Live Weight Basis Research Articles

Average daily gain in lambs grazing mixed annual forage species compared with single species and relationship to feed on offer

Context Annual forage crops provide high-quality fodder for livestock during typical autumn and winter feed-gaps in the south-east of Australia and benefits through rotations in cropping systems. While benefits from intercropping with cereals and pasture or mixing canola and peas have been studied in Australia, the potential animal-production benefits of grazing mixed annual species forage crops have not been examined. Aims To determine average daily gain (ADG) and rumen fluid parameters when sheep graze mixtures of annual fodder crops compared with a single species. Methods Ninety six Dorset × Border Leicester × Merino lambs (mean = 44.3 ± 0.55 kg) were allocated to one of the following four treatment groups (n = 24/treatment) on the basis of sex and liveweight; a single species brassica control (canola) (Br) or annual forage species mixes containing brassica (canola, turnip, radish) and cereal (wheat, cereal rye) (B + C), brassica and legume (vetch, arrowleaf clove) (B + L) or brassica, cereal and legume (B + C + L). Liveweight and rumen fluid parameters were assessed prior to grazing and again 21 and 35 days after the commencement of grazing. Key results Mean ADG from Day 0 to Day 21 was lower for female, but not male, lambs grazing the Br control (231 ± 23 g head−1 day−1) than for those grazing any forage mix (B + C = 292 ± 23 g head−1 day−1, B + L = 296 ± 23 g head−1 day−1, B + C + L = 310 ± 22 g head−1 day−1). Liveweight change over 35 days of grazing was not different between any forage mixtures. Rumen fluid pH was higher (P < 0.001) for sheep grazing forages containing cereals (B + C = 6.97 ± 0.06, B + C + L = 6.86 ± 0.06) than for those grazing brassica or legume (Br = 6.59 ± 0.06, B + L = 6.68 ± 0.06). Total volatile fatty acid concentration was lower and rumen pH was higher when sheep grazed B + C than when they grazed any other forage mix. Conclusions The higher ADG in females grazing mixtures than in those grazing the Br was related to higher dry matter on offer. Further research should determine whether the lower pH observed when sheep grazed brassica and legume than when grazing mixes containing cereals is associated with subacute rumen acidosis and reduced fibre degradation and forage energy utilisation. Implications Mixed forage species can provide higher DM on offer and ADG. Improved rumen efficiency could be related to improved growth.

THE EFFECTS OF SINGLE CELL PROTEIN ON AL-AWASSI LAMBS IN IRAQ

The effects of single cell protein (SCP) were studied in Al-Awassi lambs in Iraq. Four groups of lambs received 0%, 5%, 10% and 15% of (SCP) as a replacer for a soybean. The influence of (SCP) on the performance and carcass data of lambs and their blood pictures were studied. The total uric acid, blood urea and the histopathological changes were also investigated. The results - showed” that ‘there were no significant (P>0.05) differences ‘among the initial, slaughtered, total weights gained and chilled carcass weights. The wholesale cuts showed. no significant (P>0.05) differences. The eye rib area, fat thickness of. longissmus doris muscle, average percentage of organs and offal dressing percentage (calculated in live and empty body weight basis) were similar in all groups examined. the blood and serum parameters did not differ significantly (P>0.05) among the experimental groups.

Quantification of relative stock units for horses to permit correct application within pasture-based production systems

Context Overseer® is the primary software tool used to estimate farm-level nutrient cycle and management for regulatory purposes in New Zealand. The model compares feed demand among different livestock by using ‘revised stock units’ (RSUs, the annual energy requirement of a mature ewe to raise a single lamb to weaning; 6000 MJ metabolisable energy). The RSUs for several common equine stock classes are not yet available, while those currently available within the model are based on the linear scaling of feed demand to liveweight, which does not consider allometric scaling of metabolism to liveweight or the differences in digestive physiology and nutrient metabolism between ruminants and monogastric hindgut fermenters (horses). Aim To compare the current RSU values used in Overseer® for different equine stock classes, with the equineRSU values calculated using equine-specific models. Methods Weighted average estimates of the bodyweight for the different equine livestock classes were calculated from the published literature. These weighted average estimates of bodyweight were used to estimate the energy requirements on the basis of data published by National Research Council. The resulting dry-matter intake and N intake from the equineRSU values and the current RSU values in use within Overseer® were modelled using published data on diet composition, crude protein content and the digestibility of the different feeds offered. Results The current RSUs in Overseer were 2.5–6.8 units higher than the equineRSU values obtained from the equine-specific models. This overestimation in feed demand resulted in N-intake estimates at an animal level being 52–108% higher than values derived using the equine-specific estimates. Conclusion The use of RSUs based on linear scaling of feed demand from ruminants on the basis of liveweight overestimates feed demand and N intake in horses. If horses are to be included within nutrient management models, feed demand must be based on published equine data for energy requirements to avoid over-inflation of N excretion. The equineRSUs calculated in this study reduce the risk of over-inflation of N intake and excretion, and subsequently the N leaching estimations. Implication Failure to accurately model feed demand of horses within nutrient management software would unfairly compromise stocking density and horse management on large commercial breeding farms. The implication for these errors on economic impact and restricted livestock number is greatest for the Thoroughbred breeding industry due to the scale of the operations.

Nutrient digestibility, rumen parameters, and (cannabinoid) residues in sheep fed a pelleted diet containing green hemp (Cannabis sativa L.) biomass.

The feeding value for ruminants of green hemp biomass, from the low Δ9-tetrahydrocannabinol (Δ9-THC) variety of Cannabis sativa L., is unknown. Twelve Merino ewes were individually penned and randomly allocated on a stratified liveweight basis to one of two pelleted dietary treatments, control (0% hemp, n = 6) or hemp (42% green hemp biomass, n = 6) that delivered a diet meeting the nutrient requirements of the animals. The experimental period consisted of 17 d dietary and housing adaptation, followed by 7 d total urine and feces collection for determination of apparent nutrient digestibility. A ruminal fluid sample was collected on day 27 and assessed for pH, ammonia, volatile fatty acid (VFA), and cannabinoid concentrations. A blood sample from the jugular vein and incisional subcutaneous fat biopsy from an area around the base of the tail were collected on day 28 with additional fat biopsies taken 35 d and 140 d post-feeding to measure cannabinoids. The dry matter (DM), organic matter (OM), and crude protein (CP) digestibilities, along with total VFA concentration did not differ (P = 0.713) between the two diets; however, acid detergent fiber (ADF) and neutral detergent fiber (NDF) digestibilities (P < 0.001), water intake (P = 0.023), and fecal water output (P < 0.001) were significantly lower for the sheep-fed Hemp. Rumen pH did not vary (P = 0.256) between diets, but ruminal ammonia concentration was significantly lower (P = 0.024) for sheep consuming Hemp. Sheep-fed Hemp had significantly greater molar proportions of butyric (P = 0.039) and hexanoic (P = 0.012) acids and lower molar proportions of propionic acid (P = 0.003). There were no differences between diets for N intake (P = 0.175), fecal N output (P = 0.253), and N balance (P = 0.695), with all sheep in positive N balance; however, there was significantly lower (P = 0.001) urinary N output for sheep-fed Hemp. Cannabidiolic acid (CBDA) and tetrahydrocannabinolic acid (THCA) were detected in plasma of all sheep-fed Hemp. ∆9-tetrahydrocannabinol was present in the subcutaneous fat of four of the six sheep on the final day of being fed Hemp, and in all (six) sheep 35 d post-feeding and one sheep 140 d post-feeding Hemp. No cannabinoids were detected in the corresponding samples taken from the sheep-fed Control. Thus, despite green hemp biomass being nutritionally a suitable feed for ruminants, under current Food Standards in Australia, the presence of these cannabinoid residues restricts its use in ruminant diets.

DETERMINATION OF BREEDING VALUE AND PREPOTENCY OF DAIRY BULLS

DETERMINATION OF BREEDING VALUE AND PREPOTENCY OF DAIRY BULLS

Efficiency of feed conversion and milk yield in Murrah buffaloes fed with linseed and linseed oil

The present experiment was carried out to study the influence of feeding linseed and linseed oil on feed conversion and milk production efficiency (gross efficiency of milk production and gross protein efficiency) in lactating Murrah buffaloes. For this purpose, 18 lactating Murrah buffaloes were grouped in control (T0), T1 and T2 (06 animals in each) on basis of average live weight (516.55±9.53 kg), milk yield (7.50±0.3 kg), fat percentage in milk (6.70±0.29%) and lactation stage (2 weeks after parturition). Murrah buffaloes in all three groups were fed a same ration, consist of available green fodder, wheat straw and concentrate (69.03:30.97; roughage: concentrate ratio) to fulfill their nutrient requirement for maintenance and milk production of experimental Murrah buffaloes. In the treatment group (T1) 250 g/d linseed oil and 570 g/d whole linseed (T2) was supplemented with basal ration. The experimental feeding to the Murrah buffaloes was started 15 days after parturition and continues for 60 days. However, the experimental data were taken for the period of 6 months (i.e. 180 days). A 7 days digestion trial was conducted at the last of feeding experiment to know the digestibility of nutrient. The milk production, 4% FCM yield, SCM yield, ECM yield, change in body weight, dry matter intake and roughage to concentrate ration didn’t differ significantly between groups. No significant difference was observed in nutrient intake (TDN and CP) between groups. The digestibility of organic nutrient also didn’t differ significantly among experimental groups. The average gross efficiency of milk production was 26.51% and average gross protein efficiency of milk production was 36.49% and didn’t differ significantly. The average feed conversion efficiency as milk yield (kg) / DMI (kg) was 0.61, FCM yield(kg) / DMI (kg) was 0.86, average ECM yield (kg) / DMI (kg) was 0.89 and average SCM yield (kg) / DMI (kg) was 0.85 in lactating Murrah buffaloes. It was concluded that feeding linseed and linseed oil in lactating Murrah buffaloes didn’t affect the milk production efficiency (gross efficiency of milk production and gross protein efficiency) and feed conversion efficiency.

Age and Sex Affect Carcass Traits and Meat Quality in Malpura Sheep

Background: Small ruminants play a vital role in livelihood and nutritional security in India. The sheep population in the country is showing positive growth. Malpura sheep from the semi-arid region of India is an important mutton purpose breed. Methods: Twenty-four animals viz., ram lamb (G-Rl), ewe lamb (G-El) (10-12 months each), ram (G-Ra) and ewe (G-Ea) (20-24 months each) were slaughtered to assess carcass traits and meat quality. Result: The average pre-slaughter weight and dressing yield on an empty live weight basis for G-Rl, G-El, G-Ra and G-Ea groups were 23.83, 17.00, 35.82 and 28.08 kg; 52.35, 51.26, 53.70 and 52.93% respectively. The loin eye area (cm2) differed significantly. The weights of edible and inedible offals were significantly higher (P less than 0.001) in males in the same age group. The average lean content in different cut-up parts was higher (P less than 0.05) in G-3(G-Ra). The shear force values and other meat quality attributes were significantly different among the groups. It is concluded that age and sex had a significant effect on carcass traits and meat quality in Malpura sheep.

Standardized Ileal Digestible Lysine Requirement of 20 to 40-kilogram Philippine Black Tiaong Native Pigs (Sus scrofa domesticus)

Twenty growing Philippine black Tiaong native pigs were randomly allotted to 1 of 4 dietary treatments using a randomized complete block design to determine whether there were differences in SID Lys Requirements. There were five (5) replicate pigs per treatment. Diets were formulated with 0.717, 0.865, 1.010, and 1.156% SID Lys, respectively, which corresponded to SID Lys:ME ratios of 2.11, 2.54, 2.97, and 3.40 g/Mcal. All pigs were offered ad libitum intake from d 0 to 35. Overall (d 0 to 35), Philippine black Tiaong native pigs fed with 1.01% SID Lys had better performance than pigs not fed with 1.001%SID Lys. Moreover, pigs fed with increasing % SID Lys had quadratic relationships in ME efficiency at d 0 to 3(P=0.01). However, no significant differences (P&gt;0.05) were observed in carcass and meatquality characteristics. Meanwhile, a quadratic relationship (P=0.02) was observed in the kidney, whereas a linear response (P=0.004) was noted in the liver with increasing graded levels of % SID Lys. Additionally, a quadratic response was observed in the value of gain/pig(P=0.02), feed cost/kg gain (P=0.02), and margin over feed cost (MOFC)/pig (P=0.01) on a live weight basis and there is a linear relationship were revealed in carcass basis (feed cost/pig, P=0.009; feed cost/kg gain, P=0.006) and live weight basis (feed cost/pig, P=0.009). From the results of this study, it is concluded that diets containing 1.01% SID Lys and alysine: ME ratio of 2.97 g/Mcal are recommended for use in the feeding of Philippine black Tiaong native pigs at 20 to 40-kg.

Effects of various doses of lubabegron on calculated ammonia gas emissions, growth performance, and carcass characteristics of beef cattle during the last 56 days of the feeding period.

Lubabegron (LUB; Experior, Elanco, Greenfield, IN, USA) was approved by the U.S. Food and Drug Administration in 2018 and is indicated for the reduction of ammonia (NH3) gas emissions·kg−1 body weight (BW) and hot carcass weight (HCW) when fed to feedlot cattle during the final 14 to 91 d of the finishing period. LUB demonstrates antagonistic behavior at the β 1 and β 2 receptor subtypes and agonistic behavior at the β 3 receptor subtype in cattle and is classified by the Center for Veterinary Medicine as a “beta-adrenergic agonist/antagonist.” This report describes a randomized complete block study that evaluated LUB dose (0, 1.5, 3.5, and 5.5 mg·kg−1 dry matter) during the last 56 d of the feeding period on calculated NH3 gas emissions, live weight, carcass weight, and associated ratios in beef feedlot cattle. Carcass characteristics, mobility, and health were also evaluated. All cattle received monensin and tylosin throughout the study. Ammonia gas emissions were calculated using the equation developed by Brown et al. (Brown, M. S., N. A. Cole, S. Gruber, J. Kube, and J. S. Teeter. 2019. Modeling and prediction accuracy of ammonia gas emissions from feedlot cattle. App. Anim. Sci. 35:347–356). The reduction in calculated cumulative NH3 gas emissions with LUB ranged from 1.3% to 11.0% (85 to 708 g/hd). When NH3 gas emissions were expressed on a live weight (unshrunk) and carcass weight basis, calculated NH3 gas emissions decreased by 3.0% to 12.8% and 3.8% to 14.6%, respectively. Daily dry matter intake was 2.3% greater (Ptrt < 0.05) for steers that received LUB. Average daily gain was 13.7% greater (Ptrt < 0.05; 1.68 vs. 1.91 kg), while gain efficiency was 10.8% greater (Ptrt < 0.05; 0.167 vs. 0.185) for steers fed LUB. Animal mobility was scored in the pen approximately 1 wk prior to harvest, when cattle were loaded on trucks scheduled for harvest, and at antemortem inspection during lairage. No treatment differences (Ptrt ≥ 0.170) were observed at any time for the percent of cattle receiving mobility scores of 1 or 2 (normal or minor stiffness but moving with the normal cattle, respectively). Cattle mobility scored as a 1 or 2 equaled or exceeded 92% at all times. Final BW and HCW increased (Ptrt < 0.05) 11.6 to 15.7 kg and 11.3 to 17.1 kg, respectively, in cattle receiving LUB compared to cattle receiving monensin plus tylosin alone.

PSIV-11 Effects of Phytogenic Feed Additives on Growth Performance Traits of Finishing Swine

Abstract This study was conducted at a commercial research facility and utilized 1,092 finishing pigs (PIC® 337 × Camborough®) in a RCBD with 3 dietary treatments to determine the effects of commercially available phytogenic feed additives on growth performance traits in finishing swine for the last 35 d prior to marketing. The dietary treatments were as follows: 1) Control; 2) Aromex Pro® (AP; Delacon) fed at 0.01%; and 3) Ambitine® (AM; PMI) fed at 0.1%. Pens with 13 pigs/pen and 0.66 m2/pig were randomly allotted to treatments on the basis of live weight and gender. Pigs had ad libitum access to corn-soy diets that met or exceeded the pig’s requirements (NRC, 2012). Aromex Pro® and Ambitine® were added to the diets at the expense of corn. Dietary treatments started on day 0 (BW = 97.7 kg; SEM = 1.04) and were fed throughout the 35 d trial period. On d 21, the two heaviest pigs per pen were marketed, while the remaining pigs in each pen were marketed on d 35. Pigs and feeders were weighed on d 0, 21, and 35. Data were analyzed by using PROC MIXED of SAS® version 9.4, and pen was the experimental unit. The model included the fixed effect of treatment and random effect of replicate. Pre-planned orthogonal contrasts were used to compare AP vs. Control and AM vs. Control. Feeding AP or AM for the last 35 d in finishing both improved (P &amp;lt; 0.05) ADG by 4%, ADFI by 3% and final BW by 1.6 kg over Control, but did not change feed to gain or mortality. These data demonstrate that phytogenic feed additives can improve growth performance traits in finishing swine.

Effects of varying levels of dietary protein on the carcass characteristics of growing rabbits

Sixteen New Zealand White rabbits aged 9-10 weeks and weighing 0.72-0.99 kg were used to examine the effects of varying levels of dietary protein on carcass characteristics of rabbits. They were divided into four groups and allotted to four dietary treatments A, B, C and D formulated with 10, 13, 16 and 20 % crude protein (CP) respectively. Average dressing percentage and average weights (on liveweight basis) of carcass, hind limbs, forelimbs, breast, lumbo-sacral, heart, liver, kidneys and lungs were not affected by the dietary treatments. The results indicated that different levels of dietary protein had no significant (P&gt;0.05) effect on carcass yield in rabbits.

Effect of Supplementing Herbal Feed Additive Anethum sowa on Nutrient Utilization, Productive Performance and Carcass Characteristics of Male Beetal Kids

A 90d growth trial was conducted on eight male Beetal goat kids (5 months old; average BW 14.85±0.31 kg) to assess the effect of supplementing Anethum sowa-a herbal feed additive (HFA) containing essential oils-on their nutrient utilization, productive performance and meat quality. The animals, divided into two equal groups, were offered either a control total mixed ration (CON) or the same supplemented with Anethum sowa at 2.0% of DM intake (HFA). Rumen studies were conducted simultaneously on three adult Beetal bucks fitted with permanent rumen fistulae adopting a complete crossover design involving two periods. Results indicated that the concentrations of various N fractions were higher (P<0.01) in the rumen contents of animals in the HFA group as compared to the CON; however, the ammonia-N as percent of total-N was depressed (P<0.01) in the HFA group. The total and individual VFAs concentrations were improved (P<0.01) in HFA group, with improved acetate to propionate ratio. The daily DM intake, digestibility of nutrients, N-retention, blood profile and urinary purine derivatives, and ADG were statistically comparable in both the groups. The dressing percentage and edible offal percentage were similar between the two groups. The ready-to-cook carcass expressed on weight basis (P<0.05) or as percent of live weight (P<0.01) basis was improved significantly in HFA group. The weight of non-carcass components was improved in the group fed HFA as compared to CON group. It was concluded that total mixed ration supplemented with A. sowa at 2.0% of DM intake improved the carcass characteristics of Beetal goat kids.

Validation of NutriOpt dietary formulation strategies on broiler growth and economic performance

Summary With the continued development of highly accurate and rapid near-infrared reflectance spectroscopy (NIRS) analyses of nutrient profiles of poultry feed ingredients, it is possible to successfully implement NIRS into large-scale commercial formulation programs. In addition, these real-time feed ingredient analyses make use of modeling programs that factor nutrient cost and quality along with bird performance and revenue parameters more applicable. Trouw Nutrition has developed the NutriOpt System, a modular precision-feeding system, which uses NIRS-determined nutrient values of feed ingredients, advanced nutrient analysis, and dynamic modeling. The purpose of the current research was to validate the performance and economic impact of NutriOpt formulation technologies and NutriOpt Broiler Model solutions during a 49-day broiler production period. Relative to broilers fed a consultant-formulated control diet, based on wet chemistry analyzed standard nutrient values for the ingredients, broilers fed with diets formulated using NIRS analyzed nutrient profiles of the ingredients had at least equivalent growth rates and feed-to-gain ratios from 0 to 49 D of age. However, this equivalent or better performance was achieved at lower feed costs and improved profitability. Formulating diets based on the NIRS nutrient values of the ingredients and a model to optimize margin per bird on a live weight basis or to maximize breast meat yield resulted in numerically improved profit margins. Taken together, the results indicate that Trouw Nutrition formulation technologies under certain conditions can be used to reduce formulation costs and improve overall profitability relative to a representative feeding program.

Effects of increasing copper from either copper sulfate or combinations of copper sulfate and a copper-amino acid complex on finishing pig growth performance and carcass characteristics.

A total of 1,089 pigs (PIC 280 × 1050; initially 37.3 ± 2.8 kg) were used to determine the effects of increasing Cu provided from either CuSO4 alone or a 50:50 blend of CuSO4 and a Copper-amino acid complex (Cu-AA) on growth performance and carcass characteristics of finishing pigs. Pens of pigs were blocked by body weight; within blocks, pens were randomly allotted to one of six dietary treatments. The six dietary treatments consisted of a control diet which contained 17 mg/kg Cu from CuSO4 from the trace mineral premix, or the control diet with either added CuSO4 to provide 70 and 130 mg/kg total Cu or a 50:50 blend of Cu from CuSO4 and Cu-AA (CuSO4/Cu-AA blend) to provide 70, 100, and 130 mg/kg total Cu. Experimental diets were corn-soybean meal-dried distillers grains with solubles-based and fed in meal form in five phases (approximately 37 to 46, 46 to 63, 63 to 77, 77 to 103, and 103 to 129 kg body weight). From d 0 to 43, neither Cu source nor level influenced growth performance. From d 43 to 105, average daily feed intake (ADFI) decreased (P = 0.037) for pigs fed the CuSO4/Cu-AA blend compared to those fed added Cu from CuSO4 alone. Gain:feed ratio (G:F) tended to be improved (linear, P = 0.056) as Cu concentration increased. Overall, d 0 to 105, neither Cu level nor source influenced average daily gain (ADG). Pigs fed 70 or 130 mg/kg total added Cu from the CuSO4/Cu-AA blend had lower (P = 0.045) ADFI but G:F tended to be improved (P = 0.051) compared with those fed the same amount of total Cu from only CuSO4. Owing to the decreased ADFI and improved G:F of pigs fed the CuSO4/Cu-AA blend, carcass G:F also improved (P = 0.033) compared with those fed added Cu from CuSO4 alone. In conclusion, providing a 50:50 blend of CuSO4 and Cu-AA improved G:F on both a live and carcass weight basis compared to CuSO4 alone with no differences in ADG or carcass ADG observed.

Lactobacillus-based fermentation product and lactose level in the feed for weanling pigs: Effects on intestinal morphology, microbiota, gas emission, and targeted intestinal coliforms

A 2 × 2 factorial arrangement was used to investigate the interactions between lactose levels (100 g/kg versus 200 g/kg) and Lactobacillus-based fermentation product (FP; 0 and 1 × 1011 CFU Lactobacillus casei/kg) on weanling piglet performance and nutrient digestibility. Two hundred and forty weaned piglets (24 days old, 7.05 kg live weight) were blocked on the basis of live weight and assigned to one of four dietary treatments with six replicates and 10 piglets per replicate in two phases (phase 1, from d 1 to 14; phase 2, from d 14 to 28). Volatile fatty acid concentrations and bacterial counts were performed in ileal, cecal, and colonic contents. In phase Ⅰ, ADG was increased (P < 0.01) in pigs fed FP. The digestibility of DM and GE were greater (P < 0.01) in pigs offered high lactose level. The interactions between lactose level and FP were significant for the concentration of ileal acetate (P < 0.05) and propionate (P < 0.01). The concentration of propionate in the cecum and colon, as well as butyrate in the ileum, were greater (P < 0.05) in high lactose treatment. Dietary supplementation of FP decreased acetate level in the cecum. The emission of total organic carbon and ammonia in pigs feces were decreased (P < 0.01) in both high lactose and FP-supplemented diets. The interactions between lactose and FP were significant (P < 0.05) for the population of Salmonella spp. in the ileum. The pH of colon digesta was lower (P < 0.05) in pigs offered high lactose level. The abundance of Lactobacillus spp. was increased (P < 0.05) only in the cecum digesta in pigs offered high lactose diet. In phase Ⅱ, there was a significant improvement in the feed:gain in pigs fed the diet with high lactose content. The overall result showed that ADG and ADFI were increased in pigs in FP treatment. The greater digestibility of DM was observed in pigs offered FP. The concentration of butyric acid in the colon was increased in pigs fed FP. The supplementation of FP decreased ileal and cecal Escherichia coli. This study demonstrates that dietary FP improved the growth performance and DM digestibility of weanling pigs. When the dietary FP, and the lactose level were combined there was no evidence of an interaction on growth performance. However, both lactose and FP decreased the emissions of total organic carbon and ammonium.

Development of a model for investigation of perennial ryegrass toxicosis in sheep

AIMSTo develop a clinical model of perennial ryegrass toxicosis (PRGT) based on feeding a known dose of lolitrem B and ergotamine, and to produce a consistent clinical presentation for assessment of disease pathophysiology, neurological changes and neurohistopathology.METHODSMale lambs, aged between 10–12 months, were randomly assigned to either Treatment (n=9) or Control (n=9) groups. Lambs in the Treatment group received feed containing a novel endophyte-infested perennial ryegrass seed, commencing on Day 0 of the Feeding phase with a low induction dose, then increasing after 3 days to provide 0.16 mg/kg live bodywight (LBW)/day of lolitrem B and 0.054 mg/kg LBW/day ergotamine. Lambs were examined daily and when defined signs of PRGT were observed they were transferred to the Testing phase. Neurological examinations, assessment of gait, surface electromyography (EMG) and mechanosensory nociceptive threshold testing were carried out and blood samples collected during both phases of the trial, with a full necropsy, histopathological examination and measurement of faecal cortisol metabolites (FCM) performed on Day 2 of the Testing phase.RESULTSTypical clinical signs of PRGT, including ataxia of vestibulocerebellar origin leading to stumbling, were observed in all Treatment lambs. The median interval from the start of the Feeding phase to entry into the Testing phase was 21 (min 18, max 34) days. Histopathological characterisation of neurological lesions included the presence of Purkinje cell vacuolation, pyknotic granular layer neurons and proximal axonal Purkinje cell spheroids. Lesions were most apparent within the vestibulocerebellum. Mean root-mean-square voltages from triceps EMG increased in Treatment lambs between Feeding phase Day 0 and Testing phase Day 2 (p<0.001). Daily water intake during the Testing phase for the Treatment group was less than in Control group lambs (p=0.002), and concentrations of FCM at necropsy were higher in Treatment compared to Control lambs (p=0.02).CONCLUSIONS AND CLINICAL RELEVANCELolitrem B and ergotamine dosing in feed on a live weight basis combined with neurological/gait assessment provides an effective model for investigation of PRGT and potential therapeutics. Assessment of gait changes using defined criteria and RMS voltages from EMG appear to be useful tools for the assessment of the severity of neurological changes.

An economic and greenhouse gas emissions evaluation of pasture-based dairy calf-to-beef production systems

The objectives of the current study were to investigate the effects of production system on Holstein-Frisian bulls and steers and also to evaluate the profitability and greenhouse gas (GHG) emissions of these production systems. Calves were assigned to one of five production systems; bulls finished indoors on a concentrate ad libitum diet for 200days and slaughtered at 15months of age (15MO); bulls finished indoors on a concentrate ad libitum diet for 100days and slaughtered at 19months of age (19AL); bulls supplemented with 5kg of concentrate dry matter (DM) per head daily at pasture for 100days and slaughtered at 19months of age (19PC); steers supplemented with 5kg DM of concentrate per head daily at pasture for 68days and slaughtered at 21months of age (21MO) and steers finished indoors on grass silage plus 5kg DM of concentrate per head daily for 92days and slaughtered at 24months of age (24MO). All calves were rotationally grazed at pasture, supplemented with 1kg DM of concentrates per head daily, during the first season. With the exception of 15MO all production systems were fed grass silage and 1.5kg DM of concentrate during the winter period and returned to pasture for a second season. The Grange Dairy Beef Systems Model was used to simulate whole-farm system effects of production systems while GHG emissions associated with production were simulated using the Beef Systems Greenhouse Gas Emissions Model. Carcass weight was lowest for 21MO, greatest for 19AL and 24MO with both 15MO and 19PC intermediate. Conformation score was greater for bull (15MO, 19AL and 19PC) compared to steer production systems (21MO and 24MO). Fat score was greatest for 24MO and lowest for both 15MO and 19PC; 19AL and 21MO were intermediate. Concentrate feed costs represented 68, 59, 47, 39 and 39% of the total variable costs for 15MO, 19AL, 19PC, 21MO and 24MO, respectively. The most profitable production system was 19PC, while the least profitable systems were 15MO and 24MO. Greenhouse gas emissions, on a per kg live weight and carcass weight basis were lowest for 15MO and 19AL and greatest for 21MO and 24MO. The current study showed that slaughtering bulls at 19months of age and finishing at pasture was the most profitable production system with moderate GHG emissions.

Effect of Dietary Supplementation of Organic Acids in Combination on Performance and Carcass Traits of Broiler Chicken

The present study was carried out with an objective to investigate the production performance and carcass traits of broilers fed with different organic acid combination supplemented diets. Basal pre-starter, starter and finisher broiler diets were formulated as per the nutrient requirements (ICAR, 2013). Six experimental diets, viz. T1 (Basal diet), T2 (Basal diet+antibiotic @ 50 g/100 kg), T3 (Basal diet+20: 40: 40 combination of citric, formic and propionic acids @ 1.5 g/100g), T4 (Basal diet+30: 40: 30 combination of citric, formic and propionic acids @ 1.0 g/100g), T5 (Basal diet+ 30: 30: 40 combination of citric, formic and propionic acids @ 1.0 g/100g), T6 (Basal diet+10: 45: 45 combination of citric, formic and propionic acids @ 1.5 g/100g) were prepared. Two hundred and seventy day old, straight run commercial broiler chicks were distributed randomly to six treatments with three replicates of fifteen birds each and fed with the experimental diets from 0 to 42 days of age. Body weight gains and feed efficiency were significantly (P 0.05) difference in the ready-to-cookyields among the groups, but significantly (P<0.05) increased giblet yields on % live weight basis. The organic acid combination of citric, formic and propionic at 20: 40: 40 combination could be safely incorporated at 1.5% level in broiler diets for better performance.

Case Study on a Successful Woman Livestock Entrepreneur in Shivamogga District of Karnataka

Case study on Successful Livestock Entrepreneur of Agasavalli village in Shivamogga district of Karnataka state was conducted to examine the economics of the enterprise and the entrepreneurship skills of women in sheep and goat farming. Structured interview schedule observation method and farm records were used for collection of primary data. A woman entrepreneur Smt. Chitra. M , 41 year old runs the farm successfully. “Samrudhi sheep and goat farm” which is 14 k.m away from Shivamogga city. The entrepreneur owns 200 sheep, breed reared were Deccani, Kenguri sheep. These were selected based on local preference of consumers. This unit generated income and provided employment and food security. The animals were sold at their farm gate on live weight basis. In addition study also revealed that entrepreneur acquired entrepreneurship skills like self-confidence, creativity, calculated risk taking capacity, determination, need for achievement, individuality, leadership and optimism.

Stochastic model designed to estimate variability in the relative economic value betweem cattle with and without lung lesions in U.S. feedlot production systems

Feedlot cattle with lung lesions, associated with bovine respiratory disease (BRD], display a reduction in average daily gain (ADG) compared to cattle without lung lesions. However, a moderate degree of variability in prevalence and ADG reduction has been observed in peer-reviewed literature; therefore, the true economic impact of lung lesions in feedlot cattle populations is unknown. The study objective was to estimate and compare the relative economic value between feedlot cattle with and without lung lesions through stochastic modeling methods. The model commenced at animal purchase and upon pen placement. Within each pen, cattle with and without lung lesions were modeled in parallel throughout the feeding phase, incorporating all production expenses and revenue. The final outcome was the difference in economic value between both cohorts when marketed on a live-weight basis. Based upon the assumption of this model, cattle with lung lesions lose, on average, $38.69 (90% probability interval: $12.28 to $79.32] compared to cattle without lung lesions. The reduction in ADG among cattle with lung lesions was a major driver in these outcomes supporting the findings from prior studies. Improved BRD diagnostic and therapeutic modalities are necessary to reduce lung lesion prevalence and subsequent negative economic impacts to the feedlot industry.