Different Planes Of Nutrition Research Articles

PSVIII-29 Nutritional Epigenetic Modifications in Beef Cattle

Abstract Nutrition of the beef cow during pregnancy influences fetal development and potential changes in phenotype. On average 9 to 10% of the beef cattle herd are below the optimal body condition score of 2.5/5 at both pre-breeding and pregnancy tests, indicating potential nutritional stress during gestation. Epigenetic modifications are reported to regulate the changes in phenotype due to maternal nutrition during gestation. Our objective was to evaluate the influence of maternal nutrition during gestation on possible epigenetic mechanisms regulating development and biological function in Longissimus dorsi (LD) and Semimembranosus (SM) muscles, and liver (LV) at slaughter in steer progeny born from dams fed two different planes of nutrition during gestation. We also wanted to explore if the genetic potential of the offspring for residual feed intake (RFI) would interact with prenatal maternal diet to have differential effects on these epigenetic mechanisms. Purebred Angus steer calves (n = 23) were born from dams which were fed a diet formulated for an average daily gain (ADG) of either 0.5 or 0.7 kg/d from 30 to 150 days of gestation. Mating was designed so that calves were born from parents with differential genetic potential for high or low RFI. Calves were raised together as per normal industry standards and fed to be slaughtered as finished steers at approximately 512.1 ± 10.1 days of age. One approximately 10 g sample each of LV, LD, and SM muscles was aseptically collected within 30 to 45 min post-mortem and snap frozen in liquid nitrogen and subsequently stored at -80°C. Both DNA and RNA were isolated from the tissue samples and investigated for differences in methylation and gene expression, respectively. Fifteen potentially differently methylated regions (DMRs) in the DNA were measured using EpiTYPER MassARRAY technology, while expression of genes corresponding to the potential DMRs was measured by the nCounter Element Tagset by NanoString technologies. Average methylation across each DMR as well as gene expression within each tissue was profiled using principal component analyses (PCA). Distinct clustering was seen within both DNA methylation and gene expression PCAs such that the two muscles were clustered together and were separate from DNA methylation and gene expression measured in LV, representing expected functional variation due to tissue type. Between LD and SM, methylation patterns in the two muscles overlap, while there is much less overlap in gene expression patterns. This implies that the methylation pattern between the two muscle types is relatively similar compared with their patterns in gene expression, and that smaller differences in DNA methylation may lead to relatively larger differences in gene expression. These analyses are an important first step to interrogate the quality of our data that will be further analyzed for responses to maternal diet treatment and selection for genetic potential for RFI.

Intake, total apparent digestibility, and microbial efficiency of sheep fed pineapple waste silage in different planes of nutrition

The study aimed to nutritionally evaluate the silage of pineapple crop waste in sheep feeding in different planes of nutrition (L). We used eight growing sheep and four male castrated adults, in individual metabolic cages distributed in a switch-back design with two treatments and three periods. The treatments were the different planes of nutrition: L = MEI⁄Mm, MEI⁄1.5Mm, and MEI⁄2.5Mm, in which L = MEI/Mm, MEI is the energy amount of the feed intake and Mm is the maintenance. [...]

Effect of rumen-protected fat on performance, carcass characteristics and beef quality of the progeny from Nellore cows fed by different planes of nutrition during gestation

The objective of this research was to evaluate the performance, carcass traits, meat quality and the expression of myogenic and lipogenic genes in muscle of steers finished with or without rumen-protected fat and born from dams that were supplemented with protein or not during mid- to late gestation. Forty-eight Nellore steers with an initial body weight (BW) of 341 ± 7.54 kg at 21 ± 0.7 months of age, were distributed in a completely randomized design using a 2 × 2 factorial arrangement with the following treatments: two offspring feedlot diets and two nutritional planes for pregnant dams. Steers born from dams of both maternal nutritional planes and reared on pasture, were allocated to individual pens for 135 days, with half of each group being fed a diet without (NFAT) or with rumen-protected fat (RPF; 6% calcium salts and 7.6% ether extract - EE). Regarding maternal nutritional planes, after 124 ± 21 days of gestation until calving, half of the grazed cows received 1 kg/cow/day protein supplement (SUPP; ∼369 g of crude protein [CP] per kg of dry matter [DM]), and the other half received only mineral salt (CTL). Steers were weighed at the beginning and at the end of the experimental period, and the weight of the feed and orts was recorded daily for performance measures. After slaughter in a commercial slaughterhouse, carcass evaluations were performed and longissimus thoracis muscle samples were collected for meat quality and gene expression analyzes using RT-qPCR. There was no interaction between the finishing diets and the maternal nutritional background for performance, carcass and meat quality traits, and gene expression of the offspring. Feeding with RPF decreased the dry matter intake, final BW, average daily gain and carcass weight (P < 0.05). Diet with RPF upregulated the MyHCI, MyHCIIx, IGFR1, COL3A1, FN1 and ACACA genes (P < 0.05) and tended to upregulate the SREBF1 (P = 0.07). Maternal supplementation did not affect feedlot performance, carcass and meat quality traits (P > 0.05). Maternal supplementation upregulated the MyHCI and CPT2 genes (P < 0.05) and tended to upregulate the FASN and ACACA genes (P < 0.10) of the offspring. In conclusion, feeding RPF to the offspring regardless of maternal nutritional background affected the performance and weight of the carcasses, as well as the expression of myogenic and fibro/lipogenic genes, without affecting the deposition of intramuscular fat, total collagen or meat tenderness.

Long Intergenic Non-Coding RNAs in the Mammary Parenchyma and Fat Pad of Pre-Weaning Heifer Calves: Identification and Functional Analysis.

Simple SummaryThe development of mammary gland is directly related to the productivity of dairy animals. Some studies showed that feeding the enhanced plane of nutrition at pre-weaning stage are advantageous to the development of mammary gland. However, regulators which are involved in this biological process remain largely unknown. In this work, we have identified some long intergenic non-coding RNAs (lincRNAs) in mammary parenchyma (PAR) and mammary fat pad (MFP) of heifer calves under different levels of nutrition at pre-weaning stage by using the published RNA-seq database. Furthermore, those putative lincRNAs, which were highly correlated with these key protein-coding genes in mammary gland development, were highlighted. Our results not only confirmed the advantages of feeding calves with enhanced feeding plane in pre-weaning stage, but also provided fundamental base for further research on the biological processes of mammary gland development.Enhanced plane of nutrition at pre-weaning stage can promote the development of mammary gland especially heifer calves. Although several genes are involved in this process, long intergenic non-coding RNAs (lincRNAs) are regarded as key regulators in the regulated network and are still largely unknown. We identified and characterized 534 putative lincRNAs based on the published RNA-seq data, including heifer calves in two groups: fed enhanced milk replacer (EH, 1.13 kg/day, including 28% crude protein, 25% fat) group and fed restricted milk replacer (R, 0.45 kg/day, including 20% crude protein, 20% fat) group. Sub-samples from the mammary parenchyma (PAR) and mammary fat pad (MFP) were harvested from heifer calves. According to the information of these lincRNAs’ quantitative trait loci (QTLs), the neighboring and co-expression genes were used to predict their function. By comparing EH vs R, 79 lincRNAs (61 upregulated, 18 downregulated) and 86 lincRNAs (54 upregulated, 32 downregulated) were differentially expressed in MFP and PAR, respectively. In MFP, some differentially expressed lincRNAs (DELs) are involved in lipid metabolism pathways, while, in PAR, among of DELs are involved in cell proliferation pathways. Taken together, this study explored the potential regulatory mechanism of lincRNAs in the mammary gland development of calves under different planes of nutrition.

Feed intake, digestibility, and energy contents in growing bull fed pineapple crop waste silage in different planes of nutrition.

The objective of this study was to nutritionally evaluate the use of pineapple crop waste silage in the feeding of growing bull in different planes of nutrition. We used eight non-castrated growing bull housed in individual covered pens, provided with free access to water and individual trough. Two balanced Latin squares conducted simultaneously were used. Treatments consisted of four planes of nutrition (L), formed by multiples of maintenance, i.e., L = ME/Mm; they were ME/Mm, ME/1.5Mm, ME/2Mm, and ME/2.7Mm. The intake of nutrients in diets was determined by the difference between the total mass of food offered and the mass of orts. To determine nutrient digestibility and nitrogen balance, total feces, and urine, collections were performed for seven consecutive days in each animal per period. The increase in planes of nutrition affected (P < 0.05) nutrient intake between L = 1 and L = 1.5. However, there was no effect nutrients intake to 1.5, 2, and 2.7. Nutrient digestibility was affected by the increase in planes of nutrition (P < 0.05), except for dCF (P = 0.0659). Digestible and metabolizable energies were affected (P < 0.05) by the increase in nutritional plans, as well as nitrogen balance. In conclusion, the pineapple crop waste silage presents itself as a good forage alternative for cattle diets, especially during forage shortage periods. Inclusion in the diet at 2.7 × the maintenance level does not compromise growing bull performance. However, the increases in planes of nutrition reduce the digestible energy contents of the diet.

Plane of nutrition during gestation affects reproductive performance and retention rate of hyperprolific sows under commercial conditions

Defining a maternal plane of nutrition during gestation is pivotal for improving sow productivity and the cost-effectiveness of feeding. The benefits of increasing the amount of feed during late gestation have been controversial. The objective of this study was to investigate the effects of different planes of nutrition during gestation on reproductive performance of hyperprolific sows and pre-weaning litter performance. One hundred and thirty-five gestating sows were randomly assigned to one of three planes of nutrition throughout parities three and four (P4), as follows: Req – plane designed to meet requirements of prolific sows (2.3 kg per day from day 1 to 21; 1.8 kg per day from day 22 to 75; 2.3 kg per day from day 76 to farrowing); Bump – plane designed as the Req, with increased feed intake during late gestation (3.0 kg per day from day 91 to farrowing); and Maintenance – plane designed to closely meet maintenance requirements of sows (1.8 kg per day from day 1 to farrowing). All treatments were fed the same gestation diet (2.50MCal NE/kg; 0.67% SID Lysine; 15.17% CP). Sow biometrical parameters at farrowing and at weaning, and litter characteristics were recorded. Also, blood samples were collected for pre- and post-prandial serum glucose and plasma insulin, as well as triglycerides, calcium, and phosphorus analyses. Culling, stratified by cause, and retention rates were recorded in all treatments for each parity. Over two parities, Bump sows had higher weight gain and, at P4, had a higher number of piglets born alive (P < 0.05). Bump sows lost more weight between the end of gestation and weaning over two parities (P < 0.05). Maintenance sows showed reduced body condition score with a higher percentage of piglets removed throughout lactation (due to inappetence and inability to reach the udder) at P4 (P = 0.03). Pre- and post-prandial glucose levels were higher in Bump sows, as well as post-prandial insulin and phosphorus levels at P4 (P < 0.05). Bump sows also showed increased plasma triglycerides compared to the other treatments (P = 0.03). Retention rate was reduced in Maintenance compared to Bump and Req sows at parity 5 (P = 0.02). Taken together, our results indicate that higher feed intake allowance during late gestation may improve the sow’s nutritional status triggering positive results on litter size of hyperprolific sows (e.g., more than 17 total born). However, body condition score must be carefully evaluated to prevent excessive weight gain during successive parities.

Energy requirements for pregnant dairy cows.

This study aimed to estimate energy requirements of pregnant Holstein × Gyr cows. Different planes of nutrition were established by two feeding regimens: ad libitum or maintenance. Sixty-two nonlactating cows with average body weight of 480 ± 10.1 kg and an age of 5 ± 0.5 years were used. Cows were divided into three groups: pregnant (n = 44), non-pregnant (n = 12), and baseline reference (n = 6). The 56 pregnant and non-pregnant cows were randomly allocated into a feeding regimen: ad libitum or maintenance. To evaluate the effects of days of pregnancy, pregnant and non-pregnant animals were slaughtered at 140, 200, 240, and 270 days of pregnancy. Energy requirements for maintenance differed between pregnant and non-pregnant cows, thus two equations were developed. Net energy and metabolizable energy requirements for maintenance of non-pregnant cows were 82 kcal/kg empty body weight0.75/day and 132 kcal/kg empty body weight0.75/day, respectively. The efficiency of use of metabolizable energy for maintenance of non-pregnant cows was 62.4%. Net energy and metabolizable energy for maintenance of pregnant cows were 86 kcal/kg empty body weight0.75/day and 137 kcal/kg empty body weight0.75/day, respectively. Efficiency of use of metabolizable energy for maintenance of pregnant cows was 62.5%. The efficiency of use of metabolizable energy for gain was 41.9%. The efficiency of use of metabolizable energy for pregnancy was 14.1%. Furthermore, net energy requirement for pregnancy was different from zero from day 70 of pregnancy onwards. In conclusion, net energy and metabolizable energy requirements for maintenance of non-pregnant cows are different from pregnant cows. Furthermore, we believe that the proposed non-linear equations to estimate net energy requirements for pregnancy are more adequate than current NRC equation, and should be recommended for Holstein × Gyr cows.

Energy metabolism and partition of lactating Zebu and crossbred Zebu cows in different planes of nutrition.

The aim of this study was to determine the energy metabolism and partition of lactating Gyr and F1 Holstein x Gyr (F1 HxG) cows in different planes of nutrition. Six F1 HxG and six Gyr cows with 130 days in milking (DIM) fed corn silage and concentrate were evaluated. The experiment consisted of four periods with different levels of feeding: 1st ad libitum dry matter intake (DMI) and the others with 5, 10 and 20% restricted DMI, related to the first one. An apparent digestibility assay was performed before measurements in the respiration chamber. Total feces were collected for three days. The cows were confined for 24h in the chamber in each period to determine methane and heat production (HP). F1 HxG had higher gross energy intake (GEI), metabolisable energy intake (MEI) and digestible energy intake (DEI). GE lost in feces was higher in F1 HxG (23.7% GEI) than in Gyr (20.5%) cows. Energy lost as methane and urine was similar between the groups. The metabolisability (q) was 0.67, and the efficiency of converting ME to NE (k) was 0.56. There was no difference in the energy requirements for maintenance between breeds (426.6 MJ/kg BW0,75 average value). The energy requirements for lactation were higher in F1 HxG animals due to the higher volume of milk produced, since there was no difference in energy requirements for production of one kg of milk.

Corpora lutea in superovulated ewes fed different planes of nutrition

The corpus luteum (CL) is an ovarian structure which is critical for the maintenance of reproductive cyclicity and pregnancy support. Diet and/or diet components may affect some luteal functions. FSH is widely used to induce multiple follicle development and superovulation. We hypothesized that FSH would affect luteal function in ewes fed different nutritional planes. Therefore, the aim of this study was to determine if FSH-treatment affects (1) ovulation rate; (2) CL weight; (3) cell proliferation; (4) vascularity; (5) expression of endothelial nitric oxide (eNOS) and soluble guanylate cyclase (sGC) proteins; and (6) luteal and serum progesterone (P4) concentration in control (C), overfed (O), and underfed (U) ewes at the early- and mid-luteal phases. In addition, data generated from this study were compared to data obtained from nonsuperovulated sheep and described by Bass et al. Ewes were categorized by weight and randomly assigned into nutrition groups: C (2.14 Mcal/kg; n = 11), O (2xC; n = 12), and U (0.6xC; n = 11). Nutritional treatment was initiated 60 d prior to day 0 of the estrous cycle. Ewes were injected with FSH on day 13–15 of the first estrous cycle, and blood samples and ovaries were collected at early- and mid-luteal phases of the second estrous cycle. The number of CL/ewe was determined, and CL was dissected and weighed. CL was fixed for evaluation of expression of Ki67 (a proliferating cell marker), CD31 (an endothelial cell marker), and eNOS and sGC proteins using immunohistochemistry and image analysis. From day 0 until tissue collection, C maintained, O gained, and U lost body weight. The CL number was greater (P < 0.03) in C and O than U. Weights of CL, cell proliferation, vascularity, and eNOS but not sGC expression were greater (P < 0.001), and serum, but not luteal tissue, P4 concentrations tended to be greater (P = 0.09) at the early- than mid-luteal phase. Comparisons of CL measurements demonstrated greater (P < 0.01) cell proliferation and serum P4 concentration, but less vascularity at the early and mid-luteal phases, and less CL weight at the mid-luteal phase in superovulated than nonsuperovulated ewes; however, concentration of P4 in luteal tissues was similar in both groups. Thus, in superovulated ewes, luteal cell proliferation and vascularity, expression of eNOS, and serum P4 concentration depend on the stage of luteal development, but not diet. Comparison to control ewes demonstrated several differences and some similarities in luteal functions after FSH-induced superovulation.

Luteal function during the estrous cycle in arginine-treated ewes fed different planes of nutrition.

Functions of corpus luteum (CL) are influenced by numerous factors including hormones, growth and angiogenic factors, nutritional plane and dietary supplements such as arginine (Arg), a semi-essential amino acid and precursor for proteins, polyamines and nitric oxide (NO). The aim of this study was to determine if Arg supplementation to ewes fed different planes of nutrition influences: (1) progesterone (P4) concentrations in serum and luteal tissue, (2) luteal vascularity, cell proliferation, endothelial NO synthase (eNOS) and receptor (R) soluble guanylate cyclase β protein and mRNA expression and (3) luteal mRNA expression for selected angiogenic factors during the estrous cycle. Ewes (n = 111) were categorized by weight and randomly assigned to one of three nutritional planes: maintenance control (C), overfed (2× C) and underfed (0.6× C) beginning 60 days prior to onset of estrus. After estrus synchronization, ewes from each nutritional plane were assigned randomly to one of two treatments: Arg or saline. Serum and CL were collected at the early, mid and late luteal phases. The results demonstrated that: (1) nutritional plane affected ovulation rates, luteal vascularity, cell proliferation and NOS3, GUCY1B3, vascular endothelial growth factor (VEGF) and VEGFR2 mRNA expression, (2) Arg affected luteal vascularity, cell proliferation and NOS3, GUCY1B3, VEGF and VEGFR2 mRNA expression and (3) luteal vascularity, cell proliferation and the VEGF and NO systems depend on the stage of the estrous cycle. These data indicate that plane of nutrition and/or Arg supplementation can alter vascularization and expression of selected angiogenic factors in luteal tissue during the estrous cycle in sheep.

Performance of growing yak calves on different planes of nutrition

Four divergent rations with 2 levels of DCP and TDN (100 and 75%) namely low protein-low energy (LP-LE), low protein-high energy (LP-HE), high protein-low energy (HP-LE) and high protein-high energy (HE-HP) were supplied to 24 growing yaks (12 male and 12 female) randomly divided into 4 groups of 6 animals (3 male and 3 female) each in completely randomized design. The average daily gain and feed efficiency was highest in HE-HP group. The blood glucose level was highest in HP-HE group in comparison to the others; however, plasma protein, albumin and urea levels were almost similar for all the experimental groups. The study revealed that growing yak calves ranging from 250 to 300 kg body weight consumed an average 79.86 g DM, 6.10 g DCP and 47.15 g TDN/kg W0.75/day to support an average body weight gain of 371.8 g/day.

Lipid droplets in cultured luteal cells in non-pregnant sheep fed different planes of nutrition

Accumulation of lipid droplets (LD) in luteal cells likely is important for energy storage and steroidogenesis in the highly metabolically active corpus luteum (CL). The objective of this study was to determine the effect of plane of nutrition on progesterone (P4) secretion, and lipid droplet number and size in cultured ovine luteal cells. Ewes were randomly assigned to one of three nutritional groups: control (C; 100% NRC requirements, n=9), overfed (O; 2×C, n=12), or underfed (U; 0.6×C, n=10). Superovulation was induced by follicle stimulating hormone injections. At the early and mid-luteal phases of the estrous cycle, CL were dissected from ovaries, and luteal cells isolated enzymatically. Luteal cells were incubated overnight in medium containing serum in chamber slides. Media were then changed to serum-free and after 24h incubation, media were collected for P4 analysis, and cells were fixed in formalin and stained with BODIPY followed by DAPI staining. Z-stacks of optical sections of large and small luteal cells (LLC and SLC, respectively) were obtained using a laser-scanning microscope. Rendered 3D images of individual LLC and SLC were analyzed for cell volume, and total and individual LD volume, number and percentage of cellular volume occupied by LD by using Imaris software. Concentrations of P4 in serum and media were greater (P<0.05) at the mid than early-luteal phase, and were not affected by nutritional plane. LD total volume and number were greater (P<0.001) in LLC than SLC; however, mean volume of individual LD was greater (P<0.02) in SLC than LLC. In LLC, total LD volume was greater (P<0.02) in O than C and U ewes. In SLC, total LD volume and number was greater (P<0.003) at the mid than early-luteal phase, and percentage of cell volume occupied by LD was greater (P<0.002) in U than C and O ewes. These data demonstrate that both stage of luteal development and nutritional plane affect selected LD measurements and thus may affect luteal functions. Furthermore, these data confirm that LD dynamics differ among parenchymal steroidogenic luteal cell types.

Effect of average daily gain on body size, metabolism, and milk production of Italian Holstein heifers raised on two different planes of nutrition and calving at two different ages

The aim of this experiment was to study the effect of two average daily gains between 5 and 15mo of age on body measurements, fat deposition, metabolic profile, interaction with age at first calving, and milk production in first lactation. A total of 141 Italian Friesian heifers, in two experimental herds, were allotted to 2 feeding regimens formulated for a moderate (M, 0.7kg/d) or an accelerated (H, 0.9kg/d) average daily gain diet from 5 to 15mo of age. Half of the heifers on M were programmed to be bred at 15mo (ME), and half at 18mo (ML) of age; heifers on H were programmed to be bred at 15mo of age (HE). Every 28d, body weight, withers height, hip height, body length, heart girth, and body condition score were recorded. Also each week in one herd from −14 to 70d post-calving, the body condition score was evaluated. In one herd, metabolic profile was assessed at 9 and 15mo of age. Growth curve parameters were estimated for the body measurements for each heifer. Metabolic profiles from both ages (9 and 15mo) were processed by Principal Components Analysis (PCA). For the first lactation, milk production and composition were recorded. The M heifers grew slower (0.73 vs. 0.81 kg/d) than H heifers, and this difference was reflected also in a faster heart girth gain in H than M heifers (0.184 vs. 0.169 cm/d). The body condition score of heifers fed on H diet increased faster than that of heifers fed on M diet by 9mo of age. At this age, plasma concentration of urea, Ca, Na, albumin, and γ-glutamyl transferase activity were greater in H than in M heifers. At 15mo of age, plasma concentration of bilirubin and alkaline phosphatase activity were lower in H than M heifers. At 9mo, plasma urea concentration was correlated with hip height and heart girth curve parameters. At 15mo, plasma glucose concentration was correlated with body weight curve parameters. Plasma ceruloplasmin concentration was correlated with hip height curve parameters at both ages, and with body weight curve parameters at 15mo. The results from the PCA have shown that the first principal component was correlated with the parameters of the growth functions for body weight, hip height, and heart girth. Experimental diet and age at first calving per se did not affect milk production in first lactation, but the peak of milk production of HE heifers occurred 15d earlier than that of ML heifers.

Effects of diet-induced differences in growth rate on metabolic, histological, and meat-quality properties of 2 muscles in male chickens of 2 distinct broiler breeds

This paper, the second from a comprehensive study, describes the effects of varying growth rate by feeding at different planes of nutrition with a constant ME:CP ratio on muscle characteristics and meat quality in 2 distinct broiler breeds of male chickens (Arbor Acres, a commercial line; and Beijing-You, a Chinese nonimproved line). Experimental diets, differing on average by 2% CP, were formulated with high-, medium-, or low-nutrient densities for 3 growing phases. Male hatchlings (216 of each breed) were randomly assigned to 6 pens of 12 birds in each treatment. Altered histological characteristics of muscle fibers, early postmortem muscle metabolism, and meat quality were investigated in the pectoralis major and biceps femoris. At their market age, Arbor Acres broilers had significantly higher concentrations of plasma protein and lipid metabolites, ratios of white to red and intermediate fibers, pH, L* and b* values, and lower concentrations of plasma glucose metabolites, muscle-fiber diameter, muscle contents of energy stores, a* value, drip loss, and shear force than the values found for the Beijing-You chickens (P < 0.01). Higher nutrient density increased the size of the muscle fibers, decreased glycogen reserve, and reduced the rate and extent of acidification in the Arbor Acres chickens, while accelerating transformation of red and intermediate-to-white fibers, enhancing energy stores, and hastening the decrease in pH postmortem in the Beijing-You chickens (P < 0.05). In each breed, most meat quality variables (e.g., shear force, drip loss, and color) were consistent with the histological and biochemical changes caused by the feeding strategy. Together, dietary nutrient density can influence meat quality as a result of altered histological and initial energy and metabolic characteristics of the muscle. Many of the responses to diet are breed and tissue dependent in broiler chickens.

Effect of monensin inclusion in supplements for cattle consuming low quality tropical forage

A pen feeding study was carried out over 70 days to determine the effects of monensin (M) inclusion in two commercial supplements designed to provide different planes of nutrition to recently weaned steers. Thirty Bos indicus crossbred steers (191.4 ± s.d. 7.1 kg) were individually fed a low quality pangola grass hay (57 g crude protein/kg DM; 497 g/kg DM digestibility) ad libitum (Control) with either a urea/molasses-based supplement of Rumevite Maxi-graze 60 Block (B), fed at 100 g/day, or grain-based Rumevite Weaner Pellets (WP), fed at 7.5 g/kg liveweight (W).day, both with and without M, viz. B, B+M, WP and WP+M, respectively. There were no significant interactions between supplement type and M inclusion for any measurement. Growth rates (main effects) averaged 0.17, 0.35 and 0.58 kg/day for the Control, B and WP supplements, respectively, with all means different (P &lt; 0.05), while the response (P &lt; 0.05) to M across supplement type was 0.11 kg/day. Hay DM intake was similar for the Control and B treatments (18.6 and 19.6 g/kg W.day) but was reduced (P &lt; 0.05) with the WP supplement (16.8 g/kg W.day) while corresponding total DM intakes increased from 18.6 to 20.0 to 23.5 g/kg W.day (all differences P &lt; 0.05), respectively. Monensin inclusion in the supplements did not affect supplement, hay or total DM intake. Inclusion of M in supplements for grazing weaners in northern Australia may increase survival rates although the effect of M with cattle at liveweight maintenance or below requires further investigation.

Effect of different planes of nutrition on the some minerals concentration in the blood of goats

The effect of different levels of energy and protein on the blood concentration of calcium, phosphorus, copper and zinc were evaluated in four experiments. A total of nine growing castrated male balady kids having nearly the same age (8-9 months) and body weight (15-18kg) were experimented on. Four experiments, 3 trials per each were done on the same animals, with about 10 days as a rest period between one experiment and another, in which the animals were fed on control ration during the interval. The nine kids were randomly divided into 3 groups (A, B and C), 3 kids per each. The first group (A) was fed the control ration and used as control, while the other two groups (B and C) were fed the tested rations which furnished 15% more or less DE and CP than the control. The results indicated that feeding high protein ration slightly increased the mean value of serum P, Cu and Zn , while decreased the serum Ca level. Feeding high energy ration for growing kids was decreased the mean value of serum Ca, Cu and Zn and increased the mean value of serum P. On the other hand, feeding of HEHP ration was decreased the mean values of serum Ca and increased value of P. However, feeding low energy ration was increased serum Ca and Zn levels, while serum P and Cu were decreased. Feeding LEHP ration was decreased the mean values of serum Ca, P, Cu and Zn, while feeding LELP ration was decreased the mean value of serum P and Cu and increased serum Ca and Zn.

Nutritional regulation of body condition score at the initiation of the transition period in primiparous and multiparous dairy cows under grazing conditions: milk production, resumption of post-partum ovarian cyclicity and metabolic parameters

The objective of this study was to investigate the effect of different body condition score (BCS) at 30 days before calving (−30 days) induced by a differential nutritional management from −100 days until −30 days on productive parameters, the interval to first ovulation and blood parameters in primiparous and multiparous Holstein cows under grazing conditions until 60 days post partum. The experimental arrangement was a randomized complete block design, where cows were blocked according to BW and expected calving date and then randomly assigned to different nutritional treatments from –100 to –30 days relative to calving to induce different BCS. As the assignment of cows to treatments was random, cows had to lose, maintain or gain BCS; thus, different planes of nutrition were offered with approximately 7, 14 or 20 kg dry matter per day. The BCS score was assessed every 15 days and animals were reassigned in order to achieve the desired BCS at –30 days. Only animals that responded to nutritional treatment were considered and this was defined as follows: primiparous and multiparous high cows (PH and MH) had to gain 0.5 points of BCS, primiparous low (PL) had to lose 0.5 points of BCS and multiparous low (ML) had to maintain BCS at least in two subsequent observations from −100 to −30 days. From −30 days to calving, primiparous and multiparous cows (P and M cows) were managed separately and cows were offered a diet once a day. From calving to 60 days post partum, cows of different groups grazed in separate plots a second year pasture. Cows were also supplemented individually with whole-plant maize silage and commercial concentrate. Cows had similar BCS at −100 days and differed after the nutritional treatment; however, all groups presented similar BCS at 21 days post partum. The daily milk production and milk yield at 60 days post partum was higher in M than P cows. The percentage of milk fat was higher in PH cows compared with PL cows. Concentrations of non-esterified fatty acids (NEFA) were affected by the BCS at −30 days within parity, and in PH cows the concentration of NEFA was higher than in PL cows. The concentrations of total protein were higher in M cows. A lower probability of cycling was found in PL than in PH cows (P < 0.05) and in ML than in MH cows (P < 0.05). Treatment affected various endocrine/metabolic profiles according to parity, suggesting that the metabolic reserves signal the productive/reproductive axis so as to induce a differential nutrient partitioning in adult v. first-calving cows.

Effects of plane of nutrition of ewes in early and mid-pregnancy on performance of the offspring: Female reproduction and male carcass characteristics1

This study investigated the effects of different planes of nutrition in early pregnancy (EP) and mid-pregnancy (MP) of crossbred ewes on carcass characteristics of male offspring and reproductive performance of female offspring. During EP (d 1 to 39 after synchronized mating) ewes were allocated 60% (low, L-EP), 100% (medium, M-EP), or 200% (high, H-EP) of their energy requirements for maintenance. Between d 40 and 90 (MP), ewes were then allocated 80% (M-MP) or 140% (H-MP) of their maintenance energy requirement. After d 90, all ewes were fed to fully meet energy requirements for late pregnancy. Male offspring (n = 83) were reared on a grass-based system and slaughtered at 42, 46, or 50 kg of BW. Female offspring (n = 60) were reared on a grass-based system, mated at 8 mo, and performance recorded until weaning of their first lamb crop. Concentrations of leptin, an adiposity indicator, in female offspring varied with the plane of maternal nutrition in early pregnancy. The L-EP offspring had greater leptin concentrations than H-EP offspring (P = 0.04), with M-EP offspring showing intermediate concentrations. Reproductive performance of female offspring was not affected by maternal plane of nutrition (P > or = 0.16). Female H-EP offspring gave birth to heavier lambs (generation 2 offspring) than M-EP (P = 0.006) with L-EP offspring intermediate. Male offspring of L-EP dams showed a trend toward poorer carcass conformation (P = 0.06) and increased fat classification (P = 0.07), consistent with increased fat depths over the loin (P = 0.02). There was a significant interaction between plane of nutrition in early pregnancy and mid-pregnancy for female offspring BW at 2 mo postmating and 16 wk postlambing (P < or = 0.04), and for male offspring perinephric and retroperitoneal fat and tissue depth (P < or = 0.02). For dams offered diet L-EP during early pregnancy, diet H-MP gave heavier offspring with more perinephric and retroperitoneal fat. In contrast, for dams offered diet H-EP during EP, diet M-MP gave offspring that were heavier or fatter or both. Maintenance level of nutrition in EP followed by M-MP or H-MP treatments resulted in offspring intermediate in fatness and BW. The data indicate that adaptations in EP and MP to compensate for nutritional deprivation or nutritional excess can alter the BW, adiposity, conformation, and leptin concentrations of offspring. Such changes have potential to alter health and lifetime productive performance.

Histochemical properties and collagen architecture of M. iliotibialis lateralis and M. puboischiofemoralis in male broilers with different growth rates induced by feeding at different planes of nutrition

1. The histochemical properties and the collagen content and architecture of the iliotibialis lateralis (ITL) and puboischiofemoralis (PIF) muscles were assessed in Red Cornish × New Hampshire cockerels reared on a high nutrient plane for 80 d (H80d), or a low nutrient plane for 80 d (L80d) or 95 d (L95d). 2. Final live weights were 3410 g in H80d, 2810 g in L80d and 3467 g in L95d. Both ITL and PIF muscle weights were lowest in L80d and did not differ between H80d and L95d. 3. ITL muscle was composed of fast-twitch myofibres such as IIA (high reduced nicotinamide adenine dinucleotide dehydrogenase, NADH-DH activity), IIB (low NADH-DH activity) and IIC (intermediate NADH-DH activity). The high percentage of type IIB myofibres in H80d (76·6%) and L95d (76·2%) birds were reflected in low percentages of type IIC myofibres (12·2%) in H80d birds and type IIA myofibres (8·2%) in L95d birds. Percentages of IIA, IIB and IIC myofibres in L80d cockerels were 12·4, 69·8 and 17·6%, respectively. 4. The myofibres in PIF muscle were divided into two basic types, I and IIA, and a transitional form (I-tr) from IIA to I. In the caudal region, all myofibres in H80d and L95d cockerels were type I but in L80d cockerels 15% of myofibres were categorised as type I-tr. In the cranial region, the great majority (52 to 63%) of myofibres were type IIA. Type I myofibres occurred at a higher percentage in H80d (30·5%) than L95d (21·8%) and type I-tr in L95d (15·7%) than H80d (7·3%) and L80d (11·5%). 5. The total amount of collagen was higher in ITL than PIF muscle in every bird group. In both muscles the highest collagen content was in L95d cockerels but the content did not differ between H80d and L80d birds. The thickness of thick and thin perimysia increased with muscle size. The circular collagen fibre in the thick perimysium was larger in ITL (6·1 to 7·0 µm) than PIF (3·7 to 3·8 µm) muscle but did not differ among the bird groups. 6. From these results, it was concluded that feeding on a high nutritional plane promotes growth of the thigh muscles, with accompanying enlargement of the perimysial thickness, no increase in collagen content and various changes of histochemical properties.

A model to account for the consequences of host nutrition on the outcome of gastrointestinal parasitism in sheep: model evaluation

This paper describes sensitivity analyses and expectations obtained from a mathematical model developed to account for the effects of host nutrition on the consequences of gastrointestinal parasitism in sheep. The scenarios explored included different levels of parasitic challenge at different planes of nutrition, for hosts differing only in their characteristics for growth. The model was able to predict the consequences of host nutrition on the outcome of parasitism, in terms of worm burden, number of eggs excreted per gram faeces and animal performance. The model outputs predict that conclusions on the ability of hosts of different characteristics for growth to cope with parasitism (i.e. resistance) depend on the plane of nutrition. Furthermore, differences in the growth rate of sheep, on their own, are not sufficient to account for differences in the observed resistance of animals. The model forms the basis for evaluating the consequences of differing management strategies and environments, such as breeding for certain traits associated with resistance and nutritional strategies, on the consequences of gastrointestinal parasitism on sheep.