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This study aimed to assess the impact of protein supplementation and its interaction with calf sex (CS) on the performance, metabolism and physiology of pregnant beef cows. Fifty‐two multiparous Zebu beef cows carrying female (n = 22) and male (n = 30) fetuses were used. Cows were individually housed from day 100 to 200 of gestation and randomly assigned to restricted (RES, n = 26) or supplemented (SUP, n = 26) groups. The RES cows were ad libitum fed a basal diet (corn silage + sugarcane bagasse + mineral mixture), achieving 5.5% crude protein (CP), while SUP cows received the same basal diet plus a protein supplement (40% CP, at 3.5 g/kg of body weight). All cows were fed the same diet during late gestation. Differences were declared at p < 0.05. No significant interaction between maternal nutrition and calf sex was found for maternal outcomes (p ≥ 0.34). The SUP treatment increased the total dry matter (DM) intake (p ≤ 0.01) by 32% and 19% at mid‐ and late‐gestation respectively. The total tract digestibility of all diet components was improved by SUP treatment at day 200 of gestation (p ≤ 0.02), as well as the ruminal microbial CP production (p ≤ 0.01). The SUP treatment increased (p ≤ 0.03) the cows' body score condition, ribeye area, the average daily gain (ADG) of pregnant components (PREG; i.e., weight accretion of cows caused by pregnancy) and the ADG of maternal tissues (i.e., weight accretion discounting the gain related to gestation) in the mid‐gestation. The SUP cows exhibited a lower maternal ADG (p < 0.01) compared to RES cows in late pregnancy. There was a 24% additional gain (p < 0.01) in the PREG components for SUP cows during late gestation, which in turn improved the calf birthweight (p = 0.05). The uterine arterial resistance and pulsatility indexes (p ≤ 0.01) at mid‐gestation were greater for RES cows. In conclusion, protein supplementation during mid‐gestation is an effective practice for improving maternal performance, growth of the gravid uterus and the offspring's birth weight. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of Vitamin A (VA) injection on the growth performance and carcass traits of Nellore × Angus crossbred steers and heifers. For that, the same sire inseminated Nellore cows from two artificial insemination (AI) groups were randomly assigned to one of three treatments at 250 d of gestation: no VA injection (Control); VA injection in pregnant cows at 250 d of gestation (VAcow; 2,000,000 IU single dose); VA injection in newborn calves at birth and 60 d of age (VAcalf; 200,000 IU each dose). Cowcalf pairs were kept in the same paddock, and calves received creep-feeding supplementation from 90 d of age to weaning. After weaning, steers and heifers [n = 36; body weight (BW) 213 ± 25.7 kg] were stratified by treatment and BW and allotted into 16 pens. After 207 d of feeding (77 d of growing diet + 130 d of finishing diet), steers and heifers were slaughtered at a commercial abattoir. Data were analyzed using the MIXED procedure of SAS 9.4 with fixed effects of VA injection, sex, and VA injection*sex interaction. The random effects were animal, AI group, and cow parity. Average daily gain before weaning ( P < 0.01) and final BW in the finishing phase were greater ( P = 0.04) in VAcow steers compared with heifers from all treatments (Table 1). Vitamin A had a positive impact on weaning BW of male calves and a negative impact on heifers ( P < 0.01). There was no treatment difference ( P = 0.35) in feedlot average daily gain (ADG), but steers had greater ( P = 0.03) ADG compared with heifers. Moreover, VAcow steers had greater dry matter intake (DMI) in the feedlot ( P = 0.04) compared with other treatments, and there was no effect of VA on DMI of heifers. On the other hand, feedlot feed efficiency tended to be greater (P = 0.07) in Control steers compared with other treatments, with no VA effect on heifers too. The ribeye area was greater ( P = 0.04) in VAcow steers than in Control steers and heifers from all treatments. Intramuscular fat content was greater ( P = 0.04) in VAcow steers than in Control and VAcalf steers. However, there was no effect of VA on heifers and VAcow steers. In addition, VAcow treatment tended ( P = 0.08) to increase backfat thickness. In conclusion, VA injection in pregnant cows can be a strategy to improve marbling in steers, but there is no effect on intramuscular fat in heifers. Additionally, VA injection in pregnant cows produced intramuscular content in beef of steers, similar to heifers. [ABSTRACT FROM AUTHOR]

The potential for increasing the productivity in cow-calf operation has gained wide acceptance in the last decade among Brazilian farms. Our objectives were to assess the impacts of providing supplementation to pregnant beef cows during the dry grazing period on cow and calf performance. During a 2-yr period, Tabapuã cows (n = 36) were blocked by parity and body weight (BW), and randomly assigned to pastures at the beginning of the rainy season. Brachiaria pastures were assigned to receive i) no application of N and cows were supplemented with mineral mix (CON), ii) application of 165 kg of N ha-1. yr-1 and cows supplemented with a commercial product containing 40% of CP, macro and micro minerals, and vitamins (SUP), or iii) application of 165 kg of N ha-1. yr-1 and cows supplemented with grass silage (GS). For SUP system, one-half of the paddocks were deferred in late summer. For GS system, one-half of the paddocks were deferred in early summer and silage was made after 90 d of regrowth. During silage making, 21% of DDGs on a dry matter (DM) basis was mixed into grass. After silage harvesting, the area was differed again. At the beginning of the dry period, deferred areas had free access to animals for SUP and GS treatments. The commercial supplement and silage were fed for 140 d (from 116 ± 27 to 256 ± 27 d of gestation). The mineral mix was offered all year round. The PROC MIXED procedure of SAS was used to analyze all variables. The statistical model included supplementation program as a fixed effect. Block, paddock, and year were included as random variables. Initial BW, initial body condition score (BCS), and gestation period of cows were included as covariates. Initial BW and BCS, and final BW and BCS did not differ among treatments. The GS treatment provided the greatest average daily gain (ADG) during prepartum (0.49 kg/d) than CON and SUP strategies (an average of 0.37 kg/d). Whereas ADG during postpartum was not altered by treatments. Considering the full cycle (prepartum and postpartum), supplementation strategies did not affect ADG and BCS. No differences were obtained for birth weight, weaning weight, and ADG in calves. Overall, the supplementation programs adopted in this study did not influence individual gains in both cow and calf. However, BW gain per area may be altered, since supplementation increases stocking rate. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the influence of snaplage on fecal characteristics, feeding behavior, and performance in fishing bulls. Seventytwo single-sourced Nellore bulls (initial shrunk BW = 400 ± 27.4 kg) were randomly assigned to 1 of 3 treatments (3 bulls per pen; 8 pen replicates per treatment). Treatments consisted of finishing diets with the following sources of fiber and energy: 1) corn silage, reconstituted corn grain silage, and dry-ground corn (CONTROL), 2) snaplage (inclusion of 65% of DM) and dry-ground corn (SNAP65), and 3) snaplage only (inclusion of 85% of DM; SNAP85). All diets contained the same inclusion of soybean meal, cotton meal, urea, and mineral mix. Diets were formulated using NASEM (2016) to provide an ADG of 1.8 kg/d. Bulls were adapted to the finishing diets over a 15-d period and fed for a total of 86 d. Fecal samples were collected on d 42, 65, and 73. Feeding behavior was assessed on d 51 and 69. Statistical analysis of experimental data was performed using the MIXED procedure of SAS 9.4. An α of 0.05 determined significance and an α of 0.06 to 0.10 was considered a tendency. No differences were obtained for initial BW, G:F, hot carcass, and dressing. SNAP85 had a greater intake, followed by SNAP65 and CONTROL diets (P = 0.02). There was a tendency of greater ADG and final BW (P = 0.07 and 0.08, respectively) for SNAP65 diets (2.0 kg/d and 572 kg), followed by SNAP85 (1.95 kg/d and 567 kg) and CONTROL (1.85 kg/d and 558 kg). A tendency (P = 0.07) was also observed for greater ribeye area in bulls consuming SNAP65 (85 cm²), followed by CONTROL (81 cm²), and SNAP85 (77 cm²). Bulls consuming SNAP65 and SNAP85 spent more time chewing (on average, 249 min/d) than those consuming CONTROL diets (177 min/d; P = 0.01). Regarding fecal characteristics, pH and fecal starch were greater for SNAP85 (P = 0.01 for both variables). Overall, snaplage is a suitable ingredient for high-starch diets for providing energy and physically effective fiber. The inclusion of 65% of snaplage and 20% of dry-ground corn (DM basis) showed a slight superior performance in Nellore bulls. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effects of two total mixed ration (TMR) silages (low and high rumen undegradable protein; RUP) on digestibility, blood parameters, and performance in pregnant beef cows. Thirty-three mid-gestation (~130 d of gestation) Tabapua beef cows were randomly assigned to 1 of 2 treatments: 1) a TMR silage containing Brachiaria grass, soybean hulls, urea, and mineral mix (low RUP; n = 16) or 2) a TMR silage containing Brachiaria grass, DDG, and mineral mix (high RUP; n = 17). The concentration of A1 fraction was, on average, 12.9% and 34.0% of N in low and high RUP silages, respectively. A preservative with a blend of organic acids, surfactants, and activated propionates was applied in both silages. Pressed bag silos were used to conserve silages for 7 wk. Cows were housed in individual pens for 100 d. During a 4-d digestion period (at 50 d of housing), fecal samples were collected for measurement of nutrient digestibility using undigested neutral detergent fiber as a marker. Blood parameters were collected at the last day of housing. Statistical analysis of experimental data was performed using the GLM procedure of SAS 9.4. Diet, calf sex (male or female), and interactions between these factors were considered fixed effects. No differences were obtained for initial BW. High RUP diet showed greater final BW (P = 0.0004) and ADG (P = 0.0003). Cows fed high RUP gained 50 g/d, while cows fed low RUP diet lost 445 g/d. Dry matter intake was greater by 23% (P < 0.0001) in cows consuming high RUP silage. Dry matter, CP, and NDF digestibility did not differ between treatments. Regarding blood parameters, no differences were observed for glucose at 0 h and 4 h post-feeding. Plasma urea at 0 h post-feeding was greater in cows fed low RUP silage (P = 0.0003). However, no differences were observed for plasma urea at 4 h post-feeding. The plasma concentrations of non-esterified fatty acids (P = 0.017) and beta-hydroxy-butyric acid (P = 0.002) were greater in cows consuming low RUP diet. Overall, feeding pregnant cows during mid-gestation with TMR silage containing high RUP promotes greater performance. [ABSTRACT FROM AUTHOR]

We hypothesized that diets with snaplage would increase the expression of lipogenic genes, resulting in higher marbling fat content, compared to a diet of whole-plant silage and reconstituted corn silage. Therefore, the objective of this study was to analyze the chemical composition, as well as the expression of genes involved in lipid metabolism and liver gluconeogenesis of Nellore bulls fed snaplage. Seventy-two Nellore bulls (24 months, initial body weight 400 ±27.4 kg) were used in a completely randomized design. Animals were stratified by body weight, housed in 24 pens (3 animals per pen), and designed to one of the three treatments (8 pens per treatment). Experimental diets (around 14% of crude protein) were: control (corn silage, ground and reconstituted corn grain, protein sources), snaplage + ground corn, replacing completely corn silage (SNAP65, with 65% snaplage), and snaplage 85, replacing completely corn silage and corn grain (SNAP85, with 85% snaplage). Data were analyzed using MIXED procedure of SAS 9.4 with fixed effects of dietary treatment, and random effects of pen nested within treatment. Overall, diets did not affect (P>0.11) the intramuscular fat. However, animals fed SNAP85 showed higher PPARG expression (P=0.03). The muscle of animals fed snaplage (SNAP65 and SNAP85) also had higher expression of ACACA and SCD1 genes (P=0.03) than the control animals. The FABP4 expression tended to be higher (P=0.10) in the muscle of animals fed SNAP85 compared with SNAP65. In addition, animals fed control diet tended to have higher (P=0.07) expression of PC in the liver compared with animals fed SNAP65 and SNAP85. Also, PEPCK2 expression was lower (P=0.05) in in the liver of animals fed SNAP65 diet than control SNAP85. We conclude that diets with snaplage increased the expression of genes involved in the muscle lipogenesis, without increase intramuscular fat. [ABSTRACT FROM AUTHOR]

The objective was to evaluate the effects of dietary forage inclusion during finishing on growth performance, feeding behavior, and ruminal fermentation in steers at risk for acidosis. Angus × Simmental steers (n = 240; body weight = 350 ± 58 kg) were blocked by body weight and allotted into 18 pens. Feeding behavior was collected and analyzed from the initial 45 d steers were fed a high-moisture corn-based finishing ration in GrowSafe bunks to determine steers (20%) at greatest risk for developing acidosis. The at-risk steers (n = 48) were utilized in a randomized complete block design. Steers were stratified by initial body weight within block and assigned to 8 pens of 6 steers. Pens were randomly assigned to 1 of 2 dietary treatments: (1) 15% (15CS) or (2) 30% corn silage (30CS) on a dry matter basis where corn silage replaced high moisture corn in the finishing diet. Overall body weight, average daily gain, dry matter intake, and gain:feed were not affected (P = 0.19) by treatment. Carcass characteristics were not affected by treatment (P = 0.39). Steers consuming 30CS had greater (P = 0.05) meal frequency and eating rate, as well as decreased meal length, from d 0 to 112. Fluctuations in dry matter intake during the final 56 d of finishing were not affected by treatment (P = 0.20). Ruminal pH was collected prior to feeding and tended to exhibit a treatment × day effect (P = 0.05) with 30CS steers having increased ruminal pH on d 56 and 112. No treatment × day effect was observed for molar proportions of acetate, propionate, and butyrate (P = 0.11) in ruminal fluid. Overall, increasing dietary forage during finishing altered feeding behaviors and ruminal fermentation in steers at risk for acidosis, but did not affect growth performance. [ABSTRACT FROM AUTHOR]

This study determined the effectiveness of two Lactobacillus buchneri strains (commercial and indigenous) and sodium benzoate ( SB) in improving the aerobic stability of corn silage under laboratory and field conditions. Two experiments were carried out to test the following treatments: untreated forage, commercial L. buchneri ( CLB), indigenous L. buchneri ( ILB) and SB at a 2 g kg−1 concentration. Both inoculants were applied at a rate of 1 × 106 colony forming units of bacteria per gram of forage. In experiment 1, five replicates of each treatment were ensiled in 15-L laboratory silos. The nutritional, fermentation and microbiological characteristics and aerobic stability of the silage were determined. In experiment 2, the top of a bunker silo was divided into four parts (blocks) along its length before it was sealed, and the treatments were randomly applied. Three bags were buried in each experimental unit (two at the top and one at the core) to determine the loss of dry matter ( DM) and the silage characteristics. In experiment 1, ILB exhibited a lower lactic acid concentration and higher 1,2-propanediol and acetic acid levels, which provided intermediate aerobic stability (67 h). In both experiments, treatment SB exhibited higher residual water-soluble carbohydrate levels and longer aerobic stability relative to the other treatments. In experiment 2, there were lower DM losses and higher digestibility coefficients when SB was applied, similar to that found at the core. Overall, SB was the most effective additive for improving fermentation, preserving nutrients and reducing the aerobic deterioration of corn silage at the top of a bunker silo in a hot-climate environment. [ABSTRACT FROM AUTHOR]

Gestating cows have an increased nutrient demand to meet the needs of developing the fetus and the midgestation is a critical period for the fetal skeletal muscle development. The aim of this study was to evaluate the skeletal muscle transcriptome in the progeny as a function of the maternal protein nutrition during mid-gestation. Eleven Tabapuã cows and their male calves were used in this study. In the first third of gestation (0 to 100 days of gestation; dg), all cows were kept on pasture. From 100 to 200 dg, the control group (CTRL; 7 animals) received a basal diet achieving 5.5% crude protein (CP), whereas the supplemented group (SUPPL; 4 animals) received a basal diet plus protein supplementation (40% CP). After 200 dg, all animals received the same diet. Weaning was performed at 205 ± 7.5 days of age and animals were kept on pasture until reaching 240 days of age, when they were transferred to a feedlot. Muscle samples were collected at 260 days of age and RNA was extracted for RNA-seq analysis. Gene expression data was analyzed with a negative binomial model to identify (q-value = 0.05) differentially expressed genes (DEG) between treatments. A total of 716 DEG were identified (289 DEG up-regulated and 427 down-regulated in SUPPL group; q-value = 0.05). From the 10 most significant down-regulated DEG in the SUPPL group, two genes associated with apoptotic process were identified: MAPK8IP1 and GRINA, with log2 Fold-Changes (log2FC) of 1.04 and 0.49, respectively. From the 10 most significant up-regulated DEG in the SUPPL group, mTOR was identified, with log2FC=0.31. This is a well-known gene involved in muscle protein synthesis. In conclusion, maternal protein supplementation during mid-gestation affects the expression of genes related to energy metabolism and muscle development, which can lead to long-term impacts on production efficiency. [ABSTRACT FROM AUTHOR]

The snaplage residue presents itself as a potential alternative roughage source in finishing systems, owing to its high fiber concentration which aids in maintaining rumen health. Nevertheless, the performance of animals will hinge on both the allowance and the nutritive value it offers. This study aimed to evaluate different stocking rates of heifers grazing snaplage residue as an exclusive source of fiber on finishing phase performance. The treatments included two stocking rates (SR): i) low stocking rate (LS; 3.5 AU/ha) and ii) high stocking rate (HS; 7.0 AU/ha), which were obtained by modifying the size of the paddocks. Crossbred beef heifers ( n  = 48; initial body weight = 276 ± 23 kg) were assigned to 16 paddocks (3 heifers/paddock). The concentrate (87% of corn, 3.5% of soybean meal, 3.9% of cottonseed meal, 1.2% of urea, and 4% of mineral; DM basis) was fed ad libitum daily at 0600 hours. Data were analyzed using the MIXED procedure of SAS. There was no SR × time effect ( P  = 0.88) on residue mass. There was less ( P  < 0.01) total residue mass for HS than LS, and total mass decreased ( P  < 0.01) over time. There was no SR × time effect ( P  ≥ 0.16) for behavior characteristics. There was no difference between HS and LS for average residue intake ( P  = 0.34; 0.44 vs 0.48 kg/d, respectively), concentrate intake ( P  = 0.84; 7.72 vs 7.78 kg/d, respectively), and daily gain (ADG; P  = 0.94; 0.95 vs 0.95 kg/d, respectively), The HS treatment increased ( P  < 0.01) gain per area (618 vs 309 kg/ha) compared to LS. No differences between SR were observed for carcass characteristics ( P  ≥ 0.12 ). The meat's chemical composition was not different ( P  ≥ 0.37) between treatments. Overall, the snaplage residue stocking rate did not affect the finishing phase performance of beef heifers, but the greater stocking rate (7.0 AU/ha) increased gain per land area., Competing Interests: The authors declare no conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science.)