Maximum Average Daily Gain Research Articles

359 Optimization of calcium inclusion levels in diets fed to growing and finishing beef cattle

Abstract Calcium (Ca) is a mineral that has an essential role in many biochemical pathways and functions of beef cattle. Limestone is the primary supplemental source of Ca in diets fed to growing and finishing cattle in the United States. Preliminary data indicated that inclusion of dietary Ca above the NASEM (2016) requirements as well as mean and modal concentrations reported by the most recent survey of consulting nutritionists may improve average daily gain (ADG) and feed efficiency (gain to feed ration; G:F) of finishing beef cattle. Thus, the objective of this experiment was to determine the optimal concentration of Ca in growing and finishing diets when limestone was the supplemental source of added Ca. A database was constructed containing 89 treatment means from 23 experiments published from 1963 to 2024 where dietary Ca inclusion via limestone represented treatments. Search parameters to construct the database included a combination of Ca, limestone, performance, efficiency, ADG, G:F, feedlot cattle, finishing cattle, growing cattle, and backgrounding cattle. Data were analyzed in JMP Pro 17 using a mixed model to determine linear and quadratic relationships between dietary Ca and ADG, DMI, or G:F with citation as a random effect. An economic sensitivity analysis was conducted to determine variables most influential to the dietary Ca concentration projected to minimize cost of gain using the above models. Concentration of dietary calcium was selected as the explanatory variable for the models rather than limestone because a greater proportion of variation was accounted for in the response variables prior to the citation adjustment (Ca R2 0.05 to 0.25; limestone R2 0.06 to 0.21). Diet Ca concentration and DMI were unrelated (P ≥ 0.75), but diet Ca was related to both ADG (R2 = 0.84; RMSE = 0.36; P ≤ 0.03) and G:F (R2 = 0.74; RMSE = 0.01; P < 0.01) in a quadratic fashion. Maximum ADG occurred when Ca was included at 1.20% of diet DM; approximately 2.6-fold greater than Ca requirements estimated by NASEM (2016). Cost of gain was minimized when Ca was 1.35% of diet DM. Sensitivity analysis revealed Ca concentration to minimize cost of gain was sensitive to changes in DMI, ADG, days on feed, ration cost and cost of yardage. These results provide further evidence that it may be beneficial to feed a greater amount of Ca than currently recommended by the NASEM (2016) for growing and finishing cattle. Future pen-scale feeding trials are warranted to validate the results of this meta-analysis and to determine the dose response of cattle fed graded levels of Ca. Future research should also be conducted to determine the mechanism of action responsible for the observed improvements in animal performance and efficiency resulting from feeding an increased amount of dietary Ca.

Effect of standardized ileal digestible arginine:lysine on growth performance of 6- to 13-kg nursery pigs.

A total of 480 newly weaned pigs (PIC 337×1050; Genus, Hendersonville, TN) with an initial body weight (BW) of 6.20 ± 0.61kg were used in a dose-response study to investigate the impact of increasing standardized ileal digestible (SID) Arg:Lys on nursery pig growth performance. At weaning, pigs were placed into 48 pens with 5 barrows and 5 gilts per pen. Pens were randomly assigned to 1 of 6 dietary treatments. The experimental diets were formulated with increasing SID Arg:Lys, achieved by substituting corn starch, glycine, and l-alanine with l-arginine, resulting in SID Arg:Lys ranging from 45% to 145%. Diets were sublimiting in SID Lys and exceeded all other essential amino acid requirements. The experimental diets were fed across two feeding phases from days 0 to 10 and 10 to 27, with adjustments made to account for the Lys requirement of the pigs. All pens were placed on a common diet for the remaining 14 d of the study to evaluate carryover effects. Pigs and feeders were weighed at the start and end of each phase to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). Data were analyzed according to a linear regression model, which included the linear and quadratic effects of SID Arg:Lys and initial BW. Pen was the experimental unit, and results were considered significant at P ≤ 0.05 and a tendency at 0.50 < P ≤ 0.10. From days 0 to 27, Arg:Lys tended to have a quadratic effect on ADFI (P = 0.058), where 97.00 ± 7.631% SID Arg:Lys maximized feed intake. Similarly, Arg:Lys had a quadratic impact on ADG (P = 0.046), where ADG was maximized at a SID Arg:Lys of 95.65 ± 7.165. Correspondingly, Arg:Lys had a quadratic effect on pig BW on day 27 (P = 0.014). These effects were carried through the end of the study, where Arg:Lys quadratically impacted days 0 to 41 ADFI (P = 0.006), ADG (P = 0.077), and day 41 BW (P = 0.028). There was no evidence of an effect of SID Arg:Lys on G:F throughout the study (P ≥ 0.315). In conclusion, SID Arg:Lys quadratically impacted ADFI and ADG in 6- to 13-kg nursery pigs, where ADFI was maximized at a SID Arg:Lys of 97.00% (95% CI [81.6%, 112.4%]), and ADG was maximized at a SID Arg:Lys of 95.65% (95% CI [81.2%, 110.1%]). Together, these data suggest that the SID Arg:Lys requirement of nursery pigs is at least 81%, based on the lower bounds of the 95% CI for maximum ADG and ADFI, and excessive Arg supplementation may negatively affect growth performance.

28 Investigation of protein deposition pattern of PIC337×Camborough commercial pigs

Abstract The objective of the trial was to investigate the protein deposition pattern of PIC337×Camborough commercial pigs. A total of 1,064 barrows and gilts [PIC337×Camborough, initial body weight (BW) = 6.0 ± 0.1 kg] were used in the trial with 38 mixed sex pens, 28 pigs per pen. At the beginning of the trial, the lightest 10% of the barrows and gilts were selected and placed in four pens (equal numbers of barrows and gilts within a pen), and the remaining pigs were randomly placed into the other pens (equal numbers of barrows and gilts within a pen). A common 6-phase corn-soybean based wean-to-finish diets were fed throughout the trial. Dietary net energy and standardized ileal digestible lysine levels were (6-10 kg BW: 2,600 Kcal/kg and 1.35%; 10-20 kg BW: 2,520 Kcal/kg and 1.30%; 20-38 kg BW: 2,470 Kcal/kg and 1.20%; 38-72 kg BW: 2,450 Kcal/kg and 0.98%; 72-127 kg BW: 2,450 Kcal/kg and 0.87%; and 127-149 kg BW: 2,450 Kcal/kg and 0.77%). On d 97 after placement, 5 barrows and 5 gilts with BW close to pen average were selected for individual BW by a portable scale and 10th rib backfat and loin depth measurements (ExaGo portable ultrasound scanner, Imv imaging, UK). Then on d 111, 117, 136, 142, and 167 after placement, the same 5 barrows and 5 gilts were measured for individual BW, 10th rib backfat and loin depth. The fat-free lean mass is estimated by the equation 6.783-0.6198×(10th rib backfat depth, mm)+0.1578×(10th rib loin depth, mm)+1.0362×(warm carcass weight, kg). A constant carcass yield of 75% was used to estimate warm carcass weight. Data were analyzed using a linear mixed model in R Studio (Version 3.5.2, R Core Team; Vienna, Austria). The average BW of pigs at the 6 measurements were: 77.2, 92.4, 99.2, 122.5, 128.0, and 153.6 kg, respectively. The average daily gain (ADG) was 1,139, 1,155, 1,145, 1,126, and 977 g/d for 77.2 to 92.4 kg BW, 92.4 to 99.2 kg BW, 99.2 to 122.5 kg BW, 122.5 to 128.0 kg BW, and 128.0 to 153.6 kg BW, respectively. The average daily 10th rib backfat depth gain was 0.05, 0.08, 0.15, 0.17, and 0.20 mm/d. The average daily 10th rib loin depth gain was 0.42, 0.43, 0.41, 0.39, and 0.23 mm/d. The average daily fat-free lean mass gain (ADFFLG) was 547, 551, 528, 515, and 422 g/d. The fitted quadratic model for ADG is 83.57782 + 19.90632 × (BW, kg)-0.09176×(BW, kg)2, and the calculated maximum ADG was 1,163 g/d when BW was 108.5 kg. The fitted quadratic model for ADFFLG is 85.90926 + 9.23773 × (BW, kg) - 0.04591 × (BW, kg)2, and the calculated maximum ADFFLG is 550.6 g/d when BW was 100.6 kg. Under the conditions of the current trial, PIC337×Camborough pigs reaches the maximum rate of protein deposition at BW between 100.6 and 108.5 kg.

27 Standardized ileal digestible lysine to metabolizable energy ratio equations for 12 to 127 kg boars, gilts, immunocastrated gilts and boars

Abstract We aimed to determine the standardized ileal digestible (SID) lysine (Lys) to metabolizable energy (ME) ratio equations for 12 to 127 kg boars, gilts, immunocastred gilts (IC gilts), and barrows (IC barrows). An average of 3,545 split-gender pigs (PIC 337×Camborough, initially 11.98 ± 1.26 kg) were used in a 21-d trial followed by a 21-d wash-out period in 2 replicates, totaling six feeding periods. In feeding phase 6, both genders were immunized against gonadotropin-releasing hormone (administrated with Vivax, Zoetis, São Paulo, SP, Brazil). Pens of pigs were weighed, blocked by body weight, and randomly allotted to 1 of 5 treatments consisting of 80, 90, 100, 110, and 120% of PIC SID Lys:Mcal of ME recommendations for mixed gender between boars, barrows, and gilts for each phase. The treatment diets were corn-soybean-meal-based and contained 3,300 Kcal of ME/kg. There were six split-gender pens•treatment-1•replicate-1 •phase-1 and 30 pigs/pen. Data were analyzed using generalized linear and nonlinear mixed models with a pen as the experimental unit. Competing models included linear, quadratic polynomial (QP), broken-line linear (BLL), and broken-line quadratic (BLQ) for average daily gain (ADG) and gain to feed ratio (G:F). There was no significant gender by quadratic coefficient interactions in all phases of this study (P &amp;gt; 0.05), then the mixed gender equation was determined, and the intact boars and gilts equation was estimated by the PIC overall difference in efficiency between genders. In the immunocastrated phase, after second dose, the mixed gender optimum level was determined and the equations for IC gilts and barrows was estimated by the differences in efficiency observed in the phase 6 of the two replicates. The SID Lys to calorie ratio recommended is based on the average for ADG and G:F (Table 1). Approximately 98.4% and 99.2% of maximum ADG and G:F were achieved at these levels, respectively, and these equations were similar compared with previous PIC biological requirements (Orlando et al., 2021).

Linear and Nonlinear Mixed Models to Determine the Growth Curves of Weaned Piglets and the Effect of Sex on Growth

This study characterizes the growth of weaned Large White × Landrace hybrid piglets from 6 to 20 kg live body weight (BW) under real farm conditions. Batches of 50 castrated male pigs and 50 gilts were weighed repeatedly over two 6-week breeding cycles. The data was fitted to various linear (quadratic and exponential) and nonlinear (Gompertz, Richards, logistic, Von-Bertalanffy) mixed models to find the best-performing model. During the postweaning phase, animal growth was modelled, and the effect of sex on growth was determined by incorporating the variable, sex, into the mixed models and using t-tests for paired samples. The average BW at weaning was 6.86 kg, and the average BW by the end of the cycle was 19.46 kg, with an average daily gain (ADG) of 0.324 kg/day. Over the study period, the variable, sex, did not show a significant effect (p &lt; 0.05) on piglet growth. The nonlinear mixed models performed better than the linear mixed models, with the Gompertz (RMSE = 0.296) and Von-Bertalanffy (RMSE = 0.288) curves as the best-performing models. When fitted to the Gompertz curve, the data showed a maximum ADG of 0.508 kg/day on day 27 postweaning. Accordingly, nonlinear mixed models can provide useful information to farmers about the evolution of weaned piglet growth and can be used for the early detection of growth anomalies.

134 Meta-Analysis to Determine the Standardized Ileal Digestible Lysine Requirements of Growing-Finishing Pigs from 11- to 150-kg Utilizing the Ingredients Database of Inra

Abstract A meta-analysis was conducted to determine the standardized ileal digestible (SID) lysine (Lys) recommendations for 11–150 kg PIC pigs housed under commercial conditions utilizing the INRA feed ingredients database. Data from 29 trials dating from 2013 to 2020 utilizing 48,338 pigs were recorded in a database. Number of pens/treatment and pigs/pen ranged from 9 to 16 and 12 to 25, respectively. Sire lines were PIC 337 in 25 trials, PIC 327 in 3 trials, and PIC TR4 and 327 in 1 trial. Dam lines were PIC Camborough in 18 trials and PIC Camborough 29 in 9 trials. The SID Lys levels reported in each trial were used, and the SID Lys to calorie ratio curves were built for both metabolizable energy (ME) and net energy (NE) systems using the feed ingredient composition in INRA for energy levels. The response variables, average daily gain (ADG) and feed efficiency (G:F), were analyzed within 7 phases using generalized linear and non-linear mixed models with heterogeneous variance (Gonçalves et al., 2016). Phases consisted of the following body weight ranges: 11-23, 23-41, 41-59, 59-77, 77-104, 104-127, and 127-150 kg . Each treatment mean within a trial (n = 288) was considered the experimental unit and each trial was used as a random effect. There was no evidence for an interaction between sire lines or dam lines and treatment (P &amp;gt; 0.10). The SID Lys to calorie recommendations are based on the average of the requirement estimates for ADG and G:F. At these levels, approximately 100% of maximum ADG and 99.7% of maximum G:F are achieved. After determining the requirement estimates within each of the 7 weight breaks, a quadratic equation of Lys to calorie ratio was fit for each energy system. The equations are described as: g of SID Lys:Mcal of ME = 0.0001381709 × (weight, kg)2 - 0.0366272129 × (weight, kg) + 4.6073086522; and g of SID Lys:Mcal of NE = 0.0000400092 × (weight, kg)2 - 0.0235648387 × (weight, kg) + 6.2762350341. These data provide the estimated SID Lys requirements for maximal growth performance for PIC pigs from 11- to 150-kg based on the ingredients database of INRA.

Dietary vitamin D3 requirement of magang goslings from 1–21 days of age

The present study was conducted to investigate the effect of dietary vitamin D3 levels (0, 200, 400, 800, 1600, and 3200 IU/kg) on growth performance, calcium-phosphorus metabolism, and tibia development of goslings from 1 to 21 days of age. A total of 720 one-day-old Magang male goslings with similar initial body weight were randomly divided into 6 treatments with 6 replicates per treatment and 20 geese per replicate. The goslings fed with 400 IU vitamin D3/kg of diet obtained the maximum average daily gain, while vitamin D3 supplementation significantly improved the feed/gain of goslings aged from 1 to 21 days (P < 0.05). The vitamin D3 requirement of gosling aged from 1 to 21 days for optimal feed/gain ratio and average daily gain were estimated from three regression models (one-slope straight, two-slope straight, and quadratic broken-line model) to be 246–352 IU/kg diet and 400–518 IU/kg diet, respectively. Serum calcium and phosphorus contents, parathyroid hormone level, and 25-hydroxycholecalciferol level responded to increasing dietary vitamin D3 levels (P < 0.05) and reached a plateau at 800, 0, and 200 IU vitamin D3/kg diet, respectively. The mRNA expressions of target genes related to calcium homeostasis such as vitamin D3 receptor, Na+/Ca2+ exchanger 1, and plasma membrane calcium ATPase 1b in the duodenum and kidney (P < 0.05) and parathyroid hormone receptor mRNA expression in the kidney (P < 0.05) were increased linearly and quadratically with the increasing dietary vitamin D3 levels, respectively. Graded doses of dietary vitamin D3 from 0 to 3200 IU/kg produced linear responses in tibial density (P < 0.05). The vitamin D3 requirement of gosling aged from 1 to 21 days ranged from 519 to 698 IU/kg diet when tibial density as an evaluation criterion. In conclusion, the vitamin D3 requirement of gosling aged from 1 to 21 days for optimal growth performance (feed/gain and average daily gain) and tibial density was estimated to be 246–352 IU/kg of diet, 400–518 IU/kg of diet, and 519–698 IU/kg of diet based on three regression models (one-slope straight, two-slope straight, and quadratic broken-line model), respectively. The most appropriate vitamin D3 requirement was recommended at 602 IU/kg of diet of young geese based on the mean estimated values of three regression models for the tibial density with the highest coefficient of determination and lowest mean square error.

GROWTH FEATURES OF ABERDEEN ANGUS BREED IN DIFFERENT HOUSING TECHNOLOGIES

The article presents results of the studies of dynamics of live weight, average daily gains and relative growth rate of Aberdeen Angus bulls under different housing technologies. The purpose of the research is to establish the degree of growth parameters for cattle of Aberdeen-Angus breed in economic and technological conditions of the Kabardino-Balkarian Republic. Bulls of Aberdeen-Angus breed were the object of the research. Group I - year-round keeping in a fenced area, group II - stall-pasture with transfer of animals in the summer to high-mountain pastures (the length of the pasture period is 152 days). Total duration of production cycles was 18 months. The suckling period was 7 months, rearing - 9 months and intensive final fattening - 2 months. It was established that (due to differences in housing technologies), differences between individuals of different groups at the age of one year reached 18.1 kg (P&gt; 0.95) in favor of animals located on high mountain pastures with high nutritional value of the grass stand. The superiority of this group of bulls over the peers of year-round keeping in a fenced area at the age of 16 months was 21.5 kg (P&gt; 0.95), at the end of the fattening period -25.1 kg (P&gt; 0.95). Over the entire period of research, as expected, the maximum average daily gain of live weight was common for Aberdeen Angus animals of remote pasture keeping - 965 g versus 919 g - ofanimals of year-round keeping in a fenced area (by 46 g, Р&gt; 0.95) , in terms of growth energy – by 0.9% (Р&gt;0.95). A comparative assessment of housing technologies for bulls of Aberdeen-Angus breed in economic and technological conditions of the Kabardino-Balkarian Republic showed higher growth parameters in the conditions of distant-mountain keeping compared to year-round keeping in a fenced area.

Impact of increasing standardized ileal digestible valine: lysine in diets containing 30% dried distiller grains with solubles on growing pig performance.

A total of 2,430 pigs (DNA 600 × Topigs Norsvin 70, initially 39.4 kg) were used in a 28-d trial to determine the standardized ileal digestible (SID) Val:Lys requirement for pigs fed with diets containing 30% DDGS. Treatments included five diets containing 30% DDGS with SID Val:Lys ratios of 60%, 65%, 70%, 75%, and 80%, plus a corn soybean meal (SBM) diet, for a total of six dietary treatments. Diets were formulated to be isocaloric through the inclusion of fat and to contain equal amounts of SID Lys within phase. Pens were assigned to dietary treatment in a randomized complete block design with initial body weight (BW) as the random blocking factor. Each dietary treatment was replicated 15 times and pens contained 27 pigs, balanced for sex. Increasing the SID Val:Lys ratio in diets containing 30% DDGS increased (Quadratic; P ≤ 0.007) 14-d BW, final BW, average daily gain (ADG), average daily feed intake (ADFI), and gain:feed (G:F) for all periods. Providing an SID Val:Lys ratio of 75% resulted in the heaviest 14-d BW and final BW as well as greater ADG and ADFI of pigs fed with 30% DDGS for all periods. The G:F response was maximized when an SID Val:Lys ratio of 70% was provided from day 0 to 14 while an SID Val:Lys ratio of 75% maximized G:F from day 14 to 28 and for the cumulative period. The SID Val:Lys requirement was estimated at 66.6% (95% CI [65.9, 67.4]), 65.7 (95% CI: [64.8, 66.5]), and 68.4% (95% CI [66.0, 70.8]) for ADG, ADFI, and G:F, respectively, using the straight broken line (SBL) method and 69.9% (95% CI [68.2, 71.5]), 67.6 (95% CI [65.4, 69.8]), and 72.8% (95% CI [69.8, 75.8]) for the quadratic broken line (QBL) method. Pigs fed the corn-SBM diet had heavier 14-d BW, final BW, and greater ADG, ADFI, G:F (P ≤ 0.032) compared to pigs fed diets containing 30% DDGS, except for cumulative ADFI compared to pigs receiving 75% SID Val:Lys (P = 0.167). In conclusion, these results suggest that when feeding 30% DDGS during the growing period, an SID Val:Lys ratio of 68% would yield more than 99% and 97% of the maximum ADG and G:F response for the 39 to 68 kg pigs. However, growth performance of pigs fed diets containing 30% DDGS did not equate to pigs consuming the corn-SBM diet regardless of the SID Val:Lys ratio.

Optimisation of branched-chain amino acid requirements for 15–21-day-old broiler chickens by using the Taguchi method

Context There are complex inter-relationships among the branched-chain amino acids (BCAAs), making the use of full factorial design experiments more complicated, costly and time-consuming when attempting to estimate the optimal levels of the BCAAs. Aims Two experiments were conducted to determine optimal concentrations of BCAAs by using the Taguchi method and mathematical models for broiler chickens during 15–21 days of age. Methods In the first experiment, the optimal concentrations of BCAAs were determined for broiler chickens, and the accuracy of the results was evaluated in the second experiment. The orthogonal array layout of L16 (43) was applied to test four concentrations of leucine (Leu), isoleucine (Ile) and valine (Val). To test the validity of the results from 16 diets selected by the Taguchi method and four additional diets from the full factorial design method, a total of 960 broiler chickens was assigned to these 20 experimental diets, with six replicates of eight birds each. The Taguchi method, the multi-objective genetic algorithm (MOGA) and the random search algorithm (RSA) were used to determine the best concentration of BCAAs on the basis of optimal bird performance, which was measured by bodyweight gain, feed intake, and feed conversion ratio (FCR). In the second experiment, six dietary treatments were formulated to establish the reliability of the predictions obtained from the first experiment (Experiment 1). Key results No exceptional concentrations of BCAAs were achieved for a maximum average daily gain and a minimum FCR; however, the diet containing 1.177–1.353% standardised ileal digestible (SID) Leu, 0.742–0.810% SID Ile, and 0.832–0.915% SID Val showed the best performance. The results of the second experiment indicated that the Taguchi method could be used instead of a full factorial design to optimise the amino acid requirements of broiler chickens. Conclusions The requirements of BCAAs were overestimated using the MOGA and RSA methods compared with the Taguchi method. Implications In commercial diets containing high levels of SID Leu, supplementation of an extra 5% SID Ile and Val may improve broiler performance during 15–21 days of age.

Propolis supplementation affects performance, intestinal morphology, and bacterial population of broiler chickens

A meta-analysis was conducted to examine the effect of supplementing the diet of broiler chickens with propolis on growth, bacterial population of the intestine, antiviral serum concentration, intestinal morphology, and digestive enzyme activities in broiler chickens. Forty peer-reviewed articles that had been published between 2003 and 2019 were identified using the PRISMA protocol and included in the study. Data were analysed with mixed model methodology, in which the studies were considered random effects, whereas the level of supplemental propolis was considered a fixed effect. Responses to propolis supplementation in bodyweight (BW) and average daily gain (ADG) were quadratic, but average daily feed intake (ADFI) was not affected. Propolis supplementation improved feed conversion ratio (FCR) significantly as a linear function of the level of supplement. The optimum level of supplementation was between 256 and 262 mg/kg feed and produced maximum ADG and final BW. There was a tendency for mortality to decrease because of propolis supplementation. Propolis had no detectable effect on serum antiviral concentration, intestinal bacterial population or intestinal morphology. Among digestive enzymes, only sucrase increased linearly as propolis was increased. Thus, supplementation with propolis increased the growth performance of broiler chickens positively and the effect was dose dependent. This may have been partly because of an improvement in sucrase activity and other factors related to the nutritional content of propolis. Future study to evaluate specific bioactive compounds of propolis is therefore warranted.

Features of growth and development of Scutellaria baicalensis Georgi under conditions of introduction in the Middle Urals

Abstract. An experiment on the topic “Features of the growth and development of Scutellaria baicalensis Georgi under conditions of introduction in the Middle Urals” was carried out at the educational farm “Uralets”. Purpose of the study: to study the influence of the feeding area on the growth and development of Scutellaria baicalensis Georgi. The objectives of the study were to study the influence of the feeding area on: the dynamics of height and average daily growth, dates of the onset and timing of phenological phases, biometric indicators of leaves and inflorescences, structural composition of aboveground biomass, productivity of aboveground and underground biomass. Research methods. The experiment scheme includes 3 options: 1 variant – 33 × 30 cm (990 cm2) – control; 2 variant – 33 × 45 cm (1485 cm2); 3 variant – 33 × 60 cm (1980 cm2). Results. It was found that an increase in the feeding area enhances the differentiation of plants in terms of the rate of passage of phenological phases. The earliest transition to the generative stage of development was noted in variants II and III (24.06). The maximum average daily gain was observed in the II and III decades of July, according to the variants it varied from 0.78 (1st stage) to 1.22 cm/day (III stage). The highest biological productivity was obtained in variant 3 with a feeding area of 33 × 60 cm; on average, it reached 251.5 g per plant, which is 162.2 g (181.6 %) higher than in the control. Scientific novelty. For the first time, there was studied, the influence of the feeding area on the most important aspects of the growth and development of Scutellaria baicalensis Georgi in the conditions of the Middle Urals. The optimal feeding area (1980 cm2) has been established, at which the Scutellaria baicalensis Georgi is able to form a fairly high productivity.

Effect of increasing levels of threonine relative to lysine on the performance and meat quality of finishing pigs.

ObjectiveThe present study aimed to evaluate the effects of varying standardized ileal digestible lysine:threonine (SID Lys:Thr) ratio in the diet on the performance and meat quality of finishing pigs.MethodsIn total 192 crossbred pigs ([Landrace×Yorkshire]×Duroc, 17 weeks old), with an initial body weight (BW) of 70.6±3.9 kg were used in an 8-wk trial. Pigs were randomly allotted to one of six dietary treatments based on their initial BW and sex (8 replications; 4 pigs per pen, 2 barrows and 2 gilts). The pigs in the 6 treatments were fed diets having different SID Lys:Thr ratios such as 1:0.65, 1:0.66, 1:0.67, 1:0.68, 1:0.69, and 1:0.70.ResultsA linear increment (p<0.05) in average daily gain (ADG) and trends in reduction in feed conversion ratio (FCR) were observed during day 29 to 56 of the experiment and the apparent total tract digestibility (ATTD) of dry matter tended to increase linearly (p = 0.094) at the end of the experiment (day 56) with the increase in the dietary SID Lys:Thr ratios. The backfat thickness and lean percentage increased (linear effect, p<0.05) on day 28. In addition, at day 56, a linear (p<0.05) increment in lean percentage was observed. Significant quadratic responses (p = 0.02) for pH and drip loss at day 7 (p = 0.02), a linear increase (p<0.05) in cooking loss and drip loss at day 7, and a trend in quadratic response (p = 0.07) in the lightness of meat color (L*) were observed, whereas other meat quality indices were unaffected by varying the SID Lys:Thr ratios.ConclusionThe SID Lys:Thr ratio for maximum ADG, minimum FCR and enhanced digestibility was found to be 0.70. However, for carcass trait and meat quality, the SID Lys:Thr ratio of 0.65 was enough.

170 Meta-analysis to Determine the Standardized Ileal Digestible Lysine Requirements of Growing-finishing Pigs from 11- to 150-kg

Abstract A meta-analysis was conducted to determine the standardized ileal digestible (SID) lysine (Lys) recommendations for 11–150 kg PIC pigs housed under commercial conditions. Data from 29 trials dating from 2013 to 2020 utilizing 48,338 pigs were recorded in a database. Number of pens/treatment and pigs/trial ranged from 9 to 16 and 12 to 25, respectively. Sire lines were PIC 337 in 25 trials, PIC 327 in 3 trials, and PIC TR4 and 327 in 1 trial. Dam lines were PIC Camborough in 18 trials and PIC Camborough 29 in 9 trials. The SID Lys to calorie ratio curves were built for both metabolizable energy (ME) and net energy (NE) systems using the feed ingredient composition in NRC (2012) for energy levels. The response variables average daily gain (ADG) and feed efficiency (G:F) were analyzed using generalized linear and non-linear mixed models with heterogeneous variance (Gonçalves et al., 2016). Each treatment mean within a trial (n = 288) was considered the experimental unit and each trial was used as a random effect. The models were developed for mixed gender pigs and the PIC 337 growth curves were used to estimate the recommendations for barrows and gilts. There was no evidence for an interaction between sire lines or dam lines and treatment (P &amp;gt; 0.10). The SID Lys to calorie recommendations are based on the average for ADG and G:F (Table 1). At these levels, approximately 100% of maximum ADG and 99.4% of maximum G:F are achieved. The NE to ME ratio that results in a similar SID Lys recommendation as a percentage of the diet ranged from approximately 0.72 to 0.74. The updated biological requirements for PIC pigs remained similar compared to previous PIC recommendations (Gonçalves et al., 2017). However, the requirement estimates have been adjusted for late nursery and late finishing phases.

Lysine requirements of finishing boars and gilts: A meta-analysis

The expected increase in boar (pig entire male) production while societal concerns for castration increase requires good estimations of their nutrient requirements. In this work, a meta-analytical approach was used to overcome the inconsistent results between studies that compared lysine requirements of boars and gilts. For this meta-analysis, data from 14 different studies analysing the effect of increasing dietary lysine on growth performance of finishing pigs, 70–100 kg average body weight, were extracted from 11 publications. Those studies represented 128 different treatments (53 for boars and 75 for gilts). Diets were reformulated based on NRC (2012) ingredient values to calculate standardized ileal digestible lysine to net energy ratio (SID Lys:NE) and daily SID Lys intake using average daily feed intake (ADFI). As expected, no evidence for differences in ADFI (P = 0.303) was observed between boars and gilts. However, boars grew faster (P < 0.001) and had higher gain to feed (G:F; P < 0.001). The divergent effect of SID Lys:NE on average daily gain (ADG) and G:F was analysed in a quadratic polynomial model showing different parameters for each sex (P < 0.001). Although performance between sexes was similar at low SID Lys:NE, differences were greater at higher SID Lys:NE. Furthermore, broken-line linear, broken-line quadratic (BLQ) and quadratic polynomial (QP) models were fitted to each sex to determine SID Lys:NE and SID Lys daily intake requirements to maximize ADG and G:F. Overall, QP models showed the best fit, and reported that to reach maximum ADG 0.88 (95% CI:[0.82–0.94]) or 1.01 (95% CI:[0.91–1.11]) g SID Lys/MJ, NE was required for gilts and boars, respectively. However, boar ADG was best fitted by BLQ using SID Lys daily intake as independent variable, with the requirement for maximum ADG at 24.2 (95% CI:[21.3–27.2]) g SID Lys/day. The three models reported wide confidence intervals for the requirements at maximum performance, and consequently those were overlapped when comparing boars and gilts. Maximum boars’ productive performance when dietary lysine was not limiting was 116% of gilts, and at those levels the amount of SID Lys intake required per kg gain was similar between both sexes. Thus, because ADFI and Lys efficiency of gain was similar, the requirement differences were driven by the increased growth rate and gain to feed ratio between boars and gilts. In conclusion, the present study confirmed a greater productive response of boars compared to gilts when increasing dietary lysine.

Vegetable biocholine supplementation in lambs during the feed transition period improves health and enhances weight gain

Lambs born from dairy ewes are removed from their mothers within hours of ingesting colostrum; this influences their growth and development, especially when artificial milk has poor quality or insufficient volume. Alternatives have been proposed to assist lambs during this phase, including providing concentrate with additives such as choline, which is involved in various physiological processes. This study's objective was to determine the effects of vegetable biocholine (VB) supplementation on growth, biochemistry, and antioxidant responses in lambs from dairy ewes during the feed transition period. We used 40 Lacaune lambs in a randomized block design, distributed in four groups with five replications (two animals per replication). VB was added to the concentrate and was consumed between 30 days pre-weaning to 30 days post-weaning (total 60 days). The treatments were as follows: T0, without added VB, control group; T2, 2 g VB per animal/day; T4, 4 g VB per animal/day; and T6, 6 g VB per animal/day. The weight gain increased in T2, T4, and T6 lambs when compared to T0. Using orthogonal polynomials analysis suggested that the ideal supplementation dose is 2.81 g/day per animal when considering the maximum average daily gain (ADG), which corresponds to 0.189 g VB/kg of body weight (BW). After weaning, there were lower serum concentrations of creatine kinase enzyme in lambs supplemented with VB than in controls. No differences were observed concerning levels of total protein, albumin, or globulins. Alanine aminotransferase (ALT) activity of T2 and T4 lambs was greater only at weaning (30 days). Glucose was greater in T2 and T4 lambs only on day 15. In general, VB supplementation decreased serum levels of reactive oxygen species (ROS) from day 15 of supplementation; these animals had lower lipid peroxidation levels after weaning. The activities of glutathione S-transferase (GST) did not differ. These data suggest that supplementation with VB increases weight gain and improves health, primarily by reducing free radical levels during the dietary transition period.

Improving the estimation of amino acid requirements to maximize nitrogen retention in precision feeding for growing-finishing pigs

Precision feeding requires a mathematical model to estimate standardized ileal digestible (SID) lysine (Lys) requirements (SIDLysR) in real time. However, this type of model requires constant calibration updates. The objective of this study was to review the calibration of the model used to estimate the real-time Lys requirements of individual growing-finishing pigs. A digestibility trial (n = 10) was conducted to evaluate amino acids digestibility during the growing and finishing phases. Additionally, 120 pigs were used in two 28-day growth experiments conducted as completely randomized design with growing (25 ± 2.1 kg BW, n = 60; 10 pigs per treatment) or finishing barrows (68.1 ± 6 kg BW, n = 60; 10 pigs per treatment). In each experiment, the pigs were divided into six equal treatment groups and fed 60%, 70%, 80%, 90%, 100% or 110% of their estimated individual SIDLysR. The Lys requirement of each pig was estimated daily using a real-time model. Body composition was measured with dual-energy X-ray densitometry on day 1 and 28 of the experiments. Average daily feed intake increased quadratically (P < 0.05) during both growth phases. Maximum average daily gain (ADG) (0.98 kg) and maximum protein deposition (PD; 170 g/day) were observed in growing pigs fed 100% of the estimated SIDLysR (P < 0.001). During the growing period, PD in BW gain (17% to 19%) and N efficiency (52% to 65%) increased linearly (P < 0.01) with increasing inclusion rates of SID Lys. Finishing pigs had maximum ADG (1.2 kg/day) when they were fed 100% of the requirements. However, the amount of protein in BW gain (13% to 16%) and N efficiency (40% to 55%) increased linearly (P < 0.01) with increasing inclusion rates of SID Lys. In conclusion, the model proposed for precision feeding is correctly calibrated to predict SIDLysR that maximize PD and ADG of average pigs from 25 to 50 kg BW. Still, there is an opportunity to improve the estimation of SIDLysR and N retention in individual pigs by better representing the individual proportion of protein in BW gain and the factors controlling the efficiency of Lys utilization in individual pigs.

177 Influence of the level of dietary digestible Ca on growth performance, bone ash, plasma Ca, and abundance of genes involved in Ca absorption in 11- to 25-kg pigs fed different levels of digestible P

Abstract A 21-d experiment was conducted to test the hypothesis that the Ca requirement to maximize growth performance expressed as the standardized total tract digestible (STTD) Ca to STTD P ratio is less than 1.40:1. The second hypothesis was that increasing dietary Ca increases plasma Ca and downregulates abundance of genes related to Ca absorption (TRPV6 and S100G) and tight junction proteins (OCLN, CLDN1, and ZO1). Twenty corn-soybean meal diets were formulated using a 4 5 factorial design (0.16, 0.33, 0.42, or 0.50% STTD P and 0.14, 0.29, 0.44, 0.59, or 0.74% STTD Ca), and 640 pigs (11.1 ± 1.4 kg) were allotted to the 20 diets in a randomized complete block design. On d 21, weights of pigs and feed left in feeders were recorded and blood, duodenal tissue, ileal mucosa, and the right femur were collected from 1 pig per pen. Abundance of mRNA was determined in duodenum and ileum via quantitative RT-PCR. Data were analyzed using a response surface model by removing the terms in the model that were not significant. Interactions (P &lt; 0.01) between dietary Ca and P for average daily gain (ADG), gain to feed ratio (G:F), and bone ash were observed (Table 1). The predicted maximum ADG (614 g), G:F (0.65), and bone ash (11.68 g) at 0.33% STTD P was obtained at STTD Ca:STTD P ratios of 1.39:1, 1.25:1, and 1.66:1, respectively. There was a linear negative effect (P &lt; 0.05) of Ca on the abundance of S100G, TRPV6, OCLN, and Z01 in the duodenum and on CLDN and ZO1 in the ileum. In conclusion, the STTD Ca:STTD P ratio needed to maximize growth performance of 11- to 25-kg pigs is less than 1.40:1, if P is at the requirement. Increasing dietary Ca reduces transcellular but increases paracellular absorption of Ca.

DYNAMICS OF GROWTH IN THE GOUSES UNDER CONDITIONS OF THE COMBINED PHARMACOPROPHYLACTIC HOMOBIOTICS, PROBIOTICS BASED ON THE RECOMBINANT BASILL AND ENROFLOXACIN STRAIN

The combined effect of homobiotics, probiotics based on recombinant strains of g. Bacillus, &amp; enrofloxacin on the dynamics of body weight gain in geese was studied. According to the principle of steam-analogs, one control and five experimental groups of 10 goslings in each group were formed. Gosyatam experimental groups used homobiotics vetom 15.1; vetom 13.1 incombination with enrofloxacin followed by replacement with a probiotic preparation Vetom 1.2. The absolute body weight and average daily gain in geese under the influence of the studied drugs increases. The severity of the effect depended on the pharmacological composition of the drugs used. The maximum absolute weight gain was observed when using the drugs according to the scheme: vetom 13.1 at doses of 25–50 mg/kg for 16 days, with further use of a 10% enrofloxacin solution at a dose of 0.5 ml/kg for 5 days and in The experiment period was 1.2 at a dose of 50 mg/kg for 16 days. After the cessation of the use of drugs, the growth rate increased for 30 days when prescribing the drugs according to the scheme: veto 13.1 at a dose of 50 mg/kg for 16 days and with further introduction of homobiotic veto 1.2 into the bird in a dose of 50 mg/kg for 16 days. The maximum average daily gain in live weight of geese was observed in the period from the 16th to the 32nd day with the administration scheme: homobiotic vetom 13.1 at a dose of 25 mg/kg of body weight 1 time per day for 5 consecutive days, then every other day for 16 days, then daily 10 % solution of enrofloxacin at a dose of 0.5 ml/kg of body weight for 5 days, then vetom 1.2 at a dose of 25 mg/kg once a day for 16 days in a row. And the maximum average daily gain in the post using period of the drug was observed on the 32ndday of the study according to the scheme: homobiotic veto 15.1 at a dose of 50 mg/kg of body weight 1 time per day for 16 days, then daily with vetom 1.2 at the same dose 1 once a day for 16 days. The studied drugs in the applied doses did not have a toxic effect on the physiological state of geese.

Effect of Soybean Isoflavones on Growth Performance, Immune Function, and Viral Protein 5 mRNA Expression in Broiler Chickens Challenged with Infectious Bursal Disease Virus.

Simple SummaryInfectious bursal disease virus (IBDV) is characterized by inflammation and subsequent atrophy of the bursa of Fabricius and immune suppression. However, nutritional strategies are able to ameliorate the negative effects of viral infections. Therefore, the aim of the present study was to determine the effect of different levels of soybean isoflavones (SI) on broiler chickens challenged with IBDV. Based on the findings, supplemental 10~20 mg/kg SI may have a positive effect on broiler chickens infected with IBDV, probably because SI decrease the severity of bursa lesions and viral protein 5 mRNA expression, and have strong antioxidant activity.A total of 200 one-day-old male broilers were assigned to five groups, and each group consisted of four replicates with 10 birds per replicate. Chicks were fed the basal diet with 0 (non-infected control), 0 (infected control), 10, 20, and 40 mg/kg soybean isoflavones (SI) for 42 days. At 21 days of age, chickens were inoculated with an infectious bursal dose (causing 50% morbidity) of the infectious bursal disease virus (IBDV) BC 6/85 strain by the eye-drop and nasal route (except for the non-infected group). Average daily gain (ADG) and average daily feed intake (ADFI) decreased (p < 0.05) in broilers infected with infectious bursal disease virus (IBDV) from 22 to 42 days. However, infected broilers fed 10 and 20 mg SI/kg had the maximum (p <0.05) ADG and ADFI from 1 to 42 days. Body weight (BW) increased (p < 0.05) in infected broilers fed the 10 and 20 mg SI /kg diet. The bursa weight at 7 days post-infection (dpi) was increased (p < 0.05) by the supplemental 10 mg SI/kg diet. Infected broilers showed the highest (p < 0.05) bursa lesions, with an average score of 4.0 ± 0.0, while the severity of bursa lesions was decreased (p < 0.05) at 3 dpi and 7 dpi by the supplemental 20 mg SI/kg diet. Supplemental SI at 20 mg/kg decreased (p < 0.05) the viral protein 5 (VP5) mRNA expression at 3 dpi and 7 dpi. The level of interferon gamma (IFNγ) was elevated (p < 0.05) in the infected group at 3 dpi and 7 dpi as compared with the control group, while its level was decreased (p < 0.05) by supplemental 10 mg/kg SI at 3 dpi. The level of nuclear factor κB in the bursal tissue showed the lowest value (p < 0.05) with supplemental 10 and 20 mg SI/kg diet at 7 dpi. Supplemental 10, 20, 40 mg/kg SI improved (p < 0.05) the serum total antioxidant activity (T-AOC) in infected broilers at 3 dpi. In addition, the serum level of malondialdehyde (MDA) decreased (p < 0.05) in the group fed 20 mg/kg SI at 7 dpi. In conclusion, supplemental 10~20 mg/kg SI may have a positive effect on broiler chickens infected with IBDV, probably because SI decrease the severity of bursa lesions and viral protein 5 mRNA expression, and have strong antioxidant activity.