Back Fat Research Articles

Metabolic Characteristics of Lame Cows During Puerperium and the Beginning of the Reproductive Period

This study presents findings from two discrete experimental processes that examined the impact of lameness events on two consecutive, critical time points in the annual production cycle of dairy cattle (early in puerperium—first study, and later at the onset of the reproductive period—second study) regarding liver function, glucose levels, milk production, body condition score, and back fat thickness. In the first study, 47 cows (lame group n = 22, control group n = 25) were monitored from 10 days ante partum (ap) to 46 days post-partum (pp). In the second study, 79 cows (lame group n = 52, control group n = 27) were monitored from day 28 ± 5 pp to day 65–72 ± 5 pp. Lame cows had greater gamma-glutamyl transferase (GGT) concentrations in the blood serum compared to control cows (25.83 vs. 23.56, p = 0.02, respectively) early in puerperium, whereas the two groups did not differ in the second study. The concentration of glutamate dehydrogenase (GLDH) was lower for lame compared to control cows in both studies (17.24 vs. 24.60, respectively, p = 0.02 in the first study, and 30.50 vs. 51.10, respectively, p = 0.02 in the second study). The concentrations of aspartate transaminase (AST) and glucose did not differ between groups in both studies. Lame cows had a lower body condition score (BCS) and backfat thickness (BFT) scores compared to the control in both studies overall. The lame cows of the first study experienced a significant loss of milk production, especially during the second month of lactation, while in the second study, milk production remained unaffected. Conclusively, lame cows have lower BCS and BFT values, whereas milk yield can be negatively affected only if lameness occurs early in the puerperium, probably beginning at the dry period. However, the current research shows that acutely lame cows, as described in this study, exhibit only mild alterations in liver function compared to non-lame ones.

Genome-Wide Association Integrating a Transcriptomic Meta-Analysis Suggests That Genes Related to Fat Deposition and Muscle Development Are Closely Associated with Growth in Huaxi Cattle

Growth traits are among the most important economic phenotypes targeted in the genetic improvement of beef cattle. To understand the genetic basis of growth traits in Huaxi cattle, we performed a genome-wide association study (GWAS) on body weight, eye muscle area, and back fat thickness across five developmental stages in a population of 202 Huaxi cattle. Additionally, publicly available RNA-seq data from the longissimus dorsi muscle of both young and adult cattle were analyzed to identify key genes and genetic markers associated with growth in Huaxi cattle. In total, 7.19 million high-quality variant loci (SNPs and INDELs) were identified across all samples. In the GWAS, the three multilocus models (FarmCPU, MLMM, and BLINK) outperformed the conventional single-locus models (CMLM, GLM, and MLM). Consequently, GWAS analysis was conducted using multilocus models, which identified 99 variant loci significantly associated with growth traits and annotated a total of 83 candidate genes (CDGs). Additionally, 23 of the 83 CDGs overlapped with significantly differentially expressed genes identified from public RNA-seq datasets of longissimus dorsi muscle between young and adult cattle. Furthermore, gene functional enrichment (KEGG and GO) analyses revealed that over 30% of the pathways and GO terms were associated with muscle development and fat deposition, crucial factors for beef production. Specifically, key genes identified included MGLL, SGMS1, SNX29 and AKAP6, which are implicated in lipid metabolism, adipogenesis, and muscle growth. In summary, this study provides new insights into the genetic mechanisms underlying growth traits in Huaxi cattle and presents promising markers for future breeding improvements.

The Effect of Dietary Propylene Glycol on the Fatty Acid Composition of Three Fat Depots in Male Akkaraman Lambs.

This study tested the effects of propylene glycol (PG) on the fatty acid composition of Akkaraman lambs in three different anatomical depot locations (ADLs). Twenty-four lambs were assigned to a randomized complete block design comprising three groups of 8 animals as follows: Con, 1.5%, body weight (BW)0.75 (PG1.5) and 3% BW0.75 supplemental PG. The animals were slaughtered 90 days after the commencement of feeding. Tail, perirenal and back fat were collected, and their fatty acid compositions were analysed. PG was associated with lower levels of capric acid (C10:0) and lauric acid (C12:0), and higher levels of arachidic acid (C20:0), D-ɣ-linolenic acid (C20:3n6), behenic acid (C22:0), docosadienoic acid (C22:2n6), tyricosylic acid (C23:0) and eicosapentaenoic acid (C20:5n3; p<0.05, p<0.01 and p<0.001). The ADLs differed for all fatty acids except C12:0 and C14:0 (myristic acid). Perirenal fat had the highest SFA levels, while n6/n3 was higher in tail fat than in fat from the other ADLs (p<0.001). The high correlation of ∆9 C16 and ∆9 C18 index values with other sum and index values indicates that desaturation enzyme activity was elevated in the lambs' depot fats (p<0.05, p<0.01 and p<0.001). This suggests that perirenal fats have less favourable fatty acid compositions than the other ADLs.

Effect of K2CO3 on konjac glucomannan/κ-carrageenan-based camellia oil Pickering emulsion gel for the development of fat analogs.

Konjac glucomannan (KGM) undergoes deacetylation in alkaline conditions, while κ-carrageenan (CRG) is sensitive to potassium ions. This study examines the influence of K2CO3 on the mechanical properties of KGM/CRG-based camellia oil Pickering emulsion gels. Texture analysis and rheological testing revealed that the addition of K2CO3 significantly enhanced the mechanical properties of emulsion gels. Texture parameters, such as the hardness, gumminess, and chewiness of the gel, were closer to those of pork back fat when the K2CO3 concentration was 0.2M. The addition of K2CO3 enhance the intermolecular crosslinking within the gel and formed a more uniform and dense gel network, promoting gelation and structural stability, which were confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, and microstructural analysis. Besides, low-field nuclear magnetic resonance and thermogravimetric analyses indicated that the addition of K2CO3 reduced the water mobility of the gel and improved its thermal stability. Physicochemical and color analysis results showed that the energy value of the camellia oil Pickering emulsion gel was only 15.9% that of pork back fat, and its appearance was closer to that of pork back fat than hydrogels. This study provides technical support for the use of KGM/CRG-based camellia oil Pickering emulsion gels as fat analogs.

Fulvic acid inhibits the differentiation of 3T3-L1 adipocytes by activating the Ca2+/CaMKⅡ/AMPK pathway.

Type 2 diabetes increases the risk of developing obesity. Although fulvic acid alleviates back fat thickness in pigs, the mechanism underlying its anti-obesity effect remains unclear. Therefore, we investigated the anti-obesity mechanism of fulvic acid using 3T3-L1 adipocytes. We examined the effects of fulvic acid on adipocyte differentiation, cell viability, and lipid accumulation using molecular techniques. Fulvic acid treatment significantly decreased intracellular lipid accumulation in 3T3-L1 cells during the differentiation compared with that in the control group. Western blotting revealed fulvic acid-induced downregulated expression of the adipocyte differentiation-related markers peroxisome proliferator-activated receptor gamma, CCAAT/enhancer-binding protein alpha, and sterol regulatory element-binding protein 1. The fulvic acid treatment decreased the expression of the lipid uptake-related markers fatty acid-binding protein 4 and the cluster of differentiation 36 in 3T3-L1 cells. Moreover, fulvic acid significantly increased cytosolic Ca2+ concentration via Ca2+ sequestration from the endoplasmic reticulum, enhanced Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity, and upregulated AMP-activated protein kinase (AMPK), thereby reducing adipocyte differentiation. Conclusively, fulvic acid attenuates adipocyte differentiation by activating the Ca2+/CaMKⅡ/AMPK pathway, suggesting its anti-obesity potential.

Allometric Growth of Non-Carcass Components, Carcass Cuts and Hind Limb Tissues in Kivircik Lambs Finished Under Concentrate- and Pasture-Based Systems.

Obtaining information about the growth rates of animals' organs and tissues can help understand their meat production potential and determine the ideal slaughter weight (SW). This study aimed to determine the effects of production system and SW on the allometric growth of the non-carcass components, carcass cuts, and hind limb tissues of Kivircik lambs. A total of 54 single-born male lambs were randomly allocated into production systems (concentrate- and pasture-based) and SW groups: 25-26kg (LOW), 30-31kg (MEDIUM), and 35-36kg (HIGH). The data for weights of non-carcass components, carcass cuts and hind limb tissues were analysed using General Linear Model (GLM). The allometric growth of non-carcass components, carcass cuts and hind limb tissues was estimated using the nonlinear allometric equation (Y=aXb). The mean of carcass components increased linearly with SW (p<0.05). Similar omental-mesenteric fat, kidney knob and channel fat (KKCF), back fat thickness, subcutaneous fat, intermuscular fat and total fat levels were observed in the different SW groups in a pasture-based system (p>0.05). Carcass cuts and hind limb fat tissues show late development (b>1) in the concentrated system. Development of subcutaneous fat and total fat was late maturing (b>1) in the pasture-based system. Allometric growth of KKCF, subcutaneous fat and total fat was rapid. If more carcass weight is desired from Kivircik lambs in the concentrated production system, they should be slaughtered at higher weights than the HIGH group. Continuing to fatten pasture-based lambs after 30-31kg may result in fatty carcasses.

Differences in severity of reticulo-rumen pH drop in primiparous Holstein cows fed the same diet during transition and early lactation: effects on performance, energy balance, blood metabolites, and reproduction.

We recently reported factors leading to different severity of ruminal pH drop in primiparous cows fed the same diet during transition and early lactation. The present study evaluates the effects of those severities on performance and several blood and balance parameters in the same 24 primiparous cows from 3wk before calving until week 10 in lactation. The dietary concentrate was increased for all cows from 32 before calving to 60% dry matter (DM) basis over the first week in lactation, resulting in a diet with 40% non-fiber carbohydrates (NFC), and 14.4% physically effective fiber [peNDF > 8]. Ruminal pH was monitored with indwelling systems in all cows during the study; then several indices of duration and magnitude of pH change were used as indicators of the severity of ruminal pH drop. Accordingly, as reported in the companion paper, the cows were classified as either higher pH drop (HIGH; n = 9), moderate (MOD; n = 9), or lower (LOW; n = 6) severity of pH drop. In the present report, body weight, body condition score, and back fat thickness decreased but rumen mucosa thickness increased after calving in all cows (P < 0.05). Post-partum daily energy intake in HIGH was greater (P < 0.05) than in the other categories. In addition, there were 5.6kg extra of energy-corrected milk in HIGH (P < 0.05). Independent of the severity of pH drop, blood glucose, non-esterified fatty acids, beta-hydroxybutyrate, bilirubin, and cortisol were higher, whereas triglycerides, total protein, globulin, albumin, urea nitrogen, cholesterol, calcium, and phosphorous were lower at calving (P < 0.05). Blood cholesterol was greater in HIGH than the other pH categories (P < 0.05); insulin and reproductive variables were not affected by the severity of the pH drop. Overall, primiparous cows fed the same diet showed different severity of ruminal pH drop, but the individual variation in ruminal pH depression was not related to a negative impact on milk yield, energy balance, or blood metabolites during the study. This indicates that the impact of low ruminal pH on the animals may depend not only on the severity of the pH drop (average of 403min/d of pH < 5.8 over 13wk) but also on diet characteristics. Specifically, drops of ruminal pH can be tolerated by primiparous cows during the first 10wk in milk consuming a diet containing 40% NFC and 14.4% peNDF > 8. It would be worth studying the severity of ruminal pH drop in a larger sample size during the entire lactation and if the severity is sustained on the next lactation.

Dietary 25-Hydroxycholecalciferol Supplementation from Day 85 of Gestation to Farrowing Enhances Performance, Antioxidant Capacity, and Immunoglobulins of Sows and Newborn Piglets.

In this study, the aim was to evaluate the effects of dietary 25-hydroxycholecalciferol supplementation from day 85 of gestation on performance, antioxidant capacity, and immunoglobulin level of sows and newborn piglets. On day 85 of gestation, forty Landrace × Yorkshire gestating sows (average body weight of 241 ± 6.8 kg; average parity of 3.47 ± 0.6) were allotted into two treatments (20 replicates per treatment) based on parity, body weight, and back fat thickness. From day 85 of gestation to farrowing, sows were fed a normal vitamin D3 diet as control (containing 50 μg/kg vitamin D3; CON), or a 25-hydroxycholecalciferol-supplemented diet (containing 50 μg/kg 25-hydroxycholecalciferol). Compared with CON, dietary 25-hydroxycholecalciferol supplementation increased (p < 0.05) protein and fat content in colostrum and the average birth body weight of newborn piglets. Sows fed 25-hydroxycholecalciferol showed increased (p < 0.05) apparent total tract digestibility of crude protein compared with CON. Diets supplemented with 25-hydroxycholecalciferol also increased (p < 0.05) the content of superoxide dismutase (SOD), and tended to increase (p = 0.06) the total antioxidant capacity content and reduce (p = 0.09) the malondialdehyde (MDA) level in colostrum. An increase (p < 0.05) in the content of SOD and a reduction (p < 0.05) in the content of MDA in the serum of newborn piglets was also observed in the 25-hydroxycholecalciferol treatment compared with CON. Dietary 25-hydroxycholecalciferol supplementation also enhanced (p < 0.05) the immunoglobulin G content and reduced (p < 0.05) the concentration of tumor nuclear factor-α in the serum of sows, as well as reducing (p < 0.05) the content of immunoglobulin G and immunoglobulin A in the serum of newborn piglets compared with CON. Supplementation of 25-hydroxycholecalciferol in sow diets increased (p < 0.05) the content of alkaline phosphatase in the serum and colostrum of sows, the concentration of insulin and crosslap in serum of sows, and the serum calcium content of newborn piglets compared with CON. In conclusion, dietary 25-hydroxycholecalciferol supplementation from day 85 of gestation could enhance performance, antioxidant capacity, and immunoglobulin in sows and newborn piglets.

Effects of Acorns on Fatty Acid Composition and Lipid Metabolism in Adipose Tissue of Yuxi Black Pigs.

The objective of the present research was the examination of how varying proportions of an acorn diet affects the deposition of subcutaneous fat and the composition of fatty acids (FAs) in Yuxi black pigs. Ninety pigs (with a balanced sex ratio and a similar weight 99.60 ± 2.32 kg) were stochastically assigned to the control group (CON) and the dietary acorn experimental groups (AEG). The CON was fed basal diets and the AEG1, AEG2, AEG3, and AEG4 groups were provided with dietary regimens comprising twenty, thirty, forty, and fifty per cent acorns, respectively. Each group consisted of six pigs, with three replicates. The breeding cycle was four months. The results demonstrated that, in comparison with the CON group, the lean meat rate was significantly increased in all test groups (p < 0.05), while in backfat thickness, loin eye area, carcass weight and slaughter rate was no significant difference (p > 0.05). The serum TC/HDL (total cholesterol divided by high-density lipoprotein-cholesterol) and TG/HDL (Triglyceride divided by high-density lipoprotein-cholesterol) levels in the AEG1 and AEG2 groups were significantly lower than the CON group (p < 0.05). There was no significant effect on the composition of FAs (p > 0.05). The number of fat cells in subcutaneous back fat and subcutaneous abdominal fat was significantly increased, and the area of fat cells was decreased (p < 0.05). Furthermore, the levels of ATGL and HSL expression in the subcutaneous back fat, as well as ACC, FAS, ATGL, PPARγ, and HSL expression in the subcutaneous abdominal fat, were significantly increased in the AEG2 group compared to the CON group (p < 0.05). Additionally, the expression of ACC, FAS, FABP4, PPARγ, C/EBPα, and FAS/HSL in the subcutaneous back fat, as well as FABP4, C/EBPα, and FAS/HSL in the subcutaneous abdominal fat, were significantly lower in the AEG2 group compared to the CON group (p < 0.05). In conclusion, it has been found that a 30% acorn diet can inhibit subcutaneous fat deposition and enhance the nutritional value of pork and the health of Yuxi black pigs.

Back Fat Thickness, Body Condition Score and Rib Eye Muscle Area of Young Sheep Fed with Carica Dieng Seeds Based on Ultrasonography

A study to compare the back fat thickness, rib eye muscle area, and body condition score (BCS) of young thin-tailed lambs fed various levels of carica Dieng seeds in rations. Eighteen male lambs aged 3-4 months with an initial body weight of 10.68 ± 1.30 kg were applied three feeding treatments (T) following a completely randomized design, T1 = complete feed containing 5% carica seeds, T2 = complete feed containing 12.5% carica seeds, and T3 = complete feed containing 20% carica seeds, with six replications each. At the end of 14 weeks of feeding treatment, back fat thickness and rib eye muscle area were measured using the Digital Veterinary Ultrasound Imaging System CTS-800. Yield grade value was determined using back fat thickness data, while the BCS assessment was carried out visually. The results showed that various levels of carica seeds addition to complete feed did not produce significant differences (P&gt;0.05) in all variables measured. Back fat thickness, BCS, and rib eye muscle area in young thin-tailed sheep were 1.46 mm, 3.06, and 15.52 cm2, respectively. It might be concluded that supplementation of carica Dieng seeds up to 20% in the complete feed can still be utilized by young thin-tailed sheep.

Relationship of Hot Carcass Weight and Back Fat Thickness with the Fatness of Whole Pork Belly and Belly Slices.

This study evaluated the correlation between hot carcass weight (HCW), back fat thickness (BFT), and fatness of whole pork belly and belly slices. Pork bellies were obtained from 50 barrows and 50 gilts. The fat content (v/v) of the whole pork belly and belly slices was measured using computer tomography and hyperspectral image analysis, respectively. Barrows and gilts showed significant differences only for HCW (p<0.05). The fat content of pork belly slices varied with location and was the highest at the 10th thoracic vertebra (TV). Although no significant difference was observed in the fat content between the belly slices of the 6th TV and the 12th-14th TVs (p>0.05), a difference in the fat distribution was observed. HCW and BFT were significantly correlated with the fat content of whole pork belly, but not with the fat content of pork belly slices. Therefore, HCW and BFT are not suitable for monitoring the fatness of pork belly slices, and further research on the factors that can be used for monitoring the fatness of pork belly is necessary.

Determination of the Impact of Extruded Soybean Press Cake on Rearing and Health Indices of Piglets

The study was conducted to evaluate the alternative to imported soybean meal—extruded soybean press cake—in feeding weaning pigs. The experiment was carried out with 20 35-day-old weaned pigs weighing about 8.8 kg, divided into 2 groups (10 pigs in each) differing in the main protein source: group I—control, solvent-extraction soybean meal, group II— extruded soybean press cake. The feed mixtures were iso-protein and iso-energetic. After 35 days of feeding, the pigs were slaughtered. The samples of blood, intestinal tissue and digesta, meat, and back fat were collected for analyses. Replacement of soybean meal with extruded soybean press cake in the weaners’ diet had no statistically significant effect on growth performance and feed utilization. Histomorphometry analysis of the intestines did not indicate any harmful changes. The soybean press cake did not affect the sum of volatile fatty acids in the large intestine, but the ammonia concentration was lower in the distal colon (p ≤ 0.05). It was found that the extruded soybean press cake in the feed significantly affected the fatty acid profile (p ≤ 0.05) of meat and back fat, increasing the amount of PUFAs; however, no negative impact on the durability of meat and back fat during storage was noted. In conclusion, the study confirmed the possibility of completely replacing solvent-extraction soybean meal with extruded soybean press cake in the feeding of weaned pigs.

Effect of Bacillus amyloliquefaciens supplementation on intramuscular fat accumulation and meat quality in finishing pigs.

This study evaluated the potential of Bacillus amyloliquefaciens to improve growth performance and meat quality in finishing pigs. Thirty-two female Landrace × Duroc pigs, 21 weeks old with initial body weight 77.45±3.29 kg, were divided into two groups: a control group (basal diet) and a probiotic group (basal diet with Bacillus amyloliquefaciens at 1×109 CFU/kg). Body weight and average daily gain (ADG) were recorded at the start and at fortnight intervals for a 56-d feeding trial. At the end of the experiment, carcass traits, meat quality and intramuscular fat related gene expression of longissimus dorsi muscle were analyzed. The probiotic group showed significantly higher final body weight and D0-D56 ADG (p < 0.05). Additionally, the probiotic group had greater carcass weight, back fat thickness and marbling score (p < 0.05), while the lean meat percentage remained unchanged. Meat quality analysis revealed that the probiotic group had a higher b* value (5.47) (p < 0.05), and a lower shear value (p < 0.001), but there was no effect on the a* value and water holding capacity. Moreover, probiotic treatment increased the gene expression of fatty acid uptake and regulator, such as LPL, CD36, and SLC27A1 (p < 0.05). Our findings suggest that the supplementation of Bacillus amyloliquefaciens not only enhanced growth performance and carcass weight in finishing pigs, but also improved marbling and tenderness in the longissimus dorsi muscle through the up-regulation of lipogenic-genes related to fat accumulation. This indicates its potential as feed additive to enhance pork quality.

Impact of an extended light regimen imposed during nursery period on the performance and lipid metabolism of weanling pigs.

This study aimed to assess the impact of a prolonged photoperiod on the growth performance and lipid metabolism of weaned piglets. Twenty-four piglets weaned at 28 days of age were randomly dichotomized into two groups that were alternatively subjected to either long photoperiod (LP) group (16L:8D) or short photoperiod (SP) group (10L:14D) for 42days. Four replicates of three animals per replicates were used per experimental treatment. Our results demonstrated that prolonged photoperiod increased piglet body weight, average daily weight gain (ADG), backfat thickness (BF), backfat index during the nursery period, and increased ADG, average daily feed intake (ADFI), and decreased the F/G of piglets during the experiment days 29 to 42. Meanwhile, we observed LP piglets' plasma melatonin, growth hormone and serotonin levels were decreased at 14 d and 42 d compared to SP piglets. Moreover, up-regulated mRNA or protein expression of PPARγ and CEBPα, and lower mRNA or protein expression of MTR1, ATGL, HSL, PPARα, and CPT1α, were observed in back subcutaneous fat (BSF) of LP group compared with that of SP group. Significant increases were observed in the mRNA or protein contents of lipogenic genes, including C/EBPα, SREBP-1c, ACCα, and FAS, in the liver of LP piglets, whereas CPT1α and ACOX1 mRNA levels and PPARα and MTR1 protein expression were significantly down-regulated in LP group compared to SP group. Extended photoperiod also increased lipid content in longissimus dorsi muscle (LDM) that was associated with higher mRNA or protein levels of SREBP-1c, ACCα, FAS, Pref1, and LPL, decreased mRNA or protein contents of LeptinR, MTR1, HSL, and ACOX1. Together, these findings suggest that there is an advantage, in terms of growth performance and fat deposition, in imposing a prolonged light program (16-h light/day) on nursery piglets to alleviate the negative aspects of weaning stress.

Assessment of skeletal muscle dynamics and milk production across a 300-day lactation in multiparous dairy cattle

The objective of this study was to evaluate changes in longissimus dorsi muscle depth (LDD) across lactation (0 to 300 DIM) and identify the impact of low versus high muscle reserves immediately after parturition on body weight and body reserve changes as well as production variables across a 300-d lactation. Forty multiparous cows were classified as high muscle (HM; LDD > 5.0 cm; n = 18) or low muscle (LM; LDD ≤ 5.0 cm; n = 22) based on LDD measurements collected within 24 h of parturition. Body weights (BW) and ultrasound scans to assess LDD and back fat depth (BFD) were collected monthly from parturition until 300 DIM. Ultrasound scans captured and measured using available software. Blood samples were taken at 7, 150 and 300 DIM, and plasma was analyzed for markers of metabolic status by measuring insulin, nonesterified fatty acids (NEFA), creatinine, and 3-methylhistidine (3-MH). Milk yield was recorded daily and milk components were analyzed monthly. Data analysis was performed and the statistical models included the fixed effect of muscle group, time, their interaction, and the random effect of cow nested within muscle group with repeated measures using a first-order autoregressive covariance structure. Muscle group was not related with BW or BFD for any of the time points measured. Cows lost BW from 0 to 60 DIM and gained weight from 60 to 300 DIM. Similarly, BFD decreased between 0 to 90 DIM and increased BFD after 90 DIM until 300 DIM. A muscle group by time interaction was observed for LDD. The HM cows had more muscle at 0 DIM, indicative of treatment assignment (1.34 cm more), and 300 DIM (0.78 cm more) and tended to have more muscle at 60 DIM (0.66 cm more) compared with LM. After 240 DIM, both muscle groups began net accretion of muscle reserves until 300 DIM. No differences were observed for blood metabolites measured based on muscle group. However, there were significant time effects for creatinine, 3-MH, and NEFA concentrations, which reflected the observed changes in BFD and LDD measured in ultrasound scans. For statistical analysis of daily milk production, observations were grouped into 3 stages of lactation, early (0-60 DIM), mid (60-240 DIM), and late lactation (240-300 DIM). There was a muscle group by stage of lactation interaction, where in early and mid-lactation, HM cows produced, on average, 1.9 kg more milk/d; however, in late lactation, LM cows produced 1.8 kg more milk/d. Our results indicate that muscle reserves are depleted in early lactation, and accreted in late lactation, whereas BW and BFD started to increase by 90 DIM. Data also supports that cows with more extensive muscle depletion in early lactation had greater milk production, however, substantial muscle accretion in late lactation may result in reduced milk production.

Effect of polysaccharide on structures and gel properties of microgel particle reconstructed soybean protein isolate/polysaccharide complex emulsion gels as solid fat mimetic

In this work, a soybean protein isolate (SPI)/polysaccharide microgel particle reconstructed emulsion gels (MPEG) were fabricated through heat-induced gel (HG)–microgel particle–transglutaminase (TG) induced gel process in the presence of four polysaccharides (κ-carrageenan, κC; konjac glucomannan, KGM; high-acyl gellan, HA and xanthan gum, XG). HG exhibited a higher springiness than that of pig back fat (PBF) regardless of polysaccharide type and concentration. After forming MPEG, the springiness was significantly lowered at ≥0.6 % κC, which made MPEG exhibit similar springiness of PBF; while SPI/KGM, SPI/XG and SPI/HA systems failed to regulate the springiness property. Rheological behavior revealed the loss in elasticity, the increase in the plastic deformation of SPI/κC MPEG, while KGM, XG and HA systems still exhibited elasticity dominated rheological properties. Compared with KGM, XG, the presence of excess κC and HA disturbed the continuous protein network structure, resulting to the aggregation of microgel particles and oil droplets. Disulfide bonds and hydrophobic interactions mainly contributed to the formation of MPEG, while the addition of κC weakened the contribution of them, which was not conducive to the formation of gel network. This study provides a guidance on the development of solid fat mimetic based on the microgel particle emulsion gels.

PSXIII-20 Impact of Aspergillus oryzae fermentation-derived prebiotic-like additive combined with monensin on feedlot performance in finishing steers

Abstract The aim of this study was to investigate the effects of supplementing a prebiotic-like action additive product derived from the fermentation of Aspergillus oryzae (AM; 2 g Amaferm/d) in combination with monensin throughout the entire feedlot period. The primary objective was to evaluate the impact of this dietary intervention on feedlot performance, focusing on parameters such as feed intake, feed-to-gain ratio, body weight (BW), average daily gain (ADG), and carcass quality. Steers (n = 1,200), aged approximately 18 mo with an initial BW of 307.8 ± 17 kg, were randomly assigned to 8 pens (150 steers per pen) and each pen was randomly assigned to two treatments: a control diet with monensin (M; monensin supplemented at 33 mg/kg DM) and a treatment diet with the addition of AM (M+AM; monensin supplemented at 33 mg/kg DM and 2 g Amaferm/d). The feedlot period comprised three steps, with daily feed delivery adjustments using a feed bunk management system. A multilevel model using the PROC MIXED procedure of SAS with pen as experimental unit, was employed to evaluate feed intake, feed to gain ratio, BW and ADG for each period, also including effects on carcass quality and growth measured by ultrasound (random sample of 45 animals per pen; 30% of each pen). No significant differences were observed in feed intake across the three diet steps (P &amp;gt; 0.10). During the adaptation period, steers fed AM had greater ADG (+0.168 kg/d; P = 0.003) and increased BW at d 20 (+5.5 kg; P &amp;lt; 0.001). Although ADG during the finishing phase was similar for both treatments, a trend was observed for greater BW at d 108 (+4.6 kg; P = 0.095) when supplemented with AM. The inclusion of AM showed no impact on feed-to-gain ratio for the entire period (P = 0.589). In the finishing period, a positive effect on ribeye area (REA) growth rate (+0.54 cm2/mo; P = 0.016) and a trend towards greater back fat deposition rate (+0.11 mm/mo; P = 0.069) were observed with AM supplementation. At the end of the finishing period, a trend towards greater REA (+1.39 cm2; P = 0.101) was noted with no differences in back fat. Overall, this study demonstrates that the addition of AM throughout the feedlot period positively influenced the productive response during the adaptation period, leading to improvements in carcass growth during the finishing period.

PSIX-27 Ultrasound scanning of carcass traits in Katahdin lambs for predictive breeding value and marketing premium

Abstract Ultrasound scanning (USS) technique has been routinely used in performance testing of meat animals, such as swine and beef cattle. This study is to evaluate USS application in organic lamb production, selection, and the accuracy of carcass traits and market value prediction. Ewes (n = 60) were bred, pregnancy diagnosed at 40 d post-mating, and their suckling lambs were assigned to two groups, a non-creep feeding (control) and creep feeding (treatment) group. Each group was balanced with sexes and litter size when allocated into groups at 30-d of age. All lambs had unrestricted suckled their dams during pasture grazing or grazing with creep feeding supplementation until weaning. There were 28 control and 32 treatment group lambs presented at weaning 90 d of age. Lambs were continued to graze as two groups on fescue-based pasture or grazing with creep feeding supplementation till marketing at 120 d. Weaning body weight (BW), average daily gain (ADG), and post-weaning growth weight were significantly (P &amp;lt; 0.05) greater than control 24.0 kg, 226 g/d, and 28.0 kg for treatment group compared with control group at 21.3 kg, 196 g/d, and 25.3 kg, respectively. However, AGD was not significantly increased during the post-weaning creep supplementary feeding period. The ultrasound scanned carcass traits increase in creep feeding over control lambs at weaning and post-weaning measurements (Figure 1). The average ultrasound scanned back fat depth, loineye muscle depth, muscle width, and loineye muscle area were 2.2 mm, 17.9 mm, 45.6 mm and 5.8 cm2 at weaning age of 90 d; and 2.6 mm, 20.9 mm, 48.0 mm, and 7.0 cm2 at 120 d, respectively. The correlative associations (Table 1) between carcass traits and lamb BW, such as loineye muscle depth (LED), loineye muscle width (LEW), loineye muscle depth (LED) and loineye muscle area (LEA), and LEA were significantly improved (P &amp;lt; 0.05) with increased BW. However, there was no difference in these traits due to treatment except backfat depth, which was significantly higher for treatment and females. Creep supplementary feeding lambs during pre-weaning has increased ADG and weaning weight; therefore, will enhance market values of organically raised lambs. The results indicate that USS technique is worthy of application in meat lamb selection, post-weaning performance and market premium prediction.

52 Differences in body composition measurements for developing Angus heifers

Abstract The profitability of beef cow-calf operations relies on the reproductive ability of females to calve at 2 yr of age and provide a calf each subsequent year for her lifetime. The management of replacement heifers could affect her ability to conceive early, calve, and rebreed. Common management practices use heifer body weight (BW) (and body condition score (BCS) as indicators of puberty onset but do not indicate body composition and fat deposition. The objective of this study was to use ultrasound measurements of carcass traits to compare the effect of different diet management practices on muscle development and fat deposition of post-weaning heifers. The heifers placed on a higher energy diet are expected to have greater mean carcass trait measurements than the lower energy diet heifers. A total of 124 purebred Angus heifers from the Iowa State University McNay Memorial Research and Demonstration Farm were used for this study. Two diets were administered in this study. One group of heifers (G1; n = 61) was developed on a low-energy roughage diet to reach a target BW of 55% of mature BW at the time of breeding. The second group (G2; n = 63) was developed on a grain diet to reach the target BW of 65% mature BW at breeding. Body weight and ultrasound measurements for backfat (BFAT), ribeye area (REA), and intramuscular fat (IMF) were collected over three time points (0-d, 55-d, and 123-d) during the study to quantify the development of body composition characteristics. The initial measurements were collected 1 wk post-weaning. Significant mean differences between the two groups were observed for BW, BFAT, and REA at 55-d (P = 0.027, P = 0.008, and P &amp;lt; 0.0001, respectively), and 123-d (P &amp;lt; 0.001). The mean differences for BW, BFAT, and REA at 123-d between G1 and G2 were 30.98 kg, 0.10 cm, and 7.81 cm2, respectively No significant difference was found between the groups for IMF measurements at 55-d (P = 0.927) or 123-d (P = 0.169). This suggests IMF is not significantly influenced by diet during the early, post-weaning heifer developmental stage. Although further research is needed, the results from this study suggest the development of weight, BFAT, and REA in early post-weaning beef heifers is influenced by the energy concentration of the diet.

494 Long-term effects of canola meal inclusion in gestation and lactation diets on sow and piglet performance over two reproductive cycles

Abstract The experiment was conducted to determine the long-term effects of dietary canola meal (CM) inclusion as the main protein source in gestation and lactation diets on sow and litter performance. Sows (n = 68) from two baches were randomly allotted 1 of 2 diets on d 80 of pregnancy. The two diets were a corn-barley and soybean meal control diet (CTRL) and a corn-barley and CM treatment diet (CCM). All diets were formulated to be similar in standardized ileal digestible amino acid and net energy contents. Sow body weight (BW) and backfat (BF) thickness were determined on d 1, 35, 80, and 111 of pregnancy, on d 1 and 21 post-farrowing. Piglets were weighed on d 0 and at weaning (d 21). Data were analyzed using the PROC MIXED procedure of SAS 9.4 for a randomized complete block design with repeated measures. Over the two reproductive cycles, dietary treatments did not influence sow BW and BF thickness on d 80 and 111 of pregnancy, as well as d 1 and 21 post-farrowing (P &amp;gt; 0.10). However, sows fed the CCM diet had less (P &amp;lt; 0.05) BW and BF thickness on d 1 and 35 of pregnancy in the second reproductive cycle than sows fed the CTRL diet. The CCM diet decreased gestation gain from d 80 to d 111 of pregnancy compared with the CTRL diet over the two reproductive cycles (P &amp;lt; 0.05). No dietary effect on litter size or litter performance was found during the experimental period (P &amp;gt; 0.10). However, reproductive cycle had significant effects (P &amp;lt; 0.05) on BW gain and BF thickness from d 80 to 111 of pregnancy as well as BW and BF thickness on d 1 of lactation. In addition, litter weight at birth and after cross-fostering were significantly improved during the second reproductive cycle compared with the first cycle (P &amp;lt; 0.05). An interaction between dietary treatment and reproductive cycle on BW gain and BW on d 1 of lactation was observed (P &amp;lt; 0.05). In conclusion, feeding gestation and lactation diets containing CM as the main protein source to sows over two reproductive cycles supported similar sow reproductive and litter performance as the control.