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The DNA methylome of spermatozoa results from a unique epigenetic reprogramming crucial for chromatin compaction and the protection of the paternal genetic heritage. Although bull semen is widely used for artificial insemination (AI), little is known about the sperm epigenome in cattle. The purpose of this review is to synthetize recent work on the bull sperm methylome in light of the knowledge accumulated in humans and model species. We will address sperm-specific DNA methylation features and their potential evolutionary impacts, with particular emphasis on hypomethylated regions and repetitive elements. We will review recent examples of interindividual variability and intra-individual plasticity of the bull sperm methylome as related to fertility and age, respectively. Finally, we will address paternal methylome reprogramming after fertilization, as well as the mechanisms potentially involved in epigenetic inheritance, and provide some examples of disturbances that alter the dynamics of reprogramming in cattle. Because the selection of AI bulls is closely based on their genotypes, we will also discuss the complex interplay between sequence polymorphism and DNA methylation, which represents both a difficulty in addressing the role of DNA methylation in shaping phenotypes and an opportunity to better understand genome plasticity.
Nutrition is one of the main factors influencing physiological processes, e.g., growth and antler development, in Cervidae. The aim of this study was to demonstrate a possible effect of supplementation with different levels of calcium (Ca) and phosphorus (P) on the mineral composition of antlers and bones, and its effect on the content of macroelements — Ca, potassium (K), magnesium (Mg), sodium (Na), and P — in the muscle tissue, liver, and blood of farmed fallow deer fawns. The results show a positive effect of increased doses of Ca and P on body weight at the age of 14 mo. Additionally, there was a significant increase in the content of Ca, Mg, Na, and P in antlers and Ca, Na, and P in bones. The muscle tissue was characterised by a significant increase only in the content of Na, whereas Ca, K, and P levels increased significantly in the liver. In turn, the serum P content decreased significantly. Adequate Ca and P supplementation exerts a positive effect on the mineral composition of bones and whole antlers of farmed fallow deer fawns, and it enhances the concentrations of macroelements in tissues, which may constitute a reservoir used for future development of antlers. It also has a positive effect on body weight.
Effect of timing of xylanase supplementation to weanling pigs and its effect on growth performance, nutrient digestibility, and fecal microbiota was investigated. A total of 128 weanling pigs [(Hampshire × Duroc) × (Yorkshire × Landrace); 6.2 ± 0.6 kg body weight (BW); weaning age: 21 d] were assigned to four treatments, with eight replicate pens and four pigs per pen. Treatments were a combination of two dietary treatments (without or with xylanase) in two periods; (period 1, days 0–14) and period 2 (days 14–42): xylanase–xylanase, xylanase–control, control–xylanase, and control–control. Fecal microbiota diversity and apparent total tract digestibility (ATTD) were determined. From days 0–14, pigs had lower (P < 0.01) BW, average daily gain (ADG), and feed efficiency when xylanase was included in the diets. The final BW (P < 0.05) and overall ADG (P < 0.02) at day 42 were greater when xylanase was supplemented from day 14 compared with supplementation from day 0. The apparent ileal digestibility and ATTD of dry matter, gross energy, nitrogen, and phosphorus were increased (P < 0.05) by xylanase. Xylanase significantly decreased (P < 0.05) the relative abundance of Veillonella spp. and tended (P = 0.08) to decrease the relative abundance of Megasphaera spp. in period 2 compared with the non-supplemented group.
Chickens under appropriate light–dark programs can develop diurnal rhythms. However, actual needs of layer pullets for the light and dark environments are not fully understood. This study was to investigate the diurnal rhythms of pullets in the light (30 lx) and dim (<1 lx) environments. The preferences of pullets on the light and dim environments were examined. The testing system contained four identical compartments (0.96 m length × 1.20 m width × 2.00 m height for each). A light-emitting diode tube, a camera, and weighing sensors were installed in each compartment. Four groups of eight Chinese domestic layer pullets, Jingfen, were used at the weeks 15–18. Choices of environments and feeding behaviors were monitored by weighing sensors, and activity was measured by digital image processing. The results show that pullets spent on average 35.5 ± 2.2 min under the light and 24.5 ± 2.1 min under the dim in each hour. Human inspection can stimulate bird feeding and activity. Overall, pullets behaved more actively under the light than under the dim environment. Pullets stayed in the light and dim environments throughout each hour of a day, which may suggest that lighting environments with free choices in a pullet house might better serve for pullet preference.
Decades of selection for increased litter size has caused a proportion of sows to consistently produce low birth weight (LBW) litters resulting in economic loss for producers due to reduced piglet survivability and growth. We hypothesized that piglets from LBW litters would have altered gut microbial composition, intestinal architecture, and intestinal transcriptomic profiles compared with piglets from high birth weight (HBW) litters. Sows were designated LBW (n = 45) or HBW (n = 46) based on litter birth weights of three successive parities. LBW piglets were 22% lighter (P < 0.001) at birth; however, no longer differed (P > 0.05) in weight at weaning compared with HBW piglets. LBW piglets had reduced (P < 0.05) fecal microbial diversity with a 114% increase in fecal Enterobacteriaceae (P < 0.05), as well as reduced (P < 0.05) abundance of cecal Roseburia and Faecalibacterium, fiber-degrading butyrate producers. Several genes associated with metabolic (PER2, CES1, KLHL38, and HK2) and immune pathways (IL-1B, IRF8, and TNIP3) were differentially expressed, suggesting altered metabolic and immune function in LBW piglets. In conclusion, LBW piglets had potentially unfavorable shifts in microbial structure in comparison to HBW piglets accompanied with alterations in metabolic and immune gene expression. Results indicate some biological consequences linking LBW phenotype to changes in production efficiency later in life.
Responses of growth performance, gut morphology, blood biochemistry, and quality of breast meat to varying lengths of water deprivation were assessed. Ninety broilers were randomly allocated to water deprivation treatments, where water was either supplied ad libitum (0 h) or for 30 min at intervals of 6, 12, 18, and 24 h. Average daily feed intake (ADFI) and gain (ADG) were estimated weekly. Six birds from each treatment were randomly slaughtered. The duodenum, jejunum, and ileum were sectioned to determine gut morphology. Breast meat muscles (pectoralis major) were sampled to determine its physicochemical properties. There were linear decreases in ADG (P < 0.01) and ADFI (P < 0.05), crypt depth (P < 0.01) and crypt width (P < 0.05) in the jejunum, villus height (VH) (P < 0.01) and total mucosa thickness (P < 0.05) in the ileum, crude fat (P < 0.05), b*0 (yellowness at 0 h), a*24 (redness at 24 h), and L*24 (lightness at 24 h) (P < 0.01), and aspartate aminotransferase enzyme (P < 0.05) with increases in length of water deprivation. Positive quadratic responses of VH in the duodenum (P < 0.01) and jejunum (P < 0.05) were observed after 7.6 and 19.4 h of water deprivation, respectively. Severe water deprivation periods reduced growth performance, but induced positive growth of VH, suggesting that broilers may adapt to water stress. The appropriate length of water deprivation was 7.64 h.
The effects of ingestion of antibiotics on the microbiome of the young calf are not well understood. The objective of this study was to evaluate the effect of feeding milk containing pirlimycin on the prevalence of antibiotic resistance genes in the fecal microbiome of dairy calves using a metagenomic approach. In this study calves were assigned to either pasteurized whole milk (control; n = 5) or pasteurized whole milk containing 0.2 mg L-1 of pirlimycin (treatment; n = 5). Fecal samples were collected on days 1, 42, and 84. Functional analysis of DNA via metagenomic rapid annotations using subsystems technology revealed that pirlimycin had no effects on abundance of sequences coding for different cell functions except in the “phage, prophage, and transposable elements” category. Evaluation of the major antibiotic resistance types in samples via annotation against the Comprehensive Antibiotic Resistance Database analysis showed no difference between the two groups. The results of this study will help assess the risk of use of antibiotics in animal agriculture and increase our understanding of how antibiotics present in waste milk affects both calves and their manure, and will lay the groundwork for future research on manure treatment or other strategies to minimize any negative impacts.
Seal by-products (grey seal with the bone in, grey seal with the bone removed, and harp seal) were subjected to five different processing methods: high (100 °C) and low (45 °C) temperature oven-drying, freeze-drying (FD), silage by acid or natural fermentation. Growth performance of diets containing these seal by-products was evaluated in rats as a monogastric model species. With the exception of naturally fermented grey seal without bone, weight gains for rats fed the boneless grey seal products were highest of the seal products (24.65–30.04 g rat-1) and statistically similar to those of rats fed casein (32.15 g rat-1). An in vivo crude protein (CP) digestibility study was conducted using 12 adult white rats in metabolic cages that allowed separate collection of urine and feces. The 16% CP diets contained chromic oxide as an inert fecal marker at 0.5%. Total fecal and urine production, as well as feed and water intake, were recorded daily within the three experimental periods. Digestibility of CP was significantly higher for the naturally fermented grey seal without bone silage (94.0%) than casein (89.0%), whereas the other seal products were statistically similar (91.7%–92.7%). The CP content of FD grey seal was as high as 91.7% (FD). Seal by-products have the potential to be used as alternative high-protein feedstuffs in monogastric diets.
Leukemia inhibitory factor (LIF) is an important productivity-related gene in pigs. We found two polymorphisms — g.6646C>T and g.6988C>T — in exon 3 of LIF in pigs by using DNA sequencing and polymerase chain reaction-restriction fragment length polymorphism. Three genotypes were obtained and associated with litter size traits in Anqing Six-end-white (AQ), Wei (W), Wannan Black (WNB), and Large White (LW) pigs. At locus g.6646C>T, the g.6646C allele frequency variation was 0.6869 (AQ), 0.7473 (W), 1 (WNB), and 0.6852 (LW). In AQ pigs, sows with the TT genotype had higher total number of piglets born (TNB) and number of piglets born alive (NBA) in the first parity and multiparities (P < 0.01). In W and LW pigs, sows with the CC genotype had higher TNB and NBA in multiparities (P < 0.01). At locus g.6988C>T, the g.6988C allele frequency variation was 1 (AQ), 0.6154 (W), 1 (WNB), and 0.6667 (LW). The CC genotype significantly differed from CT or TT genotypes (P < 0.01) for TNB and NBA in W and LW pigs. Thus, LIF was shown to have a significant influence on litter size. Therefore, g.6646C>T and g.6988C>T loci of LIF could be potential marker-assisted selection tools for improving litter size in pig production.
The objective of this study was (i) to analyze antibiotic residues, two which were beta-lactam antibiotics, one tetracycline, and one quinolone in the milk of lactating animals; (ii) to evaluate the interference of the drug ceftiofur which is considered as discard-zero. The SNAPduo™ ST Plus kit was used to evaluate the presence of beta-lactam antibiotics and tetracyclines in natural milk. Medications based on penicillin, ceftiofur, enrofloxacin, and oxytetracycline were used. As expected, the milk from control animals and animals administered with enrofloxacin did not present antibiotic residue because it is not one of the classes detected by the SNAPduo™ ST Plus kit, and thus it was used to prove the efficiency of the test. Ceftiofur, known as a “discard-zero” antibiotic, tested positive for the SNAPduo™ ST Plus kit and the BetaStar Combo® “S” test. Chemical residues were detected in cow’s milk treated with different groups of antibiotics after the withdrawal time indicated in the package inserts of the medicines used.
This study was conducted to determine if artificial neural networks (ANN) can be used to more accurately predict physiological stress responses in goats compared with statistical regression. Prediction models were developed for plasma cortisol and glucose concentrations, creatine kinase (CK) activity, neutrophil (N) and lymphocyte (L) counts, and N:L ratio as a function of time (0, 1, 2, 3, and 4 h; n = 16 goats per time) after a 2.5 h transportation (input 1) and stocking density (25 vs. 50 goats; input 2). However, input 2 was not included in the final models because density did not have a significant effect. The NeuralWorks Predict® software and SAS were used to develop ANN and regression models, respectively. Backpropagation (BP) and Kalman filter (KF) learning rules were used to develop nonparametric models. Correlations between predicted and observed values were better with ANN-BP (R values = 0.87, 0.67, 0.56, 0.27, 0.42, and 0.53) and ANN-KF (R values = 0.84, 0.67, 0.58, 0.27, 0.42, and 0.50) models for cortisol, glucose, CK, N, L, and N:L ratio, respectively, than with regression models (R values =0.85, 0.52, 0.27, 0.13, 0.31, and 0.12). The results showed that the ANN models can predict responses more robustly compared with statistical regression.
The objective was to evaluate the effects of dietary mannan and β-mannanase supplementation on growth performance and serum acute-phase proteins in nursery pigs. Pigs (n = 480) were blocked by initial body weight (6.6 ± 0.4 kg), and 12 pens per treatment were randomly assigned to one of four treatments in a 2 × 2 factorial arrangement for 28 d. Two levels of dietary mannan (0.4% vs. 2.8%) were offered with and without 0.05% endo-1,4-β-mannanase. Serum was collected (one pig per pen) for haptoglobin and C-reactive protein (CRP) analysis on days 0 and 28. There were no significant interactions between mannan level and β-mannanase supplementation. High-mannan diet decreased average daily gain (P = 0.027) and average daily feed intake (P = 0.024) compared with low-mannan diets with no effect of β-mannanase (P > 0.10). Haptoglobin and CRP were not affected by mannan level or β-mannanase supplementation (P ≥ 0.160). Therefore, dietary β-mannans as high as 2.8% did not induce a systemic innate immune response. Thus, the levels of β-mannan found in practical diets (<2%) are unlikely to induce an immune response; therefore, supplementation of β-mannanase to avoid this response is not warranted.
The objective of this study was to test a diet enriched in the most abundant components of foot fat pads (oleic and palmitic acid) to increase its thickness in gilts. We evaluated the effects of two oleic and palmitic acid dietary concentrations (control and test) and three treatment durations (35, 45, and 65 d) on 116 gilts (Landrace × Large White), all 180-d-old and slaughtered at the end of the study. Both test and control diets contained 5.9% total fat. The control diet contained 0.9% oleic acid and 0.6% palmitic acid; the test diet contained 1.9% and 1.2%, respectively. Body weight (BW), backfat (BF), lateral, and medial plantar pad thickness from the left rear leg were measured. No significant differences were detected for BW or BF between the test and control groups. The lateral pad was always thicker than the medial one (P < 0.001). No significant difference for plantar pad thickness was detected for the 35 d treatment. For the other treatments, thickness increased with respect to the control group (P < 0.01); the percentage of increase ranged from 20.8% (lateral side, 45 d treatment) to 37.8% (lateral side, 65 d treatment). Its effects on foot health must still be demonstrated.
This study was conducted to evaluate the effect of carbohydrases on growth performance, nutrient digestibility, blood profiles, and fecal microbiota in weanling pigs fed reduced energy diet. A total of 160 crossbred [(Yorkshire × Landrace) × Duroc)] weanling pigs with an initial body weight (BW) of 7.23 ± 1.08 kg were used in this 42 d trial. Pigs were randomly allocated in one of the following four dietary treatments: (1) CON, basal diet [net energy (NE) 2545 kcal kg-1]; (2) LE, low-energy diet (NE 2470 kcal kg-1); (3) LEC1, LE + 0.1% carbohydrase; and (4) LEC2, LE + 0.2% carbohydrase based on the sex and BW. There were eight replications (pens) per treatment with five pigs (two male and three female) per pen. During day 0–7, pigs fed with LE diet had lower (P < 0.05) average daily gain (ADG) and average daily feed intake than those fed with CON and LEC2 diets. LE group reduced (P < 0.05) ADG throughout the experiment compared with CON and LEC2 groups. LE group reduced (P < 0.05) the digestibility of dry matter, nitrogen, and gross energy compared with LEC2 diet. Taken together, LE diet caused detrimental effects on growth performance and nutrient digestibility in weanlings, whereas the addition of carbohydrases (0.2%) partially counteracted these negative effects.
This study was conducted to evaluate the effect of supplementation of different flavors (apple and anise) on growth performance, nutrient digestibility, blood profiles, and carcass quality in growing–finishing pigs. A total of 96 growing pigs [(Yorkshire × Landrace) × Duroc] with an average body weight (BW) of 28.2 ± 0.7 kg were randomly assigned to one of the following three treatments: (1) CON, basal diet; (2) APF, basal diet + 0.05% apple flavor; (3) ANF, basal diet + 0.05% anise flavor, according to their BW and sex in this 15 wk experiment. There were eight replications (pens) per treatment and four pigs per pen (two barrows and two gilts). During week 0–5, pigs fed ANF diets had greater (p < 0.05) average daily gain (ADG) and average daily feed intake than those fed CON and APF diets. Dietary ANF treatment increased (p < 0.05) ADG during 0–15 wk compared with CON treatment. At the end of 5 wk, the apparent total tract digestibility of nitrogen in ANF treatment was improved (p < 0.05) compared with that in CON treatment. Dietary treatments did not affect the studied traits of carcass and meat quality. The inclusion of anise flavor increased ADG, but apple flavor had no effect on growth performance in growing–finishing pigs.
Zhiqiang Jiu, Bimol C. Roy, Chamali Das, Wendy V. Wismer, Manuel Juárez, Carolyn Fitzsimmons, Changxi Li, Graham Plastow, Jennifer L. Aalhus, Heather L. Bruce
Effects of residual feed intake (RFI) and genetic group on growth, carcass, and meat quality characteristics of bovine longissimus lumborum (LL), triceps brachii (TB), semimembranosus (SM), and gluteus medius (GM) muscles were investigated using 72 purebred Angus, purebred Charolais, and Angus crossbred steers (n = 24 per genetic group) classified as either high (inefficient) or low (efficient) RFI (n = 12 high and low RFI steers within genetic group). There was no RFI effect (P > 0.05) on growth, carcass, and meat quality measurements except high RFI steers had the highest dry matter intake (P < 0.05), and low RFI TB was rated as having reduced beef flavour intensity and sustained juiciness (P < 0.05). Purebred Angus and Charolais LL and GM had lower shear force values (P < 0.05) than Angus crossbreds and ageing reduced mean shear force values except in TB. For TB, SM, and GM, Angus crossbred steers had the highest mean beef flavour intensity scores, and Charolais SM and TB were less tender than those of Angus crossbred (P < 0.05). Overall, RFI did not influence most meat quality traits; therefore, low RFI animals may contribute to reducing feed costs or environmental impact without compromising meat quality and palatability.
The aim of this study was to investigate the alteration in growth performance and lipid metabolism during the development of yellow fat in pigs. A total of 30 pigs (9.23 ± 0.21 kg) were assigned to three treatments: (1) low fish oil (LFO), basal diet + 2% fresh fish oil; (2) high fish oil (HFO), basal diet + 8% fresh fish oil; and (3) oxidized fish oil (OFO), basal diet + 8% OFO (peroxide value = 250 meqO2 kg-1). Pigs fed HFO and OFO diets showed yellow staining of fat and decreased growth performance, including average daily gain, average daily feed intake, and final body weight (P < 0.01). The oxidized lipid markers malondialdehyde, yellowness b* of backfat, perirenal fat, and abdominal fat were markedly increased in the pigs fed with HFO and OFO (P < 0.05). Furthermore, following HFO feeding, pigs showed significant decreases in n-6 polyunsaturated fatty acid, n-6/n-3 polyunsaturated fatty acid ratio and mRNA expression levels of CCAAT-/enhancer-binding protein alpha, fatty acid synthase, lipoprotein lipase, and hormone-sensitive lipase in backfat (P < 0.01). Overall, pigs with yellow-fat trait showed decreased growth performance and altered lipid metabolism by the high fish oil feeding.
The aim of this study was to determine the effect of heat treatment alone or in combination with the addition of lignosulfonate (LSO3) on canola cake protein, lysine, and methionine degradation in the rumen. Cold-pressed canola cake was left untreated, heated at 90, 110, 130, or 150 °C, or processed with 5% of LSO3 (in dry matter) and then heated. Effective rumen degradability of crude protein (CP), lysine, and methionine was less for treated than untreated canola cake (P < 0.05) and decreased with increased temperature of heating, but particularly when canola cake was heated at 150 °C (quadratic, P < 0.01). In general, effective rumen degradability of CP, lysine, and methionine was less for canola cake heated at 130 °C in combination with LSO3 compared with canola cake heat treated only (quadratic × LSO3 interaction, P ≤ 0.07). Results of this study indicate that high temperature heating (130 °C or greater for 60 min) may be necessary to protect canola cake protein from degradation in the rumen, and the combination of heat treatment and LSO3 may be more effective in protecting canola cake protein, lysine, and methionine from degradation in the rumen than the use of heat treatment only.
Genetic evaluation records for the Canadian Holstein, Ayrshire, Jersey, and Brown Swiss bulls and cows born from 1950 and 1960, respectively, were used to study the generation intervals (L) along the four-path selection model. The objectives of the study were to determine the L in the four dairy cattle breeds and the effects of some environmental factors and variations among herds or artificial insemination (AI) studs on the L achieved. Total L of the four selection paths was reduced by 55% from 29.2 yr in 1980 to 13.2 yr in 2016 in the Holstein breed. Substantial reductions in total L were also observed in the Ayrshire, Jersey, and Brown Swiss populations between 1980 and 2016. Unlike progeny year of birth, housing system, agricultural region in Québec (region) — as well as their interaction — were not important on realised L of sires and dams used on Canadian dairy farms. There were significant variations among herds and AI studs on the age of sires and dams used for breeding. The considerable variations in realised L among herds and AI studs offer opportunities to increase the annual rate of genetic progress in the four Canadian dairy cattle populations.
The objective of this study was to calculate the environmental impact of raising pigs fed diets with 192, 182, 172, or 162 g kg-1 crude protein (CP) from 15 to 30 kg live weight, using a life cycle assessment (LCA) based on either predicted or observed performance and excretion data. The predicted data were calculated for two animal profiles: one with feed intake and weight gain data being representative of the national Brazilian average (yp-AVG), and the other being representative of the specific experimental farm conditions (yp-SPC). Performance and excretion of pigs were either measured (yobs) or predicted (yp) for each CP scenario by using InraPorc® model and LCA impacts were calculated from these data. The yp and yobs data of performance, nutrient excretion, and LCA were then compared using a Bayesian paired approach. Whatever the calculation methods, the decrease in dietary CP reduced the environmental impacts per kilogram of weight gain on acidification potential (AP), eutrophication potential (EP), and land occupation. Predicted data from yp-SPC did not differ from yobs data except for nitrogen excretion and AP and EP impacts. Predicted data from yp-AVG differed from yobs for all criteria except for body weight gain, phosphorus excreted, and cumulative energy demand, mainly because of the lower feed conversion ratio for average data. It was concluded that the use of predicted data calculated from specific farm indicators could better explain the environmental impact of pig farming in Brazil compared with the use of national average indicators.
Hippophae rhamnoides L. polysaccharide (HRP) has antioxidant and immunomodulatory actions. It has been reported that HRP can reduce the release of reactive oxygen species (ROS). The objective of this study was to investigate the effects of HRP on immunomodulatory and antioxidant activity in intestinal porcine jejunum epithelial (IPEC-J2) cells. Effective conditions of HRP (0, 200, 400, 600, and 800 μg mL-1) were evaluated by pretreatment of IPEC-J2 cells for 24 h. The results showed that pretreatment with 0–600 μg mL-1 of HRP enhanced cell survival rate, while more than 600 μg mL-1 posed a threat to IPEC-J2 cell viability and lowered cell survival rate (p < 0.05). In addition, results revealed that, compared with the control group, the treatment of IPEC-J2 cells with 200–600 μg mL-1 of HRP for 24 h decreased ROS, malondialdehyde, protein carbonyl levels, and cell apoptosis. Meanwhile, the levels of superoxide dismutase, glutathione peroxidase, interleukin-1 beta, interleukin-2, interleukin-6, interleukin-8, tumour necrosis factor-alpha were elevated, and enhanced relative mRNA levels were also shown in the IPEC-J2 cells. Both the contents of immunoglobulin M, immunoglobulin A, and immunoglobulin G elevated with the increases of HRP concentration (200, 400, and 600 μg mL-1), and an increase of catalase relative mRNA levels were also observed in IPEC-J2 cells. Data indicated that 600 μg mL-1 of HRP had a potent protective effect on IPEC-J2 cells. Taken together, these results suggested that HRP was effective in regulating intestinal epithelial cells in piglets.
A total of 150 weaning pigs (7.53 ± 1.23 kg) were randomly assigned to three treatments consisting of basal diet, and the basal diet supplemented with 300 and 600 mg kg-1 of probiotics, respectively, in a 42 d trial. The incremental levels of probiotics linearly increased average daily gain during week 1 and through the overall experimental period (P < 0.05). The average daily feed intake, body weight, and the apparent total tract digestibility of dry matter, nitrogen, and gross energy also increased (P < 0.05) with the increased level of probiotics. A significant reduction in Escherichia coli counts (P = 0.0037) and increase (P = 0.0016) in Lactobacillus counts were observed on day 42.
A survey was carried out on 19 dairy farms in Manitoba that varied in size, diet composition, housing, and feeding strategy to identify factors that affect the phosphorus (P) content of feces. On each farm, 10 early, 10 mid, and 10 late lactation cows were included. Multiple regression analysis showed that high dietary P concentrations and free-stall instead of tie-stall housing were mostly associated with high P contents of feces. Hence, a closer matching of the requirements and supply of P of dairy cows enhances the utilization of dietary P on these farms.
Over- or under-supplying energy by 15% to gestating sows had minimum consequences for piglet chemical body composition or energy storage (liver and muscle glycogen) at birth, when estimated amino acid requirements were met. Providing gestating sows with energy 15% below versus 15% above requirements increased piglet serum insulin-like growth factor 1 (IGF-1) concentrations at birth (P < 0.05). Piglets from first versus second parity sows had lower serum IGF-1 but greater liver glycogen and body fat. Precisely matching the estimated energy and nutrient requirements throughout gestation and across parities likely improves piglet quality; over-supplying energy appears most detrimental for piglet IGF-1 serum concentrations at birth.
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