Low Plane Of Nutrition Research Articles

Finisher lamb growth and rumen fermentation responses to the plane of nutrition and naturally occurring coccidiosis.

The objective of the present study was to investigate the interaction of plane of nutrition and naturally occurring coccidiosis on finisher lamb growth performance, FAMACHA score, and rumen volatile fatty acid profile. The study included 30 Suffolk, Dorset or Suffolk x Dorset lambs and were divided into 2 groups based on their initial body weight and assigned to 2 feeding groups differing in dietary energy intake to create lambs representing divergent growth curves due to differing nutritional management. Lambs with naturally occurring coccidiosis and healthy lambs were present in both feeding groups making a 2 × 2 factorial arrangement of treatments, (a) high plane of nutrition (HPN) lambs with no clinical coccidiosis diagnosis (HPNH), (b) HPN lambs with clinical coccidiosis (HPNC), (c) low plane of nutrition (LPN) lambs with no clinical coccidiosis diagnosis (LPNH), (d) LPN lambs with clinical coccidiosis (LPNC). Body weight and FAMACHA scores were recorded once every 2 weeks. On d 65 of feeding, lambs were slaughtered, and rumen fluid samples were collected and analyzed for volatile fatty acid concentrations. All response variables were analyzed statistically using a linear mixed effects model with fixed effects for plane of nutrition, health status, and a random effect for initial body weight nested within the pen. The total and average weight gain were not associated with planes of nutrition, health status, or the interaction. Health status had an impact on FAMACHA© score (P = 0.047) and concentration of isobutyrate (P = 0.037) and tended to affect total VFA (P = 0.085) and acetate (P = 0.071) concentrations. The interaction between the plane of nutrition and the health status tended to affect butyrate concentration (P = 0.058). These data support the conclusion that coccidiosis infection impacted on rumen fermentation in a manner independent of the plane of nutrition; however, the translation of these rumen level impacts did not translate to the production responses.

PSIX-14 The Influence of Previous Plane of Nutrition on Feedlot Performance, Water Intake and Carcass Characteristics of Beef Steers

Abstract The objective of this study was to evaluate how the background diet can affect the feedlot performance and carcass characteristics of finishing steers. Crossbred Angus steers (n = 24; 298.01 ± 10.17 kg) were fed either a low plane of nutrition (LP, n =12 ; triticale only, 91g/kg CP, 0.25Mcal/kg NEm, and 0.10Mcal/kg NEg) or adequate plane of nutrition (AP, n =12; 850g/kg alfalfa and 150g/kg beardless wheat, 126.2g/kg, 0.25Mcal/kg NEm, and 0.13 Mcal/kg NEg) during the background phase (85d). After this period, body weight (BW) of LP (362.81 kg ± 10.237) was less than the BW of AP (405.97kg ± 10.237). Animals were then transitioned to a finishing diet (800 g/kg whole corn and 200 g/kg alfalfa; 108 g/kg, 0.97Mcal/kg NEm, and 0.65 Mcal/kg NEg) and fed for 105d. Water intake (WI) and dry matter intake (DMI) were individually measured daily. Animals were then havested, and hot carcass weight (HCW) was obtained. Carcasses were chilled for 24 h, and qualified personnel measured longissimus dorsi area via direct grid reading between the 12th and 13th rib, USDA marbling score and yield grades. Differences amongst treatments were compared via orthogonal contrast using the GLIMMIX procedure of SAS (version 9.4). No differences were observed for WI, DMI, final BW and average daily gain among groups. Carcass characteristics such as HCW, yield grade, rib eye area, and dressing percentage were also similar between groups. On the other hand, animals previously on LP had a reducedr marbling score (421.11) than the AP treatment (493.21) (P = 0.0014). Therefore, even though the previous plane of nutrition did not affect intakes, performance, and carcass characteristics, the decreased amount of nutrients during the background decreased marbling of LP animals, which affects the final quality grade of the carcass as well as price per kg of carcass.

Effect of pre-conceptional nutrition and season on fetal growth during early pregnancy in sheep

Gestational age in sheep can be closely predicted through ultrasonographic measurement of fetal bones when correlated to standardized fetal growth curves. However, these standardized curves do not account for factors that are known modulators of fetal growth, such as maternal nutrition or health status. Despite being seasonal breeders, and studies reporting an effect of season on birth weight, the influence of season on fetal growth has not been well characterized. In this study, we hypothesized that season of conception will affect fetal growth curves during mid-gestation and that pre-conceptional nutrition would have no effect. We investigated this by provisioning treatments of low, control, and high planes of nutrition during the lactation and flushing pre-conceptional periods to multiparous Dorset x Polypay and Dorset ewes over two seasons (the optimal breeding season [n = 97] and the suboptimal breeding season [n = 104]). Females were mated naturally with mating dates recorded, fetal biparietal diameter measured via ultrasound between gestational days 35–71, and newborn weights recorded at lambing. Pre-conceptional nutritional treatments did not affect fetal biparietal diameter. However, low vs. high nutrition in the pre-conceptional lactation (but not flushing) period resulted in reduced lamb birth weights (P < 0.001). Early fetal growth tended to be faster in the suboptimal breeding season than in the optimal breeding season (P < 0.061) with lambs being heavier at birth in the optimal breeding season (P < 0.001). There was no effect of fetal sex or litter size on fetal biparietal diameter during the first half of pregnancy, however both sex and litter size influenced lamb birth weight (P < 0.001) with males being heavier than females and singletons being heavier than twins and triplets. Mating date within the flushing period had a significant effect on lamb birth weight regardless of season and independent of treatment, with ewes that conceived later in the flushing period having heavier lambs at birth (P = 0.007). These findings suggest that pre-conceptional under- or overnutrition resulting in substantial changes in body condition does not affect fetal growth during the first half of pregnancy. However, the reduction in lamb birth weight indicates that pre-conceptional maternal nutrition during the previous lactation period may affect fetal growth later in pregnancy.

180 Supplementation of One-Carbon Metabolites to Beef Heifers During Early Gestation Increases Fetal Organ Weight at Day 63 of Gestation

Abstract We hypothesized a low maternal plane of nutrition will impair fetal growth in early gestation and that supplementation of one-carbon metabolites (OCM) will rescue the growth restriction. The experimental design was a 2 × 2 factorial with 2 levels of gain, each with or without supplementation of OCM. Angus-cross heifers were bred with female-sexed semen from a single sire. At breeding (d 0), beef heifers were individually fed using a Calan gate system and assigned to treatment (n = 8 per treatment): Control intake (targeted: 0.45 kg/d, actual: 0.60 kg/d ADG) without OCM (CON-OCM), CON with OCM (CON+OCM), Restricted intake (targeted/actual: -0.23 kg/d ADG) without OCM (RES-OCM), or RES with OCM (RES+OCM). The OCM supplement consisted of ruminal-protected choline (60 g/d) and methionine (10 g/d) in a fine-ground corn carrier fed daily, and weekly injections of folate (320 mg) and vitamin B12 (10 mg). The -OCM heifers received the corn carrier and saline injections. Heifers were slaughtered and fetal tissues collected on d 63. Data were analyzed using the MIXED procedures of SAS. Fetal body weight tended (P = 0.07) to be lighter and stomach complex weight was lighter (P = 0.03) in RES than CON. When organ weights were normalized to total brain weight to assess allometric growth, OCM × gain interactions were observed in heart (P = 0.04), left longissimus dorsi (P = 0.04), and right hemisphere (P = 0.01) with CON+OCM greater than CON–OCM. The normalized left hemisphere trend to be greater in RES+OCM than RES-OCM (P = 0.08). These data suggest that OCM supplementation during early gestation increases allometric growth of fetal cardiac and skeletal muscle tissue. Day 63 is within the period of peak primary myogenesis in cattle, therefore differences in muscle growth during this time could have lasting implications in post-natal calf growth and performance.

Perspectives on the Management of Surplus Dairy Calves in the United States and Canada.

The care of surplus dairy calves is a significant issue for the United States and Canadian dairy industries. Surplus dairy calves commonly experience poor welfare as evidenced by high levels of mortality and morbidity, and negative affective states resulting from limited opportunities to express natural behaviors. Many of these challenges are a result of a disaggregated production system, beginning with calf management at the dairy farm of origin and ending at a calf-raising facility, with some calves experiencing long-distance transportation and commingling at auction markets or assembly yards in the interim. Thus, the objectives of this narrative review are to highlight specific challenges associated with raising surplus dairy calves in the U.S. and Canada, how these challenges originate and could be addressed, and discuss future directions that may start with refinements of the current system, but ultimately require a system change. The first critical area to address is the management of surplus dairy calves on the dairy farm of origin. Good neonatal calf care reduces the risk of disease and mortality, however, many dairy farms in Canada and the U.S. do not provide sufficient colostrum or nutrition to surplus calves. Transportation and marketing are also major issues. Calves can be transported more than 24 consecutive hours, and most calves are sold through auction markets or assembly yards which increases disease exposure. Management of calves at calf-raisers is another area of concern. Calves are generally housed individually and fed at low planes of nutrition, resulting in poor affective states and high rates of morbidity and mortality. Strategies to manage high-risk calves identified at arrival could be implemented to reduce disease burden, however, increasing the plane of nutrition and improving housing systems will likely have a more significant impact on health and welfare. However, we argue the current system is not sustainable and new solutions for surplus calves should be considered. A coordinated and holistic approach including substantial change on source dairy farms and multiple areas within the system used to market and raise surplus dairy calves, can lead to more sustainable veal and beef production with improved calf outcomes.

Effects of dry yeast supplementation on growth performance, rumen fermentation characteristics, slaughter performance and microbial communities in beef cattle

This study aimed to investigate the effects of active dry yeast (ADY) on growth performance, rumen microbial composition and carcass performance of beef cattle. Thirty-two finishing beef cattle (yak ♂ × cattle-yaks ♀), with an average body weight of 110 ± 12.85 kg, were randomly assigned to one of four treatments: the low plane of nutrition group (control), low plane of nutrition group + ADY 2 g/head daily (ADY2), low plane of nutrition group + ADY 4 g/head daily (ADY4) and the high plane of nutrition group (HPN). Supplementation of ADY increased average daily gain compared to the control group. The neutral detergent fiber and acid detergent fiber apparent digestibility in HPN group was greater than that in control group. The propionic acid concentration in the rumen in ADY2, ADY4, and HPN groups was greater than that in control group. The Simpson and Shannon indexes in control and HPN groups were higher than that in ADY4 group. At the phylum level, the relative abundance of Firmicutes in the HPN group was higher than that in ADY4 group. The relative abundance of Ruminococcaceae UCG-002 in ADY4 group was higher than that in control and HPN groups. In conclusion, supplementation ADY 4 g/head daily shift the rumen microbial composition of beef cattle fed low plane of nutrition to a more similar composition with cattle fed with HPN diet and produce the similar carcass weight with HPN diet. Highlights The ADY can improve the utilization of nitrogen and decrease the negative impact on the environment in beef cattle. Cattle fed low plane of nutrition diet supplemented with ADY 4 g/head daily increased growth performance. Supplementation ADY 4 g/head daily in low plane of nutrition diet might be produced comparable carcass weight to HPN diet.

EFFECTS OF PLANE OF NUTRITION AND REARING METHOD ON YANKASA LAMBS: GROWTH RATE, SCROTAL DEVELOPMENT

The study examined the effects of plane of nutrition and rearing method on growth rate, increase in scrotal size; and age, body weight and scrotal circumference at puberty, in Yankasa ram lambs. Thirty-six ram lambs and 18 ewe lambs with mean age and body weight of 1453±17.7 days and 10.1 1±2.6kg respectively were used for the four-month trial. Animalswere randomised in a 3x2 factorial design with plane of nutrition at 3 levels (low, medium and high) and rearing method at 2 levels (males alone and mixture of males and females). Plane of nutrition had bighly significant (P&lt;0.01) effect on average daily gain (ADG). Animals on the low, medium and high planes gained daily 66.8±5.5, 77.8±5.6 and 89.0±5.6 respectively. Effects of plane of nutrition and rearing methods on changes in scrotal circumference were not significant. Age, body weight and scrotal circumference at puberty in the ram lambs averaged 232.5±12.7 days, 18.3±0.4 kg and 22.7±3.1 cm respectively. Body weight at puberty averaged 17.2±1.7, 18.6±0.9 and 19.0±1.4 kg for animals fed low, medium and high planes of nutrition respectively.

Effects of dietary n-3-PUFA supplementation, post-insemination plane of nutrition and pregnancy status on the endometrial transcriptome of beef heifers

Supplementation of cattle diets with n-3-polyunsaturated fatty acids (PUFA) can improve reproductive efficiency. Conversely, short-term fluctuations in feed supply can impact pregnancy establishment. The objectives of this study were to examine the effects of (1) dietary supplementation with n-3-PUFA and (2) post-insemination plane of nutrition on the endometrial transcriptome. Beef crossbred heifers were offered concentrate based diets fortified with n-3-PUFA (PUFA; n = 32) or not (CONT; n = 28) for 30 days prior to breeding at a synchronised oestrous. Following artificial insemination, heifers were allocated within treatment to either a high or low plane of nutrition. Heifers were maintained on these diets for 16 days following which endometrial tissue was harvested at slaughter for subsequent RNAseq analysis. The influence of pregnancy status on the endomentrial transcriptome, within each dietary treatment group, was also examined. Post-insemination diet affected (P < 0.05) the endometrial transcriptome. Specifically, within n-3-PUFA-supplemented heifers, genes involved in embryonic development and mTOR signalling pathways, important in pregnancy establishment, were identified as differentially expressed. Results indicate that dietary supplementation of cattle diets with n-3-PUFA may have a positive effect on the expression of key fertility-related genes and pathways, during the critical window of maternal recognition of pregnancy, particularly where animals are underfed.

Differing planes of pre- and postweaning phase nutrition in Holstein heifers: I. Effects on feed intake, growth efficiency, and metabolic and development indicators

The objectives of this study were to determine the effects of pre- and postweaning planes of nutrition on feed and metabolizable energy (ME) intake, growth, concentrations of glucose, insulin, insulin-like growth factor 1 (IGF-1), and β-hydroxybutyrate (BHB) in blood and rumen volatile fatty acids (VFA) from birth to 25 wk of age in Holstein heifers. Heifer calves (n = 36) were randomly assigned to receive either a low (5 L/d of whole milk) or high (10 L/d of whole milk) preweaning plane of nutrition from 1 to 7 wk of age, and either a low (70% concentrate dry total mixed ration) or high (85% concentrate dry total mixed ration) postweaning plane of nutrition from 11 to 25 wk of age. From birth to 25 wk of age, feed intake was recorded daily, and body measures were obtained weekly. Circulating hormone and metabolite concentrations were measured biweekly and total ruminal VFA, fecal starch, and body condition were assessed monthly. Overall, average daily gain and body weight were greater for heifers offered increased planes of nutrition during both the pre- and postweaning phases. Heifers offered the high preweaning plane had greater milk intake (7.7 ± 0.1 vs. 4.5 ± 0.1 L/d) but lower starter intake (0.3 ± 0.04 vs. 0.7 ± 0.04 kg/d) during the preweaning phase than those offered the low plane. High preweaning plane heifers also had greater ME intake from wk 1 to 7, but less ME intake at wk 9 (5.3 ± 0.3 vs. 6.6 ± 0.2 Mcal/kg) than those offered the low plane. Furthermore, overall glucose (118.8 ± 2.9 vs. 110.1 ± 2.9 mg/dL) and IGF-1 (101.6 ± 3.6 vs. 75.9 ± 3.6 ng/mL) concentrations were greater for high versus low preweaning plane heifers, although circulating insulin and BHB did not differ between preweaning plane groups. However, heifers offered the high preweaning plane had reduced total rumen VFA concentrations compared with heifers offered the low plane in the preweaning phase (47.3 ± 2.0 vs. 55.6 ± 2.1 mM). During the postweaning phase, dry matter intake and ME were consistently greater in heifers offered the high postweaning plane. Overall insulin (2.0 ± 0.1 vs. 1.8 ± 0.1 ng/mL), glucose (97.1 ± 0.6 vs. 92.1 ± 0.6 ng/mL), IGF-1 (178.0 ± 4.8 vs. 155.8 ± 4.8 ng/mL), and BHB concentrations (8.8 ± 0.2 vs. 8.1 ± 0.2 ng/mL) were greater in heifers offered the high than the low postweaning plane. In addition, heifers offered the high postweaning plane had increased VFA concentrations in the postweaning phase (73.4 ± 1.3 vs. 63.9 ± 1.3 mM) compared with heifers offered the low postweaning plane. The results indicated that increasing the pre- and postweaning planes of nutrition along with energy levels positively influenced several indicators associated with heifer development before 25 wk of age. Nevertheless, there was limited interaction in growth and development indicators between the 2 phases.

Effects of plane of milk-replacer nutrition on the health, behavior, and performance of high-risk Holstein bull calves from a commercial calf ranch

ObjectiveThis research study aimed to determine whether preweaning plane of milk-replacer nutrition influences health, standing and oral behaviors, and performance of high-risk calves.Materials and MethodsThirty-six Holstein bull calves (1 d of age) from a commercial calf ranch were assigned to either a high plane of milk-replacer nutrition (HPN; n = 18; 20 and 28% DM lipid and protein, respectively, Cow’s Match, Land O’Lakes Animal Milk Protein Co., Shoreview, MN) or a low plane of milk-replacer nutrition (LPN; n = 18; 20% DM lipid and protein, Herd Maker, Land O’Lakes Animal Milk Protein Co.) through weaning. Total serum protein concentrations confirmed that 72 and 76% of calves had failure of passive transfer (<5.2 g/dL) in HPN and LPN, respectively. All calves were bottle fed twice daily. The LPN were fed 455 g of DM/d of milk replacer (MR) until weaning, and the HPN calves were fed 830 g of DM/d of milk replacer during the first 10 d and 1,080 g from 11 d until weaning. Calf starter and water were offered ad libitum. Calves were step-down weaned beginning at 51 d and completely weaned after 58 d when consuming 1 kg of calf starter (as-fed basis). Data are reported as HPN versus LPN throughout, respectively.Results and DiscussionRisk for bloat and scouring were greater for calves fed the HPN, but there was no difference in antibiotic treatment or mortality. The HPN calves had greater performance over the preweaning period including final BW, ADG, and feed:gain (total kg of milk replacer + calf starter, kg of DM/kg of BW gain), but weaning was more stressful for HPN calves.Implications and ApplicationsIn conclusion, the high-risk calves fed a HPN had increased preweaning ADG, but there was also an increased incidence of scours. There may be differences in the health status of calves that may affect the ability to consume and use high MR levels. When feeding high-risk calves there may be a need for alternate strategies when determining the quality and quantity of MR being fed when compared with low-risk calves. Differences in gut integrity may influence the ability of high-risk calves to handle high levels of MR early in life. Potential issues with high-risk calves being fed a HPN might be reduced with increased feeding times per day, a gradual step-up method, or other nutritional strategies that improve gastrointestinal development and function.

PSX-40 Effects of nutritional plane before breeding on performance of hair sheep

Abstract The objective of the study was to determine effects of the nutritional plane before breeding on performance of different hair sheep breeds. Twenty-five Dorper, 27 Katahdin, and 32 St. Croix ewes with initial BW of 65.6, 65.7, and 54.3 kg (SEM=1.95) and body condition score (BCS; 1–5) of 3.35, 3.29, and 3.09, respectively, consumed wheat straw ad libitum for 11 wk before breeding. Ewes of each breed were divided into four groups, with two groups per nutritional plane (NP). Ewes on a low NP (Low-NP) were supplemented with 0.16% BW (DM) of soybean meal (SBM) and ewes on the high NP (High-NP) received 0.8% BW (DM basis) of 0.25% soybean meal and 0.75% ground corn. Ewes were divided into two groups for estrus synchronization. Four rams of each breed were used, two for the first 17 d of breeding and the other two from d 17 to 34. Conception and embryo mortality were determined by ultrasound imaging at 25 and approximately 40 d post-breeding. Average daily gain and BCS change were similar among breeds, but both were greater for High-NP vs. Low-NP (ADG: 57 vs. -4 g, SEM=8.1; BCS change: 0.22 vs. -0.02, SEM=0.041). Wheat straw DMI was greater (P = 0.01) for Low-NP than for High-NP (2.02 and 1.58% BW, respectively; SEM=0.042) and for St. Croix than for Dorper and Katahdin (P = 0.04; 1.96, 1.68, and 1.74% BW, respectively, SEM=0.060). There were no differences in the number of services or conception (P &amp;gt; 0.05), and no embryo mortality was noted. In conclusion, NP did not influence reproductive performance assessed early after breeding despite differences in ADG and BCS change. This may be due to moderate initial BCS and increased straw intake by Low-NP ewes.

Effects of the plane of nutrition for grower pigs on their grow-finish performance and meat quality in winter.

Little is known about the effects of the plane of nutrition on growth performance and meat quality of grow-finish pigs under commercial production conditions. The present study was thus addressed to this virtually unanswered question. One hundred and two barrows and 102 gilts weighing approximately 24 kg were fed phase I and II grower diets with a high, medium, or low plane of nutrition (HP, MP, or LP) to approximately 43 and 70 kg, respectively, in 6 replicates (pens). Subsequently, the HP and MP groups were fed the HP and MP1 finisher diets, respectively, the LP group being fed a second MP (MP2) finisher diet (LP1 group). Moreover, 68 LP-grower-fed barrows and gilts were added to the feeding trial and fed the MP1 and LP finisher diets to approximately 95 kg and thereafter, respectively (LP2 group). All MP diets had the lysine:calorie ratios comparable to the RNC recommendations, with < 18% differences between those of the HP and LP diets. The finisher pigs were reared in 16 pens and slaughtered at approximately 115 kg. The gain:feed ratio, but not average daily gain (ADG), was greater for the HP group than for the MP and LP during the grower phase I whereas during the grower phase II, ADG was greater (p < 0.05) for the HP and LP groups vs. MP. During the finisher phase I, ADG was less for the LP (LP1 + LP2) group vs. HP and MP, with no difference between the HP and MP groups; the gain:feed ratio was less for the LP vs. MP group. Backfat thickness was greater for the LP vs. HP group. The water holding capacity of fresh longissimus dorsi muscle (LM) and the sensory juiciness score for cooked LM were greatest for the LP group, the sensory flavor and tenderness scores being greater for the LP group vs. MP. In conclusion, results suggest that compensatory growth occurred for the LP and MP groups during the grower phase II and finisher phase I, respectively, with fat deposition increased for the LP group and that meat quality could be improved by the use of LP.

Effects of the plane of nutrition during the latter grower and entire finisher phases on grow-finish pig performance in summer.

The present study was undertaken to investigate the effects of the plane of nutrition (PN) for growing-finishing pigs on growth performance and meat quality in summer. One hundred and two barrows and 102 gilts weighing approximately 44 kg were placed on a high-, medium-, or low-plane grower diet (HPG, MPG, or LPG) with ME and lysine concentrations ranging from 3.33 to 3.40 Mcal/kg and 0.93% to 1.15%, respectively, for 29 days in 6 replicates (pens) in total. Pigs from each grower pen were divided into two finisher pens and provided with a high-plane finisher diet (HPF) containing 3.40 Mcal ME and 9.5 g lysine/kg and a low-plane finisher diet (LPF; 3.25 Mcal ME and 8 g lysine/kg), respectively, up to approximately 110 kg, and slaughtered. Growth performance of the pigs, including average daily gain (ADG), average daily feed intake (ADFI), and gain:feed ratio, was not influenced by the grower-phase PN during any of the grower phase, a 31-d finisher phase I, and ensuing phase II. However, both the ADG and gain:feed ratio were greater (p < 0.05) for the HPF group than for the LPF group during the finisher phase I (748 vs. 653 g with SEM = 13 g and 0.333 vs. 0.299 with SEM = 0.008, respectively). The ADG, but not gain:feed ratio, was greater for the HPF group vs. LPF during the finisher phase II (673 vs. 623 g with SEM = 15 g for ADG and 0.322 vs. 0.323 with SEM = 0.005 for the gain:feed ratio). The carcass backfat thickness (BFT) was greater for the LPF group vs. HPF within the pigs which had been placed on LPG during the grower phase, but not within the pigs from the HPG or MPG group. Physicochemical characteristics of the longissimus dorsi muscle (LM) and sensory quality attributes of fresh and cooked LM were not influenced by either the grower-phase or finisher-phase PN. In conclusion, high PN is necessary for finishing pigs during the hot season to minimize the reduced rate of weight gain and also to prevent the increase of BFT that could result from low PN.

Effects of the Low Plane of Nutrition on Carcass and Pork Quality of Finishing Pigs

Effects of the Low Plane of Nutrition on Carcass and Pork Quality of Finishing Pigs

Effect of Early Calf-Hood Nutrition on the Transcriptional Regulation of the Hypothalamic-Pituitary-Testicular axis in Holstein-Friesian Bull Calves

The aim of this study was to investigate the effect of early calf-hood nutrition on the transcriptomic profile of the arcuate nucleus of the hypothalamus, anterior pituitary and testes in Holstein-Friesian bulls. Holstein-Friesian bull calves with a mean (±S.D.) age and bodyweight of 19 (±8.2) days and 47.5 (±5.3) kg, respectively, were offered a high (n = 10) or low (n = 10) plane of nutrition in order to achieve an overall growth rate of 1.2 and 0.5 kg/day. At 126 (±3) days of age, calves were euthanized, hypothalamus (arcuate region), anterior pituitary and testicular parenchyma samples were harvested and RNAseq analysis was performed. There were 0, 49 and 1,346 genes differentially expressed in the arcuate nucleus, anterior pituitary and testicular tissue of bull calves on the low relative to the high plane of nutrition, respectively (P < 0.05; False Discovery Rate <0.05). Cell cycle processes in the anterior pituitary were down regulated in the low relative to the high plane of nutrition; there was no differential expression of genes related to reproductive processes. Gene expression involved in cholesterol and androgen biosynthesis in the testes were down regulated in animals on the low plane of nutrition. This study provides insight into the effect of early life plane of nutrition on the regulation of the HPT axis.

Effect of early calf-hood nutrition on the transcriptomic profile of subcutaneous adipose tissue in Holstein-Friesian bulls

BackgroundAdipose tissue is a major endocrine organ and is thought to play a central role in the metabolic control of reproductive function in cattle. Plane of nutrition during early life has been shown to influence the timing of puberty in both male and female cattle, though the exact biological mechanisms involved are currently unknown. The aim of this study was to investigate the effect of early calf-hood nutrition on the transcriptomic profile of subcutaneous adipose tissue in Holstein-Friesian bulls to identify possible downstream effects on reproductive physiology.ResultsHolstein-Friesian bull calves with a mean (±S.D.) age and bodyweight of 19 (±8.2) days and 47.5 (±5.3) kg, respectively, were assigned to either a high (n = 10) or low (n = 10) plane of nutrition. Calves were fed in order to achieve an overall growth rate of 1.08 and 0.57 kg/day for the high and low plane of nutrition treatments, respectively. At 126 days of age, the bulls were euthanized, subcutaneous adipose tissue samples were harvested and RNAseq analysis was performed. There were 674 genes differentially expressed in adipose tissue of calves on the low compared with the high plane of nutrition (P < 0.05; FDR < 0.05; fold change > 2.0). High plane of nutrition positively altered the expression of genes across an array of putative biological processes but the most dominant cellular processes affected were cellular energy production and branched chain amino acid degradation. A high plane of nutrition caused upregulation of genes such as leptin (LEP) and adiponectin (ADIPOQ), which are known to directly affect reproductive function.ConclusionsThese results provide an insight into the effect of augmenting the plane of nutrition of Holstein-Friesian bull calves in the prepubertal period on the transcriptome of adipose tissue.

Plane of nutrition before and after 6 months of age in Holstein-Friesian bulls: I. Effects on performance, body composition, age at puberty, and postpubertal semen production

The aim of this study was to examine the effect of plane of nutrition (1) during the first 6 mo of life and (2) from 6 mo of age to puberty on early growth characteristics, age at puberty, and postpubertal semen production in Holstein-Friesian bulls. Holstein-Friesian bull calves (n = 83) with a mean (standard deviation) age and body weight of 17 (4.4) d and 52 (6.2) kg, respectively, were assigned to a high (Hi) or low (Lo) plane of nutrition for the first 6 mo of life. The Hi and Lo calves received 1,200 and 450 g of milk replacer, respectively; Hi calves were fed concentrate ad libitum and Lo were fed a maximum of 1 kg concentrate daily, and concentrate allowances remained the same after weaning. At 24 wk of age, bulls were reassigned within treatment to either remain on the same diet or to switch to the opposite diet until puberty, resulting in 4 treatment groups: Hi-Hi, Hi-Lo, Lo-Lo, and Lo-Hi. After puberty, all bulls were fed a moderate plane of nutrition until 60 wk of age; thereafter, the diet was ad libitum concentrates until slaughter at 72 wk of age. Bulls were weighed weekly before weaning and every 2 wk after weaning. Scrotal circumference (SC) was measured every 2 wk, beginning at 15 wk of age. Beginning at a SC of 24 cm, electro-ejaculation was carried out every 2 wk to establish the onset of puberty. Semen collection continued monthly after puberty. Thermal images of the scrotum were taken monthly from 28 to 36 wk of age. Scrotal skin thickness (SST) was measured monthly (from 16 wk of age to puberty) using a digital calipers. Bulls on the Hi diet had a higher scrotal temperature and SST at each time point than those on the Lo diet. Average daily gain (ADG) was greatest in Hi-Hi bulls, with Hi-Lo and Lo-Hi having similar ADG but both being greater than Lo-Lo. Bulls on the Hi diet pre-6 mo of age were younger at puberty, regardless of diet offered post-6 mo of age. Bulls offered a Hi diet post-6 mo were heavier at puberty. Neither scrotal temperature nor dietary treatment affected postpubertal semen production variables. In conclusion, a high plane of nutrition during the first 6 mo of age hastened the onset of puberty and the availability of saleable semen, regardless of plane of nutrition post-6 mo of age.

Plane of nutrition before and after 6 months of age in Holstein-Friesian bulls: II. Effects on metabolic and reproductive endocrinology and identification of physiological markers of puberty and sexual maturation

The aim of this study was (1) to examine the effect of plane of nutrition during the first and second 6 mo of life on systemic concentrations of reproductive hormones and metabolites in Holstein-Friesian dairy bulls, and (2) to establish relationships with age at puberty and postpubertal semen production potential. Holstein-Friesian bull calves (n = 83) with a mean (standard deviation) age and body weight of 17 (4.4) d and 52 (6.2) kg, respectively, were assigned to a high or low plane of nutrition for the first 6 mo of life. At 24 wk of age, bulls were reassigned, within treatment, either to remain on the same diet or to switch to the opposite diet until puberty, resulting in 4 treatment groups: high-high, high-low, low-low, and low-high. Monthly blood samples were analyzed for metabolites (albumin, urea, total protein, β-hydroxybutyrate, glucose, nonesterified fatty acid, triglycerides and creatinine), insulin, insulin-like growth factor-1, leptin, adiponectin, FSH, and testosterone. A GnRH challenge was carried out at 16 and 32 wk of age (n = 9 bulls per treatment). Blood was collected at 15-min intervals for 165 min, with GnRH administered (0.05 mg/kg of body weight, i.v.) immediately after the third blood sample. Blood samples were subsequently analyzed for LH, FSH, and testosterone. Stepwise regression was used to detect growth and blood measurements to identify putative predictors of age at puberty and subsequent semen quality traits. Metabolic hormones and metabolites, in general, reflected metabolic status of bulls. Although FSH was unaffected by diet, it decreased with age both in monthly samples and following GnRH administration. Testosterone was greater in bulls on the high diet before and after 6 mo of age. Testosterone concentrations increased dramatically after 6 mo of age. Luteinizing hormone was unaffected by diet following GnRH administration but basal serum LH was greater in bulls on a high diet before 6 mo of age. In conclusion, the plane of nutrition offered before 6 mo of age influenced metabolic profiles, which are important for promoting GnRH pulsatility, in young bulls.

Plane of nutrition during the rearing phase for replacement ewes of four genotypes: II - effects on performance during first pregnancy and to weaning, and of their progeny

Plane of nutrition (PN) offered to ewe replacements during the rearing phase (8 to 17 months) and first pregnancy may affect reproductive and progeny performance when replacements are joined at ~19 months. The effects of PN offered to spring-born ewe replacements during their first winter (winter_1), second summer (summer_2) and subsequent winter (mid and late pregnancy; winter_2) were evaluated, over 3 consecutive years, using 287 ewe lambs of four genotypes: Charmoise×Scottish Blackface (C×SBF), Belclare×SBF (Bel×SBF), Belclare (Bel) and Belclare×SBF (heterozygous for a gene, either FecGH or FecXG mutations, that increases ovulation rate: BelMG×SBF). Ewe lambs were offered, daily, a deferred-grazed herbage allowance (HA) of either 0.75 or 1.75 kg dry matter during winter_1. During summer_2 the replacements were set-stocked to maintain sward heights of 4 or 6 cm. Ewes were housed during mid and late pregnancy (winter_2) and offered either medium or high-feed-value grass silage, thus yielding a 2×2×2 factorial design. Increasing HA during winter_1 and residual sward height during summer_2 increased ewe BW post joining (P<0.001) and at lambing (P<0.01), but had no effect (P>0.05) on number of lambs reared. Increasing HA during winter_1 increased lamb BW at birth (P<0.05) and reduced carcass fat score (P<0.05). There was a significant interaction between PN offered during winter_1 and summer_2 for average daily gain (ADG) from birth to 5 weeks (P<0.01) and from 5 to 10 weeks (P<0.05): progeny of replacements that experienced either a high or low PN throughout the rearing phase had lower ADG than lambs born to the replacements that experienced a low PN only during winter_1 or summer_2. Increasing PN during winter_2 increased ewe BW (P<0.001), lamb BW at birth (P<0.001) and weaning (P<0.05) and reduced the proportion of ewes that failed to lamb (P<0.01). Ewe genotype had a significant (P<0.001) effect on litter size (1.48 to 2.45), number of lambs reared, lamb BW at birth and weaning, lamb ADG and age at slaughter. It is concluded that, among the nutrition treatments examined, increasing PN during mid and late pregnancy had the greatest effect on ewe and progeny performance. Although increasing PN offered during winter_1 increased lamb birth BW, PN offered during summer_2 had no effect on lamb performance. There were no significant interactions between PN and ewe genotype.

96 Follicular Fluid and Serum Biochemical Composition in Alpacas (Vicugna pacos) with Different Nutritional Planes

The importance of nutrition on composition of follicular fluid and oocyte quality is recognised in several species but limited information is available on alpacas and would explain the high rate of early embryo mortality. The aim of this study was to analyse the biochemical composition of serum and follicular fluid (FF) from alpacas (Vicugna pacos) with different nutritional planes. Twelve adult female alpacas between 6 and 8 years old were assigned randomly to either a high (n = 6) or low (n = 6) plane of nutrition. Nutritional planes were defined by the grazing condition of the natural pasture with (high) or without (low) supplementation with 200 g of concentrate/day (total digestible nutrients: 52%, protein: 16%, and metabolizable energy: 2.8 Mcal kg−1). The nutritional conditions were imposed 1 month before the start of the experiment.The concentrations of total glucose, cholesterol, triglycerides, and proteins were determined with a semi-automatic biochemical analyzer (SINOWA, China). When an ovulatory follicle ≥7 mm was detected by ultrasonography using a 5-MHz linear-array transducer (SSD-500, Aloka, Tokyo, Japan), a transvaginal transducer with an attached needle guide (UST-945BP-5, Aloka) was used to collect follicular fluid. Follicular puncture was performed using a disposable 19-gauge # 12 mm hypodermic needle connected to a 50-mL conical tube via a silicon tube. A caudal epidural anaesthesia was induced with 4 mL of 2% lidocaine. Blood samples were obtained by jugular venipuncture into serum vacutainers and kept at room temperature for 30 min. Follicular fluid and serum were centrifuged at 1500 × g for 20 min, decanted, and stored at –20°C until analysed. Results were analysed by Student’s t-test. The results are presented in Table 1. The results suggest differences in biochemical composition of glucose and cholesterol in follicular fluid, which could explain the oocyte quality and embryo survival in alpacas. Table 1.Biochemical composition of follicular fluid (FF) and serum from alpacas (Vicugna pacos) under 2 nutritional planes Research was supported by INNOVATE PERU Grant 405-PNICP-PIAP-2014.