &amp;lt; 0.05, for B1 and B2, respectively), and decreased FCR initial and overall (overall: 1,64 vs. 1.60, P &amp;lt; 0.05, for B1 and B2 respectively). B2 also minimized fecal TPO compared with other treatments (Uּּ•mL-1: 13.7 vs. 21.3 vs. 7.0 vs. 10.1, P &amp;lt; 0.001, for NC, B1, B2 and B3, respectively). B3 did not provide statistical benefit over B2. In this trial, immune stimulation decreased initial growth and reduced feed efficiency. Anti-inflammatory essential oils tempered consequences of gut inflammation and restored performance, while protected betaine did not provide additional benefit.

PSV-15 Effect of functional amino acids and fiber on growth performance of post-weaning pigs

Abstract This study evaluated the effect of increasing levels of functional amino acids (FAA), including Met, Thr, and Trp with 1.4% standardized ileal digestible (SID) Lys on performance and the effect of high levels of fiber when high levels of FAA combined. A total of 216 pigs [21 d old; 6.46 ± 0.63 kg body weight (BW)] were allotted to one of 6 treatments with 3 pigs of single sex per pen, and 12 replicates/treatment. Treatments were: 1) Control basal diet (BD), 2) BD + 23% more Met+Cys (HMet), 3) BD + 22% more Thr (HThr), 4) BD + 20% more Trp (HTrp), 5) BD + 20% more Met, Thr, and Trp (HFAA, with 9% NDF and 4%ADF), 6) HFAA+ high fiber (27% NDF and 18% ADF in diet by adding soy hulls at expense of corn, HFAA+HF). The experiment lasted for 42 d and pigs were fed experimental diets for 21 d followed by a common diet for the last 21 d. Pigs fed HFAA+HF diet were initially fed HFAA diet for the first 8 d and followed by HFAA+HF diet for the next 13 d, and fed the common diet during the last 21 d. On d 0, 9, 21, and 42, BW and feed intake were recorded, and fecal scores (1 as normal to 4 as watery diarrhea) were assessed during the trial. Data were analyzed using the lme4 package of R 4.1.2, and the statistical models included the fixed effect of treatment and random effect of sex and BW block. Growth performance data were analyzed as single factor ANOVA, whereas stool quality was analyzed using ordinal model. Contrasts were used to test the effects of FAA (by comparing treatments 2, 3, 4, and 5 to BD) and fiber (by comparing HFAA+HF to HFAA). Pigs fed HFAA had reduced (P &amp;lt; 0.05) average daily gain (ADG) and average daily feed intake (ADFI) from d 21 to 42 and tended (P &amp;lt; 0.10) to have reduced overall ADG compared with BD (Table 1). Increasing individual amino acids did not affect performance, with the exception that pigs fed HTrp tended (P &amp;lt; 0.10) to have increased gain to feed ratio (G:F) from d 21 to 42 compared with BD. Greater fiber content did not affect ADG or ADFI; however, it reduced (P &amp;lt; 0.05) G:F during the whole trial compared with HFAA. Treatment did not influence stool quality. In conclusion, combination of increased amounts of Met, Thr, and Trp with SID 1.4% Lys under non-disease challenged conditions resulted in a reduction of performance, but this was not the case with increased individual amino acids, and increased fiber content with increased FAA which reduced feed efficiency of pigs.

Epidemiological investigation of coccidiosis and associated risk factors in broiler chickens immunized with live anticoccidial vaccines in China.

Coccidiosis is a costly intestinal disease of chickens caused by Eimeria species. This infection is associated with high mortality, reduced feed efficiency, and slowed body weight gain. The diagnosis and control of coccidiosis becomes challenging due to the fact that chickens can be infected by seven different Eimeria species and often occur mixed-species co-infections. Grasping the epidemiology of Eimeria species is crucial to estimate the efficiency of poultry management. This study aimed to explore the distribution of Eimeria species in broiler chickens in China after administering live anticoccidial vaccines. A total of 634 samples were obtained, and the survey results showed that the prevalence of Eimeria was 86.12% (546/634), and the most common species were E. acervulina (65.62%), E. necatrix (50.95%), E. mitis (50.79%), E. tenella (48.42%), and E. praecox (41.80%). Most samples indicated mixed-species infections (an average of 3.29 species per positive sample). Notably, 63.98% of samples contain 3 to 5 Eimeria species within a single fecal sample. The most prevalent combinations were E. acervulina-E. tenella (38.96%) and E. acervulina-E. necatrix (37.22%). Statistical analysis showed that flocks vaccinated with trivalent vaccines were significantly positive for E. necatrix in grower chickens (OR = 3.30, p < 0.05) compared with starter chickens, and tetravalent vaccinated flocks showed that starter chickens demonstrated a higher susceptibility to E. tenella-E. brunetti (OR = 2.03, p < 0.05) and E. acervulina-E. maxima (OR = 2.05, p < 0.05) compared with adult chickens. Geographically, in the case of tetravalent vaccine-immunized flocks, a substantial positive association was observed between E. necatrix infection rates and flocks from eastern (OR = 3.88, p < 0.001), central (OR = 2.65, p = 0.001), and southern China (OR = 3.17, p < 0.001) compared with southwestern China. This study also found a positive association between E. necatrix (OR = 1.64, p < 0.05), E. acervulina (OR = 1.59, p < 0.05), and E. praecox (OR = 1.81, p < 0.05) infection and coccidiosis occurrence compared with non-infected flocks in tetravalent vaccinated flocks. This molecular epidemiological investigation showed a high prevalence of Eimeria species in the field. The emergent species, E. brunetti and E. praecox, might be incorporated into the widely-used live vaccines in the future. These insights could be useful in refining coccidiosis control strategies in the poultry industry.

Hidden Hazards Revealed: Mycotoxins and Their Masked Forms in Poultry.

The presence of mycotoxins and their masked forms in chicken feed poses a significant threat to both productivity and health. This review examines the multifaceted impacts of mycotoxins on various aspects of chicken well-being, encompassing feed efficiency, growth, immunity, antioxidants, blood biochemistry, and internal organs. Mycotoxins, toxic substances produced by fungi, can exert detrimental effects even at low levels of contamination. The hidden or masked forms of mycotoxins further complicate the situation, as they are not easily detected by conventional methods but can be converted into their toxic forms during digestion. Consequently, chickens are exposed to mycotoxin-related risks despite apparently low mycotoxin levels. The consequences of mycotoxin exposure in chickens include reduced feed efficiency, compromised growth rates, impaired immune function, altered antioxidant levels, disturbances in blood biochemical parameters, and adverse effects on internal organs. To mitigate these impacts, effective management strategies are essential, such as routine monitoring of feed ingredients and finished feeds, adherence to proper storage practices, and the implementation of feed detoxification methods and mycotoxin binders. Raising awareness of these hidden hazards is crucial for safeguarding chicken productivity and health.

Afflatoxine Effect on Livestock Health: A Review

Aflatoxins have been the cause of numerous deaths in livestock and it also the cause for economic losses. Aflatoxins belong to a group of mycotoxins that are produced by fungi species (molds) as they grow on their substrates. The major ones are aflatoxins B1, B2, G1 and G2, thus named depending on their fluorescence under blue and green light. Aspergillus parasiticus can synthesize AFB1, AFB2, AFG1, and AFG2. AFB1=AFM1&gt;AFG1&gt;AFB2=AFM2&gt;AFG2 from strongest to weakest in terms of toxicity. Pigs so affected became lethargic, did not eat, and eventually became hypothermic, icteric, and had blood in their feces. Acute aflatoxicosis is characterized by an acute hepatotoxic disease that manifests itself with depression, anorexia, jaundice, hemorrhages, edema of the lower extremities, abdominal pain and vomiting. Chronic exposure leads liver cancer. The major target organ for aflatoxins in animals is the liver. Aflatoxins are probably not major causes of livestock disease and low productivity, but are contributing factors which are likely to become more important as livestock production intensifies. The animal feeds most likely to be contaminated are maize, cottonseed, and groundnuts. These feeds are at high risk for aflatoxin contamination. Aflatoxins cannot be detected by sight or smell in contaminated food or feed. Aflatoxins are not eliminated by boiling, cooking, or by processing into compound feeds. Animal source foods, especially milk, may also contain aflatoxins if animals eat contaminated feeds. This is often the case with milk; carry-over rates are relatively high, consumption is high, and milk is often given to infants and young children who are most at-risk for negative health outcomes related to aflatoxin exposure. Affected animals may exhibit reduced feed consumption, weight loss, and reduction in production. The more significant effects in cattle may occur when animals consume lower levels of aflatoxins and chronic effects appear such as reduced reproductivity, immunosuppression, and reduced feed efficiency. An increase in dietary protein protects against adverse effects of the toxin. Feeding of extra vitamins, A and K could also decrease the detrimental effects of aflatoxins. The prevention ways are removing the sources; promotes better agricultural and storage techniques; have good resources for testing and early diagnosis; strict food quality standards; General awareness and personal protection; Better livestock feeding &amp; management.

Corn grain rehydration methods: Water vs. cactus pear in the diet for feedlot lambs

The goal was to evaluate the productive performance, nutrient digestibility, nitrogen balance and blood parameters of feedlot lambs fed silages of corn grain rehydrated with water or cactus pear. Thirty male intact lambs, mixed breed, and with an average initial weight of 22 ± 4.29 kg were assigned to a completely randomized design with three treatments and ten replications. The treatments were defined as diet containing ground dry corn grain - CG (Control); diet containing corn grain silage rehydrated with water (CW) and; diet containing corn grain silage rehydrated with cactus pear (CCP). No significant differences were observed (P > 0.05) among the treatments in terms of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), total carbohydrate (TCHO), and metabolizable energy (ME). However, the ME content (P = 0.0204) of the diets containing rehydrated corn grain silage (CW) (2.57 Mcal/kg DM) was significantly higher than that of the CG diets (2.29 Mcal/kg DM). This difference in ME was associated with improved digestibility of DM (P = 0.0148), OM (P = 0.0032), and TCHO (P = 0.0027) in the CW diets. Animals fed the CG diets exhibited lower total weight gain, daily weight gain, and reduced feed efficiency. Additionally, a higher percentage of starch was found in the feces of animals consuming CG diets. In contrast, animals fed the CCP diet had higher plasma glucose concentrations (P = 0.0177). The inclusion of rehydrated corn grain silage in the diets proved to be a valuable nutritional strategy to enhance the overall nutritive value of corn grain for lambs, leading to improved animal performance. Furthermore, the utilization of cactus pear as a source of rehydration for grain silage can be particularly advantageous in regions where water resources are limited.

213 Increasing Growth Performance by Attenuating the Transportation Stress Response in Nursery Pigs Through L-Tryptophan Supplementation

Abstract Weaning and transport stress impairs intestinal function and reduces nutrient absorption leading to reduced growth performance and feed efficiency. The objective of this study was to eliminate or reduce short- and long-term, transport-induced reductions in feed efficiency and growth by providing supplemental Tryptophan (Trp) above NRC (2012) pre- and/or post-weaning. A total of 480 pigs were blocked by sex, ancestry, and body weight (BW) and used in a RCB design with a 2x2x2 factorial arrangement of pre-weaning treatment (oral gavage of Trp at 0.35, 0.45, and 0.55 g/d (increasing every 5d) pre-weaning or control), transport (transported or not at weaning), post-weaning nursery treatment (1X or 2X NRC Trp). At farrowing pigs were blocked by sex, within litter, and randomly assigned to either a pre-wean Trp or control treatment, where Trp supplementation began on d 5 post-farrowing and stopped at weaning. Post-weaning Trp supplementation included a 3 d oral gavage of Trp and 2X Trp in the diet for the entire 42 d nursery period. At weaning, all pigs were blocked by sex, weaning weight and pre-wean treatment and randomly assigned to transport and post-wean treatments. Pigs were fed four nursery phases with diets containing 1X or 2X NRC recommended concentrations of Trp. There were 10 pens/trt with 6 pigs/pen (equal barrows and gilts). Individual BW were determined every 5 d pre-weaning and every 7 d post-weaning along with pen feed intakes. Data were analyzed as a RCB using GLM procedure in SAS 9.4 with fixed effects of pre-wean dietary treatment, transport treatment, and post-wean dietary treatment, the interactions, and random effect of replicate. Pre-weaning Trp supplementation had no effect on pre-weaning growth performance. A 3-way interaction of pre-wean treatment x transportation x post-wean treatment was observed for overall nursery BW (P = 0.0148) and ADG (P = 0.0175). This interaction was the result of post-weaning Trp supplementation increasing BW and ADG in all pigs, except for transported pigs that did not receive Trp pre-weaning. While there were 2-way interactions of pre-wean treatment x post-wean treatment on ADFI at week 1 ( P= 0.0123) and week 6 (P = 0.0297) and a 3-way interaction of pre-weaning treatment x transportation x post-weaning treatment at week 2 (P = 0.0092), there were no consistent or overall effects on overall ADFI or G:F. Tryptophan improves transported pigs BW and ADG when supplemented pre- and post-weaning but does not benefit transported pigs when only supplemented post-weaning, suggesting transportation induced reductions in BW and ADG can be mitigated by supplementing Trp prior to and following transportation.

Effect of feeding Yucca schidigera extract and a live yeast on the rumen microbiome and performance of dairy cows fed a diet excess in rumen degradable nitrogen.

Nitrogen (N) loss from livestock agriculture via ammonia and nitrous oxide can reduce feed efficiency, production and negatively affect the environment. One option to reduce N loss is to add dietary supplements such as Yucca schidigera extract which has ammonia-binding properties and contains antimicrobial steroidal saponins, or Saccharomyces cerevisiae yeast, which can stabilise rumen pH and promote fibre degradation, increasing microbial growth and demand for degradable N. To determine the effect of Yucca schidigera extract when fed alone or in combination with a live yeast on the performance, rumen metabolism, microbiome and N balance, six rumen cannulated dairy cows were fed a mixed ration (C), mixed ration with Y. schidigera extract (De-Odorase®, Alltech®; 5g/cow/day; D), or mixed ration with Y. schidigera extract (5g/day) and Saccharomyces cerevisiae (Yea-Sacc®, Alltech®, 1g/cow per day; DY), in a 3×3 Latin rectangle design study with three periods of 49-day duration. Digesta samples were collected via the ruminal cannula during the final week of each period and separated into liquid (LPD) and solid (SPD) phases for microbiome analysis using 16S rRNA amplicon sequencing. DM intake was 0.8kg/d lower (P<0.05) in cows fed DY than C or D, with milk protein concentration 1.7g/kg higher in C than D or DY. There was a beta diversity (Bray Curtis) clustering of the LPD in cows fed D or DY compared to C (P<0.05), driven by an increase in Prevotella ruminicola-related operational taxonomic units (OTUs), and a decrease in P. brevis and P. bryantii OTUs. A methanogen OTU, Methanobrevibacter olleyae, was decreased in cows fed D or DY and an unclassified species of Gammaproteobacteria was increased in DY (LDA>2.0, P<0.05) compared to C. Rumen pH, ammonia and total VFA concentration were not affected by treatment (P>0.05) but the concentration of propionate and iso-butyrate were lower at 1700 and 2000h in cows fed DY compared to C (P <0.05). Measurements of N balance were unaffected by supplementation with D or DY, and there was no effect of treatment on slurry pH. In conclusion, supplementing with an extract of Yucca schidigera either alone or in combination with a live yeast had only a small effect on performance, with Yucca schidigera altering species associated with carbohydrate and protein metabolism, and reduced Methanobrevibacter olleyae which is involved in methanogenesis.

Auction market placement and a rest stop during transportation affect the respiratory bacterial microbiota of beef cattle.

Bovine respiratory disease (BRD) is a significant health problem in beef cattle production, resulting in considerable economic losses due to mortalities, cost of treatment, and reduced feed efficiency. The onset of BRD is multifactorial, with numerous stressors being implicated, including transportation from farms to feedlots. In relation to animal welfare, regulations or practices may require mandatory rest times during transportation. Despite this, there is limited information on how transportation and rest stops affect the respiratory microbiota. This study evaluated the effect of cattle source (ranch-direct or auction market-derived) and rest stop duration (0 or 8 h of rest) on the upper respiratory tract microbiota and its relationship to stress response indicators (blood cortisol and haptoglobin) of recently weaned cattle transported for 36 h. The community structure of bacteria was altered by feedlot placement. When cattle were off-loaded for a rest, several key bacterial genera associated with BRD (Mannheimia, Histophilus, Pasteurella) were increased for most sampling times after feedlot placement for the ranch-direct cattle group, compared to animals given no rest stop. Similarly, more sampling time points had elevated levels of BRD-associated genera when auction market cattle were compared to ranch-direct. When evaluated across time and treatments several genera including Mannheimia, Moraxella, Streptococcus and Corynebacterium were positively correlated with blood cortisol concentrations. This is the first study to assess the effect of rest during transportation and cattle source on the respiratory microbiota in weaned beef calves. The results suggest that rest stops and auction market placement may be risk factors for BRD, based solely on increased abundance of BRD-associated genera in the upper respiratory tract. However, it was not possible to link these microbiota to disease outcome, due to low incidence of BRD in the study populations. Larger scale studies are needed to further define how transportation variables impact cattle health.

Exploring the interaction of viscosity and nipple design on feeding performance in an infant pig model.

Infant feeding behaviors are modulated via sensorimotor feedback, such that sensory perturbations can significantly impact performance. Properties of the nipple and milk (e.g., nipple hole size and viscosity) are critical sources of sensory information. However, the direct effects of varying milk and nipple properties on infant motor output and the subsequent changes in feeding performance are poorly understood. In this study, we use an infant pig model to explore the interaction between nipple hole size and milk viscosity. Using high-speed videofluoroscopy and electromyography, we measured key performance metrics including sucks per swallow and suck duration, then synchronized these data with the onset and offset of activity of jaw opening and closing muscles. The combination of a small nipple hole and thick milk resulted in negative effects on both suck and swallow performance, with reduced feeding efficiency compared to the other treatments. It also appears that this combination of viscosity and hole size disrupts the coordination between correlates of tongue and jaw movements. We did not see a difference in feeding efficiency between viscosities when infants fed on the large-hole nipple, which may be the result of non-Newtonian fluid mechanics. Our results emphasize the importance of considering both fluid and nipple properties when considering alterations to an infant's feeding system.

The Beneficial Effect of Salicornia herbacea Extract and Isorhamnetin-3-O-Glucoside on Obesity

Salicornia herbacea is a halophyte indigenous to marine coastal areas and salt fields and has been used as a traditional remedy for diarrhea, abdominal pain, constipation, and indigestion. Its component isorhamnetin-3-O-glucoside (IR3G) may have antioxidant, anti-inflammatory, and anti-adipogenic properties. In the present study, we aimed to investigate the anti-obesity effect of S. herbacea extract and IR3G on mouse 3T3-L1 adipocytes and db/db obesity mice. S. herbacea extract and IR3G inhibited lipase in a concentration-dependent manner. Oil Red O staining disclosed that S. herbacea extract and IR3G significantly suppressed lipid accumulation and adipogenesis and also inhibited the expression of the C/EBPα in the 3T3-L1 adipocytes. In experiments using db/db mice, administering of S. herbacea extract limited body weight gain and significantly reduced feed efficiency and adipose tissue weight. Moreover, analyzing blood triglycerides, total cholesterol, high-density lipoprotein, and low-density lipoprotein, it was confirmed that LDL was significantly decreased and total cholesterol slightly reduced by S. herbacea extract. However, there was no significant change by S. herbacea extract in the changes in blood levels of leptin and adiponectin. Taken together, these results suggest that S. herbacea extract and IR3G inhibit adipogenesis by suppressing the pro-adipogenic transcription factors in 3T3-L1 preadipocytes and prevent obesity by regulating the blood lipid profile as well as the weight of adipose tissue.

Sublethal effects on the hard clam Mercenaria mercenaria after exposure to Aureococcus anophagefferens Chinese strain isolates

Brown tides caused by Aureococcus anophagefferens occur frequently worldwide and have contributed to the collapse of Mercenaria mercenaria farming in the United States. This economically valuable hard clam has been used in China for more than 20 years. To date, it has remained unknown whether A. anophagefferens Chinese strain has an impact on hard clam cultivation in the coastal areas of China or other sea areas worldwide if it enters through ship ballast water and other ways. In this study, a Chinese strain of A. anophagefferens isolated from the brown tide waters of Bohai Bay, China, was selected to explore its influence on the feedback of hard clams. After being fed with A. anophagefferens, hard clams showed characteristics similar to starvation. The reduced feeding efficiency of hard clams leads to reduced energy intake. However, the immune response and oxidative stress, result in increased energy consumption. An imbalance in the energy budget may be an important reason for hard clam starvation. This study has described the response characteristics of the A. anophagefferens Chinese strain to M. mercenaria, explored the reasons for the negative impact of A. anophagefferens on hard clams, and provides ideas for reducing shellfish aquaculture caused by brown tides.

Caprine Roundworm Nematode Resistance to Macrocyclic Lactones in Northeastern Thailand

Roundworm nematodes are a significant problem in goat meat farming worldwide. These parasites can cause production losses, reduce feed efficiency and compromise animal health and welfare. Macrocyclic lactones (MLs) are common anthelmintic drugs to treat roundworm nematode infection in livestock. The objective of study was to detect roundworm resistance to MLs in meat goats in Northeast Thailand. One hundred and nineteen goats from 6 herds were studied from June to December 2022. Each herd was randomly allocated to control (n=21), epinomectin (n=34), ivermectin (n=40) and moxidectin (n=24) groups. Anthelmintic resistance (AR) was assessed based on the Fecal Egg Count Reduction Test (FECRT) and larva culture at pre-treatment (D0) and 14 days post-treatment (D14). Prevalence of Strongyle nematodes and Trichuris spp. infection was 100% (6/6 herd), and 66.7% (4/6 herd), respectively. The number of Strongyle eggs was significantly reduced in the eprinomectin group (p &lt; 0.01). In contrast, the ivermectin group was significantly increased (p &lt; 0.01). The prevalence of ML resistance of Strongyle nematodes and Trichuris spp. was 83.3% (5/6 herd) and 25.0% (1/4 herd), respectively. The dominant larva was Haemonchus contortus at pre- and post-treatment in every herd. This study demonstrated the presence of ML resistant Strongyle nematodes as H. contortus and Trichuris spp. in this area. To reduce ML resistance it can be useful to use drugs in combination or rotate MLs with other classes of anthelmintics or in targeted treatment programs and integrated parasite management strategies. Consequently, the efficacy of anthelmintic drugs in small ruminants needs to be monitored and surveilled in this area.

Toward the automated detection of behavioral changes associated with the post-weaning transition in pigs.

We modified an automated method capable of quantifying behaviors which we then applied to the changes associated with the post-weaning transition in pigs. The method is data-driven and depends solely on video-captured image data without relying on sensors or additional pig markings. It was applied to video images generated from an experiment during which post-weaned piglets were subjected to treatments either containing or not containing in-feed antimicrobials (ZnO or antibiotics). These treatments were expected to affect piglet performance and health in the short-term by minimizing the risk from post-weaning enteric disorders, such as diarrhea. The method quantified total group feeding and drinking behaviors as well as posture (i.e., standing and non-standing) during the first week post-weaning, when the risk of post-weaning diarrhea is at its highest, by learning from the variations within each behavior using data manually annotated by a behavioral scientist. Automatically quantified changes in behavior were consistent with the effects of the absence of antimicrobials on pig performance and health, and manifested as reduced feed efficiency and looser feces. In these piglets both drinking and standing behaviors were increased during the first 6 days post-weaning. The correlation between fecal consistency and drinking behavior 6 days post weaning was relatively high, suggesting that these behaviors may have a diagnostic value. The presence or absence of in-feed antimicrobials had no effect on feeding behavior, which, however, increased over time. The approach developed here is capable of automatically monitoring several different behaviors of a group of pigs at the same time, and potentially this may be where its value as a diagnostic tool may lie.

The effects of increasing dietary total Ca/total P ratios on growth performance, Ca and P balance, and bone mineralization in nursery pigs fed diets supplemented with phytase.

The objective of this study was to investigate the effects of increasing dietary total Ca/total P ratios on growth performance, digestibility of Ca and P, bone mineralization, and concentrations of Ca and P in urine and plasma in nursery pigs. There were six diets in a randomized complete block design, including one positive control and five diets corresponding to five total Ca/total P ratios: 0.55, 0.73, 0.90, 1.07, and 1.24 (analyzed as 0.58, 0.75, 0.93, 1.11, and 1.30). These five diets were deficient in P but supplemented with 1,000 phytase units/kg feed. Each diet was fed to six pens of eight pigs (four barrows and four gilts per pen). All diets contained 3 g/kg TiO2, and fecal samples were collected from each pen on days 5-7 of trial. At the end, one pig per pen was sacrificed to collect the right tibia and urine in the bladder. The results showed that increasing dietary Ca/P ratio to 0.93 increased gain:feed but then gain:feed decreased as the Ca/P ratio was increased to 1.30 (linear and quadratic, P < 0.05). Although average daily gain and final BW were unaffected by changing Ca/P ratio in diet, dry bone weight; weights of bone ash, Ca and P; and bone Ca/P ratio increased linearly (P < 0.001) with increasing dietary Ca/P ratio. The percent bone Ca showed a tendency to increase (P = 0.064). Increasing dietary Ca/P ratio decreased apparent total tract digestibility (ATTD) of Ca and P linearly (P < 0.05) and the concentration of digestible P linearly (P < 0.001), but increased the concentration of digestible Ca (linear and quadratic effects: P < 0.01) and the digestible Ca/P ratio (linear effect: P < 0.001). In plasma, the concentration of Ca increased both linearly (P < 0.01) and quadratically (P = 0.051), whereas the concentration of P tended (linear and quadratic, P < 0.10) to decrease with increasing dietary Ca/P ratio. Similarly, in urine, the concentration of Ca increased both linearly and quadratically (P < 0.05), whereas the concentration of P decreased linearly (P < 0.01). In conclusion, increasing the dietary Ca/P ratio reduced feed efficiency but increased bone mass and the amounts of Ca and P deposited in bone of nursery pigs fed diets supplemented with 1,000 FYT/kg phytase. The increases in bone growth led to a reduction of urinary P excretion that exceeded the decreased digestible P supplied in diet with the widening dietary Ca/P ratios.

Production, physiological response, and calcium and magnesium balance of lactating Holstein cows fed different sources of supplemental magnesium with or without ruminal buffer

The objective of this study was to evaluate the effects of dietary replacement of magnesium oxide (MgO) with calcium-magnesium hydroxide [CaMg(OH)2] and its interaction with ruminal buffer (sodium sesquicarbonate) supplementation on production, Ca and Mg balance, and overall physiological response of mid-lactation Holstein dairy cows. Sixty cows averaging 40.5 ± 7.0 kg of milk/d were used. Treatments were assigned following a 2 × 2 factorial arrangement: (1) MgO, (2) MgO + buffer, (3) CaMg(OH)2, or (4) CaMg(OH)2 + buffer. Diets were formulated to have 16.5% of crude protein, 1.82 Mcal/kg of net energy for lactation, 0.67% Ca, 0.39% P, and 0.25% Mg, all on a dry matter (DM) basis. Treatments were individually top dressed. Milk production, composition, and DM intake were evaluated. A subsample of 20 cows were randomly selected for the evaluation of Ca and Mg balance, blood gases, and electrolytes. Ruminal fluid was also collected for evaluation of pH and Ca and Mg solubility. Effects of Mg source, buffer, and the interaction Mg source × buffer were analyzed through orthogonal contrasts. An interaction of Mg source × buffer was found for DM intake and feed efficiency, in which cows fed CaMg(OH)2 had a similar feed efficiency regardless of ruminal buffer inclusion; however, when cows were fed MgO, the inclusion of buffer reduced feed efficiency. No effects on body weight and milk yield were observed. Buffer addition tended to increase the concentrations of fat, protein, and solids-not-fat, without affecting the yields of these milk components. Magnesium source and buffer did not affect ruminal fluid, blood, urine, or fecal pH; however, buffer supplementation increased urinary pH. Treatment with CaMg(OH)2 increased blood concentration of HCO3-, total CO2, and base excess compared with cows fed MgO. No differences were observed in the ruminal solubility of Ca and Mg or on milk or urinary Ca and Mg excretion. Greater plasma Mg concentration was observed for animals fed MgO compared with cows fed CaMg(OH)2; however, both sources were above the threshold recommended in the literature for dairy cows. Also, a reduction in fecal Mg excretion was observed in animals fed CaMg(OH)2. In summary, we provide evidence that CaMg(OH)2 could replace MgO without affecting performance, overall physiological response, or Ca and Mg balance of mid-lactating dairy Holstein cows.

Management of Enteric Methane Emissions in Ruminants Using Feed Additives: A Review.

In ruminants' metabolism, a surplus of hydrogen is removed from the reduction reaction of NAD+ (nicotinamide adenine dinucleotide) by the formation of methane by methanogenic bacteria and archaea methanogens. The balance of calculations between VFA (volatile fatty acids), CO2, and CH4 indicates that acetate and butyrate play a role in methane production, while the formation of propionate maintains hydrogen and therefore reduces methane production. CH4 formation in ruminant livestock is not desired because it reduces feed efficiency and contributes to global warming. Therefore, numerous strategies have been investigated to mitigate methane production in ruminants. This review focuses on feed additives which have the capability of reducing methane emissions in ruminants. Due to the environmental importance of methane emissions, such studies are needed to make milk and meat production more sustainable. Additionally, the additives which have no adverse effects on rumen microbial population and where the reduction effects are a result of their hydrogen sink property, are the best reduction methods. Methane inhibitors have shown such a property in most cases. More work is needed to bring methane-reducing agents in ruminant diets to full market maturity, so that farmers can reap feed cost savings and simultaneously achieve environmental benefits.