Higher Live Weight Gain Research Articles

Undegradable dietary protein limits growth and carcass yields in crossbred Boer kids fed Desmanthus hay or Rhodes grass (Chloris gayana) hay supplemented with urea and/or cottonseed meal

Context Low-protein tropical forages required protein supplementation, which might affect growth of meat goats. Aims This study was aimed to compare liveweight gain, carcass/non-carcass yields and meat quality in crossbred Boer kids fed isonitrogenous diets varying in undegradable (UDP) and rumen-degradable (RDP) dietary protein sources. Methods Twenty-five female crossbred Boer kids were randomly allocated into the following five dietary treatments: Rhodes grass (Chloris gayana) hay supplemented with urea (U), urea plus cottonseed meal (UCSM), cottonseed meal (CSM), gliricidia (Gliricidia sepium) (Gliri) or Desmanthus (Desmanthus leptophyllus) only (Desman). The diets were formulated to supply 135 and 195 g crude protein/kg DM for the two experiments. Experiment 1 lasted 78 days and the dietary UDP:RDP ratio (g/kg DM) was 35:102 (U), 37:100 (UCSM), 40:97 (CSM), 55:82 (Desman) and 46:91 (Gliri). Experiment 2 lasted 138 days and the dietary UDP:RDP ratio (g/kg DM) was 45:150 (U), 52:143 (UCSM), 58:137 (CSM), 83:112 (Desman) and 71:124 (Gliri) respectively. Data were subjected to one-way ANOVA and general linear model. Key results After 138 days of supplementation, the Desman goats had the highest liveweight gain (83 g/day) and heaviest cold carcass weight (12.1 kg) in Experiment 2. This was followed, in descending order, by CSM (58 g/day and 9.6 kg), UCSM (48 g/day and 7.8 kg), Gliri (41 g/day and 7.6 kg) and U (6 g/day and 6.0 kg). Heavier carcass weight was associated with larger eye-muscle area and fat depth at the 12th rib. Aus-meat Beef Colour Standard scores of 3–4 for the eye muscle of the Desman and CSM goats compared with scores of 1C-2 in the other goats meant that the darker meat in Desman and CSM diets was associated with heavier carcass weight and a more rapid rate of decline in carcass pH. Conclusions Crossbred Boer kids fed high dietary UDP had higher intakes of UDP, RDP, metabolisable protein (MP) and metabolisable energy (ME), even though an isonitrogenous diet was offered. The Desman kids had higher liveweight gain, heavier carcass yield, greater eye-muscle area, thicker fat depth and heavier mass of non-carcass components. Implications The higher liveweight gain and carcass/non-carcass yields for Desman goats than for others was associated with increased DM, UDP, RDP, MP and ME intakes.

Beef production systems with dairy × beef heifers based on forage and semi-natural grassland

ABSTRACT Beef production on semi-natural grassland provides meat and nature conservation of biodiverse habitats. In this study, heifers born to a dairy cow and an Angus (ANG) or Charolais (CHA) sire were allocated to a HIGH or LOW production system, varying in indoor feed intensity, number of summers on grass and slaughter age. CHA crosses had higher liveweight gain, conformation score, and proportion of high-value retail cuts than ANG crosses, which had higher scores for fatness and marbling. The LOW system gave lower liveweight gain and carcasses with lower fatness scores than the HIGH system. CHA-LOW had leaner carcasses than the other groups. Per kilogram salable meat produced, ANG-HIGH, CHA-HIGH, ANG-LOW, and CHA-LOW resulted in 18, 15, 58, and 46 m2 grazed semi-natural grassland. These results indicate that dairy × beef heifers can be used for nature conservation grazing of semi-natural grassland while still achieving acceptable performance and market-oriented carcass characteristics.

Use of electrolyte and betaine water supplementation to support improved liveweight gain of commercial Pekin ducks exposed to adverse high temperature in the week prior to processing

Context Commercial Pekin Ducks housed in conventional open-sided sheds often experience heat stress in summer. Electrolyte or osmolyte supplements can help birds cope under heat stress. Aims To assess the effects of water electrolyte/betaine supplementation or betaine in feed on the growth performance of Pekin ducks exposed to high ambient temperature. Methods Commercial Cherry Valley Pekin ducks were fed diets with a dietary electrolyte balance (DEB) of 160 (L-DEB) or 209 (H-DEB) over Days 15–41 (D15–41) of age. Over D36–41, ducks were provided with water alone or supplemented with betaine in the feed (BF), or betaine and an ‘in-house’ electrolyte (E) formulation at 50%, 100% or 150% (D36–41) or at 100% for only 36 h on D40–41. There were 12 treatments with four replicate pens for each treatment. On D36–41 of age, temperature was increased to 28–32°C for 9 h (from 08:30 hours to 17:30 hours) and then returned to 22–24°C for the remainder of the day. Individual liveweights were taken on D28, D35, D41. During these times, feed intake and water consumption were determined. On D41, one male and one female from each pen were weighed, euthanised and breast muscle was removed and weighed. Birds were collected for commercial processing at 04:00 hours on D42. Key results Over D15–35, the DEB had no effect on bird performance. Over D36–41, for liveweight gain (LWG) there were significant interactions between treatment × week (P < 0.001) and treatment × diet (P = 0.017). Supplements E150 and E100 + 36 h supported LWG more than did other treatments, while treatments BF, E50 and E100 supported higher LWG than in controls. On the L-DEB diet, the control birds had a LWG lower than in other treatments (P < 0.05). On the H-DEB diet, the E50 supplement had highest LWG, but comparable to that in E100 + 36 h. The supplements had no effects on breast muscle yield, weight losses during transport and lairage or processed carcass weights. Conclusions The electrolyte supplements supported higher LWG during exposure to moderately adverse high temperature. Supply for 36 h supported LWG equivalent or better than did other treatments given over 6 days. The benefits could be related to increased water intake and not just electrolyte supply. Implications Water electrolyte plus betaine supplementation supports improved Pekin duck performance during a moderately high temperature challenge.

Utilising locally based energy supplements in leucaena and corn stover diets to increase the average daily gain of male Bali cattle and the income of smallholder farmers

Context Supplementing a leucaena-based diet with locally available energy sources is an important strategy to extend the use of leucaena, increase liveweight (LW) gain of Bali cattle and increase profit for the smallholder. Aims This study was conducted to evaluate the effect of various local energy supplements in leucaena-based diets on the LW gain of Bali cattle and income-over-feed costs (IOFC). Methods Forty male Bali cattle were divided into five treatment groups (n = 8) and each was fed one of the following diets: (A) control diet, including leucaena ad libitum, with corn stover at 0.5% DM LW and mineral mix, (B) control + cassava meal at 1.0% DM LW, (C) control + cassava peel at 1.0% DM LW, (D) control + cassava peel and corn grain mix at 1.0% DM LW or (E) control + commercial feed at 1.0% DM LW. The experiment was run for 140 days, which included a 20-day adaptation period. Parameters measured included intake, digestibility, imbibed-water intake, LW gain, rumen and faecal parameters, feed conversion and IOFC. Key results Supplementation of local energy sources in combination with leucaena and corn stover diets increased LW gain of male Bali cattle above that of the control diet (P < 0.05). The bulls receiving the cassava peel and corn mix supplement had the highest LW gain (0.57 ± 0.09 kg/day), which was associated with an increase in digestible organic-matter intake (DOMI). There were no treatment differences (P > 0.05) in the rumen parameters (rumen fluid pH, rumen ammonia-N concentration and volatile fatty acids) and all parameters were optimum for rumen digestion. Conclusions The addition of local energy supplements supplied at 1% of LW improved growth rate and extended the use of a limited amount of leucaena and provided a higher IOFC. Implications Replacing approximately 40% of leucaena with energy sources can have three benefits, including an increase in LW gain, an increased capacity of farmers to feed more cattle per hectare and an increased income per cattle being fattened. This can increase the production scale and subsequent farmer income, provided that the energy sources are available at affordable prices and obtainable.

ВОЗРАСТНАЯ ДИНАМИКА ЖИВОЙ МАССЫ КАЗАХСКОЙ БЕЛОГОЛОВОЙ ПОРОДЫ МЯСНОГО СКОТА

The aim of the study is to establish the age dynamics of the variability of live weight with the average daily liveweight gain of the Kazakh whiteheaded breed of beef cattle. In all analyzed agricultural enterprises at the age of six months, the live weight of bulls varied from 172.4 kg to 196.5 kg, and in heifers – from 160.1 kg to 180.7 kg, respectively. According to the indicators of the average daily liveweight gain, there are some differences between bulls and heifers. From birth to 210 days of age, the average daily liveweight gain was 846.03 g in bulls, 784.4 g in heifers; from 210 days of age to one year of age it was 732 g in bulls and 599 g in heifers; from birth to one year of age, the average daily liveweight gain was 793.6 g in bulls and 707.5 g in heifers. Bulls at the age of six months generally meet the requirements of the breed standard, characterized by high coefficients of variability. The live weight of bulls in the farms “Zhannat”, “Tolegen” and “Alem” at the age of six months meets and slightly exceeds the requirements of the breed standard by 15.2 kg (8.2%), 13.0 kg (7.1%), 13.6 kg (7.4%), and in heifers by 15.7 kg (8.9%), 8.1 kg (4.8), 13.2 kg (7.6%), respectively. The value of the coefficient of variability of live weight has average values with a slight excess in heifers. It was found that the live weight of bulls in the farm “Kairat” and the farm “Naryn” exceeded the breed standard by 26.5 kg (13.5%) and 21.1 kg (11%), heifers by 20.7 kg (11.5) and 7.8 kg (4.6%), respectively, and belongs to the elite classes. The average daily liveweight gain of young Kazakh white-headed breed in the studied farms varied from 826.7 to 944.2 g in bulls, and in heifers from 711.1 to 887.2 g, respectively that indicates a relatively high liveweight gain obtained in farm conditions.

COMPOUND FEED WITH DIFFERENT LEVELS OF OIL FLAX CAKE IN THE DIETS OF FATTENED YOUNG CATTLE

The use of oil flax makes it possible to reduce the deficiency of fodder protein in the diet and balance the protein nutrition of animals. The article contains the results of scientific work, the purpose of which was to determine the effect of feeding oil flax
 cake on the efficiency of young cattle fattening. Studies showed that the use of different levels of oil flax cake in the compound feed had a positive effect on the productivity of fattened animals. Higher live weight gain and relatively low feed costs contributed
 to a decrease in price cost of rearing products by 8.7-10.8% during the period of the beginning of young cattle fattening.

Effect of dietary phenylalanine levels on growth, hemato-biochemical composition and tyrosine replacement value for phenylalanine in stinging catfish Heteropneustes fossilis –Bloch 1974 fingerling

Two 10-week feeding experiments were conducted to determine the total aromatic amino acid requirement and tyrosine (Tyr) replacement value for phenylalanine (Phe) for fingerling Heteropneustes fossilis by feeding casein + gelatin based amino acid test diets [400 g/kg crude protein (CP); 17.90 MJ/ kg gross energy (GE)]. In experiment 1, Phe was determined by feeding six test diets containing graded levels of Phe (4.5–14.5 g/kg diet, as fed) with 6.0 g/kg Tyr fixed and fed in triplicate groups of 20 fish each in 60-L troughs fitted with continuous flow-through. Significantly (P < 0.05) highest live weight gain (LWG%), best-feed conversion ratio (FCR), highest protein efficiency ratio (PER) and body protein deposition (BPD) was reported at 10.5 g/kg dietary Phe with constant level of Tyr 6.0 g/kg fed group. Quadratic regression analysis of live weight gain, FCR, PER and BPD data indicated Phe requirement at 11.08, 10.75, 10.45 and 10.45 g/kg of diet, respectively. Based on the above results, Phe requirement of H. fossilis is recommended at 10.8 g/kg of diet. A second experiment under similar experimental design was conducted containing graded levels of Tyr (2.1–12.1 g/kg diet, as fed) with 10.8 g/kg Phe fixed in all the diets to determine the replacement value of Tyr for Phe. Significantly (P < 0.05) highest LWG%, best-FCR, PER and BPD values were obtained at 8.1 g/kg dietary tyrosine level. Quadratic regression analysis of LWG%, FCR, PER and BPD data indicated Tyr requirement at 8.7, 8.7, 8.05 and 8.05 g/kg of diet, respectively. The above results suggest that 8.4 g/kg Tyr, corresponding to 21.0 g/kg of protein would be useful for optimum growth of H. fossilis at fingerling stage and the replacement value of Tyr for Phe is 43.75% on weight and 39.89% on molar basis. Thus, the total aromatic amino acid requirement was recommended to be 19.2 g/kg of diet, corresponding to 48.0 g/kg of protein for optimum growth of H. fossilis.

Gastrointestinal nematodes and mineral deficiencies in yearling cattle in Santiago del Estero, northern Argentina.

The aims were to study the epidemiology and the effect of gastrointestinal nematodes (GINs) on yearling cattle in a semiarid region in Argentina and to evaluate the mineral serum levels. Ten- to twelve-month-old calves were monitored between November and April 2019. Animals were divided into three groups: untreated control (CONG; n = 20); group treated with moxidectin (MXD, 200µg/kg) every 30-40days (MXDG; n = 20); group equally MXD treated and mineral supplementation administered in November and January (MMG; n = 20). Individual GIN egg counts (epg) and fecal cultures were made every 30-40days. Animal live weight gain was determined. On 7-11-18, 25-1-19, and 3-4-19, serum levels of Se, Cu, Zn, Mg, and Ca were determined by atom absorption spectrophotometry. At the start of the trial, epg values were low (x̄ = 5.5), which increased only in CONG towards the end of the assay (x̄ = 229). In both GMXD and MMG, epg remained very low (x̄ = 4.1). Cooperia spp. (81%) prevailed over Haemonchus spp. (9%) and Oesophagostomum spp. (9%). Deficiency of Se ranged between marginal and important, except for MMG, although mean values were always below normal. Cu was marginally deficient in CONG and MXDG on the first two sampling dates, whereas MMG had normal values after treatment. Mg had low values in the three groups (x̄ = 1.5mg/dl), whereas Ca and Zn exhibited normal values. Live weight gain (LWG) was higher in MMG than in MXDG, with significant differences (p < 0.05) by mid-January and then, when epg increased, dewormed groups showed higher LWG (p < 0.034) than CONG. A negative effect of GINs on LWG was observed, as well as low to marginal levels of Se, Cu, and Mg.

Impact of rangeland enclosure and seasonal grazing on protected and unprotected rangelands in Chakwal region, Pakistan

Scrub rangelands support livestock grazing and provide ecosystem services to their inhabitants. The present study was conducted in Chakwal, an important tract of the Pothwar Plateau, which sustains herds of small domestic and nomadic ruminants. Urbanization and uncontrolled grazing practices have reduced rangeland productivity and increased soil erosion and resulted in poor land conditions. This study assessed the influence of two years of rangeland protection on aboveground vegetation biomass and the chemical composition of plants and aimed to determine the influence of seasonal grazing on the live-weight gain of small ewes. Using the line intercept method, vegetation data from protected and unprotected plots in 2015 and 2016 were collected at two sites, Dhulli and Begal. Vegetation cover was assessed from images using VegMeasure. Results showed that protected study sites displayed higher vegetation biomass (834 and 690 kg ha-1) compared to the unprotected study site (477 and 326 kg ha-1) during April and August of both years. In the seasonal grazing trial, the experimental ewes that grazed on protected rangelands showed higher live-weight gain (33–63 g day-1) compared to live weight of ewes (17–21 g day-1) that grazed on unprotected rangelands during the experimental period of 127 days at both sites. The results suggest that the Chakwal rangeland has tremendous potential to improve vegetation productivity but modern livestock management and seasonal grazing practices are needed to improve carrying capacity and livestock productivity.

Feeding strategies for improving ruminant productivity in the post-COVID 19 pandemic era particularly for small holders

COVID-19 has highlighted the need for robust cattle supply chains using local feed resources. Higher Income Over Food Costs (IOFC) are usually achieved when live weight gains are high and the cost of the ingredients are low. There is a need to formulate rations with high metabolisable energy (ME) and crude protein (CP) to achieve the high live weight gain. Rations can be formulated locally by farmer co-operatives, entrepreneurs and local commercial enterprises to take advantage of cheaper prices for local ingredients. To do this, rations need to be altered quickly to take advantage of local fluctuations in prices and availability of ingredients. A recent ACIAR funded project has developed a least cost ration (ACIAR LCR) system to formulate rations to meet minimum ME and CP contents for beef cattle using locally available ingredients. The use of cassava and its various products in combination with protein sources, such as tree legumes and high protein by-products, have markedly improved IOFC.

Formulating rations with cassava meal to promote high live weight gain in crossbred Limousin bulls

Formulating rations with high energy and protein feeds such as cassava and locally sourced protein meals is an important strategy to increase live weight gain (LWG) of crossbred bulls in Indonesia. Current systems of production for Indonesian smallholders fatten bulls using cut and carry. Formulating a diet for an optimal combination of available feeds will increase production and potential profitability for smallholders. An experiment was conducted to evaluate the effect of using cassava meal in the diet at levels of 70C, 60C, 50C, 40C and 30C% (with most of the remainder being the protein meals) on the LWG of Limousin × Ongole bulls so as to determine the optimum combination of cassava meal and protein meals for LWG. Thirty bulls were allocated in a completely randomized block design with 6 blocks based on initial live weight (LW) and 5 treatments based on level of cassava meal. The combination of cassava meal (with 2% urea) and protein meals significantly affected LWG with the highest (1.35 kg/day) recorded at 40C (40% cassava meal, 40% protein meals and 20% maize stover). The LWG and nutrient intake increased curvilinearly with decreasing cassava meal and increasing protein meals (P < 0.05). Measured cassava meal inclusion in the final ration as a consequence of the changes in intake was 60, 56, 47, 37 and 28% for the designated 70C, 60C, 50C, 40C and 30C treatments, respectively. Dry matter intake reached 96 g/kg0.75 per day or equal to 2.24% LW at this 40% level of inclusion. At the 70C treatment with 60% cassava meal and 9% protein meals, DM digestibility (69.1%) was lowest and that value increased as the proportion of cassava meal decreased and was highest at the 40C treatment (75.8%). Feed treatments significantly affected rumen pH, ammonia N (NH3N) and volatile fatty acid concentrations (P < 0.05). There was no significant effect on protozoal population (P > 0.05). Rumen pH ranged from 6.3 to 6.9. It was concluded that a combination of 40% dried cassava meal and 40% protein meals with roughage (20%) maximized intake and LWG and beyond that level of cassava meal inclusion, LWG and intake decreased markedly.

An investigation on the gamete quality of Black Sea trout ( Salmo trutta labrax ) broodstock fed with mealworm ( Tenebrio molitor )

In this study, the effect of combined feeding Black Sea trout (Salmo trutta labrax) broodstock with commercial feed and mealworm larvae (Tenebrio molitor) for 50 days before the breeding period in order to evaluate the gamete quality. While the control group was fed with commercial feed, mealworm larvae were given as an additional protein source 2 days a week and 3 days a week to the experimental groups formed from female and male individuals. In addition to the growth parameters, the number of eggs (number/individual) and the egg diameter (mm), sperm volume (ml), density of spermatozoa (×109 cell/ml), total motility (%), progressive motility (%) and average curvilinear velocity (VCL, µm/sec) values were determined. At the end of the study, the highest live weight gain was found as 46.2 g in the control group of male. The egg diameters were 4.3 ± 1.8 mm and 4.5 ± 1.4 mm in the worm treatment groups fed twice and three times with mealworm respectively. As a result, it was determined that feeding fish with mealworm larvae as an addition to the commercial diet in female individuals did not affect the amount of eggs (p > .05), but the egg diameters were significantly smaller in the control group than the mealworm groups (p < .05). In spermatological characteristics, only the amount of sperm was different between the groups (p < .05); all other parameters were found to be similar to each other with no statistical differences (p > .05).

Improved Arachis hypogeae variety effect on grain yield, fodder quality and livestock growth

The hypothesis that improved groundnut (Arachis hypogea) varieties could improve seed and fodder yield and livestock growth performance was evaluated in two experiments: 1) an agronomic trial to determine the yield and yield component of groundnut varieties; and 2) fodder quality of groundnut varieties and its effect on growth performance of sheep. Four improved groundnut varieties (early-maturing: Yenyawoso, late-maturing: Azivivi, Obolo and Mani pinta) were evaluated for 2 yr in a randomized complete block design with four replications in the agronomic and livestock feeding trials. The results from the agronomic trial showed that the late-maturing varieties had significantly higher pods/plant, pod size, seed and fodder yields than Yenyawoso. Obolo had significantly higher seed yield whilst Azivivi had significantly higher fodder yield among the late-maturing varieties. The fodder quality and feeding trial showed that Yenyawoso had significantly higher dry matter, crude protein and resulted in significantly higher live weight gain of Djallonke rams than the other varieties. The Mani pinta variety had significantly higher live weight gain among the late-maturing varieties. Smallholder crop-livestock farmers interested in both seed and livestock growth could use Mani pinta, those interested in only seed yield could use Obolo and those interested in quality fodder for fattening of small ruminants could use Yenyawoso. Thus, groundnut breeding programs could consider fodder quality in addition to seed and fodder yield as selection criteria to develop varieties that best fit into crop-livestock farming systems.

Backgrounding steers on temperate grasses mixed with vetch and/or using energy supplementation.

ObjectiveThe aim was to evaluate backgrounding beef steers on oat + ryegrass pastures mixed with vetch and/or using energy supplementation.MethodsA randomized block design with three treatments and three replications was used. The treatments were: grass + supplement (oat + ryegrass + supplementation), legume + supplement (oat + ryegrass + vetch + supplementation) and grass + legume (oat + ryegrass + vetch). A continuous grazing system with a variable stocking rate was used. Twenty-seven intact crossbred steers (1/4 Marchigiana, 1/4 Aberdeen Angus and 2/4 Nellore) aged 7 months old and average weight of 190 kg were used. Steers were supplemented at 1% of the body weight of ground corn. The experiment lasted 84 days, between May and August 2014. Behavioral assessments were performed two times per experimental period, for 24 hours.ResultsThe forage mass was different between treatments, being greater for steers fed without legume. The accumulation rate, forage allowance, and stocking rate did not differ between treatments due to the adequate adjustment of forage allowance. The final weight of animals, as well as the dry matter intake (kg/d), did not differ between treatments. However, forage intake was higher for non-supplemented animals in relation to supplemented steers. Supplement intake did not alter the total digestible nutrient intake due to pasture quality. Animals fed grass + supplement had higher live weight gain per area than those fed grass + legume. Animals without supplementation spent more time in grazing.ConclusionFeeding behavior was not altered by mixing with vetch or supplementation. Non-supplemented animals started the grazing peak earlier and spent more time in grazing than those supplemented; however, the average daily gain was similar between treatments. The live weight gain per hectare was 47% higher in pastures in which the animals received supplementation compared with those mixed with vetch, a consequence of the substitutive effect.

Utilization of Fermented Pistia Leaves in the Diet of Rohu, Labeo rohita (Hamilton): Effects on Growth, Digestibility and Whole Body Composition

The present study aimed at re-cycling of an aquatic weed (water lettuce, Pistia sp.) as a component in formulation of low cost non-conventional carp diet. Dried Pistia leaves (PL) was bio-processed through solid state fermentation (SSF) for 15 days at 32 ± 1 °C by a tannase producing yeast, Pichia kudriavzevii (GU939629) isolated from the gut of a freshwater carp, Cirrhinus cirrhosus. SSF of PL was effective in reducing the contents of crude fibre and antinutritional factors (e.g., tannin, phytic acid and trypsin inhibitor) significantly (P < 0.05), whereas enhancing crude protein, lipid, ash, total free amino acids and fatty acids. Six isonitrogenous (35%) and isocaloric (17 kJ g−1) experimental diets were prepared incorporating raw (R1–R3) and fermented (F1–F3) PL at 10, 20 and 30% levels by weight replacing fishmeal (FM) and other feed ingredients into a FM-based reference diet and fed to rohu, Labeo rohita fingerlings (initial weight 3.39 ± 0.06 g) for 80 days. In general, fish fed diets with SSF-processed PL resulted in significantly better growth, nutrient digestibility, carcass composition and digestive enzyme activity compared to the diets with raw PL. Fish fed the diet F2 containing 20% fermented PL had the highest live weight gain (106.3%), specific growth rate (SGR, % day−1), protein efficiency ratio and apparent net protein utilization. The highest protein gain (40.84%) and lipid accumulation in the carcass were also recorded in the fish reared on the diet F2. The present study might suggest incorporation of bio-processed PL up to 20% level (12.5% of FM replacement) without interfering growth, feed utilization efficiency and body composition in L. rohita fingerlings.

&lt;b&gt;Replacing fish meal by mealworm (&lt;i&gt;Tenebrio molitor&lt;/i&gt;) on the growth performance and immunologic responses of white shrimp (&lt;i&gt;Litopenaeus vannamei&lt;/i&gt;)

The objective of this study was to determine the effect of replacing FM with mealworm ( Tenebrio molitor ) on the growth performance and immunologic responses of white shrimp. In addition, the toxicity of such replacement to white shrimp was measured. Mealworm was incorporated to partially or totally replace fish meal in diets for white shrimp. Experimental groups of shrimp with an average initial body weight of 2.39 ± 0.49 g were fed each of 4 isonitrogeneous diets formulated to include 0, 25, 50 and 100% (control, MW25, MW50 and MW100 respectively) of mealworm substituted for fish meal. After eight weeks of feeding trials, shrimp fed diets MW25, MW50 and MW100 had higher live weight gain (10.05 ± 3.06, 11.41 ± 2.08, and 10.36 ± 1.57, respectively), higher specific growth rate (2.56 ± 0.11, 2.79 ± 0.09, and 2.61 ± 0.07, respectively), and better feed conversion ratio (2.89 ± 0.08, 2.69 ± 0.09, and 2.72 ± 0.19, respectively) compared to those of shrimp fed control diet. Survival rate was 98% in all treatments. No toxicity was found in post-mortem pathophysiologic examinations. The levels of immune markers such as beta-glucan binding protein, prophenoloxidase and crustin associated with shrimp’s cellular and humoral immunity were found to be higher in 25 and 50% mealworm replacement groups. These results clearly indicated that replacement of fish meal with 50% mealworm for shrimp diet was optimal in promoting the growth performance of shrimp without any adverse effect.

Epidemiology and effect of gastrointestinal nematodes on beef cattle from tropical Argentina

The aim of this work was to study the epidemiology and the harmful effect of gastrointestinal nematodes (GINs) on beef cattle in the piedmont forest and grassland region of northwestern Argentina, between March 2015 and March 2016. Sixty weaned female calves were divided into three groups: STG-calves treated systematically with 200mcg/kg moxidectin every 40-50days; LTG-calves treated as usually locally implemented, with 200mcg/kg ivermectin on May 4 and August 5; and UTG-calves not receiving treatment. Moreover, a group of 20 untreated first-calving cows was monitored. Eggs per gram of faeces (epg) and faeces cultures were performed. Live weight gain (LWG) was recorded. Differences among groups were compared using analysis of variance and Tukey test. At the start of the experiment, mean epg was from moderate to high (595 ± 480); therefore, this group was treated in May. Mean UTG epg peaked (907 ± 754) in mid-winter, decreasing toward spring. LTG epg only decreased partially after treatment, showing 54.2% of ivermectin efficacy. Epg values of STG were always negligible values (95.8% of moxidectin efficacy). The dominant nematode genus was Cooperia (81.9%), followed by Haemonchus (15.5%). The effect of treatments was evident from middle autumn, with STG showing a significantly (p < 0.002) higher LWG than the other groups. Toward the end of the trial, LWG of STG and LTG increased by 27.2 and 8.2%, respectively, to those of UTG. This preliminary study showed a winter epg peak and a negative effect of GINs on LWG, even in moderately infected calves.

Effects of essential oils from Liquidambar orientalis Mill. leaves on growth performance, carcass and some organ traits, some blood metabolites and intestinal microbiota in broilers

ABSTRACT1. This study was carried out to investigate the effects of liquidambar essential oils (LEO) isolated from Turkish sweet gum (Liquidambar orientalis Mill.) leaves on growth performance, carcass, edible inner organs (EIO), gastrointestinal traits (gut), some blood metabolites and jejunum microbiota in broilers.2. A total of 375 one-d-old male broilers (Ross 308) were randomly allocated to 5 treatments with 5 pens with 15 birds. The birds were fed on diets without antibiotics (CONT), with antibiotic (50 mg per kg, AB), with LEOs at 0.0405 (0.04LEO), 0.0811 (0.08LEO) or 0.1622 (0.16LEO) g/kg feed up to 42 d of age. The levels of LEOs included to diets were determined according to in vitro antimicrobial activity.3. From d 1 to 42, the 0.08LEO treatment had higher live weight gain (LWG) compared to others. The 0.08LEO treatment increased feed intake (FI) compared to the CONT, AB and 0.04LEO. However, the feed conversion ratio (FCR) of these birds was lower than those in the AB and 0.16LEO treatments. From 1 to 42 d of age for LWG, the effects were quadratic and cubic, while those for FI and FCR were cubic and quadratic, respectively. Birds that fed 0.08LEO and AB diets had higher and lower carcass weights (CW) than those that fed other diets. The effect of LEO levels was cubic on the CW. The 0.08LEO and 0.16LEO decreased abdominal fat (AF) weight compared to the AB. The blood cholesterol decreased by the 0.04LEO and 0.08LEO treatments compared to the CONT. For the blood cholesterol, the effects of LEO levels were cubic. The 0.08LEO treatments decreased Escherichia coli counts in jejunum compared to the CONT and 0.16LEO.4. Feeding a diet with LEO at 0.0811 g/kg might increase the LWG, FI and weights of carcass and AF, whereas it might decrease blood cholesterol and E. coli counts without affecting blood high-density lipoprotein, low-density lipoprotein, triglyceride, glucose, aspartate transaminase and alanine transaminase concentrations.

Energy balance and body reserves in rabbit females selected for longevity

&lt;p&gt;The aim of this study was to compare the energy balance and dynamic of body reserves in rabbit females divergently selected for longevity. One hundred and twenty-nine females from a high longevity line (HL) and 131 females of a low longevity line (LL) were studied from the 1&lt;sup&gt;st&lt;/sup&gt; to the 3&lt;sup&gt;rd&lt;/sup&gt; kindling. Litter size and weight and female body weight were measured at kindling (1&lt;sup&gt;st&lt;/sup&gt;, 2&lt;sup&gt;nd&lt;/sup&gt; and 3&lt;sup&gt;rd&lt;/sup&gt;), insemination (2&lt;sup&gt;nd&lt;/sup&gt; and 3&lt;sup&gt;rd&lt;/sup&gt;) and at weaning (1&lt;sup&gt;st&lt;/sup&gt; and 2&lt;sup&gt;nd&lt;/sup&gt;). The total body electric conductivity (TOBEC) method was used to estimate the body reserves in all females at artificial insemination and at weaning, and at kindling in females that achieved parturition. Energy balance between the 11&lt;sup&gt;th&lt;/sup&gt; and the 21&lt;sup&gt;th&lt;/sup&gt; d of lactation was also calculated for these females. No significant difference was found for fertility or for the number of offspring born alive and weaned. However, the total number of offspring born was higher in the LL line than in the HL line at the 2&lt;sup&gt;nd&lt;/sup&gt; parturition (+1.12±0.46 g; P&amp;lt;0.05). Consequently, the number of stillborn offspring was higher in the LL line. LL females were 4% heavier than HL females at the first parturition (P&amp;lt;0.05), but then HL females had a higher live weight gain than LL females from the 1st parturition to the 2&lt;sup&gt;nd&lt;/sup&gt; artificial insemination (+107.0±29 g; P=0.049), leading to a similar weight between the lines at the 2&lt;sup&gt;nd&lt;/sup&gt; artificial insemination. There was no significant difference between lines for estimated energy used for growth between the 11&lt;sup&gt;th&lt;/sup&gt; and the 21&lt;sup&gt;th&lt;/sup&gt; d of lactation, or for estimated milk production (2365±30 g in HL line vs. 2398±30 g in LL line), estimated using the weight gain of the kits between the 11&lt;sup&gt;th&lt;/sup&gt; and 21&lt;sup&gt;st&lt;/sup&gt; d of lactation, for feed intake measured during this period (351±5 g/d in HL line vs. 359±5 g/d in LL line) or for energy balance (–6.11±0.3 MJ in HL line vs. –6.30±0.3 MJ in LL line). However, body energy content was higher in HL females than in LL (+2.72±0.64 MJ; P=0.001). In conclusion, selection for higher functional longevity results in a better ability of females to use body reserves in their early reproductive life.&lt;/p&gt;

Animal performance and sward characteristics of two cultivars of Brachiaria brizantha (BRS Paiaguás and BRS Piatã)

The objective of the present study was to evaluate live weight gain per animal and per area and its relationship with the characteristics of pastures of Brachiaria brizantha cv. Paiaguas and Piata. A randomized blocks experimental design was used, with two treatments and six replicates. The experimental area was 8.0 ha, divided into twelve paddocks of 0.67 ha. The grazing method used was continuous stocking, with variable stocking rate. Three tester steers were used per paddock. Sward heights were measured once a week, and the stocking rate (SR) was adjusted using regulator steers to maintain the sward height at 30 cm. Pasture samples were collected once a month, and herbage accumulation rate (HAR), percentage of leaves (PL), leaf:stem ratio (LSR), and nutritive value (NV) were determined. Animals were weighed every 28 days. No differences between the two cultivars were observed during the wet season for any of the evaluated parameters. However, cv. Paiaguas presented higher HAR and, consequently, higher SR than cv. Piata during the dry season. As a result of its higher regrowth, cv. Paiaguas pastures presented significantly higher PL, LSR, and NV and, consequently, significantly higher average daily live weight gain. These differences resulted in higher live weight gain per area for Paiaguas grass (695 kg/ha per year) than for Piata grass (645 kg/ha per year). Thus, Brachiaria brizantha cv. Paiaguas is a good alternative to decrease the temporary forage shortage and for the diversification of pastures in the Cerrado biome region.