Body Condition Score Research Articles

Saturated Fatty Acids in Wool as Markers Related to Intramuscular Fat Content in Lambs.

The aim of this study was to identify Longissimus lumborum (LL) muscle from lambs with high IMF content (≥3%) using wool FA. The FA composition was characterized in two sections of wool from Suffolk Down lambs, and its relationship with IMF content assessed. One hundred and forty lambs of similar body weight, body condition score, and age were selected. IMF content from LL muscle, and the wool fat and FA composition of the wool were determined. The proportions of FAs in the wool of lambs with low IMF were 51.96 ± 7.3% of saturated, 31.96 ± 7.7% polyunsaturated, and 16.08 ± 2.3% monounsaturated. Similar proportions of FAs were observed in wool samples of lambs with high IMF. Significant differences were found only in the SFA proportion between groups (p < 0.05). The predominant FAs in the wool samples were C16:0, C17:0, C18:0, C18:1n9c and C18:2n6c, representing over 60% of total FA methyl esters. Correlations were found between the wool FAs C16:1, C17:0, C18:0, C18:1n9c, C24:0, and C22:6n3 in wool samples divided into two sections. Discriminant analysis identified SFAs, particularly FAs C22:0 and C24:0, as potential candidate for predicting lambs with high IMF content with an accuracy of over 92%. These results provide to our knowledge evidence that IMF content could potentially be determined using wool FAs as a non-invasive method.

An evaluation of a Browse-aid at the doorsteps of (agro)pastoralists to improve consumption of in situ browses and shrubs and prevent animal deaths during droughts

BackgroundThousands of animals die in Ethiopia during droughts due to unavailability of feed. Large amounts of browses are available during droughts, which animals do not consume because of the presence of tannins. The hypothesis of the study was that the provision of small amounts of Browse-aid (polyethylene glycol-4000) to animals at farmers’ doorsteps would increase browse consumption and body weight gain, and prevent deaths during droughts.MethodsA field study was conducted at two sites in Ethiopia to assess the dietary inclusion of the Browse-aid (daily 5 g and 10 g for shoats; and 15 g and 30 g for cattle) to farmers’ sheep, goats and cattle in areas devoid of grasses during a very dry spell.ResultsInclusion of the Browse-aid to sheep and goats significantly increased the percent body weight gain, and improved the body condition score, skin coat appearance and shine in eyes when compared with those of animals not given the Browse-aid. Similar results were observed in cattle. The foraging frequency of the animals also increased. Nutrient availability to the animals from the increased consumption of browses also increased. Furthermore, the body condition scores of the animals given the Browse-aid were greater than those of the animals that did not participate in the trial but were grazing in the same area.ConclusionBrowse-aid made a positive impact on the production of animals during periods of severe feed scarcity. This strategy of providing the Browse-aid (daily 5 g for sheep and goats, and 15 g for cattle) to animals during droughts is highly cost effective; additionally, compared with currently used feeding strategies, the cost in late 2023 was 60% and 90% lower for sheep and goats, and cattle respectively to prevent animals from dying during droughts. A large number of animals can be prevented from dying during droughts, at a much-reduced cost by the dietary inclusion of a small amount of the Browse-aid. The implications of the study are not restricted to Ethiopia but extend to countries in the Horn of Africa. This is the first study that has investigated the effect of the Browse-aid at the farmers’ doorsteps in the field.

Effect of sward species diversity combined with a reduction in nitrogen fertilizer on the performances of spring calving grazing dairy cows

The objective of this study was to evaluate the impact of sward diversification combined with a reduction of chemical nitrogen (N) fertilizer on the performance of spring calving grazing dairy cows within a farm systems experiment. Three farmlets were created; a monoculture of perennial ryegrass (Lolium perenne L.; PRG) fertilized with 250 kg N/ha (PRG-250N), a PRG - white clover (Trifolium repens; WC) sward fertilized with 125 kg N/ha (PRGWC-125N) and a multispecies sward (MSS) comprising of grasses, legumes and herbs also fertilized with 125 kg N/ha (MSS-125N). Each farmlet had its own herd of dairy cows on a total area of 18.7 ha divided into 20 paddocks. Each herd was comprised of pure Holstein-Friesian (HF) and HF Jersey crossbred (JFX) animals and randomly assigned through the 3 treatments. For 3 years (2021 to 2023), the performances of both swards (grass yield, botanical composition, nutritive value) and grazing animals (milk production and composition, body weight (BW) and body condition score (BCS)) were recorded. There were no significant differences in pasture production or sward nutritive value between sward systems and grazing season length was also similar (264 d). On average over the 3 years, PRGWC-125N contained 150 g/kg DM of legumes and the MSS-125N contained 160 g/kg DM legumes, 130 g/kg DM plantain and 40 g/kg DM chicory. Both individual cow milk and fat plus protein (Milk solids; MS) yield were lower for PRG-250N (5,018 and 452 kg, respectively), intermediate for PRGWC-125N (5,139 and 463 kg, respectively) and highest for MSS-125N (5,297 and 476 kg, respectively) while milk and MS production per hectare from grazing were similar during the study period (11,523 and 1,016 kg/ha, respectively). Breed also had a significant effect with the JFX having lower milk yield but higher fat and protein concentration compared with HF. This resulted in higher MS production per kg of BW for the JFX compared with HF (0.96 and 0.87 kg MS/kg BW, respectively). The results of this study highlight the possibility for more diverse pastures to reduce chemical N fertilizer input requirements and maintain pasture productivity while increasing animal performance within pasture-based spring calving systems.

Nutrition, Growth, and Age at Puberty in Heifers

Puberty onset and age at first calving have a critical impact on livestock production for good reproductive efficiency of the herd and to reduce the duration of the non-productive stage of the growing heifer. Besides genetic factors, sexual maturation is also affected by environmental factors, such as nutrition, which can account for up to 20% of the observed variability. The rate of body weight gain during growth is considered the main variable influencing the age at puberty, dependent on planes of nutrition in growing animals during the prepubertal-to-pregnancy stage. This paper reviews current knowledge concerning nutrition management and attainment of puberty in heifers, considering the relevance of some indicators such as body measurements and hormones strictly linked to the growth and puberty process. Puberty onset is dependent on the acquisition of adequate subcutaneous adipose tissue mass, as it is the main source of the hormone leptin. Until a certain level, body condition score and age at puberty are negatively correlated, but beyond that, for fatter animals, such correlation is gradually lost. Age at puberty in heifers was reported to be negatively related to IGF-1. Future research should be planned considering the need to standardize the experimental animals and conditions.

Saliva as a Potential Source of Biomarkers in Cows with Metritis: A Pilot Study.

Metritis affects 5-20% of cows after parturition, negatively impacting animal welfare and the profitability of dairy farms, increasing culling rates and costs, and decreasing productivity and reproduction rates. This study compared the results of a comprehensive biochemical panel consisting of 25 salivary and 31 serum analytes between healthy cows (n = 16) and cows with metritis (n = 12). Descriptive parameters such as depression, rectal temperature, body condition score (BCS), heart rate, respiratory rate, mucous color, ruminal motility, vaginal discharge, milk production, and complete hematology analyses were also assessed for comparative purposes. The biochemistry analytes comprised five analytes related to stress, five to inflammation, five to oxidative status, and nineteen to general metabolism. The two-way ANOVA analysis revealed that, in saliva, eight biomarkers (lipase, adenosine deaminase (ADA), haptoglobin (Hp), total proteins, g-glutamyl transferase (gGT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and creatine kinase (CK)) were significant higher in cows with metritis. In serum, eight biomarkers (ADA, Hp, serum amyloid A (SAA), fibrinogen, ferritin, AOPPs/albumin ratio, non-esterified fatty acids (NEFAs), and bilirubin) were significantly higher in cows with metritis, whereas six (total esterase (TEA), albumin, urea, lactate, phosphorus, and calcium) were lower. Of the total number of 23 biomarkers that were measured in both saliva and serum, significant positive correlations between the two biofluids were found for six of them (Hp, FRAP, CUPRAC, AOPPs, urea, and phosphorus). Urea showed an R = 0.7, and the correlations of the other analytes were weak (R < 0.4). In conclusion, cows with metritis exhibited differences in biomarkers of stress, inflammation, cellular immune system, and general metabolism in both salivary and serum biochemistry profiles. These changes were of different magnitudes in the two biofluids. In addition, with the exception of ADA and Hp, the analytes that showed changes in the saliva and serum profiles of cows affected by metritis were different. Overall, this report opens a new window for the use of saliva as potential source of biomarkers in cows with metritis.

Fecal microbiome and functional prediction profiles of horses with and without crib-biting behavior: A comparative study

Crib-biting is a stereotyped oral behavior with poorly understood etiology and pathophysiology. The relationship between the gut microbiome and brain function has been described in behavioral disorders such as schizophrenia, depression and anxiety in humans. In horses, studies of behavioral problems and the microbiome are very limited. This study aimed to characterize the fecal microbiome and the predicted functional profile of horses with and without aerophagia. Fecal samples were collected from 12 Colombian Creole Horses of both sexes, divided into two groups: group 1, composed of six horses with crib-biting (3 females and 3 males), average body weight of 330 ± 10 kg, age of 7.0 ± 1.2 years and body condition score (BCS) of 5/9 ± 1 and group 2, consisting of six horses without crib-biting (3 females and 3 males), average body weight of 335 ± 5 kg, age 6.5 ± 1 years and BCS of 6/9 ± 1. From each horse in both groups fecal total DNA was obtained and 16S ribosomal RNA gene amplicons were sequenced to characterize the bacterial community structure. Community structure and differential abundance analyses revealed significant differences between the two conditions (p < 0.05). Specifically, the fecal microbiota at the family level in crib-biting horses, showing a decrease in Bacteroidales and an increase in Bacillota and Clostridia, differed from that of healthy horses without crib-biting, consistent with findings from previous studies. Furthermore, metagenome prediction suggests metabolic profile changes in bacterial communities between both conditions in horses. Further studies are required to validate the role of the microbiota-gut-brain axis in the etiology of crib-biting and other abnormal and stereotyped behaviors.

Effects of Supplementing Different Quantities of Moringa stenopetala Leaves on Plasma Metabolite and Acylcarnitine Profile, Body Condition Score and Milk Yield Performance in Zebu (Bos indicus) Cattle.

The formulation of multi-nutrient blocks based on low-cost and locally available browse feed resources can be a valid feeding strategy in Sub-Saharan Africa, where inadequate feed supply, both in quality and quantity, is a major constraint. We evaluated the four different inclusion percentages (M-0%, M-25%, M-35% and M-45%) of Moringa stenopetala leaf powder to multi-nutrient blocks on their change on blood metabolite of dairy cows under practical, ranging conditions. Multi-nutrient blocks with four inclusion rates of M. stenopetala leaves were applied as complementary feed for free ranging dairy cows. The study was performed on 24 free ranging dairy cows reared around Arba Minch town in the Southern Ethiopian Rift Valley. Blood samples were collected from the jugular vein of dairy cows both before and after supplementation. Plasma glucose, beta hydroxy butyrate (BHB), urea, creatinine, triglycerides and nonesterified fatty acids (NEFA) concentration was quantified spectrophotometrically. Dried serum spots were subject to quantitative electrospray tandem mass spectrometry to estimate changes in nutrient metabolism based on selected carnitines. Based on these measurements, the milk yield and body condition score were increased during the period of multi-nutrient block supplementation. During the supplementation period, the cows got higher plasma glucose, triglyceride and urea concentrations and lower concentrations of BHB, NEFA and creatinine. From the metabolite profiles, a more efficient nutrient use could be concluded. Although no clear dose-response relationship was observed, the highest inclusion of the M. stenopetala leaves in the multi-nutrient blocks gave the best performance. This outcome supports the idea of implementing M. stenopetala based multi-nutrient blocks on tropical smallholder farms that are not easily accessible to conventional extension services.

PSXII-10 Post-weaning energy balance in dual-purpose replacement heifers (Giroland-Brown Swiss cross) confined-raised and grazing-raised before and after rainy season in tropical systems livestock

Abstract Common management of dual-purpose (Giroland-Brown Swiss cross) cattle in the Mexican Tropical region is to rear heifer replacement post-weaning in group pens. It is assumed that placing post-weaning heifers in group pens has more access to higher energy reserves due to the reduced foraging behavior. This study compared β-hydroxy-butyrate (BHB), body condition score (BCS), and average daily gain (ADG) in the post-weaning barn-raised and grazing-raised calves. Giroland-Brown Swiss cross (n = 8) were divided into 2 groups: confined-group (CG; n = 4) and grazing-group (GG; n = 4) for 4 mo (June to September). Both groups had ad libitum access to the same pasture (star grass; Cynodon plectostachyus) containing 6.5 % and 12.4 % crude protein (CP) during 2 regional seasons (drought and rainy season). Commercial concentrate was offered daily (0.5 kg; 17.5 % CP and 1 881 Mcal/kg net energy) at 1000 h. CG bunk feeders were refilled with pasture when empty during the day and mineral salts and water were provided at libitum to both groups. BHB was estimated monthly using a test strip (Freestyle Optium Neo, Witney UK). Additionally, BCS and ADG were estimated twice per month. An analysis of variance (ANOVA) model with a factorial design was implemented to assess BHB, BCS, and ADG as dependent variables and group treatment (GG and CG), month (4 levels), and season (drought and rainy) as independent variables. BHB values were not significant in the 2 treatment groups (GG: 300 ± 40 and CG: 230 ± 20 µmol/L; P &amp;gt; 0.05). The ADG (LS Means ± SEM) did not differ between treatment groups during drought season (GG: 419 ± 115 g compared with CG 310 ± 15 g; P &amp;gt; 0.05). Nevertheless, the ADG was significantly different between treatment groups during the rainy season (GG 790 ± 131 g compared with CG - 110 ± 63 g; P &amp;lt; 0.05). In addition, BCS was significantly different at the end of the experiment among treatment groups (GG: 3.13 ± 0.22 compared with CG: 2.6 ± 0.19). Our conclusion is that both management (grazing and confined) were equal to rear calves after weaning during the drought season. However, grazing the calves performed better (&amp;gt; ADG, and BCS) than confined management during the rainy season.

PSX-4 Exploring the impact of age and body condition score on the genetic analysis of mature cow weight in American Angus cattle

Abstract Selecting sires with optimal genetic merit for mature weight (MWT) is crucial for profitability of beef producers, ensuring cost-effective production and increased economic returns per animal. The main objective of this study was to determine how different statistical approaches [e.g., including the fixed effects (FE) of age and body condition score (BCS) in the statistical model and/or pre-adjusting the weights for these effects] affect variance components estimation and genetic parameters for MWT, and their impact in the posterior selection decisions. The dataset provided by the American Angus Association (AAA) comprised 80,296 MWT records from 37,934 cows aged 2 to 15 yr. Contemporary groups (CG) were defined by concatenating herd, year, and season of measurement. Model 1 analyzed unadjusted MWT with CG and BCS as categorical FE and age as a covariable (quadratic). Model 2 was model 1 without BCS, model 3 was model 1 without age, and model 4 considered CG as the only FE. In model 5, MWT was pre-adjusted for 6 yr of age and BCS of 6, and CG was the only FE included in the statistical model. Additive genetic and permanent environment (pe) random effects were included in all statistical models except model 5, which did not include pe (only one adjusted record per animal). Variance components were calculated using REML implemented in the BLUPf90+ family of programs. Sires with at least 10 offspring (n = 1,483) were ranked according to their breeding values (EBVs) predicted for MWT, and all and the top 10% sires were used to estimate the rank correlation across models. The heritability (± SE) estimated for MWT was 0.43 (± 0.011), 0.42 (± 0.011), 0.70 (± 0.008), 0.72 (± 0.082), and 0.37 (± 0.013) for models 1, 2, 3, 4, and 5, respectively. Repeatability values were 0.64, 0.67, 0.72, and 0.76 for models 1, 2, 3, and 4, respectively. The EBV ranks were highly correlated between models 1 and 2 (Top 10%: 0.96; All: 0.99), and models 3 and 4 (Top 10%: 0.99; All: 0.99). Inflated heritabilities in models 3 and 4 suggest that the effect of age is confounded with the additive genetic effect, which will not translate to greater genetic progress. Therefore, disregarding age in the genetic evaluation of MWT is not recommended. Similarities between models 1 and 2 suggest that BCS has a relatively small impact on MWT, probably related to the relatively low genetic correlation between these traits. Models 1 and 5 cannot be directly compared, as they use slightly different response variables (body weight vs. pre-adjusted weight) and may lead to slightly different selection decisions (correlation between Top 10%: 0.85; All: 0.95). Further investigations in this field are warranted.

PSI-18 Intra-articular triamcinolone acetonide administration does not affect microbial culture or synovial fluid volume in young, exercising Quarter Horses

Abstract Intra-articular corticosteroids (IAC) are administered to horses experiencing joint inflammation, at times with a concurrent articular antibiotic for prophylaxis. However, information regarding the biologic effects of IAC and potential for microbial contamination in IAC-administered joints is limited in young, exercising horses. The objective of this study was to evaluate the impact of IAC on traditional microbial culture, synovial fluid (SF) volume, and the presence of IAC; hypothesizing negative microbial culture, no change of SF volume, and detection of IAC in SF post-administration. To test this, 2-yr-old Quarter Horses {n = 24; body weight (BW) = 409 ± 6 kg; 825 ± 21 d of age; 12 fillies, 12 geldings) were stratified by BW, age, and sex, and randomly assigned to 1 of 3 treatment groups for a 56-d trial. Horses were housed individually in stalls with runs and fed concentrate offered at 0.75% BW/d split evenly every 12 h with ad libitum Coastal bermudagrass hay and water. Every 21 d, BW and body condition score (BCS) were recorded, and concentrate was adjusted accordingly. Horses were exercised 5 d/wk, up to 45 min/d in a progressive workload using a free-stall exerciser. Blood was collected post-exercise during wk 1, 4, and 7 via jugular venipuncture and lactate (BL) was measured to monitor increasing workload. Intra-articular treatments consisted of 0 mg (CON; n = 8), 6 mg (CORT6; n = 8), or 12 mg (CORT12; n = 8) of triamcinolone acetonide (TA). On d 0, treatments were administered in one randomly selected radiocarpal joint per horse. Following aseptic preparation, SF from both radiocarpal joints was collected before administration (pre), and on d 7, 14, 28, and 56. Volume of SF was recorded, and standard microbial culture and detection of TA were performed by a commercial laboratory. Data were analyzed using PROC MIXED (BW, BCS, BL, SF volume) and PROC GLM (TA) of SAS. For SF volume, data from the contralateral radiocarpal joint were used as a covariate. Horses increased BW and BCS over time (P ≤ 0.01) across treatments. Post-exercise BL increased from wk 1 to 4 and remained increased through wk 7 (P &amp;lt; 0.01). Microbial culture for all horses and time points were negative. Concentration of TA was not evaluated on d 7 due to limited SF volume, but TA was detected on d 14 and concentration did not differ between CORT6 and CORT12 (P = 0.13). Recorded SF volume did not change from d 0 (pre) to 7 but increased to d 56, regardless of treatment (P &amp;lt; 0.01). These results indicate that, based on standard culture, TA administration did not result in positive microbial culture, or decrease SF volume in young horses undergoing regular exercise, however, TA was detectable to d 14.

PSV-25 Investigating the effects of Chromium Propionate supplementation on productive and reproductive performance of beef cows

Abstract We investigated the effects of Chromium Propionate supplementation on reproductive performance of beef cows from pre-partum to weaning. Suckled beef cows at nine locations were enrolled in the study. Within location, cows were stratified by parity, dam age, and day postpartum (DPP) and randomly assigned to one of two treatments: 1) Control, supplementation of a mineral product at 113 gּ animal-1ּ d-1 (n = 464 cows; 13 experimental units); or 2) CrP, supplementation of mineral product at 113 gּ animal-1ּ d-1 containing 1.4 g of Chromium Propionate (0.4%KemTRACE Chromium 0.4%, Kemin Industries, Inc., Des Moines, IA; n = 489 cows; 13 experimental units). Treatments were initiated at approximately 37 d pre-calving until weaning for a total of 250 ± 12 d. Cows were enrolled in the 7-d CO-Synch+CIDR fixed-time artificial insemination (TAI) protocol followed by natural service for a 70-d breeding season. Pregnancy diagnosis was performed by ultrasonography at 55 d after TAI protocol and 40 d after the end of the breeding season. Cow body weight (BW) and body condition score (BCS) were recorded at initiation of the TAI protocol (d -10), at pregnancy diagnosis (d 55 and 110), and at weaning (d 285). Within group, mineral disappearance was determined by the difference in weight between offered mineral and refusals. Data were analyzed using the GLIMMIX and MIXED procedures of SAS with pasture/group as the experimental unit with the effect of treatment and included group (treatment × location), cow (group), and location as random variables. Age, DPP, d -10 BCS, and BW were similar (P &amp;gt; 0.05) between treatments (5.4 and 5.3 ± 0.61 yr, 79.2 and 79.9 ± 4.61 d, 5.1 and 5.2 ± 0.05, 515.7 and 515.6 ± 15.11 kg for Control and CrP, respectively). Mineral disappearance was similar (P = 0.999) between treatments (165.5 and 152.9 gּ animal-1ּ d-1, for Control and CrP, respectively). Cow BW was similar (P &amp;gt; 0.05) between treatments on d 55, 110 and 285 (558.5 and 551.4 ± 14.50 kg, 580.8 and 594.6 ± 13.51 kg, and 574.2 and 570.9 ± 14.32 kg for Control and CrP, respectively). Similarly, cow BCS did not differ (P &amp;gt; 0.05) between treatments on d 55, 110 and 285 (5.4 and 5.4 ± 0.09, 5.3 and 5.3 ± 0.10, and 5.1 and 5.2 ± 0.10 for Control and CrP, respectively). Calf birth and weaning BW were similar (P &amp;gt; 0.05) between treatments. However, CrP-supplemented cows tended (P = 0.081) to have greater estrus expression (60.2 and 68.3 ± 3.1 %, for Control and CrP, respectively) and CrP-supplemented cows had greater (P = 0.045) TAI pregnancy rate when compared with Control cows (49.9 and 55.2 ± 2.1 %). Supplementation of Chromium Propionate to beef cows from pre-partum through weaning did not affect cow BW and BCS, tended to increase estrus expression and increased TAI pregnancy rate.

PSXII-11 Impact of pre-breeding and breeding supplementation in May-born range heifers on growth rates and reproductive performance

Abstract Our objectives were to determine the impact rumen undegradable protein (RUP) supplementation prior to and during the breeding season had on growth rates and reproductive performance in May-born yearling range heifers. This study was conducted over a 3-yr period at the University of Nebraska, Gudmundsen Sandhills Laboratory (GSL) near Whitman, NE and utilized May-born Red Angus x Simmental crossbred heifers [n = 192; weaning body weight (BW) = 200 kg ± 28 kg]. Heifers were randomly assigned by pre-breeding BW to one of two treatments: 1) received 0.908 kg of a dried distillers grain supplement (DDGS; Supp, n = 66) pre-breeding through the breeding season or 2) received no supplement (NoSupp, n = 138). Each year, treatments were initiated in July and ended in August (55 ± 3 d). Using a C-Lock Smart Feeder (Rapid City, SD) heifers had individual access to their allotted DDGS supplementation. On average, NoSupp heifers consumed 0.09 kg/d (yr 1) and 0.02 kg/d (yr 2 and 3); whereas, Supp heifers averaged 0.59, 0.74, and 0.76 kg/d in yr 1, 2, and 3, respectively. Heifer BW was collected pre-trial (May), pre-breeding (July), breeding (August), pregnancy diagnosis (October), and pre-calving (April). Body condition score (BCS) was collected at pregnancy diagnosis (October) and pre-calving (April; Yr 1 and 2). Before each breeding season, two blood samples were collected 10 d apart to determine pubertal status. Heifers were synchronized with a single 5 mL intramuscular injection of prostaglandin F2 alpha (Lutalyse, Zoetis, Parsippany, NJ) 5 d after bull turnout during a 30 d natural service breeding season. Pregnancy diagnosis was determined via rectal ultrasound in October. No differences (P &amp;gt; 0.12) in BW were noted among treatments for all measurement timepoints. Moreover, SUPP heifers had greater (P &amp;lt; 0.02) average daily gain (ADG) from pre- trial to pregnancy diagnosis compared with NoSUPP heifers. However, there was no differences (P = 0.11) in ADG from pregnancy diagnosis to pre- calving. At pregnancy diagnosis (October), a treatment x year interaction (P = 0.02) for BCS was present where Supp heifers had a greater BCS than NoSupp heifers in yr 3. Heifer BCS pre-calving was not affected (P = 0.12) by treatment. There was a greater percentage (P &amp;lt; 0.01) of SUPP heifers cycling compared with NoSUPP heifers. However, there were no differences (P &amp;gt; 0.24) in pregnancy rates, the percentage that calved in the first 21 d, calf birth BW, or subsequent calving date. Ultimately, this study implies that providing a RUP supplement prior to and during the breeding season will increase the percentage of heifers that are cycling before breeding and have a greater ADG through pregnancy diagnosis; however, supplementation will not impact other reproductive parameters or BW gains.

PSIII-20 The effects of vitamin E and/or C on parasite burden in hair sheep

Abstract Anthelmintic resistance in flocks is an occurring issue for small ruminant producers due to increasing gastrointestinal nematode (GIN) infections. Prevalence of high virulence GINs decreases immunity and growth, therefore not making anthelmintics economically sustainable for producers. In this current research study, we examined the role of vitamins E and/or C supplemented to crossbred hair sheep (Dorper, Katahdin, Barbados crosses) on parasite burden over time. The hypothesis of this research was that supplementing vitamin E and/or C will work comparable to anthelmintic treatment to control GIN in hair sheep. Mature ewes (n = 30) were stratified based on FAMACHA score. Ewes were placed into one of five treatment groups: 1) no dewormer or vitamin treatment (CON; n = 6), 2) anthelmintic treatment (Levamed; 0.08mg/kg; Bimeda Animal Health, Schaumburg, IL; n = 6), 3) combination of vitamin E and vitamin C (Vitamin E300; 0.33IU/kg of body weight (BW) administered subcutaneously; Durvet Animal Health; Blue Springs, MI; Vitamin C; Orally drenched at 0.56 mL/kg of BW; Radix Laboratories; Eau Claire, WI; n = 6), 4) vitamin C (Vitamin C;0.56 ml/kg of BW; Radix Laboratories; Eau Claire, WI; n = 6), and 5) vitamin E (Vitamin E 300; 0.33 IU/kg of BW; Durvet Animal Health; n = 6). Growing lambs (n = 30) were also placed into the same treatment groups. Evaluation of vitamin supplementation was observed on individual time points from d 0, 14, 28, 56, and 77 from the sheep. Parameters collected include body condition score (BCS), FAMACHA score, packed cell volume (PCV), and fecal egg count (FEC). There was no effect (P &amp;gt; 0.05) on BCS in either lamb or mature groups on any of the days within the trial. However, on d 56, there was a tendency for the FAMACHA score to be improved in the vitamin E lambs compared with the control lambs. Additionally, on d 56 for the mature group, there was a significant difference (P ≤ 0.05) that was observed within the Vit E+C group being less than the Dewormer and vitamin C groups. Treatments did not affect (P &amp;gt; 0.05) packed cell volume (PCV) throughout the trial in either lamb or mature ewes. On d 14 of the trial, lambs receiving vitamin E and C, or the anthelmintic treatment had decreased (P ≤ 0.05) strongyle FEC compared with the control lambs. The preliminary data analyzed suggests that vitamin E and/or C may work similarly to pharmaceutical anthelmintics in hair sheep to combat GIN. However, more research is essential to confirm the viability that vitamins may work as a sustainable alternative.

PSXII-26 The influence of protein supplementation in beef cows during early lactation on growth performance, carcass characteristic and meat quality of progeny

Abstract At 11 ± 4 d of lactation, 30 multiparous Angus cows [body weight (BW) = 476 ± 17 kg, body condition score (BCS) = 4.5 ± 0.3) were stratified by BW and allotted in 6 pens (5 cows/pen). During 75 d of experiment, all pens received ad libitum low quality hay (Panicum italicum; 54.7% TDN, 6.1% CP DM basis) and were randomly assigned to one of two treatments: 1) PS; cows received ad libitum 30% CP supplement including an intake limiter component (Controlmix, Nutralmix SRL, Argentina), or 2) NS; cows were not supplemented. After the experimental period, dams and their calves (PS: 7 males and 8 females; NS: 8 males and 7 females) were managed on improved pastures as a single group until weaning at 213 d of age. After weaning, heifer and steer calves were reared on improved pastures until 448 d of age, then placed into a feedlot with a finishing diet during 73 d until slaughter. Pens were considered the experimental unit and data were analyzed using the PROC MIXED of SAS, considering treatment and sex as a fixed effects and pen as a random effect. Overage dry matter intake (DMI) of hay was not affected by treatments (P &amp;gt; 0.10), and DMI of supplement in PS cows was 4.4 kgּ cow-1ּ d-1. Milk production was greater in PS than NS cows (PS: 5.3, NS: 3.6 kgּ cow-1ּ d-1; P &amp;lt; 0.01). Progeny from PS cows increased BW at weaning (PS: 180, NS: 141 kg; P &amp;lt; 0.01), BW at initial feedlot phase (PS: 300, NS: 252 kg; P = 0.01) and final BW (PS: 415, NS: 354 kg; P = 0.01). After slaughter, progeny from PS cows tended to have increased dressing percentage (PS: 59.0, NS: 58.1%; P = 0.09), had an increased hot carcass weight (PS: 227, NS: 191 kg; P &amp;lt; 0.01), and increased Longissimus muscle (LM) area (PS: 68.5, NS: 60.1 cm2; P = 0.02), while rib fat thickness was not affected by treatments (PS: 7.8, NS: 7.6 mm; P = 0.68). There was no effect of protein supplementation on color (L*, a*, b*) and pH of LM at 24 h postmortem (P &amp;gt; 0.10). In addition, moisture, ether extract and shear force of LM after 4 d of aging were similar between treatments (P &amp;gt; 0.10). There was no treatment × sex interaction for any variables (P &amp;gt; 0.10). This study showed that protein supplementation during early lactation improved growth performance and carcass quality, but did not result in enhanced meat quality of progeny.

PSX-2 Productive performance of Raramuri Criollo, Angus x Raramuri Criollo and Hereford x Angus cows in a low-input cow-calf system in northern Mexico

Abstract Raramuri Criollo cattle (RC), a local heritage breed in the Chihuahua state of Mexico, are highly rustic and well-adapted animals that can contribute to cow productivity in a low-input cow-calf production system. The aim was to evaluate traits related to productive performance of purebred RC, Angus x RC (AC) and Hereford x Angus (HA) cows. Each cow breed group was randomly assigned to one of three pastures within each of two mountains dominant exposures and evaluated during 2022 and 2023 at Rancho Teseachi (28◦48′ N, 107◦25′ W) belonging to Universidad Autonoma de Chihuahua. The six grazing pastures ranged from 263 to 400 ha, with similar slope, altitude and water sources characteristics. The stocking rate was moderate (forage utilization &amp;lt;50%). Forage biomass availability for the period of use was sampled in October, and stocking rate adjusted accordingly in March. RC cows were bred with RC bulls, and AC and HA with Angus bulls. The breeding season was from September to November, and pregnancy diagnosis at mid-January. Non-pregnant cows were replaced by pregnant cows from other pastures of the same farm. Feed supplementation was limited in 2022 and according to nutritional requirements in 2023. Evaluated variables included calf birth (BW) and weaning weight adjusted (WW) to the average age at weaning (190 d in 2022 and 165 d in 2023); body condition score (BCS 1 to 9), cow body weight (CBW) at the beginning of the breeding season, as well as body weight of calf weaned by unit of cow weight (WW/CBW), and pregnancy rate (PR). A general linear model with fixed effects of breed group, sex, dominant exposure of mountains, their interaction, cow age subclass (Young, 4 yr; Middle, 5 to 8 yr; Adult, &amp;gt; 9 yr) and Julian date at calving as a covariate was adjusted using PROC GLM of SAS for continuous, normally distributed variables, and PROC CATMOD for pregnancy rate, leaving out sex and interaction effects. Means of BW and WW on calves from AC and HA cows were greater (P &amp;lt; 0.5) than those from RC cows in both years (Table 1). In 2022, the mean CBW of HA was greater (P &amp;lt; 0.5) than for AC, and this greater (P &amp;lt; 0.5) than for RC cows; BCS was greater for AC than for HA and RC, and PR lower (P &amp;lt; 0.5) for HA than for AC and RC. In 2023, there was no difference in CBW between AC and HA; BCS was similar (P &amp;gt; 0.05) among the three groups; and PR was the lowest (P &amp;lt; 0.5) for HA. The AC cows had the greatest WW/CBW mean (P &amp;lt; 0.5) in both years. Overall, using AC cows resulted on a combination of traits that outperformed on general productivity in the evaluated production system.

PSXIII-7 Effects of whole corn on gain and subsequent feedlot and carcass traits of Brahman steers stocked on Tifton 85 bermudagrass

Abstract Supplementation (SUP) of stocker calves is used to enhance gain and/or adjust for stocking rates (SR). Our objective was to determine the influence of whole corn on performance of steers stocked on Tifton 85 bermudagrass [Cynodon dactylon (L.) Pers. X Cynodon nlemfuensis Vanderyst] (T85) that has documented forage crude protein ranging from 18.5% in June to 13.5% in September. For a 3-yr period, Brahman (Bos indicus) steers, 15 mo old and 275 kg body weight (BW), were stocked on T85 and received daily whole corn at 0 (PAS), 0.3% BW (SUP3), or 0.6% BW (SUP6). A fourth treatment included SUP6 at an increased stocking rate (SUP6SR). The 3-yr average SR of 275 kg steers was 11 steersּ ha-1 on PAS, SUP3, and SUP6, and 15 steersּ ha-1 on SUP6SR. Average daily gain (ADG) was similar for SUP steers at 0.98 kgּ d-1 (SUP6), 0.92 kgּ d-1 (SUP3), and 0.92 kgּ d-1 (SUP6SR), but greater (P = 0.002) than PAS steers at 0.84 kgּ d-1. Steer gainּ ha-1 was greatest (P = 0.001) for SUP6SR at 1230 kgּ ha-1. Gain ha-1 was similar for SUP6 and SUP3 at 1,010 kgּ ha-1 and 941 kgּ ha-1, respectively, and similar for SUP3 and PAS (860 kg-1). Body weights off pasture tended to be greater (P = 0.083) for all SUP steers at 370 kg than PAS steers at 354 kg. Body condition score off pasture was similar for all SUP steers at 5.7 and different (P = 0.001) from PAS steers at 5.2. At termination of stocking, steers were shipped 700 km to a commercial feedlot in South Texas. Each year, steers were fed in the same pen until a visual assessment of about 1.25 cm backfat was attained. Days on feed were similar for all steers at 190 d. Feedlot ADG was similar for steers on SUP3 (1.36 kgּ d-1), PAS (1.34 kgּ d-1), and SUP6SR (1.29 kgּ d-1), but greater (P = 0.045) than steers on SUP6 (1.24 kg d-1). These feedlot ADG exhibited some compensatory gain effects from pasture treatments. Off feedlot weights were similar at 620 kg. Steers were transported 60 km to an abattoir for harvest and carcass trait evaluations. There were no differences across treatments for steer hot carcass weight, 367 kg; 12th rib fat thickness, 1.13 cm; marbling score, 395; calculated yield grade, 3.10; longissimus dorsi area, 85.02 cm2; or internal fat (kidney-pelvic-heart), 1.92%. With SUP:extra gain at 12.5:1 for SUP3 and 13.8:1 for SUP6, supplementation of whole corn for Brahman steers stocked on T85 was not as efficient as previous T85 x SUP experiments with DDGS, but may offer management options for specific cattle classes and ownership-stocking strategies.

The impact of restricted grazing systems on the behaviour and welfare of ponies.

Equine obesity is a growing concern. Much of the current management advice centres on dietary restrictions, including the removal or limitation of grazing. Little is known about the impact of these approaches on the welfare of the horse. This study investigates the effect of two commonly used grazing systems advocated for the control of weight-the 'strip-grazing' and the 'track' systems-on the behaviour and welfare of outdoor-living ponies. A within-subject cross-over experimental design with four groups of pasture-kept ponies experiencing each system for 4 weeks in a random order. Time budgets and behavioural indicators of welfare were measured using 24-h electronic surveillance, morphometric parameters including weight, body condition score and cresty neck score were measured weekly and activity levels were tracked. The effect of grazing system on movement and behaviour was tested using a general linear model. Ponies moved more [median (IQR) % time spent moving, track: 3.23% (2.08%), strip: 2.02% (0.90%); p = 0.001] and travelled a greater distance [median (IQR) metres/24 h, track: 7013.47 m (1761.49 m), strip: 5331.91 m (494.16 m); p < 0.001] and engaged in less overt agonistic behaviour on the track system compared with the strip system [median (IQR) prevalence per hour; track: 0.14 (0.30), strip: 0.21 (0.37) p = 0.02]. A relatively short time period of exposure to each grazing system. Ponies on strip systems moved less and exhibited increased agonistic interactions compared with the track system, maybe as a result of a perceived reduction in space or concentration of resources, although the accessible areas were matched. These results suggest that there may be physical as well as psychological health benefits to the track system.

288 Maternal fatty acid supplementation and its impact on dam and offspring performance

Abstract Fatty acid supplementation has multiple benefits to the offspring when supplemented to the dam during pregnancy; limited to no benefits to the dam have been documented. We hypothesized that maternal fatty acid supplementation during pregnancy would result in improved body weight (BW) and body condition score (BCS) in the ewes and improve lamb growth until weaning and male offspring growth following weaning when ewes were supplemented fatty acids. On d -8 of the study (35 d of gestation), all ewes were weighed, BCS was collected, and pregnancy status determined. Pregnant Targhee ewes (n = 83) were assigned to a treatment group based on age, BW, and BCS, to one of four treatment gr: 1) 22 g/ewe daily of Ca salts of saturated and monosaturated fatty acids based on palmitic and oleic acids (CON; EnerGII, Virtus Nutrition, LLC, Corcoran, CA); 2) 22 g/ewe daily of Ca salts of PUFA based on eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids (ɷ-3, Strata; Virtus Nutrition LLC); 3) 22 g/ewe daily of Ca salts of PUFA based on linoleic acids (ɷ-6, Prequel; Virtus Nutrition LLC); or 4) 11 g/ewe of Ca-salts enriched with EPA+DHA (Strata) and 11 g/ewe of Ca-salts enriched with linoleic acid (Strata) daily (ɷ-3 + 6; Virtus Nutrition LLC). Fatty acid supplementation occurred from d 0 until d 88 of the study, and all ewes were fed grass hay. Ewe BW and BCS were recorded at d -8, 51, 93, and 240 of the study. Twenty-four hours after birth, lamb sex was identified and weighed (n = 136 lamb; CON = 33; ɷ-3 = 32; ɷ-6 = 36; ɷ-3 + 6 = 35). Lambs were weighed at d 175 and 240 (weaning) of the study (n = 86; CON = 22; ɷ-3 = 22; ɷ-6 = 21; ɷ-3 + 6 = 21). Body weight, BCS, and scrotal circumference (SC) were collected on all ram lambs at d 352, 380, and 408. No differences were observed in ewe BW or BCS at d -8, 51, or 93 of the study (P ≥ 0.26) between the treatment groups (Table 1). A treatment × day interaction was observed at d 240 of the study when ɷ-6 ewes had a greater (P = 0.03) BCS compared with group cohorts. No differences in lamb birth weight, lamb weight or average daily gain at d 175 or 240 of the study between treatment groups (P ≥ 0.25; Table 2). No differences were reported in ram lamb BW, BCS, or SC at d 352, 380, and 408 (P ≥ 0.31; Table 3). These results indicate that maternal fatty acid supplementation alters ewe BCS at the time of weaning; however, supplementation does not impact lamb growth from birth until weaning or ram lamb growth and scrotal circumference.

262 Why are some cows skinny? An evaluation of stress and immune factors

Abstract For the mature cow with low body condition scores (BCS), being too thin can accompany health issues, reduced pregnancy rates, more days to rebreeding, and decreased milk production resulting in lighter calves at weaning. In addition, reduced fat insulation in low BCS cows during the winter equates to additional feed requirements for warmth. The hypothesis of this study was that stress and immune factors contribute to low BCS in mature cows. The objective of this study was to determine whether there were differences in hematology parameters, hair cortisol concentrations, and plasma cytokine concentrations among animals with low body condition (BCS ≤ 4). Over a 3 yr study, we collected 62 pairs of cows which included cows with a BCS ≤ 4, and a matched control animal born in the same year with the same or similar breed composition from the same population of animals with a BCS of 5 or higher. Hematology parameters, cytokine concentration, and cortisol concentrations were analyzed using a model with BCS classification and sample year as fixed effects and age in years as a covariate. Hemoglobin, hematocrit, red blood cell and mean platelet volume were all less among the low BCS cows, and neutrophil count was greater (P &amp;lt; 0.05). Platelet, monocyte counts, mean corpuscular volume, and mean corpuscular hemoglobin tended to be greater in low BCS cows (0.05 &amp;lt; P ≤ 0.1), and lymphocyte count tended to be less. Hair cortisol concentrations, a longer-term measure of cortisol, tended to be greater in low BCS cows (P = 0.09). None of the 15 cytokines tested differed with BCS. The combination of reduced RBC parameters with greater neutrophils suggests that low BCS cows were responding to or were the reflection of some type of chronic stressor, such as a subclinical disease state or a physiologic stressor. This was also supported by the tendency for greater cortisol concentrations in low BCS cows. USDA is an equal opportunity provider and employer.

112 Effects of maternal body condition on colostrum, foal weight, and foal IgG concentration

Abstract Foals are born with little to no immunity and rely on maternal colostrum to develop adequate circulating immunoglobulin G (IgG) concentrations in the periparturient period. Colostrum directly impacts the health of the foal, and there are limited data assessing how maternal metabolism and body condition impacts IgG in colostrum and in the foal postnatally. To determine the influence of maternal body condition score (BCS) and cresty neck score (CNS) on glucose and insulin metabolism in the pregnant mare, colostrum composition, and colostrum and foal IgG concentrations, light breed mares (n = 6) were divided into two groups based on BCS and CNS at 315 ± 0.45 d of gestation. The groups were identified as moderately obese (MO; n = 3, BCS) and lean (LN; n = 3). Mares were fasted overnight and then underwent an intravenous (iv) glucose tolerance test at 315 ± 0.45 d gestation. Blood samples were collected at -30, -15 and 0 min and mares were administered dextrose iv [0.3 g/kg body weight (BW)] over 3.7 ± 0.17 min followed by an intravenous infusion of insulin (0.3 mU/kg BW) 20-min later. Additional blood samples were collected 2, 5, 10, 15, 20, 25, 30, 45, 60, and 120 min after initiation of dextrose infusion. At parturition, a colostrum sample was collected before foals nursed and analyzed for protein and fat, and IgG concentration. A foal blood sample was collected 18 h after birth to determine passive transfer of IgG. Placental, mare, and foal weights were measured at birth. Data were analyzed using a t-test with significance at P ≤ 0.05 and a tendency at 0.05 &amp;lt; P ≤ 0.10. The MO group had greater BCS (P = 0.01) and CNS (P = 0.01) than the LN group. Moderately obese mares tended to have 9% greater glucose area under the curve (AUC) after dextrose (P = 0.10) and a 9% greater glucose AUC after insulin infusion (P = 0.10) than LN mares. Colostrum IgG concentrations, and protein and fat content (P ≥ 0.3) did not differ between groups. Foal serum IgG concentrations, foal BW, and placental weights were similar between groups (P ≥ 0.8). The ratios between foal BW and placenta weight, and between foal BW and mare BW were similar between groups (P ≥ 0.3). Moderately obese maternal BCS and CNS scores may decrease maternal glucose clearance during late gestation but did not impact colostrum quality or foal IgG concentrations within 24 h postpartum. As the equine fetus matures later in gestation than other livestock species and relies heavily on glucose uptake from the placenta, it is critical to increase our understanding of the impacts of maternal obesity and glucose clearance on foal development and pre- and post-natal health.