Subcutaneous Backfat Research Articles

PSV-15 Evaluating the relationship between subcutaneous backfat thickness and sperm morphology in young beef bulls

Abstract Literature indicates that high-energy diets can lead to reductions in both sperm motility and morphology in bulls. This study aimed to investigate the relationship between individual variation in subcutaneous backfat thickness (SCBF) and sperm morphology in young beef bulls exposed to the same diet. We hypothesized that bulls with excessive subcutaneous fat thickness have increased sperm morphology defects compared with bulls with adequate subcutaneous backfat thickness. Historical data collected from yearling Bos taurus beef bulls (n = 557) enrolled in a bull development program were used in an observational retrospective cohort study to test this hypothesis. Over the course of 5 yr, bulls in two locations were developed according to industry standard practices, and performance was evaluated over 84 d with a 21-d adaptation period. At the end of the performance evaluation period, a carcass ultrasound was performed to evaluate ribeye area, SCBF, and intramuscular fat. Furthermore, breeding soundness examinations (BSE) were performed according to the Society of Theriogenology guidelines within 40 d after carcass ultrasonography. Bulls that failed the BSE for reasons unrelated to semen quality were excluded from this study. Within each year, bulls were ranked based on SCBF and classified as top 10% (TOP; n = 55), middle 80% (MID; n = 446), and bottom 10% (BTM;n = 56) for SCBF. Initial body weight (BW) was greater (P < 0.01) in TOP bulls compared with MID and BTM (Table 1). Off-test BW was also greater in TOP compared with MID and BTM bulls (P < 0.01). In contrast, average daily gain and scrotal circumference did not differ between experimental groups (P = 0.35 and P = 0.65, respectively). TOP bulls had greater (P < 0.01) SCBF compared with MID and BTM, and MID bulls had greater (P < 0.01) SCBF compared with BTM bulls. Similar results were observed for intramuscular fat (P < 0.01) and ribeye area (P < 0.01). Percentage of normal sperm cells was greater in both BTM and MID bulls compared with TOP bulls (P < 0.01). Additionally, percentage of primary abnormalities tended (P = 0.07) to be greater in TOP bulls compared with BTM and MID. There were no differences in the percentage of secondary abnormalities between experimental groups (P = 0.45). There was a tendency (P = 0.07) for a greater percentage of TOP bulls to fail the BSE compared with MID and BTM bulls. Moreover, there was a positive linear relationship (P = 0.01) between SCBF and the probability of failing the BSE. In summary, elevated SCBF in bulls exposed to the same diet was associated with an increase in sperm morphological abnormalities and tended to increase the percentage of bulls failing the BSE.

Predicting fat deposition in growing Boer goat castrates and does using ultrasonography

Ultrasonography was used to determine the subcutaneous backfat deposition of Boer goat castrates and does from weaning until one year of age. Logarithmic regressions of subcutaneous backfat measurements were constructed using body weight and age as inputs. The logarithmic regression of subcutaneous backfat deposition with bodyweight had a moderate to good fit, with Boer goat does displaying a better fit (R2=0.70) than castrates (R2=0.65). The logarithmic regression of subcutaneous backfat with age indicated a good fit for both sexes (R2=0.85). Castrates and does displayed similar rates of subcutaneous backfat deposition. The models proposed here will enable producers to estimate the subcutaneous backfat depth of Boer goat castrates and does with reasonable accuracy and can be utilized as benchmarks in precision Boer goat rearing applications, such as predicting an appropriate slaughter weight.

Genetic correlation estimates between calving ease in primiparous cows and economically important traits in Nellore cattle.

This study aimed to estimate (co)variance components and genetic parameters for calving ease (CE) and their genetic correlations with growth, reproductive, carcass, and feed efficiency traits in Nellore cattle. Phenotypes for CE are scored in two categories: normal calving and assisted calving. The traits considered were probability of precocious calving, age at first calving, stayability, adjusted scrotal circumference at 365 days of age, accumulated cow productivity, age at puberty of males, gestation length, birth weight, adjusted weights at 210 and 450 days of age, adult cow weight, frame score, hip height, rib eye area, subcutaneous backfat thickness, rump fat thickness, intramuscular fat percentage, residual feed intake and dry matter intake. The estimation of genetic parameters was performed using a two-trait threshold-linear animal model, except for CE, stayability, and probability of precocious calving, which were evaluated through a two-trait threshold animal model. The direct (0.27) and maternal (0.19) heritability estimates for CE in heifers primiparous Nellore indicated that selecting for this trait is feasible. The selection to improve the female sexual precocity should consider CE during the selection and mating decisions to reduce calving problems. Genetic correlation estimates between CE and BW suggest that selecting low birth weight to reduce calving problems is not an appropriate strategy to improve calving ease in heifers Nellore. Therefore, adopting a multi-trait selection model with CE and BW in the Nellore breed would reduce calving difficulties, particularly in sexually precocious heifers, without impairing the growth, reproductive, feed efficiency conversion, and carcass indicator traits.

Unveiling microwave and Roasting-Steam heating mechanisms in regulating fat changes in pork using cell membrane simulation

Fat reduction due to heating or cooking is an important issue in a healthy diet. In the current study, pork subcutaneous back fat was treated via microwave heating (MH) within 10—90 s and roasting - steam heating (RSH) within 2—30 min and their dynamic changes of individual adipocytes were explored by using vesicles as a bio-membrane model. The result showed that MH and RSH significantly increased fat loss (P < 0.05), with the maximum losses being 74.1 % and 65.6 %, respectively. The mechanical strength of connective tissue decreased and then increased slightly. The microstructure demonstrated that MH and RSH treatments facilitated a large outflow of fat, showing that the particle size of the vesicle and individual adipocytes increased and then decreased. It is thus feasible to study the dynamic changes of individual adipocytes in regulating fat reduction using cell membrane simulation.

Poly-p-dioxanone Thread Leads to Fat Metabolism Around the Thread in Pig Subcutaneous Back Fat.

When poly-p-dioxanone (PDO) thread is implanted subcutaneously, in addition to collagen hyperplasia, it can also cause denaturation of surrounding adipocytes and reduce the thickness of the fat layer. Hitherto, no studies have thoroughly investigated the effects of PDO thread on adipose tissue. In this study, the effect of PDO thread on adipose tissue was investigated in an animal model. In the current study, PDO thread was implanted into subcutaneous adipose tissue of the back in a miniature pig. Implantation site tissue and control site tissue were taken 12 weeks after implantation for hematoxylin and eosin (H&E) staining and transcriptome sequencing. Gene ontology functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis were performed to investigate the differential gene expression between PDO thread implantation and control site tissue. An obvious decrease in the number, fusion, and denaturation of adipocytes can be seen by H&E staining. Sequencing analysis results showed that many of the genes identified, which were downregulated after PDO thread implantation, were involved in functions and pathways related to lipid metabolism, such as fatty acid metabolism, fatty acid degradation, and lipid cell lipolysis regulation. Some genes related to fatty acid metabolism were significantly downregulated in the PDO tissue at 12 weeks compared to the control tissue. Our results showed PDO thread implantation can cause a decrease in the number of adipocytes, as well as a significant alteration of the expression levels of some genes involved in lipid metabolism-related pathways. PDO thread might play an important role in promoting lipolysis.

Inbreeding in the Zwartbles breed population and its influence on meat production in the Czech Republic.

The aim of this study was to estimate the inbreeding coefficient in the Zwartbles sheep population in the Czech Republic, as well as to investigate the effect of inbreeding on meat yield indicators. The analysis used data on the entire population since 1997, with the original database containing 13 150 animals. In this population, the average inbreeding coefficient is 3.64 %. There is a significant increase in inbreeding - from zero values to more than 4 % between 1997 and 2021. The effect of inbreeding on the weight of the animals at 100 d of age, the weight at bonitation prior to breeding, the thickness of the musculus longissimus dorsi (MLD), the thickness of the subcutaneous back fat, and the fleshiness of the animals were all evaluated. The value of the inbreeding coefficient had a statistically significant effect on weight at 100 d, MLD thickness, and back fat thickness. A negative relationship between inbreeding and all of these parameters was found when the inbreeding coefficient was increased by 1 %, resulting in a 60.2 g weight reduction at 100 d, 0.06 mm reduction in MLD thickness, and 0.013 mm reduction in back fat thickness.

Insight into the effect of microwave treatment on fat loss, fatty acid composition and microstructure of pork subcutaneous back fat

In this study, the effects of different microwave treatment times (10, 20, 30, 40, 50, and 60 s) on fat loss, fatty acid profile, lipid transfers, and microstructure of pork subcutaneous back fat (PSBF) were investigated. Results showed that the fat loss of PSBF after microwave treatment for 60 s was significantly increased (53.31%). Microwave treatment increased the proportion of saturated fatty acids but reduced the relative content of monounsaturated and polyunsaturated fatty acids. Cryo-scanning electron microscopy, ordinary optical microscope and confocal laser scanning microscope analysis demonstrated that microwave treatment facilitated a large outflow of fat from the adipocytes, and the increasing and then decreasing changes in the size of individual adipocytes. Magnetic resonance imaging enabled the visualization of fat migration of PSBF. Overall, PSBF can be used as a biological model to evaluate the effect of microwave treatment on the change and migration mechanism of fat.

Transcriptomic Profiling of Subcutaneous Backfat in Castrated and Intact Alentejano Pigs Finished Outdoors with Commercial and Fiber-Rich Diets.

In this work, we studied the backfat transcriptome of surgically castrated (C), intact (I) and intact fed an experimental diet (IE) outdoor-reared male Alentejano (AL) pigs. The experimental diet was a high-fiber diet with locally produced legumes and by-products associated with a boar taint reduction effect. At slaughter (~160 kg), backfat samples were collected for total RNA sequencing. Intact pigs presented leaner carcasses, more total collagen, and more unsaturated intramuscular fat content than C animals. A total of 2726 differentially expressed genes (DEGs, |log2 FC|> 0.58, q < 0.05) were identified between C and I with overexpressed genes related to muscular activity (MYH1, ACTA1) or collagen metabolism (COL1A1, COL1A2) in I pigs. Between C and IE, 1639 DEGs of genes involved in lipidic metabolism (LEP, ME1, FABP4, ELOVL6) were overexpressed in C. Finally, only 28 DEGs were determined between I and IE. Clustering results indicated a drastic influence of the testis in the transcriptome of subcutaneous fat of AL pigs, while the diet had a marginal effect. Diet can reduce stress by increasing satiety in animals, and could have induced an increase of skatole degradation due to the higher expression of the CYP2A19 gene in the IE group.

Influence of nutrition and genetic selection for puberty on the reproductive response of Nelore heifers submitted to fixed-time AI and oocyte recovery with in vitro fertilization

This study evaluated the effects of nutrition and genetic selection for early puberty on the reproductive response of Nelore heifers submitted to FTAI and oocyte pick-up with in vitro embryo production. Prepubertal heifers (n = 198; 13.8 ± 0.07 months) were randomly assigned to a 2 × 2 factorial design with two nutritional treatments (improved nutrition, IN; moderate nutrition, MN) and two genetic groups for puberty (high genetic, HG, early puberty; low genetic, LG, normal puberty). Nutritional treatments lasted 90 days (Day -60 to 34) and body weight (BW) was recorded at regular intervals. On day 0 (beginning of 1st FTAI protocol), a subset of heifers underwent ovum pick-up (OPU; n = 39) and blood sampling (n = 81) for IGF-I, insulin, and glucose analysis. At the same time, subcutaneous fat thickness and gynecological examination were performed. All heifers then underwent an estradiol/progesterone estrus synchronization protocol twice for FTAI (24-day interval between FTAI). Data were analyzed by the GLIMMIX procedure of SAS 9.4. There was no interaction (P>0.10) between nutrition and genetics for BW, subcutaneous rump fat thickness (RFAT), subcutaneous back fat thickness (BFAT), diameter of the largest follicle (LF), uterus diameter (UT), glucose, IGF-I, P/AI, and embryo production. Regardless of genetics, BW was greater for heifers on IN than MN on Day -30 (P < 0.01) and 0 (P < 0.01). Heifers on IN had greater RFAT (P < 0.01), BFAT (P < 0.01), LF (P = 0.02) and UT (P < 0.01). Glucose and IGF-I were greater in heifers on IN (P < 0.01). The pregnancy rate at 1st FTAI (P = 0.02) and cumulative pregnancy rate were greater (P = 0.07) for heifers on IN compared to MN. The number of viable blastocysts per OPU were greater (P = 0.05) for heifers on IN than MN. Regardless of nutrition, HG heifers had greater RFAT (P = 0.03), BFAT (P < 0.01), IGF-I (P = 0.04), LF (P < 0.01) and UT (P = 0.02) than LG heifers. No effects of genetics were observed for pregnancy rate. HG heifers had a greater number of blastocysts (P = 0.05) and viable blastocysts (P < 0.01) per OPU, and a greater viable blastocyst rate (P = 0.01) compared with LG heifers. There was an interaction nutrition*genetics (P = 0.03) for insulin concentration, with insulin being lower in the MN-LG group. The findings indicate that both nutrition and genetics can impact productive and reproductive performance in Nelore heifers.

Weighted genomic prediction for growth and carcass-related traits in Nelore cattle.

This study aimed to assess the impact of differential weighting in genomic regions harboring candidate causal loci on the genomic prediction accuracy and dispersion for growth and carcass-related traits in Nelore cattle. The dataset contained 168 793 phenotypic records for adjusted weight at 450 days of age (W450), 83 624 for rib eye area (REA), 24 480 for marbling (MAR) and 82 981 for subcutaneous backfat thickness (BFT) and rump fat thickness (RFT). The pedigree harbored information from 244 254 animals born between 1977 and 2016, including 6283 sires and 50 742 dams. Animals (n=7769) were genotyped with the low-density panel (Clarifide® Nelore 3.0), and the genotypes were imputed to a panel containing 735 044 markers. A linear animal model was applied to estimate the genetic parameters and to perform the weighted single-step genome-wide association study (WssGWAS). A total of seven models for genomic prediction were evaluated combining the SNP weights obtained in the iterations of the WssGWAS and the candidate QTL. The heritability estimated for W450 (0.35) was moderate, and for carcass-related traits, the estimates were moderate for REA (0.27), MAR (0.28) and RFT (0.28), and low for BFT (0.18). The prediction accuracy for W450 incorporating reported QTL previously described in the literature along with different SNPs weights was like those described for the default ssGBLUP model. The use of the ssGWAS to weight the SNP effects displayed limited advantages for the REA prediction accuracy. Comparing the ssGBLUP with the BLUP model, a meaningful improvement in the prediction accuracy from 0.09 to 0.63 (700%) was observed for MAR. The highest prediction accuracy was obtained for BFT and RFT in all evaluated models. The application of information obtained from the WssGWAS is an alternative to reduce the genomic prediction dispersion for growth and carcass-related traits, except for MAR. Furthermore, the results obtained herein pointed out that is possible to improve the prediction accuracy and reduce the genomic prediction dispersion for growth and carcass-related traits in young animals.

Deciphering the lncRNA and mRNA profiles of Min pig backfat after acute cold stress

ABSTRACT Cold stress can promote fat metabolism and reduce fat deposition. The present study compared differentially expressed (DE) lncRNAs and mRNAs in the subcutaneous back fat of Min pigs subjected to 24 h acute cold stress. Transcriptome sequencing was used to identify DE lncRNAs and mRNAs. A lncRNA mRNA co expression network was constructed using the confirmed lncRNAs. GO and KEGG analyses were performed to investigate the biological processes involved in the response to acute cold stress. A total of 166 DE lncRNAs and 269 DE mRNAs were found. Several genes such as ANGPTL4, KLF11 and NUPR1 were related to lipid metabolism. Interferon stimulating genes (ISGS) such as RSAD2, ISG20, ISG15, DDX60, MX2, MX1 and IFI6 were all significantly up-regulated. In addition, genes related to blood flow, respiration, and oxidative stress were also up-regulated. Many terms related to defense response to a virus were found in the GO annotation. A lncRNA mRNA co expression network comprising 46 specific mRNAs and the top 10 up-regulated DE lncRNAs was constructed. According to the results, the interaction between lncRNAs and mRNAs was complex. This study provides genome-wide gene and lncRNA expression profiles in adipose tissue of pigs after acute cold stress.

Heritability and genetic correlations between marbling in longissimus dorsi muscle and conventional economic traits in Nellore beef cattle

In Nellore beef cattle, studies addressing genetic correlations between ultrasound marbling content and other economically important traits are still incipient. Therefore, this work aimed to estimate heritability and genetic correlations between ultrasound marbling content in the longissimus dorsi muscle (MARB) and growth, reproductive, feed efficiency, and carcass-related traits in a Nellore beef cattle population from Brazil. Phenotypic records of 614,395 Nellore animals were used and included adjusted weight at 210 (W210) and 450 (W450) days of age, adult cow weight (AW), early heifer pregnancy (EH), stayability (STAY), adjusted scrotal circumference at 365days of age (SC365), ribeye area (REA), subcutaneous backfat thickness (BF), rump fat thickness (RF), and marbling (MARB). The genetic parameters for all traits but EH and STAY were estimated considering a linear animal model, whereas for those two nonlinear traits, a threshold animal model was used. The direct and correlated response to selection for MARB versus the other traits, and the relative efficiency of selection, were also calculated. The heritability estimate for MARB was 0.31 and for the other conventional evaluated traits was low to moderate, with values ranging from 0.14 to 0.41. The genetic correlations between MARB and growth, reproductive, feed efficiency, and carcass-related trait were very low, with values close to zero, with similar correlated responses. The MARB displayed adequate genetic variability to respond to selection and crossbreeding programs looking forward to higher meat quality and differential market standards for the Nellore beef. The selection for growth, reproductive, feed efficiency, and carcass-related traits would not affect MARB in Nellore beef cattle and vice versa. Therefore, this trait should be included as a selection criterion in the Nellore breeding program.

Evaluation of the association between plasma glucose-dependent insulinotropic polypeptide, respiratory quotient, and intramuscular fat deposition in feedlot cattle fed different levels of dry matter intake.

The objectives of this trial were to evaluate the association between different levels of dry matter intake (DMI) on gas exchange, plasma glucose-dependent insulinotropic polypeptide (GIP) concentration, and intramuscular (IM) fat deposition. We used 60 individually fed backgrounded Angus × SimAngus-crossbred steers (n = 30) in a randomized complete block design. Steers (paired by body weight [BW] and gain to feed ratio [G:F]) were randomly allocated to one of the following treatments: ad libitum intake (AI) or restricted intake (RI; the same diet fed at 85% of the AI) of a finishing diet. The diet contained 61% cracked corn, 9% corn silage, 15% distillers’ dried grains with solubles, 5% soyhulls, and 10% of a protein-mineral-vitamin premix. Measurements of CO2 emission and consumption of O2, and respiratory quotient (RQ) were taken using the GreenFeed system (n = 15/treatment). Plasma and gas samples were collected 10 d before slaughter, 1 h before and 2 h after feeding. Plasma glucose, non-esterified fatty acids, GIP, and insulin concentration and gasses (O2, CO2, and RQ) were analyzed using the MIXED procedure of SAS evaluating the fixed effect of treatment, time (repeated measurement) and their interaction, and the random effect of the block. Final BW and carcass characteristics were analyzed with a similar model, without the time statement and its interaction. Compared with RI, AI steers had greater (P < 0.01) DMI and average daily gain (ADG). Steers on AI had greater final BW (P = 0.02), tended to have a greater ribeye area (P = 0.09), and had lower plasma GIP concentration (P = 0.04). There was no treatment effect (P ≥ 0.11) on G:F, subcutaneous backfat (BF), and IM fat, O2 consumption, CO2 emission, and RQ. Plasma glucose concentration of AI steers was greater before and after feeding than RI (P < 0.05). In conclusion, feeding steers ad libitum increased DMI, ADG, and plasma glucose and GIP concentration but does not affect G:F, BF, IM fat, CO2 emission, and O2 consumption. Plasma GIP concentration and RQ are not associated with IM fat deposition.

Selection criteria for frame score and its association with growth-, reproductive-, feed efficiency- and carcass-related traits in Nellore cattle

Context A frame score prediction equation developed specifically for Nellore cattle could be an auxiliary tool to improve mating decisions on the basis of feed resources and production-system objectives. Aims Estimate genetic parameters for frame by using a prediction equation developed for Nellore cattle and genetic associations between frame score (FRAME) and growth-, reproductive-, carcass- and feed efficiency-related traits, and five bioeconomic indexes. Methods Birth weight (BW), adjusted weight at 120 (W120), 210 (W210) and 450 (W450) days of age, adult weight (AW), age at first calving (AFC), probability of precocious calving (PPC30), stayability (STAY), accumulated cow productivity (ACP), adjusted scrotal circumference at 365 (SC365) and 450 (SC450) days of age, rib eye area (REA), subcutaneous backfat thickness (BFT), rump fat thickness (RFT), intramuscular fat percentage (IMF), residual feed intake (RFI) and dry-matter intake (DMI) were included in the analyses. Frame score was calculated using the multiple linear regression (MLR) prediction method. The estimation of genetic parameters was performed using a linear animal model, except for PPC30 and STAY, which were estimated through a threshold animal model. The correlated response in FRAME considering selection for growth-, reproductive-, carcass- and feed efficiency-indicator traits were obtained in the context of single-trait selection and a multiple-trait context. Key results Heritability estimated for FRAME was moderate (0.30 ± 0.09). Frame score showed moderate genetic correlations with growth traits, BW (0.51 ± 0.08), W120 (0.41 ± 0.07), W210 (0.35 ± 0.07) and W450 (0.29 ± 0.08). The genetic correlation estimates between FRAME and RFT was high (−0.84 ± 0.02), but low with ACP (0.25 ± 0.08) and RFI (0.10 ± 0.13). In the single-trait and multi-trait contexts, there was a lower correlated gain for FRAME when the selection was applied for traits commonly measured in beef cattle breeding programs. Conclusion Selection to increase growth traits would lead to an increase in frame size and herd nutritional requirements, and it would reduce the carcass fatness level and early heifer sexual precocity. FRAME could be an alternative trait to monitor calf birth weight. Implications Selection for FRAME is feasible, and the most suitable frame score value depends on the production system objectives and feed resources.

Stayability and consecutive rebreeding ability associated to carcass and growth traits in Brazilian Nellore cattle: A Bayesian framework

Stayability(STAY) plays a substantial role in Nellore breeding programs in Brazil, but it does not differentiate cows with different rebreeding successes. Thus, we propose consecutive rebreeding ability (CRA) as a new multi-categorical trait related to the capacity of consecutive parturitions at calving intervals of less than 14 months. The heritability for CRA and its genetic correlations with stayability at 52 (STAY52) and 76 (STAY76) months, rib eye area (REA), subcutaneous backfat thickness (BF), age at first calving (AFC), post-yearling scrotal circumference (PSC), and post-yearling weight (PW) were estimated. The pedigree information provided a genealogical relationship matrix that contained 2,042,151 animals. The genetic parameters were estimated by multiple-trait Bayesian inference using the THRGIBBS1F90 software. The heritability estimates (posterior means and posterior standard deviations) for CRA, STAY52, STAY76, REA, BF, PW, AFC and PSC were, respectively, 0.11 (0.036), 0.092 (0.009), 0.15 (0.013), 0.35 (0.015), 0.13 (0.013), 0.34 (0.012), 0.17 (0.005) and 0.41 (0.021). In general, for a proposed trait (such as CRA) be considered as a replacement for existing ones, then it must be able to significantly increase the rate of genetic progress, that is a function of genetic variation, selection intensity and generation interval. Thus, the current STAY76 remains the most appropriate criterion for Nellore breeding programs. In this context, STAY76 still being recommended as a simple and practical trait for long-term Nellore cow selection. Additionally, the genetic association for CRA would not have a negative genetic impact on subcutaneous backfat thickness (BF), age at first calving (AFC) and post-yearling scrotal circumference (PSC).

Effect of crude protein level in high grain diets on calf growth and feed utilization

This study assessed the effect of crude protein level in the diet on animal performance, feed conversion ratio and N utilization, in early-weaned lot-fed calves. Four iso-energetic rations were formulated (ME: 12.0 MJ/kg dm) differing in the crude protein content (CP: 12%, 15%, 17% and 21%, DM basis), and offered in a random experimental design to 24 Hereford calves (107.2 ± 21.5 kg). Animals were individually housed and fed ad libitum twice a day for 84 days. Increasing CP levels in the diet promoted a quadratic response (P&lt;0.01) for dry matter intake (kg/d) and liveweight gain (LWG, kg/d), with maximum LWG of 1.36 kg/d for CP= 17.5%, without differences in subcutaneous back fat thickness (3.70 ± 0.73 mm, P = 0.25) or feed conversion ratio (4.44 ± 0.26, P&gt; 0.10). As CP increased in the diet, N consumption increased quadratically (P &lt;0.01), and an improvement was observed for CP (P = 0.053) and ndf (P = 0.020) apparent digestibility. Daily excretion of N in feces tended to decrease (P = 0.06), while urea-N concentration both in blood (P = 0.013) and urine (P = 0.046) increased. These results show that a level of 17% CP in the diet would optimize the performance of lot-fed early-weaned beef calves while controlling the excretion of N to the environment.

Using sorghum dry distillers’ grains plus solubles in sorghum-based finishing diets: feed utilization, cattle performance and carcass traits

The present study evaluated the effect of increasing levels of inclusion of sorghum dry distillers’ grains plus soluble in a sorghum-grain-based diet on the performance, apparent dry matter digestibility, ingestive behavior, and carcass traits of feedlot finishing steers. Thirty-two Hereford steers (331.2 ± 33.5 kg) were randomly allocated to four total mixed rations differing in SDDGS concentrations, 0, 150, 300, or 450 g/kg. The SDDGS replaced sorghum grain and sunflower meal in the control diet (Setaria italica hay 200 g/kg, ground sorghum 650 g/kg, sunflower meal 100 g/kg, and 50 g/kg premix) balancing for at least 125 g/kg of crude protein in the diet. Animals were fed in individual pens at 2.8 kg DM/ 100 kg body weight delivered in three meals over 12 weeks. Steers were all slaughtered on the same date. The experiment was analyzed according to a randomized plot design with repeated measures, and linear and quadratic effects associated with the SDDGS level were tested. Increasing SDDGS did not affect BW gain (1.52 kg/d, SE 0.06 kg/d), carcass weight (240.0 kg SE 5.3), carcass yield (542 g/kg SE 4.7), or ribeye area (49.1 cm2 SE 2.6). However, a negative linear tendency was observed for subcutaneous backfat (P < 0.10). No differences were observed in digestible DM or digestible energy intake (P> 0.10), nor in the gain-to-feed ratio (0.142, SE 0.01). Including SDDGS reduced steers’ intake activity (P < 0.01), but linearly increased the intake rate during the first meal (g/min, P < 0.01), without affecting diet NEg (P> 0.10). Our data suggest that for sorghum grain-based diets it is feasible including SDDGS in up to 450 g/kg without affecting animal performance or carcass value.

Antioxidants and fatty acid deposition and instrumental colour as affected by subcutaneous backfat layers and slaughtering age of Iberian x Duroc crossed pigs under Montanera

The effect of various slaughtering age options on the quality characteristics of subcutaneous backfat layers from Iberian x Duroc crossbred pigs under Montanera system was assessed. Three batches (IBxD16, IBxD14 and IBxD12) were established to start the Montanera with 14, 12 and 10 months of age and similar weight. After slaughter at 16, 14 and 12 months respectively, a piece of backfat was taken from each animal, and subsequently separated into outer, inner and subinner layers, and quality traits were performed in each one separately. Higher C18:1 n-9, MUFA, α- and γ-tocopherol were found in animals slaughtered with 16 months in the subinner backfat, which might be suitable to Iberian slaughtering age traceability. Lightness and redness varied with the age of the animal, for which showed an inverse pattern, and backfat layer, while yellowness only according to the latter.

Effect of Fattening Period Length on Intramuscular and Subcutaneous Fatty Acid Profiles in Iberian Pigs Finished in the Montanera Sustainable System

Twenty-four extensively reared Iberian pigs were used to study the influence of fattening period length (30, 60 or 90 days) on the fatty acid profiles of intramuscular and subcutaneous fat and the relationships between both profiles. Regarding fatty acid (FA) percentage, PUFA was greater in backfat and MUFA was greater in intramuscular fat (IMF), regardless of fattening period length. The longer fattening period increased MUFA content in backfat (which had a more marked change in oleic acid) and decreased PUFA content in backfat and IMF, but it did not affect SFA content. Within the three-layer subcutaneous backfat, SFA content was greater in the inner layer, MUFA was greater in the outer layer and PUFA was greater in both of these layers. The few differences in FA composition between both adipose tissues suggest that the changes due to the feeding regime are slow and, therefore, although the length of the fattening phase was increased, the fatty acid profile did not change substantially. The strong relationship between the FA profiles of IMF and backfat might be used to predict one profile from the other one when the latter is more readily available for sampling or analytical reasons.

Cow milk does not affect adiposity in growing piglets as a model for children

The effect of milk consumption on childhood obesity is unclear and a direct demonstration of an association is needed. In the present study, we used piglets as a model for prepubertal children to determine the effect of milk on adipose tissue. Two studies were conducted: study 1 with 5-wk-old male piglets (n = 8) and study 2 with 8- to 9-wk-old male piglets (n = 12). The piglets were fed a normal growing diet and randomly assigned to receive daily either 750 mL of whole cow milk or an isocaloric maltodextrin solution (control). For approximately 12 wk, body weight, feed intake, and subcutaneous back fat thickness were determined ultrasonographically and recorded. At euthanasia, back and neck fat thicknesses were measured and samples of back fat were collected for adipose histology. In study 1, but not study 2, piglets receiving milk grew more and ate more compared with control. In study 1, both back fat and neck fat thickness were greater in the milk-fed piglets and they had a higher frequency of small adipocytes and a lower frequency of intermediate and large adipocytes compared with controls. In study 2, control pigs had a significantly greater frequency of intermediate adipocytes but the milk-fed piglets tended to have a higher frequency of the largest adipocytes. In conclusion, milk has no apparent causal or consistent effect on adipose tissue in growing piglets.