Livestock Science最新文献

{"title":"Focused high-protein supplementation to ewes grazing Campos grassland during mid gestation improves maternal-fetal blood flow and skeletal muscle mass of the progeny","authors":"Javier Ithurralde ,&nbsp;Ana Inés Trujillo ,&nbsp;Ana Laura Astessiano ,&nbsp;Mariana Garcia Kako Rodriguez ,&nbsp;Ezequiel Jorge-Smeding ,&nbsp;Danilo Fila ,&nbsp;Carlos Batista ,&nbsp;Alejandro Bielli ,&nbsp;Raquel Pérez-Clariget","doi":"10.1016/j.livsci.2025.105718","DOIUrl":"10.1016/j.livsci.2025.105718","url":null,"abstract":"<div><div>In order to evaluate the effect of focused-high-protein supplementation during the second third of gestation on placentome and uterine artery blood flow, growth and carcass composition of the progeny, 37 single-bearing ewes were used. Campos grazing ewes were divided in two nutritional treatments between 55 and 80 days of gestation: supplemented ewes (SUP; <em>n</em> <em>=</em> <em>22,</em> 12 carrying female and ten carrying male fetuses) were individually daily supplemented with soybean meal at 1 % of their body weight (BW), and control ewes (CON; <em>n</em> <em>=</em> <em>15</em>, nine carrying female and six carrying male fetuses) grazed adjoining Campos sub paddock without supplementation. After 80 days of pregnancy all ewes were managed together as the same flock and continued grazing on the same paddock of Campos grassland until 100 days of pregnancy when they were sheared and transferred to a multi-year pasture until lambing. Doppler ultrasonography examinations of placentome and uterine artery blood flow were performed on day 120 of pregnancy. Maternal supplementation reduced the resistance index value (<em>P</em> = 0.042) and tended to reduce the diastole/systole ratio (<em>P</em> = 0.078) in placentomes. Similarly, in the uterine artery, maternal supplementation reduced both the resistance index value (<em>P</em> = 0.022) and the diastole/systole ratio (<em>P</em> = 0.030). On the other hand, maternal supplementation did not affect lamb´s BW, body morphometric measurements or lamb´s weight gain from birth to 90 days of age (<em>P</em> &gt; 0.05). Similarly, organs’ weight and carcass objective conformation traits were not affected by maternal supplementation at slaughter (90-day-old lambs, <em>P</em> &gt; 0.05). Nevertheless, muscle weight expressed as a percentage of lamb BW was higher in SUP than in CON lambs (<em>P</em> = 0.007). Also, absolute muscle weight tended to be affected by the interaction between maternal supplementation and the sex of the lambs (<em>P</em> = 0.072), as male lambs born to SUP ewes had heavier muscles than CON male lambs (<em>P</em> = 0.059). In summary, focused high-protein supplementation offered to ewes grazing Campos grassland during the second third of gestation positively affected placentome and uterine artery blood flow but had no effect on lamb growth traits. However, our results indicate that maternal supplementation improved the BW proportion of muscles. Also, our results suggest that maternal supplementation could have influenced skeletal muscle development in a sex-specific manner, although under the conditions of the present experiment this effect was subtle and depended on the BW of the lamb.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"297 ","pages":"Article 105718"},"PeriodicalIF":1.8,"publicationDate":"2025-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic parameters for productive, reproductive, growth and morphological traits in Mertolenga cattle","authors":"Andreia Vitorino ,&nbsp;George Stilwell ,&nbsp;José Pais ,&nbsp;Nuno Carolino","doi":"10.1016/j.livsci.2025.105717","DOIUrl":"10.1016/j.livsci.2025.105717","url":null,"abstract":"<div><div>Mertolenga is the largest of Portugal’s native cattle breeds. Estimating genetic parameters and analyzing trait correlations are essential for breeding programs. This study assessed genetic parameters for reproductive, growth, production and morphological traits and conducted univariate and multivariate analyses using the BLUP Animal Model and MTDFREML program. The heritability (h2) estimated for calving interval (CI) was 0.06 ± 0.001 and it has a strong negative correlation (- 0.89 ± 0.001) with total number of calvings (TNC), which has an h2 of 0.26 ± 0.01. Age at first calving (AFC) has an h2 of 0.30 ± 0.01 and has a moderate negative correlation (- 0.40 ± 0.005) with productive longevity (PL) and TNC (-0.43 ± 0.005), which have h2 of 0.27 ± 0.01 and 0.26 ± 0.01, respectively. The h2 and correlation estimates between the direct and maternal effects in weaning weight were 0.31 ± 0.05, 0.22 ± 0.02 and - 0.30 ± 0.04, respectively. Carcass weight per day of age showed an h2 of 0.40 ± 0.02. Average daily gain (ADG) had an h2 of 0.21 ± 0.08, a moderate and negative correlation (-0.65 ± 0.167) with feed conversion ratio (FCR) and a strong positive correlation (0.87 ± 0.057) with relative growth rate (RGR). ADG shows a weaker relationship (- 0.34 ± 0.937) with residual feed intake (RFI), which has an h2 of 0.35 ± 0.08. Morphological traits had generally low heritabilities, and traits in the same body region showed moderate to high genetic correlations. The traits studied showed reasonable genetic variability supporting the potential for improving the Mertolenga breed through selection.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"296 ","pages":"Article 105717"},"PeriodicalIF":1.8,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143947172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of country-specific predictions of feed intake and methane emissions in sheep using different proxies","authors":"Q. Le Graverand ,&nbsp;N. Lambe ,&nbsp;F. McGovern ,&nbsp;E.A. Navajas ,&nbsp;P. Johnson ,&nbsp;N. McHugh ,&nbsp;I. De Barbieri ,&nbsp;G. Ciappesoni ,&nbsp;S. Rowe ,&nbsp;B.A. Åby ,&nbsp;J. Conington ,&nbsp;C. Marie-Etancelin ,&nbsp;F. Tortereau","doi":"10.1016/j.livsci.2025.105716","DOIUrl":"10.1016/j.livsci.2025.105716","url":null,"abstract":"<div><div>Ruminants are often singled out as being the main culprits when it comes to greenhouse gas (GHG) emissions, for methane (CH₄) in particular. However, with their diets based on forage and grazing, ruminants have a role to play to limit the feed-food competition. Sheep breeders are open to the prospect of including both feed efficiency and GHG emissions in their breeding programmes and whether or not it is for the purpose of genetic (or genomic) selection, the acquisition of new phenotypes for feed efficiency and GHG emissions are essential. Currently, devices recording GHG emissions and individual feed intake of animals reared indoors remains too expensive for most sheep breeders worldwide. In this study, research groups from six countries (UK (Scotland), France, Norway, Ireland, New Zealand and Uruguay) gathered their results obtained in different breeds to identify the most promising proxy measurements of feed intake and methane emissions. Despite the fact that each group set up their own protocol, there were several points in common: most feed intake trials were performed during 6 weeks on growing animals, and GHG emissions were all recorded with portable accumulation chambers (PACs). Different traits, in addition to feed intake and GHG emissions, were recorded and considered as putative proxies (body composition, growth, bodyweight, feeding behaviour, body condition score), as well as sheep genotypes and ruminal microbiota. Models' goodness of fit were estimated on training sets, whereas their prediction accuracy was assessed on actual validation datasets. The comparison of training and validation accuracies obtained with each dataset highlighted the well-documented problem of overfitting, particularly with microbiota data. In general, validation prediction accuracies were higher for feed intake than for the two feed efficiency criteria (residual feed intake and feed conversion ratio) investigated. The best predictions for feed intake were obtained when body weight and the average number of feeding events per day were included in the models (R²_valid=0.78). Methane emissions were predicted with the highest accuracy when feed intake was considered among the proxies. Prediction accuracies for methane emissions obtained with the metagenome were higher than with sheep genome, although this accuracy remains quite low (R_valid=0.32).</div><div>By comparing independent results from six countries, we highlighted that the recording of body weights, feeding behaviour and fixed effects are crucial for the prediction of feed intake. However, feed efficiency and methane emissions are relatively difficult to predict well, with the proxy measurements assessed here.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"296 ","pages":"Article 105716"},"PeriodicalIF":1.8,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of visual and audio cues in the efficacy of creating exclusion zones for cattle","authors":"Hope A. de Avila,&nbsp;Emma N. Macon,&nbsp;Karen L. Launchbaugh","doi":"10.1016/j.livsci.2025.105715","DOIUrl":"10.1016/j.livsci.2025.105715","url":null,"abstract":"<div><div>Virtual fence relies on an animal’s ability to associate a cue with a pending electric stimulus that is delivered if the animal does not retreat from the boundary. The effectiveness of these cues as a warning signal dictates the strength of the virtual boundary. Current virtual fence systems apply audio cues as warning signals because they are easy to include on a collar, allow for simple movement of boundaries, and do not require physical changes on the ground. However, vision is the dominant sense that most livestock species, including cattle, use to navigate through their environment. Previous research and our own preliminary data suggest that cattle interact differently with visual than audio cues in a virtual fence system. To compare visual vs audio cues and any combination effect from using both cues, 16 steers were tested in a Y-maze with a virtual boundary creating an exclusion zone in one of the arms. We found that animals with visual cues outperformed their audio counterparts, showing a higher proportion of exclusion zone avoidance and demonstrating that avoidance more quickly (<em>p</em> &lt; 0.05). At the small spatial scale of this study, no difference was observed between visual cues alone and the combination with audio cues (<em>p</em> = 1.0). These results suggest that visual cues may be important for virtual fence applications where training opportunities are limited or when high containment requirements are necessary.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"296 ","pages":"Article 105715"},"PeriodicalIF":1.8,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143941817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Investigation of apparent digestibility, caecal fermentation and microbiota of rabbit fed with raffinose” [Volume 295, May 2025, 105692]","authors":"Kai Yang,&nbsp;Shuo Yang,&nbsp;Zixuan Tie,&nbsp;Zhenxin Li,&nbsp;Meinan Ji,&nbsp;Kun Wang,&nbsp;Shugui Zheng,&nbsp;Fangfang Li","doi":"10.1016/j.livsci.2025.105702","DOIUrl":"10.1016/j.livsci.2025.105702","url":null,"abstract":"","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"296 ","pages":"Article 105702"},"PeriodicalIF":1.8,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143854947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Validity and reliability of animal-based measures of welfare protocols in finisher pigs","authors":"Mathilde Coutant,&nbsp;Benjamin H. Rasmussen,&nbsp;Tine Rousing,&nbsp;Lene J. Pedersen,&nbsp;Mona L.V. Larsen","doi":"10.1016/j.livsci.2025.105704","DOIUrl":"10.1016/j.livsci.2025.105704","url":null,"abstract":"<div><div>Animal-based measures are a key part of welfare protocols, but to what extent these measures can report differences in welfare among pigs provided e.g. with different accesses to valued resources (i.e., whether the measures are valid) and whether a single measurement point is representative of the entire production period (i.e., whether the measures are reliable) is not well documented. In this study, a total of 814 finishing pigs were assigned to either 1 of 4 welfare improving treatments (increased space: 1.4 [S9] or 2.1 m² [S6] per pig, provision of roughage [R], extra provision of enrichments [E]) or to a control treatment (C). Animal-based measures of a refined version of the Welfare Quality® protocol were assessed weekly (Batch 1) or once during the period (Batch 2). All parameters showed poor reliability throughout the 10 weekly assessments of Batch 1. Among the clinical parameters, only few indicators showed differences between welfare improving treatments. Among the behavioural indicators, differences were recorded for manipulation of the pen (<em>C</em> &gt; S6) and of enrichment materials (<em>E</em> &gt; all other treatments). When aggregating indicators into domains (nutrition, health, environment, behaviour), the reliability did not improve, and treatment effects were recorded within the domain of nutrition (<em>R</em> &gt; all other treatments), and behaviour (<em>E</em> &gt; S9). When aggregating domains into a final welfare score, both reliability and validity, as defined for the study, were poor. These results call for attention over the interpretation of the animal-based measures obtained from a single welfare assessment.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"296 ","pages":"Article 105704"},"PeriodicalIF":1.8,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143873482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of post-weaning feeding strategies on feed consumption and body weight variation in pigs","authors":"Katrijn Hooyberghs ,&nbsp;Sophie Goethals ,&nbsp;Amy de Mey ,&nbsp;Wim Gorssen ,&nbsp;Roel Meyermans ,&nbsp;Léa Chapard ,&nbsp;Evy Beckers ,&nbsp;Steven Janssens ,&nbsp;Nadine Buys ,&nbsp;Sam Millet","doi":"10.1016/j.livsci.2025.105703","DOIUrl":"10.1016/j.livsci.2025.105703","url":null,"abstract":"<div><div>At weaning, piglets experience stress due to various changes. Adequate post-weaning feed intake is crucial for optimal growth. Pre-starter feed may facilitate this transition. Feeding strategies were used to test the following hypotheses: 1) use of the same type of feed bowl for pre-starter feed in both farrowing pen and nursery enhances piglet performance; 2) liquid pre-starter provided post-weaning positively impacts piglet performance; and 3) these feeding strategies may have long-lasting effects on performance and carcass quality.</div><div>In two experiments, all piglets received pre-starter feed in a bowl in the farrowing pen. After weaning, piglets from one litter were split over two treatments.</div><div>In Experiment 1 (120 piglets, 26 pens), piglets received either 1) ad libitum weaning feed in a standard nursery feeder plus ad libitum pre-starter in the familiar farrowing bowl during the first week after weaning (two-feeder) or 2) ad libitum weaning feed after a fixed volume of pre-starter in a standard nursery feeder (one-feeder). One-feeder piglets therefore had to consume all pre-starter before accessing the weaning feed, while two-feeder piglets could choose between feeds at the same time. Two-feeder piglets consumed less pre-starter (77 vs. 125 g/d) but more weaning feed (188 vs. 68 g/d) and total feed (266 vs. 193 g/d) during the first week post-weaning. However, their gain-to-feed ratio was lower (0.47 vs. 0.60 kg/kg). In the following week, the two-feeder group showed slower weight gain (209 vs. 239 g/d) and tended to consume less feed (302 vs. 346 g/d/piglet) compared to the one-feeder group.</div><div>In Experiment 2 (164 piglets, 32 pens), during the first week post-weaning all piglets received pre-starter in the same type of bowl as in the farrowing pen, either as dry feed or liquid feed, with weaning feed presented to all piglets in the standard nursery feeder. Pens with liquid pre-starter consumed more pre-starter (64 vs. 26 g/d) and total feed (170 vs. 134 g/d) and showed lower weight variation (15.7 vs. 18.4 %) during the first week post-weaning. However, a lower gain-to-feed ratio (0.88 vs. 0.90 kg/kg) was observed for pens with liquid pre-starter over the first five weeks post-weaning. Furthermore, the average daily gain (370 vs. 317 g/d) during the second week post-weaning was higher with liquid pre-starter.</div><div>In summary, both feeding strategies impact post-weaning performance. Liquid pre-starter increased feed intake, body weight uniformity and growth performance short term, but reduced feed efficiency. Despite short term effects post-weaning, no significant long term effects on performance were observed.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"296 ","pages":"Article 105703"},"PeriodicalIF":1.8,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Total nutrient digestibility and small intestine starch digestion in Nellore and Nellore × Angus steers fed whole shelled corn-based diet with or without roughage","authors":"Priscilla D. Teixeira ,&nbsp;Aline C. Rodrigues ,&nbsp;Daniel R. Casagrande ,&nbsp;Erick D. Batista ,&nbsp;José M. Oliveira ,&nbsp;Ana C.O. Santos ,&nbsp;Pedro V.R. Paulino ,&nbsp;Marcio M. Ladeira","doi":"10.1016/j.livsci.2025.105699","DOIUrl":"10.1016/j.livsci.2025.105699","url":null,"abstract":"<div><div>This study aimed to evaluate total nutrient digestibility, pancreatic α‐amylase, and the expression of <em>maltase-glucoamylase (MGAM)</em> and <em>solute carrier family 5 member 1 (SLC5A1)</em> in the small intestine in Nellore and Nellore × Angus steers fed whole shelled corn-based diet with or without inclusion of sugarcane bagasse as a roughage source. Sixteen Nellore and 16 Nellore × Angus steers with 353 ± 25.3 kg were allotted in a completely randomized design using a 2 × 2 factorial arrangement (2 breeds and 2 diets). The two experimental diets [dry matter (DM) basis] comprised: 800 g/kg of whole shelled corn and 200 g/kg of protein-mineral pellet (<strong>WSC)</strong> or 740 g/kg of whole shelled corn, 200 g/kg of protein-mineral pellet, and 60 g/kg of sugarcane bagasse (<strong>WSCB</strong>). The intake of DM and other dietary components were greater in steers fed WSCB than in steers fed WSC (<em>P</em> &lt; 0.01). However, WSCB decreased the total tract digestibility of DM, organic matter, crude protein, neutral detergent fiber, and total digestible nutrients (<em>P</em> ≤ 0.01) and tended to decrease ether extract digestibility (<em>P</em> = 0.08). There were no effects of breed on DM intake, nutrient intake, or nutrient digestibility (<em>P</em> &gt; 0.10). Feeding WSCB to steers increased fecal output as well as starch excretion in feces (<em>P</em> &lt; 0.01), whereas it tended to decrease starch in feces when expressed as a percentage (<em>P</em> = 0.09). Steers fed WSCB had greater pancreatic α-amylase activity (<em>P</em> = 0.03) and tended to have greater <em>MGAM</em> (<em>P</em> = 0.09) expression. On the other hand, animals fed WSC had greater <em>SLC5A1</em> (<em>P</em> = 0.03) expressions. In conclusion, WSC diet increased total nutrient digestibility. However, there was no effect of diet on total starch digestibility, but the inclusion of sugarcane bagasse may increase small intestine starch digestibility since it has greater pancreatic α-amylase activity and <em>MGAM</em> expression.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"296 ","pages":"Article 105699"},"PeriodicalIF":1.8,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143873480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of finishing diet neutral detergent fibre content on South African Mutton Merino lamb performance, meat fatty acid composition, tenderness and stability","authors":"Inalene De Klerk ,&nbsp;Arnold Hugo ,&nbsp;Abraham Vlok Ferreira ,&nbsp;Michael Denis Fair ,&nbsp;Ockert Bernard Einkamerer","doi":"10.1016/j.livsci.2025.105698","DOIUrl":"10.1016/j.livsci.2025.105698","url":null,"abstract":"&lt;div&gt;&lt;div&gt;A trial was conducted studying the effect of reducing neutral detergent fibre (NDF) content in the diet of finishing South African Mutton Merino wether lambs on meat fatty acid (FA) composition, tenderness and stability. Fifty four-month-old lambs (29.14±1.66 kg; mean±SD) were assigned at random to the five dietary treatments with &lt;em&gt;n&lt;/em&gt; = 10 lambs per treatment (&lt;em&gt;n&lt;/em&gt; = 1 lamb per replicate), culminating into a randomised trial design. The lambs were housed individually in pens (1.404 m²) on elevated wooden slatted floors. Five dietary treatments similar in nitrogen content were formulated differing in respect to the NDF content thereof. Treatments were described as containing 379 (CON), 314 (NDF1), 251 (NDF2), 192 (NDF3) and 143 (NDF4) gram NDF/kg dry matter (DM), respectively. The production study was conducted over a period of 61 days. Means were analysed using the LSMEANS/DIFF with treatment as fixed effect, and post hoc using Tukey's HSD test. Regression analyses was conducted by PROC REG. All estimates were tested at the 5 % probability level. A reducing dietary NDF content linearly decreased the stearic and α-linolenic acid content of South African Mutton Merino muscle tissue, but linearly increased the palmitic, palmitoleic, vaccenic, linoleic acid, total omega-6 (n-6) and n-6:omega-3 (n-3) ratio, as well as ∆&lt;sup&gt;9&lt;/sup&gt; desaturase index of the same tissue. Subcutaneous lipid tissue was more extensively affected by dietary treatment and linearly increased (&lt;em&gt;P&lt;/em&gt; &lt; 0.0001) oleic, vaccenic, linoleic and arachidonic acid content, ∆&lt;sup&gt;9&lt;/sup&gt; desaturase index, as well as total mono-unsaturated fatty acid (MUFA), poly-unsaturated fatty acid (PUFA), unsaturated fatty acid (UFA), n-6, n-6:n-3 and PUFA:SFA ratios following decreased dietary NDF content. In contrast, adipose tissue lipid content, stearic acid and total saturated fatty acid (SFA) content, as well as atherogenicity index linearly decreased (&lt;em&gt;P&lt;/em&gt; &lt; 0.0001) following a decreased dietary NDF content. Treatment did not affect the conjugated linoleic acid (CLA: C18:2c9,t11) content of lamb muscle or adipose tissue. Reducing dietary NDF content linearly decreased lamb &lt;em&gt;longissimus&lt;/em&gt; muscle tissue lightness (L*) of day-4 and day-8 storage samples, yellowness (b*) and hue angle of the fresh (day-0) and day-8 samples, as well as chroma of the day-8 sample. In contrast, the redness (a*) of the day-8 storage muscle tissue increased linearly following a decrease in dietary NDF content. Dietary treatment had no effect on &lt;em&gt;longissimus&lt;/em&gt; muscle tenderness nor oxidative stability. The advantage of reducing the NDF contend of a finishing diet for South African Mutton Merino lambs seems to favourably affect the PUFA:SFA ratio of subcutaneous lipid tissue, but negatively affect the n-6:n-3 ratio of both lipid and muscle tissue, whereas the total n-3 content was left unaffected. A lipid source high in n-3 would be of benefit if added to a low-NDF fini","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"295 ","pages":"Article 105698"},"PeriodicalIF":1.8,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143799474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methane and nitrous oxide emissions from excreta of different beef cattle breeds fed with different concentrate:roughage ratios and finished in feedlots under tropical conditions","authors":"Alan Figueiredo de Oliveira ,&nbsp;Edilane Costa Martins ,&nbsp;Ramon Costa Alvarenga ,&nbsp;Mônica Matoso Campanha ,&nbsp;Bruno José Rodrigues Alves ,&nbsp;Letícia Gobbo Oliveira ,&nbsp;Leandro Sâmia Lopes ,&nbsp;Ângela Maria Quintão Lana","doi":"10.1016/j.livsci.2025.105694","DOIUrl":"10.1016/j.livsci.2025.105694","url":null,"abstract":"<div><div>Excreta from confined beef cattle are sources of greenhouse gas (GHG) emissions; however, little is known about the effects of different concentrate:roughage ratios and cattle breeds on these emissions. This study evaluates methane (CH₄) and nitrous oxide (N₂O) emissions from the excreta of Nellore or crossbred (Nellore × Angus) beef cattle that are fed diets containing 65% or 85% of concentrates under tropical conditions. The excreta were applied to the floor of feedlot pens, and N₂O and CH₄ emission rates were monitored for 84 days in static chambers. The animals were confined for 106 days to evaluate their intake, weight gain and feed efficiency. In addition to average emission rates, emissions from excreta were estimated based on ratios per kg of dry matter intake (DMI; CH₄/DMI and N₂O/DMI) and per kg of weight gain (average daily weight gain, ADG; CH₄/ADG and N₂O/ADG). The data were subjected to variance analysis in a 2 × 2 factorial arrangement, and the means were compared using a Tukey test (P &lt; 0.05). Results indicated that CH₄ emissions were 2.40 times higher from the excreta of crossbred cattle than in Nellore cattle (P &lt; 0.039). N₂O emissions were 50.1% lower from the excreta of animals consuming diets with low concentrate:roughage ratios than in those consuming diets with high concentrate:roughage ratios. The CH₄/DMI and CH₄/ADG ratios were higher in the excreta of crossbred cattle than in Nellore cattle. The N₂O/ADG and N₂O/DMI ratios in the excreta of animals fed with high concentrate:roughage ratios were also 18.2% and 36.1% higher in crossbred cattle than in Nellore cattle. The N₂O/DMI and N₂O/ADG ratios in the excreta of crossbred and Nellore cattle were lower when fed with diets containing low compared to high concentrate:roughage ratios. The results suggest that crossbred animals with more concentrate feed diets emit more CH₄ and N₂O from their excreta. This is the first study to report that Nellore cattle, the predominant breed in Brazil, and diets with lower concentrate:roughage ratios may be associated with a reduced potential for GHG emissions from excreta in confined beef cattle under tropical conditions.</div></div>","PeriodicalId":18152,"journal":{"name":"Livestock Science","volume":"295 ","pages":"Article 105694"},"PeriodicalIF":1.8,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}