Carcass Weight Gain Research Articles

PSV-8 Investigation of a haplotype and eQTL analysis of the LCORL-NCAPG locus associated with increased lean growth in beef cattle

Abstract Numerous studies have shown genetic variation at the LCORL-NCAPG locus is strongly associated with growth traits in beef cattle. However, a causative molecular variant has yet to be identified. To define all possible candidate variants, Charolais-sired calves (n = 34) were whole genome sequenced including 17 homozygous for a long-range haplotype associated with increased growth (QQ), and 17 homozygous for potential ancestral haplotypes for this region (qq). The Q haplotype was refined to an 814-kb region between chr6:37,199,897-38,014,080 and contained 218 variants not found in qq individuals. These variants include an insertion in an intron of NCAPG, a previously documented mutation in NCAPG (rs109570900), two coding sequence mutations in LCORL (rs109696064 and rs384548488), and 15 variants located within ATAC peaks that were predicted to affect transcription factor binding. Notably, rs384548488 is a frameshift variant likely resulting in loss of function for long isoforms of LCORL. To test the association of the coding sequence variants of LCORL with phenotype, 405 cattle from five populations were genotyped. The two variants were in complete linkage disequilibrium. Statistical analysis of the three populations that contained QQ animals revealed significant (P < 0.05) associations with genotype and birth weight, body weight, carcass weight, hip height, and average daily gain. Additionally, an RNAseq analysis was performed using 22 of the Charolais-sired calves. This, in conjunction with the WGS data, was used to run an eQTL analysis, which revealed 256 genes whose expression were impacted by eQTL in the region (FDR < 0.05). These findings affirm the link between this locus and growth in beef cattle and describe DNA variants that define the haplotype. However, further studies will be required to define the true causative mutation.

Neonatal vitamin A but not retinoic acid administration increases intramuscular adipocyte number in sheep by promoting vascularization

This study investigated whether vitamin A (VA) administration during the neonatal stage could increase the number of intramuscular adipocytes in Hu sheep by promoting vascularity. A total of 56 newborn male Hu sheep were divided into four groups and received intramuscular injections of either 0, 7500 IU retinoic acid (RA), 7500 IU VA, or a combination of 7500 IU VA and 5 mg SU5416 (an angiogenic inhibitor), at 1, 7, 14, and 21 days of age. At 15 days of age, 6 sheep from each group were randomly selected and sacrificed for intramuscular adipogenic capacity analysis. The remaining 8 sheep in each group were raised until they were 8 months old. VA-treated sheep exhibited an increase in preadipocytes, elevated expression of adipogenic genes (CCAAT enhancer binding protein alpha [CEBPA] and CCAAT enhancer binding protein beta [CEBPB]) and angiogenic genes (vascular endothelial growth factor A [VEGFA]), and stromal vascular fraction cells in the longissimus dorsi (LD) muscle with enhanced adipogenic capacity (P ＜ 0.05). These effects were entirely negated by SU5416. Upon slaughter, VA increased final weight, carcass weight, and average daily gain (P ＜ 0.05) but did not affect feed intake at 21-32 weeks (P = 0.824). VA increased the number of intramuscular adipocytes in the LD and semitendinosus (ST) muscle (P ＜ 0.05) without changing the adipocyte number of the omentum, perirenal and subcutaneous fats (P ＞ 0.05). VA injections also increased intramuscular triglyceride (TG) content (P = 0.016) without changing the omentum fat weight or subcutaneous fat thickness (P ＞ 0.05), but it did increase the perirenal fat weight (P = 0.011). Consistently, SU5416 mitigated the effects of VA on intramuscular TG content and adipocyte count, correlating with a decrease in vascularity. In contrast, RA injections didn’t affect the intramuscular fat (P = 0.744) but reduced the TG content of the omentum and perirenal fat (P ＜ 0.05). In conclusion, intramuscular injections of VA but not RA at the neonatal stage improved the growth performance of Hu sheep, increasing the number of intramuscular adipocytes and marbling by promoting angiogenesis.

Defining a Haplotype Encompassing the LCORL-NCAPG Locus Associated with Increased Lean Growth in Beef Cattle.

Numerous studies have shown genetic variation at the LCORL-NCAPG locus is strongly associated with growth traits in beef cattle. However, a causative molecular variant has yet to be identified. To define all possible candidate variants, 34 Charolais-sired calves were whole-genome sequenced, including 17 homozygous for a long-range haplotype associated with increased growth (QQ) and 17 homozygous for potential ancestral haplotypes for this region (qq). The Q haplotype was refined to an 814 kb region between chr6:37,199,897-38,014,080 and contained 218 variants not found in qq individuals. These variants include an insertion in an intron of NCAPG, a previously documented mutation in NCAPG (rs109570900), two coding sequence mutations in LCORL (rs109696064 and rs384548488), and 15 variants located within ATAC peaks that were predicted to affect transcription factor binding. Notably, rs384548488 is a frameshift variant likely resulting in loss of function for long isoforms of LCORL. To test the association of the coding sequence variants of LCORL with phenotype, 405 cattle from five populations were genotyped. The two variants were in complete linkage disequilibrium. Statistical analysis of the three populations that contained QQ animals revealed significant (p < 0.05) associations with genotype and birth weight, live weight, carcass weight, hip height, and average daily gain. These findings affirm the link between this locus and growth in beef cattle and describe DNA variants that define the haplotype. However, further studies will be required to define the true causative mutation.

Intestinal microflora, body fat profiles and performance of male Tegal duck fed diet supplemented with red tomato extract

The study was conducted to evaluate the effect of dietary supplementation of red tomato extract (RTE) on intestinal microflora, fat digestibility, body fat (meat fat mass, abdominal fat), and performances of male tegal duck. One hundred birds of male tegal ducks of 3 weeks old (initial body weight was 507.74±31.86 g) were randomly divided into 4 treatments with 5 replications (5 birds each) in a completely randomized design. Dietary treatments were basal diet without RTE as a control (T0), basal diet added with 0.10% RTE (T1), basal diet added with 0.15% RTE (T2) and basal diet added with 0.20% RTE (T3). Parameters measured were lactic acid bacteria (LAB), coliform, intestinal pH, fat digestibility, meat fat mass, abdominal fat, blood concentrations of malondialdehyde (MDA) and superoxide dismutase (SOD), body weight gain (BWG), carcass weight, feed consumption, and feed conversion ratio (FCR). Data were subjected to analysis of variance and continued to Duncan multiple range test when the treatment indicated significant (p&lt;0.05) effect. Supplementation of RTE at higher level significanly (p&lt;0.05) increased lactic acid bacteria (LAB), concentration of superoxide dismutase (SOD), carcass weight and body weight gain (BWG), while fat digestibility, meat fat mass, abdominal fat, malondialdehyde (MDA), intestinal pH, coliform counts and feed conversion ratio decreased (p&lt;0.05), as compared to control. Feed consumption tended to decrease but not significant (p&gt;0.05). In conclusion, feeding red tomato extract at a level of 0.20% (T3) can be categorized as effective in improving intestinal bacterial balance, body fat, increasing superoxide dismutase (SOD), an antioxidant enzyme, and performances of male tegal duck.

Supplementation with live Saccharomyces cerevisiae boulardii during the initial 42 days of the feedlot phase in Nellore beef cattle.

This study aimed to assess the effect of Saccharomyces cerevisiae boulardii CNCM I-1079 supplementation during the initial feeding period on the performance of Nellore bulls in a feedlot system. One hundred ninety-eight Nellore bulls were used in a completely randomized block design, with blocking based on weight within each treatment group: light (331.4kg; 4 pens), medium (349.7kg; 4 pens), and heavy (362.5kg; 3 pens). The treatments included CON-a basal diet, and SCB-basal diet plus a probiotic (Saccharomyces cerevisiae boulardii CNCM I-1079; 1.0 × 1010 CFU/head/d). Experimental diets were administered for the first 42 d (21 d in the step-up phase and 21 d in the finishing diet -870g concentrate/kg dry matter [DM]). Subsequently, both treatment groups were transitioned to the same basal diet for an additional 76 d, completing 118 d on feed. Linear regression analysis was conducted for dry matter intake (DMI) data. During the initial 42 d, DMI tended to be higher for SCB (P = 0.09); also bulls fed SCB reached the plateau of the curve at 9.17kg DMI/d earlier (39 d, R2 = 0.97) than those fed CON (43 d; R2 = 0.96) diets. For the first 42 d, the SCB treatment exhibited higher final weight (393.0 vs. 401.4kg, P = 0.02), total gain (49.3 vs. 53.5kg, P = 0.02), daily weight gain (1.124 vs. 1.274kg, P = 0.02), and G:F (0.174 vs. 0.188, P = 0.04). Over the entire 118-d period, SCB-fed bulls had greater final body weight (509.5 vs. 518.0kg, P = 0.02), total body weight gain (163.7 vs. 170.3kg, P = 0.01), and average daily gain (1.366 vs. 1.420kg, P = 0.01). The feed efficiency of SCB-supplemented bulls was 8.05% higher than CON (P = 0.04), and the final carcass weight was 1.69% greater for animals fed SCB (283.8 vs. 288.6kg, P = 0.04). Total carcass weight gain (110.9 vs. 114.7kg) and daily carcass weight gain (0.924 vs. 0.956kg) tended (P = 0.06) to increase by 3.46% in SCB-fed animals compared with those fed CON. Gain yield, carcass conversion, and carcass yield did not differ between treatments. There were no significant differences in the apparent digestibility of DM, crude protein, neutral detergent fiber, and ether extract between treatments. However, starch digestibility (92.7% vs. 88%) was greater for the control treatment (P < 0.001). Including live Saccharomyces cerevisiae boulardii yeast as a probiotic supplement during the initial 42 d in the feedlot enhanced early-stage growth performance in Nellore bulls. Notably, this supplementation carried over carcass gain over the entire feedlot period.

Evaluation of Megasphaera elsdenii supplementation on rumen fermentation, production performance, carcass traits and health of ruminants: a meta-analysis.

This study was conducted to evaluate the use of Megasphaera elsdenii (M. elsdenii) as a probiotic on rumen fermentation, production performance, carcass traits and health of ruminants by integrating data from various related studies using meta-analysis. A total of 32 studies (consisted of 136 data points) were obtained and integrated into a database. The parameters integrated were fermentation products, rumen microbes, production performance, carcass quality, animal health, blood and urine metabolites. Statistical analysis of the compiled database used a mixed model methodology. Different studies were considered random effects, while M. elsdenii supplementation doses were considered fixed effects. p-values and the Akaike information criterion were employed as model statistics. The model was deemed significant at p<0.05 or had a tendency to be significant when p-value between 0.05〈p〈0.10. Supplementation with M. elsdenii increased (p<0.05) some proportion of fermented rumen products such as propionate, butyrate, isobutyrate, and valerate, and significantly reduced (p<0.05) lactic acid concentration, acetate proportion, total bacterial population and methane emission. Furthermore, the probiotic supplementation enhanced (p<0.05) livestock production performance, especially in the average daily gain and body condition score. Regarding the carcass quality, hot carcass weight and carcass gain were elevated (p<0.05) due to the M. elsdenii supplementation. Animal health also showed improvement as indicated by the lower (p<0.05) diarrhoea and bloat incidences as well as the liver abscess. However, M. elsdenii supplementation had negligible effects on blood and urine metabolites of ruminants. Supplementation of M. elsdenii is capable of decreasing ruminal lactic acid concentration, enhancing rumen health, elevating some favourable rumen fermentation products, and in turn, increasing production performance of ruminants.

Anthelmintic usage on the performance of the Agouti (Dasyprocta leporina) reared intensively in Trinidad and Tobago, West Indies.

Anthelmintic drugs have been used strategically in livestock reared in the tropics. These drugs have been used in the treatment of endoparasitism which have resulted in an increase in the animals' performance. The agouti (Dasyprocta leporina) is a neo-tropical rodent with the potential for domestication and has been farmed intensively in Trinidad. However, the objective of this research was to investigate the effect of anthelmintic use of the growth performance of the agouti. In searching the literature, it was found that this type of study on the agouti has not been done. In this experiment fourteen weaned agoutis weighing 1kg were divided into two groups randomly. The first group (T1) was not given any anthelmintic treatment but the second group (T2) was treated with Endovet Ces® subcutaneously every three months. There were no significant differences (p > 0.05) between the two groups in the carcass weight, weight gain, dressing percentage (hot and cold), heart, lungs, skin, head and feet. However, a significant difference (p < 0.05) was seen between groups in the weight of liver and pluck. To the authors knowledge this is the first time that carcass parameters has been presented in literature. The live weight of the animals at the end of the experiment ranged from 2.4 kg to 2.6 kg and animals had a dressing percentage of 57% to 55%. The results are suggestive that the use of anthelmintic drugs in agoutis reared intensively had no significant effect on weight gain and dressing percentage.

Association of polymorphisms in lipid and energy metabolism-related genes with fattening performance in Simmental cattle

Lipid and energy metabolism are major constituents of mammal growth and thus fattening performance of cattle. This study was designed to evaluate the effects of polymorphisms in lipid and energy metabolism-related genes including oxidized low-density lipoprotein receptor 1 (OLR1), lactoferrin (LTF), stearoyl-CoA desaturase (SCD), beta-lactoglobulin (LGB), thyroglobulin (TG), annexin A9 (ANXA9), myogenic factor 5 (MYF5), protein kinase AMP-activated non-catalytic subunit gamma 3 (PRKAG3), and pituitary-specific transcriptional factor 1 (PIT1), on fattening performance in Simmental cattle. A total of 72 purebred Simmental bulls with a similar initial age and weight were fattened on the same farm for 10 months. Association analysis was performed using linear mixed models. The OLR1 marker was significantly associated with the final weight (FW), hot carcass weight (HCW), chilled carcass weight (CCW), dressing percentage (DP), and total weight gain (TWG). SCD affected the FW, TWG, and average daily live weight gain (ADWG). The present results clearly demonstrated the significant impact of the TG marker on fattening performance. It was highly significantly associated with the FW, HCW, CCW, and TWG. The SCD × TG and the OLR1 × TG interactions had remarkable effects on the traits analyzed. The GACC and CCCC haplotypes of the SCD × TG and OLR1 × TG, respectively, were found to be powerful markers for fattening performance in Simmentals. Novel associations in this study may be useful for further genetic evaluations to improve beef cattle breeding.

Processing weights of chickens determined by dual-energy X-ray absorptiometry: 1. Weight changes due to fasting, bleeding, and chilling

The increasing breast weight of modern broilers highlights the convenience of studying the dynamics of processing weights across the grow-out period. For models predicting these traits to work with non-fasted live birds under longitudinal studies, it is necessary to determine the changes in the weights of birds due to fasting and bleeding and carcasses due to chilling. This study aimed to develop a model to predict the fasting weight loss of broilers, determine the weight changes due to bleeding and chilling, and assess the percentage of gizzard fat in the abdominal fat. Models were fitted to fasting BW loss data from literature. A bleeding BW loss value obtained in a pilot study was compared to literature. This one and a single-source percent gizzard in the abdominal fat value were used as reference values. Birds from two experiments were selected at different ages to determine the following variables: non-fasted and fasted BW, bled weight, unchilled and chilled carcass weights, and gizzard fat and abdominal fat pad weights. Predicted and reference values were compared to the observed data based on their 95% confidence intervals, and the fitted model and reference values were validated if no statistical differences were inferred. The fasting BW loss model was refitted to the data from experiments, and the estimates of the model fitted to both datasets were compared. The fasting BW loss followed a three-parameter exponential model with reducing values as the bird aged, and the predicted and observed values showed no statistical difference (P > 0.05). The reference bleeding BW loss (2.76%) and gizzard fat percentage (18%) values showed no difference (P > 0.05) to data from broiler experiments, and a chilling carcass weight gain of 2.79% was determined. The scale and relative growth rate estimates of the fasting BW loss model showed no difference (P > 0.05) between datasets, and the asymptote showed a possible but negligible difference. The fasting BW loss model, the bleeding BW loss coefficient, and the gizzard fat percentage were validated. The model and coefficients obtained herein will not only be applied to predict processing weights using Dual-Energy X-ray Absorptiometry but also may be used in other modeling approaches.

Air chilling of Turkey carcasses: process efficiency and impact in the meat quality traits.

The study evaluated the influence of two air-spray chilling systems on the water absorption, cooling time, and the impact of both on the quality traits of the turkey meat. In system A (air/water spray + air) a weight loss of 1.78% (w/w) occurred, while in system B (continuous air/water spray) turkey meat showed a weight gain of 1.82 (w/w). The cooling time in system B was significantly (P < 0.05) shorter. Water retention capacity, the color, and the sarcomere length of turkey meat are significantly influenced (P < 0.05) by the air chilling system. Turkey meat refrigerated in system B showed smaller structural changes. Air chilling with water spray in a continuous process promotes carcass weight gain and reduces processing time, in addition to less impact on the quality traits of turkey meat.

Early fattening and improving feeding quality of Kejobong goats could reduce methane production and improve meat production

An experimental study was carried out to evaluate the implication of early fattening of Kejobong goats by improving feeding quality on methane production and meat production. Sixteen goats (8 young and 8 mature) were raised for 4 months study period. Nested design was used in this study, with young and mature as a nest factor, and diet (G7C3: 70% grass and 30% concentrate and G3C7: 30% grass and 70% concentrate) as the treatments. The main parameters observed were DMI, BWG, carcass (CWG) and meat weight gain (MWG), and methane emission. The results showed, the young goat fed G3C7 was higher than that fed G7C3 in DMI. The BWG’s of goats fed G3C7 were higher than those fed G7C3, but there was no difference between ages in BWG. The FCR of young goat fed G3C7 was lower than that fed G7C3. The DMI of mature goat was higher than young goat, but there were no differences between the ages in DM digestibility, carcass weight and meat weight gain. The young and mature goats fed G3C7 was significantly lower than that of G7C3 in methane emissions per unit of BWG (0.28 vs 0.40 and 0.36 vs 0.53, respectively), in methane emissions per unit CWG (0.60 vs 0.93 and 0.79 vs 1.47, respectively), and methane emission per unit MWG (0.89 vs 1.42 and 1.16 vs 2.19, respectively). It can be concluded that fattening young Kejobong goats by improving feed quality is more environmentally friendly than fattening the mature ones.

Correlation between insulin-like growth factor 1 gene expression and fennel (Foeniculum vulgare) seed powder consumption in muscle of sheep

It has been shown that addition of fennel in the diets of domestic animals has positive and beneficial effects on growth and meat production traits. Thus, the purpose of current study was to investigate the effect of adding fennel in the ration on growth characteristics and on insulin-like growth factor 1 (IGF1) gene expression in muscle tissue of Kermani lamb. Feeding of animals were performed with three levels of fennel including zero, 10 and 20 g/kg dry matter (DM) for 90 days. After slaughter, small pieces of tissues were removed and rapidly transferred to a nitrogen tank. Then, total RNA extracting and the Real-Time PCR reaction was performed. Results showed that as the level of fennel in the diet increases the amount of IGF1 gene expression also increases significantly in humeral muscle and femur (leg) muscle tissues (p < 0.05). In animals fed with fennel, femur muscle weight, back muscle weight, lean meat weight, final weight, warm carcass weight and live daily gain were greater than in animals fed with diet without fennel (p < 0.05). According to the findings of this investigation, it can be concluded that fennel, by creating positive effects on IGF1 gene expression can be used to improve muscle structure.

PSIX-2 Carcass traits of nelore bulls: Supplementation with probiotic (Saccharomyces cerevisiae boulardii CNCM I-1079) during adaptation in feedlot

Abstract This study aimed to evaluate the effect of probiotic (Saccharomyces cerevisiae boulardii CNCM I-1079) supplementation during feedlot adaptation period on performance of Nellore bulls. One-hundred ninety-eight Nellore bulls were used in a completely randomized block design, divided in 22 pens (9 animals/pen). Treatments were: CON – adaptation diet and finishing diet comprised of basal diet (with 28 ppm of monensin); and SCB – same diets as for the previous treatment with monensin plus probiotic (Saccharomyces cerevisiae boulardii CNCM I-1079, ProTernative® 20; Lallemand Animal Nutrition at a dose of 1.0 x 10e10 cfu/animal/d) supplementation. Supplementation was offered for the first 42 days (21 days in the step-up phase and 21 days in the finishing diet with 900 g concentrate/kg DM), then both treatments were fed the same basal diet for another 76d, reaching 118 days in total. Pen was considered the experimental unit and data were analyzed using the MIXED procedure of SAS with Tukey test at 5% significance level. Final carcass weight was 1.69% greater for animals fed SCB (283.8 vs. 288.7 kg, P = 0.04). Total carcass weight gain (111.0 vs. 114.8 kg) and daily carcass weight gain (0.924 vs. 0.956 kg) tended (P = 0.06) to increase by 3.46% in SCB-fed animals compared to the CON ones. Gain yield (P = 0.39), biological efficiency (P = 0.35) and carcass yield (P = 0.71) did not differ between treatments. Probiotic supplementation with live yeast during the first 42 days in feedlot helped Nellore bulls optimize early on growth performance with an interesting carry-over effect on carcass gain through the total feedlot time.

Life cycle assessment of pasture-based suckler steer weanling-to-beef production systems: Effect of breed and slaughter age

Demand for beef produced from pasture-based diets is rising as it is perceived to be healthier, animal friendly and good for the environment. Animals reared on a solely grass forage diet, however, have a lower growth rate than cereal-fed animals and consequently are slaughtered at an older age. This study focused on the former by conducting life cycle assessments of beef production systems offering only fresh or conserved grass, and comparing them to a conventional pasture-based beef production system offering concentrate feeding during housing. The four suckler weanling-to-beef production systems simulated were: (i) Steers produced to slaughter entirely on a grass forage diet at 20 months (GO-20); (ii) Steers produced to slaughter entirely on a grass forage diet at 24 months (GO-24); (iii) Steers produced to slaughter on a grass forage diet with concentrate supplementation during housing (GC-24), and (iv) Steers produced to slaughter entirely on a grass forage diet at 28 months (GO-28). Two breed types were evaluated: early-maturing and late-maturing (LM). The environmental impacts assessed were global warming potential (GWP), non-renewable energy (NRE), acidification potential (AP), eutrophication potential (marine (MEP) and freshwater) were expressed per animal, per kg live weight gain (LWG), kg carcass weight gain, and kg meat weight gain (MWG). The GO-20 production system had the lowest environmental impact across all categories and functional units for both breeds. Extending age at slaughter increased environmental impact across all categories per animal. The LWG response of EM steers to concentrate feed supplementation in GC-24 was greater than the increase in total environmental impact resulting in GC-24 having a lower environmental impact across categories per kg product than GO-24. Concentrate feed supplementation had a similar effect on LM steers with the exception of NRE and AP. The increase in daily LWG in the third grazing season in comparison to the second grazing and housing resulted in GO-28 having lower GWP, NRE, AP, and MEP per kg product than GO-24. Early-maturing steers had lower environmental impact than LM when expressed per kg LWG. However the opposite occurred when impacts were expressed per kg MWG, despite LM steers producing the least LWG. The LM steers compensated for poor LWG performance by having superior carcass traits, which caused the breed to have the lowest environmental impact per kg MWG. The results reaffirms the importance of functional unit and suggests reducing the environmental impact of LWG does not always translate into improvements in the environmental performance of meat.

Effect of placement weight and days on feed on feedlot cattle performance and carcass traits

One hundred and thirty six Angus steers were used to evaluate the effects of feedlot placement weight (PW; weight of the animal at the time of its placement into the feedlot) and days on feed (DOF) on feed efficiency, carcass transfer (CT), and carcass traits. The 2 × 4 factorial experiment included PW (Light (LT), 310 kg BW; or Heavy (HV), 415 kg BW) and DOF (54, 83, 111, or 145 d) before slaughtering. At d 0, four steers selected at random from each PW group were slaughtered to determine initial hot carcass weight (HCW). The rest of the steers were allocated in pens (4 pens/treatment; 4 steers/pen) with ad libitum access to feed and drinking water. No PW × DOF interactions were detected for any response variables (P > 0.05). Heavy steers showed greater (P < 0.001) daily dry matter intake (DMI) than LT steers. Daily DMI did not change (P = 0.11) across DOF. Average daily gain (ADG) and daily carcass weight gain (CWG) were not affected (P > 0.05) by PW. Although ADG showed a quadratic (P = 0.003) response across DOF, CWG was higher (P < 0.05) for steers fed 83 d or longer. This resulted in a linear increase (P < 0.001) in CT (ratio of CWG to ADG, expressed as a percentage) during the 145 feeding period. Feed efficiency (DMI: ADG and DMI: CWG ratios) was better (P < 0.001) for LT than HV steers. The ratio DMI: ADG was higher (P < 0.05) for 145 DOF steers, whereas the ratio DMI: CWG tended (P = 0.08) to be better for 111 DOF. Heavy steers showed greater (P < 0.05) final live weight, HCW, ribeye area, subcutaneous fat thickness, and marbling score than LT steers. Final weight and HCW increased linearly (P < 0.001) with DOF. Subcutaneous fat thickness was higher (P < 0.05) for steers fed 111 d or longer. Marbling score and LM total lipid increased linearly (P < 0.001) with DOF. Longissimus muscle pH and color (a*, b*), and subcutaneous fat color (L*, a*, b*) were not affected (P > 0.05) by treatments. Warner Bratzler shear force did not differ (P = 0.16) between PW but was affected (P = 0.005) by DOF. However, all steaks showed a WBS value below 4.0 kg. Regardless of treatment, WBS decreased (P < 0.001) as postmortem aging days increased. Overall, HV steers produced larger carcasses that had greater fat deposition, and similar tenderness than LT steers. Feeding up to 111 days, regardless PW, could improve animal performance and CT, and produce large carcasses with acceptable levels of subcutaneous fat thickness and palatable beef.

Fatty acid metabolism in lambs fed hazelnut skin as a partial replacer of maize

The aim of this study was to investigate the effect of dietary inclusion of hazelnut skin (HS) on growth performances and fatty acid metabolism of lambs. Twenty-two lambs were assigned to 2 treatments and fed ad libitum for 56 days: a maize-barley based diet (CON group) or a diet containing 150 g/kg on a dry matter (DM) basis of HS to replace maize (HS group). After slaughter, samples of muscle, rumen and abomasum digesta were collected and analyzed for fatty acid composition. The dietary inclusion of HS did not affect the DM intake, final body weight, carcass weight and average daily gain (P > 0.05), whereas feed conversion ratio was increased by HS diet (P = 0.014). Ruminal fluid pH, ammonia and total volatile fatty acids were not affected by the dietary inclusion of HS (P > 0.05), while HS diet increased the molar proportion of butyrate and reduced the proportion of valerate (P < 0.05). Replacing 150 g/kg dry matter maize with HS increased the concentration of vaccenic acid in ruminal digesta, abomasum content and intramuscular fat (P < 0.01). Polyunsaturated fatty acids (PUFA) of muscle were increased by hazelnut diet (P < 0.05). Although PUFA n-6/n-3 ratio was lower in the control treatment (P < 0.001), atherogenic and thrombogenic indexes were not affected by dietary treatment (P> 0.1). In conclusion, these results suggest that HS could replace 150 g/kg DM of maize without affecting animal performances and increasing the muscle concentration of PUFA and vaccenic acid.

Supplementation with calcium salts of cottonseed oil improves performance of Bos indicus animals consuming finishing diets.

Lipid ingredients are often used into feedlot cattle diets, primarily to increase energy density and improve efficiency parameters of the herd. Therefore, this study was designed to evaluate the effects of including calcium salts of fatty acids (CSFA) and increasing levels of cottonseed byproducts into feedlot diets. On day 0 of the study, 96 Bos indicus bullocks were individually weighed twice and initial body weight (BW) was considered the average of both measurements (initial BW = 287 ± 22.4 kg). Bulls were ranked by initial BW, allocated into 1 of 12 feedlot pens (eight bulls per pen), and pens randomly assigned to one of three treatments: 1) inclusion of 15.0% [dry matter (DM) basis] of cottonseed byproducts into the finishing diet (CTS-15; n = 4), 2) inclusion of 22.0% (DM basis) of cottonseed byproducts into the finishing diet (CTS-22; n = 4), and 3) inclusion of 2.7% (DM basis) of CSFA of cottonseed oil into the finishing diet (CSFA; n = 4). The experimental period lasted 135 d and consisted of 5 d of preadaptation, 15 d of adaptation (ADP), 31 d of growing (GRO), and 84 d of finishing (FIN). Performance and carcass characteristics data were evaluated at the end of the experimental period. A treatment × period interaction was observed on total DM intake (DMI; P < 0.0001), given that no treatment differences were observed during ADP (P > 0.33), whereas CSFA-supplemented animals had a reduced DMI during GRO and FIN phases (P < 0.05). When individual mean nutrient intake was evaluated, CSFA supplementation caused a reduction in crude protein and physically effective neutral detergent fiber intake (P ≤ 0.05), and tended to reduce metabolizable energy, net energy for maintenance and gain intake (P = 0.06). Additionally, CSFA inclusion or CTS increase into the diet did not affect final BW, BW change, average daily gain (ADG), hot carcass weight, carcass ADG, and yield gain (P ≥ 0.11). On the other hand, CSFA reduced DMI as percentage of BW and improved feed efficiency (FE; P < 0.02) and also tended to improve biological conversion (BC; P = 0.07) versus CTS. Similarly, increasing CTS byproducts in the diet improved FE and BC (P = 0.02) but also tended to increase dressing percentage (DP; P = 0.08). In summary, including CSFA into feedlot diets reduced DMI but improved FE and BC of beef cattle, demonstrating the efficacy of this technology on feedlot beef cattle diets. Moreover, increasing cottonseed byproducts into the diets also benefited FE, BC, and DP of finishinw B. indicus cattle.

Replacement of a protein–energy supplement by a same-cost maize-based supplement on performance and product quality of pasture-finished Nellore heifers

Context In the largest beef-producing countries in the world, the slaughter of female cows accounts for ~30–40% of all beef produced. Aims The objective of this study was to evaluate the replacement of a protein–energy supplement (PES) by a same-cost maize-based supplement (MBS) on the performance and final product of Nellore heifers grazing Brachiaria brizantha cv. Marandu pasture during the wet season in Brazil. Methods Ninety-six Nellore heifers of bodyweight (BW) 281 ± 7.55 kg and aged 23 months were used. Six were slaughtered at the start of the experiment. The remaining 90 heifers received one of the following three supplements with their predominantly pasture diet for 133 days: control, mineral salt ad libitum; PES, with protein 250 g/kg dry matter (DM) and total digestible nutrient 600 g/kg DM, offered at 3 g/kg BW.day (as-fed basis); MBS, with crude protein 90 g/kg DM and total digestible nutrient 850 g/kg DM, offered at 7 g/kg BW.day (as-fed basis). The variables were evaluated in a completely randomised block design with 30 heifers per treatment. Key results Average daily gain and final BW were similar (P &amp;gt; 0.05) in PES and MBS treatments, and relative to the control increased (P &amp;lt; 0.01) average daily gain by ~24% and final BW by 7%. Pasture intakes were decreased, with substitution levels of 8.0% for heifers receiving PES and 10.4% for those receiving MBS. Carcass weight (kg/day) and carcass gain (g carcass/kg BW) were greater (P &amp;lt; 0.001) for heifers receiving MBS and PES than for the control group. Backfat depth was greater (P &amp;lt; 0.001) in heifers receiving MBS (7.91 mm) than in those receiving PES (6.25 mm), and the lowest (P &amp;lt; 0.001) measurement was observed in the control group (4.85 mm). Conclusions Maize-based supplement (7 g/kg BW.day) provided the same growth rate as PES (3 g/kg BW.day) but yielded heavier and slightly fatter carcasses of pasture-finished Nellore heifers during the wet season (133 days) with a similar cost, and with more total digestible nutrients than pasture plus mineral salt. Implications Maize-based supplement provided to Nellore heifers on pasture may improve performance despite lower pasture intakes but needs to be evaluated carefully in terms of costs involved.

Different beef breed sires used for crossbreeding with Swedish dairy cows - effects on calving performance and carcass traits

Improved potential for weight gain and carcass classification traits in calves aimed at slaughter from dairy herds would increase the calves’ economic value, and enable an increased beef production. At present, relatively low economic weights are placed on beef traits in the comprehensive Nordic dairy cattle breeding goal. An effective way to improve beef production from dairy herds is therefore to inseminate a larger proportion of dairy heifers and cows with beef bull semen. In the choice of beef bull breed, both effects on calving traits, carcass weight gain and carcass traits need to be considered. The aim of this study was therefore to compare different beef x dairy crosses regarding calving performance and carcass traits. Field data comprising in total close to 1.6 million calving records from Swedish herds, and more than 1.1 million carcass records from commercial slaughter houses, were analyzed using linear models. Differences in least-square means between different breed combinations were estimated for percentage of calving difficulty, stillbirth, daily carcass gain, carcass weight, EUROP conformation and fat classification. The dams were purebred Swedish Red (SR) or Swedish Holstein (SH), and the sires were either of purebred dairy (SR or SH) or of the beef breeds Angus, Hereford, Limousin, Simmental or Charolais. The results showed that crossbreeding dairy cows with beef bulls, especially of late maturing breeds, has potential to considerably improve beef production from dairy herds. Improvement of carcass characteristics and carcass gain were most noticeable in young crossbred bulls, where the highest increase for single breed combinations was 67% for conformation and 17% for carcass gain. Offspring of different beef x dairy combinations displayed varying average carcass gain and characteristics in terms of fatness and conformation in heifers, steers and young bulls, and would fit different types of production systems. Whereas crossbreeding had small or favorable effects on stillbirth, the use of late maturing beef breed sires negatively influenced the calving performance, especially in primiparous dairy cows. By choosing individual beef bulls with high estimated breeding values for calving ease, the percentage of calving difficulty could be reduced, even when using late maturing beef breed sires for crossbreeding.

Modelling effects of carcass weight, dietary concentrate and protein levels on the CH4 emission, N and P excretion of dairy bulls

Cattle farming is an important agricultural contributor to methane (CH4) emissions and has also a significant environmental impact through nutrient surpluses onto arable land. Therefore, the purpose of the present study was to model the effects of carcass weight (CW) and dietary concentrate and protein levels on the CH4 production and nitrogen (N) and phosphorus (P) excretion of dairy bulls fed grass silage-based diets. The modelling was based on treatment mean data from a growing cattle feeding experiment in which the concentrate and protein supply was manipulated. The three concentrate proportions were 300 (LC), 500 (MC) and 700 (HC) g/kg dry matter (DM) fed without (LP) or with (HP) rapeseed meal (RSM) supplementation. In the LP and HP diets the crude protein content of the concentrate was 128 and 160 g/kg DM, respectively. Methane emissions and faecal N output were predicted by the dynamic and mechanistic Karoline model. Manure P was calculated as P intake – Retained P. Predicted differences between the diets in CH4 emissions were small; the greatest difference was approximately 4% lower CH4 intensity expressed per kg carcass weight gain (CWG) in cattle fed HC diet compared with those fed LC or MC diets. Total N intake decreased with increasing diet concentrate proportion, which resulted in reduced urinary and faecal N output and reduced excretions per kg body weight (BW) and CWG. Increased N intake with RSM supplementation resulted in a greater total manure N output per day and per kg BW and CWG. Most of the increase in manure N output with RSM supplementation was urinary N. Manure P output per day and per kg BW and CWG increased with greater concentrate or protein supplementation. Within the practical range of grass silage-based beef cattle diets fed to dairy bulls the effects of diet composition on methane yield or intensity were small. However, taking into account carbon footprint of feed production, increasing proportion of grain in the diet can increase total carbon footprint. Emissions per unit of CWG markedly increase with increased CW. Manure N and P output and methane emission per unit of CWG increased more rapidly in BW above 570 kg, mainly because of reduced BW gain. Manure N and P output per kg CWG were mainly related to dietary concentrations of these nutrients and CW. Decreasing dietary N and P inputs is the best nutritional strategy to reduce manure N and P outputs.