Mcal Metabolizable Energy Research Articles

220 Impact of Bump Feeding During Late Gestation on Reproductive Performance of Over-Conditioned Sows

Abstract Our objective was to evaluate the effect of bump-feeding during late gestation on reproductive performance of multiparous over-conditioned sows. A total of 220 PIC Camborough sows were assigned to one of three feeding levels in a completely randomized design. Caliper was individually collected at d 90 of gestation from a larger group of sows to assess body condition, and only sows from parity 1+ and considered over-conditioned by the sow caliper were selected for the study. Sows were equally balanced by parity (P1 and P2 as young, and P3+ as mature) when allocated to treatments. All sows were fed a common gestation diet containing 3.20 Mcal of metabolizable energy (ME) per kg and 0.56% standardized ileal digestible lysine, but feed drop-boxes were adjusted to different feeding levels according to treatment. Treatments consisted of 5.09 Mcal of ME/d (1.59 kg/d; CONTROL), 6.54 Mcal of ME/d (2.04 kg/d; 0.45kg-BUMP), or 8.00 Mcal of ME/d (2.49 kg/d; 0.90kg-BUMP); and fed to sows from d 90 of gestation until they were moved to the farrowing room. Sows were housed in crates during gestation. Sow body weight (BW) and caliper measurements were collected at pre-farrowing and weaning, and their difference was calculated. Additionally, post-farrowing 48h BW was predicted using the following equation: 48h post-farrow BW = -20.81 + (0.98 × pre-farrow BW). Total born, born alive (BA), stillborn (SB), and mummified were collected for each sow at farrowing. Individual piglet BW were recorded at birth, at cross-foster, and at weaning. Data were analyzed using a generalized linear model considering sow as the experimental unit. Models included treatment, parity group, and their interaction as fixed effects. Covariates were included if they were statistically significant and improved model fit. There was no treatment by parity group interaction for any response criteria. There was no evidence for differences between treatments for caliper at d 90 of gestation, caliper pre-farrow, caliper at weaning, or caliper change between d 90 to pre-farrow and pre-farrow to weaning (P >0.10; Table 1). Sows that received 0.90 kg-BUMP were marginally heavier at farrow than CONTROL sows (P < 0.10), with those receiving 0.45 kg-BUMP intermediate. CONTROL sows lost less BW during lactation compared with 0.45kg-BUMP sows (P < 0.05), with 0.90 kg-BUMP sows intermediate. Sows receiving 0.45kg-BUMP from d90 of gestation to farrowing had greater percentage BA piglets and decreased percentage SB compared with sows receiving 0.90 kg-BUMP (P < 0.05), with CONTROL sows intermediate. There was no evidence (P >0.10) for treatment differences for piglet birth weight, litter and piglet BW gain, or percentage weaned piglets. In summary, increasing the feeding level for over-conditioned sows during late gestation did not impact sow reproductive or litter performances.

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

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

Focused nutrition during oestrus synchronization in Pelibuey ewes with different body conditions

The aim of this study was to evaluate ovarian follicular activity, ovulation percentage, and body weight change in response to focused nutrition during synchronization of oestrus with an intravaginal device (CIDR®) (9 days) in Pelibuey ewes with high and low body condition. Seventy-two non-pregnant ewes without offspring were randomly distributed to one of four treatments, namely T1: (n = 18) ewes without focused nutrition and low body condition; T2: (n = 18) ewes without focused nutrition and high body condition; T3: (n = 18) ewes with focused nutrition and low body condition; and T4: (n = 18) ewes with focused nutrition and high body condition. While the CIDR device was in place, the ewes with focused nutrition received a supplement of 1.5 kg ewe/day, which contained 2.9 MCal metabolizable energy, 16% crude protein, 88.5% dry matter, 11.8% crude fibre, and 6.7% of ash. The concentration of progesterone (P4) was measured to determine ovulation percentage. The follicular population was quantified (2–3 mm, 4–5 mm, and >6 mm in diameter). The number of follicles between 2–3 mm and 4–5 mm in diameter was similar among treatments. The number of follicles >6 mm in diameter was higher in T4 ewes (2.2 ± 0.2) compared with T1, T2, and T3. The response to oestrus, the onset of oestrus, and the ovulation percentage were similar among treatments. Focused nutrition increased the number of ovarian follicles >6 mm in diameter in ewes with high body condition.

Bioindicadores de estrés y evolución de peso de terneros provenientes de destete precoz e hiperprecoz

Early (60 – 70 days old) & very early weaning (30 – 40 days old) are used to improve pregnancy in beef cow-calf systems. However, its application can affect the calves’ welfare. The aim of this work was to identify biomarkers levels & average weight gain in early & very early weaned calves. The animals were assigned to pens according to weaning age: very early weaned (40-d) & early weaned (66-d). The weaning practice consisted of the daily supply of extruded food (26% crude protein & 3 Mcal metabolizable energy). Live weight was registered at 14 days intervals. Blood samples were collected on the day of weaning (0) & on days 2 & 11 after. Red blood cells, hematocrit, hemoglobin, mean corpuscular value, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, white blood cells, total proteins, & albumin were measured by complete blood count. Statistical analyzes were performed using the ANOVA ((Tukey Test, α = 0,05). Any calf lost weight; also, average weight gain was higher in early weaned calves. Most of the biomarkers presented normal values after the weaning stage (day 11). In this work, weaning at early ages didn`t affect animal welfare. These results are important in the beef cow-calf systems where are applied to improve the pregnancy rate.

An In vitro Approach to Optimize Levels of Moringa oleifera Meal Incorporation in Total Mixed Ration for Crossbred Heifer Calves

An in vitro experimentation outside living animals to evaluate feed/fodders on digestibility and gas production is cheap, easy and having more control condition as compared to an in vivo evaluation on livestock which is costly and time-consuming event. The incorporation of Moringa oleifera meals @ 2.5– 22.5% with increment of 2.5% in total mixed ration-TMR replacing concentrate mixture (50%) was assessed on in vitro digestibility, total gas production (TGP) and metabolizable energy (ME) content for growing crossbred heifer calves. The roughage part (50%) of TMR was hybrid napier (15%) and ground nut straw (35%). All these ingredients were oven dried for twenty four hour at 70°C and finely ground in hammer mill using 1 mm sieve. 500 mg of each TMR were incubated at 39±1°C for 48 hours in triplicate along with blank without TMR. The results of experiment revealed that incorporation of Moringa oleifera meal @ 5.0% with increment levels of 2.5% and higher levels up to 22.5% to replace high protein concentrate mixture (50%) in total mixed ration containing 50% roughage (15% hybrid napier and 35% ground nut straw) has improved (p<0.05) in vitro dry matter digestibility (60.879±0.251 to 64.678±0.679%), in vitro gas production (81.000±9.018 to 95.667±1.764 ml/500 mg TMR) and ME content (2.356±0.068 to 3.223±0.057 Mcal ME kg-1 TMR) of total mixed ration. The levels 5% and above up to 22.5% with increment of 2.5% level in total mixed ration replacing concentrate mixture was found suitable for in vivo growth study of crossbred heifer calves.

Transition milk stimulates intestinal development of neonatal Holstein calves

Colostrum stimulates gastrointestinal development. Similar to colostrum, transition milk (TM; the first few milkings after colostrum) contains elevated nutrient levels and bioactive components not found in milk replacer (MR), albeit at lower levels than the first colostrum. We hypothesized that feeding neonatal calves TM, compared with MR, for 4 d following colostrum at birth would further stimulate intestinal development. Holstein bull calves were fed 2.8 L of colostrum within 20 min of birth, allocated to 1 of 11 blocks based on birth date and body weight (BW), randomly assigned to MR (n = 12) or TM (n = 11) treatments within block, and fed treatments 3 times per day. Milk from milkings 2, 3, and 4 (TM) of cows milked 2 times daily was pooled by milking number and fed at 1.89 L per feeding; milking 2 was fed at feedings 2 through 5, milking 3 at feedings 6 through 8, and milking 4 at feedings 9 through 12. TM was not pasteurized and contained 17% solids, 5% fat, 7% protein, 4% lactose, and 20 g of IgG per liter on average, whereas MR (as fed) contained 15% solids, 4% protein, 3% fat, 6% carbohydrate, and no IgG. Refusals were similar, so calves fed TM consumed 1.0 Mcal of metabolizable energy per day more than those fed MR. On the morning of d 5, calves were injected i.v. with 5 mg of bromodeoxyuridine per kg of BW and slaughtered 130 min later; then, intestinal sections were excised. Feeding TM, instead of MR, doubled villus length, villus width, villus to crypt ratio, and mucosal length in all intestinal sections, increased submucosal thickness 70% in the proximal and mid jejunum, and tended to increase submucosal thickness in duodenum and ileum. Mucosal surface area was also increased in both the ileum and mid jejunum when feeding TM by 19 and 36%, respectively. Treatment did not alter crypt depth. Bromodeoxyuridine labeling was increased 50% by TM compared with MR in the cells along the epithelium of the crypts and within the villi of all sections, indicating that TM increased cell proliferation compared with MR. Calves fed TM gained more BW than calves fed MR and had improved cough, fecal, nose, and ear scores. We conclude that feeding TM for 4 d following an initial feeding of colostrum stimulates villus, mucosal, and submucosal development in all sections of the small intestine in the first few days of life and improves health and growth.

Effect of storage of wet brewer's grains with incremental levels of salt on apparent total tract nutrient digestibility and purine derivative excretion in dairy heifers.

Objectives of this study were to evaluate apparent total tract nutrient digestibility and purine derivative (PD) excretion in dairy heifers limit-fed diets containing wet brewer's grains (WBG) treated with salt. A 12-wk replicated 4 × 4 Latin square was conducted using 8 Holstein heifers of 224.5 ± 19.4 d of age, and body weight (BW) of 219.2 ± 28.1 kg (mean ± SD). Fresh WBG were treated with 0%, 0.8%, 1.6%, and 2.4% salt and stored for 4 d before being fed. Salt was added either to the WBG or separately to equalize the amount of salt in the diet. The diet contained 9% grass silage, 47% corn silage, 19% corn meal, 17.6% WBG and salt, 2% soybean meal, and 3% mineral mix. Diets were formulated to be limit-fed at 2.15% of BW, provide 14% crude protein (CP) and 2.27 Mcal metabolizable energy (ME)/kg of dry matter (DM). Heifers were adapted to diets for 14 d followed by a 7-d collection period. Dry matter intake (DMI) was recorded daily during the collection week while BW was recorded once a week. Urine and fecal samples were collected during the last 4 d of the collection period. Acid insoluble ash was used as an internal marker to determine apparent nutrient digestibility. Weight loss of WBG during storage was determined from days 1 to 11 and initial and final yeast and mold counts were determined. Final yeast counts were similar among treatments while final mold counts tended to be lesser (P = 0.07) for the 0.8% and 1.6% salt treatments. Urinary volume was similar among treatments while allantoin (P = 0.14), and uric acid (P < 0.01) and total PD excretion tended to increase (P = 0.13) quadratically. DMI was varied by treatment (linear, quadratic, and cubic effects P < 0.01). Heifers fed the 0.8% treatment had the least DMI. Nonfiber carbohydrate (NFC) digestibility linearly decreased (P < 0.04) as salt increased. Digestibilities of DM, and organic matter (OM), tended to decrease (P < 0.10) with increasing levels of salt added to WBG. Fat digestibility was quadratic with the greatest value for the 1.6% treatment. Treating WBG with salt reduced its deterioration based on lesser mold counts for the 0.8% and 1.6% treatments. These treatments had resulted in greater fat digestibility and tended to have increased PD excretion suggesting improved microbial protein synthesis.

The colostrum composition of sheep fed with high-energy diets supplemented with chromium

Abstract The ewe’s colostrum is an essential food for newborns because it helps them to improve their immune system in addition to providing nutrients for a few days after birth. It also increases the survival of the newborn in the first weeks of life, given that the ovine has a higher mortality rate in the initial 15 days of life. The rate of mortality can be reduced by providing sufficient good-quality colostrum at the right time. This study aimed to evaluate whether energy nutrition and chromium supplementation, during pregnancy and lactation, can alter sheep health parameters, colostrum quality parameters, birth and weaning weights, and mortality rate until lamb weaning time. Blood metabolites were analyzed to evaluate the influence of dietary energy on sheep health. The quality parameters of colostrum studied were immunoglobulin and antioxidants. The experiment was performed with 32 sheep, at the end of gestation (last 50 days) and lactation (60 days), in a completely randomized block design and distributed in three treatments: a diet with 2.24 Mcal of metabolizable energy (ME)/kg DM with corn starch (CTL), a diet with 2.46 Mcal of ME/kg DM with corn starch (ST), or a diet with 2.46 Mcal of ME/ kg DM with corn starch and chromium propionate (ST + Cr). Samples of blood and colostrum were collected before the parturition. There were no differences (P > 0.05) in dry matter intake (DMI), and blood levels of calcium, phosphorus, non-esterified fatty acids, β-hydroxybutyrate, and insulin. A difference was found for the blood glucose in which the CTL group had a lower (P 0.05) in the blood concentrations of total protein, immunoglobulin G and M, lysozyme, lactoperoxidase, ceruloplasmin, superoxide dismutase (SOD), ferric reducing ability of plasma (FRAP), oxygen radical absorbance capacity (ORAC), latent iron-binding capacity (LIBC), total iron-binding capacity (TIBC), iron, lactotransferrin, and the lactotransferrin saturation index. The ST+CR diet provided the highest level of glutathione peroxidase (P

Increasing the ratio of SID lysine to metabolizable energy improves pig performance during a viral challenge.

Porcine reproductive and respiratory syndrome virus (PRRSV) compromises pig performance. However, increasing standardized ileal digestible Lys per Mcal metabolizable energy (SID Lys:ME) above requirement has been shown to mitigate reduced performance seen during a porcine reproductive and respiratory syndrome (PRRS) virus challenge. The objective of this study was to evaluate the effects of increasing the dietary SID Lys:ME from 100% National Research Council (NRC) requirement to 120% of the requirement in vaccinated (vac+; modified live vaccine Ingelvac PRRS) and non-vaccinated (vac−; no PRRS vaccine) grower pigs subjected to a PRRSV challenge. In addition, the dietary formulation approach to achieve the 120% ratio by increasing Lys relative to energy (HL) or diluting energy in relation to Lys (LE) was evaluated. This allowed us to test the hypothesis that pigs undergoing a health challenge would have the ability to eat to their energy needs. Within vaccine status, 195 mixed-sex pigs, vac+ (35.2 ± 0.60 kg body weight [BW]) and vac− (35.2 ± 0.65 kg BW) were randomly allotted to one of three dietary treatments (2.67, 3.23, or 3.22 g SID Lys:ME) for a 42-d PRRS virus challenge study representing 100%, 120%, and 120% of NRC requirement, respectively. Pigs were randomly allotted across two barns, each containing 24 pens with 7 to 10 pigs per pen (8 pens per diet per vaccine status). On day post-inoculation 0, both barns were inoculated with PRRSV and started on experimental diets. Within vaccine status, weekly and overall challenge period pig performance were assessed. In both vac+ (P < 0.05) and vac− (P < 0.05) pigs, the HL and LE diets increased end BW and overall average daily gain (ADG) ADG compared with pigs fed the control diet (P < 0.05). Overall, average daily feed intake (ADFI) during the challenge period was greater (P < 0.05) for pigs fed the LE diet compared with pigs fed control and HL treatments, regardless of vaccine status (20% and 17% higher ADFI than the control in vac+ and vac− pigs, respectively). The HL vac+ pigs had the greatest gain to feed (G:F) compared with the control and LE pigs (0.438 vs. 0.394 and 0.391 kg/kg, respectively; P < 0.01). Feed efficiency was not impacted (P > 0.10) by treatment in the vac− pigs. In summary, PRRSV-challenged grower pigs consumed feed to meet their energy needs as indicated by the increase in ADFI when energy was diluted in the (LE) diet, compared with control pigs. In both PRRS vac+ and vac− pigs subsequently challenged with PRRSV, regardless of formulation approach, fed 120% SID Lys:ME diets resulted in enhanced overall growth performance.

Impact of feed intake in early gestation on maternal growth and litter size according to body reserves at weaning of young parity sows.

The effect of increasing the feed level (1.8, 2.5, and 3.2 kg/d) during early gestation in parity 1 (PO1) and parity 2 (PO2) sows on maternal growth and litter size was evaluated. A total of 361 sows were group-housed and fed a diet based on a corn-soybean meal (3.15 Mcal Metabolizable Energy (ME) per kg and 0.68% standardized ileal digestible lysine) from day 6 of gestation until day 30. Sows were weighed at weaning and on day 30 of gestation. Farrowing rate, number of total piglets born, piglets born alive, stillborn piglets, and mummified fetuses were recorded at farrowing. The effect of feed level on the total number of piglets born was also evaluated according to classes of body weight (BW), body condition score (BCS), backfat (BF), and caliper unit at weaning for each parity order. There was no evidence for significant effect of the interaction between feed level × parity on the variables related to maternal growth and reproductive performance (P ≥ 0.128). Greater feed levels linearly increased the gains in body condition (i.e., BW, BCS, BF, and caliper unit) between weaning and day 30 of gestation (P < 0.001). Farrowing rate was not influenced by the feed level (P ≥ 0.200) and parity (P ≥ 0.209). The number of total piglets born decreased linearly as the feed level increased (P = 0.041), whereas no evidences for differences were observed on piglets born alive among treatments (P ≥ 0.317), neither between parities (P ≥ 0.904). For PO1 sows, the total piglets born on BW classes (≤183 vs. >183 kg) and on classes of BF (≤11.5 vs. > 11.5 mm) were quadratically affected by the feed levels (P ≤ 0.041). In contrast, the number of total piglets born was marginally affected (linear; P ≤ 0.094) by the feed level in the different classes of BW, BCS, and caliper unit in PO2 sows. There was no evidence for differences for the interaction of feed level and classes of body condition (P ≥ 0.199) for PO2 sows. Similarly, no interactions between feed level and classes of BW, BCS, and BF at weaning were observed (P ≥ 0.233) for PO1 sows; however, the total piglets born were affected by an interaction between feed level and caliper unit class (P = 0.042). In conclusion, increased feed intake from day 6 of gestation until day 30 resulted in increased maternal BW gain but reduced the number of total piglets born. Furthermore, lighter and in a poor BCS PO1 sows at weaning produced fewer total born piglets with no benefits from greater amounts of feed.

Effects of diet type on nutrient utilization and energy balance in drylot heifers1.

Feeding cattle in intensified settings allows cow-calf producers to decrease their reliance on grazed forage and utilize alternative feedstuffs. During times of intense management, diet type may alter energy utilization. Fourteen pregnant MARC III heifers (405 ± 44 kg BW) were used in a 180 d experiment to determine effects of diet type on nutrient and energy utilization. Heifers were randomly assigned to one of two treatments, a forage diet (FOR; 2.10 Mcal metabolizable energy [ME]/kg; 95.75% forage) or a concentrate diet (CONC; 2.94 Mcal ME/kg; 71% concentrate), and individually fed to meet maintenance energy requirements (0.135 Mcal ME/kg BW0.75). The CONC diet contained dry-rolled corn, corn stalks (10.16 cm grind size), soybean meal, corn silage (approximately 45% corn grain; stored in a plastic bag), dicalcium phosphate, urea, and a premix pellet; FOR contained alfalfa hay (harvested at mid-bloom), corn silage, dicalcium phosphate, and a premix pellet. Measurements of energy intake and digestibility were measured over a 4-d period on days 116, 172, and 235 of gestation. Using portable headbox calorimeters, measurements of O2, CO2, and CH4 gases were collected over a period of 24 h. Data were analyzed in a completely randomized design with diet as fixed effect. Dry matter and organic matter digestibility were greater for CONC than FOR (P < 0.01). Intake of gross energy (GE) and digestible energy (DE) were greater for FOR (P < 0.01), but by design, ME intake was not different between treatments (P = 0.26). Energy lost as methane (% of GE intake) was not different between treatments (P = 0.49). The ratio of ME to DE was greater for CONC (86.8 vs. 82.8; P = 0.01) than FOR. Heat production relative to ME was not different between treatments (P = 0.85). Maternal tissue energy did not differ and was 1.2 Mcal/d for CONC and 0.9 Mcal/d for FOR (P = 0.73). Greater nitrogen (N) consumption was observed for FOR (192.2 g/d) than CONC (134.0 g/d; P < 0.01), and retained N was greater for FOR than CONC (P < 0.01) on days 116 and 235 of gestation. Neither concentrate-based or forage-based diets affected body condition score (P = 0.26). Heifers fed concentrate-based diets retained more energy in part because they had larger calves, but this energy was not recovered in maternal tissue.

Form of calf diet and the rumen. II: Impact on volatile fatty acid absorption

Diet is known to affect rumen growth and development. Calves fed an all-liquid diet have smaller and less developed rumens and a decreased ability to absorb volatile fatty acids (VFA) compared to calves fed both liquid and dry feed. However, it is unknown how rumens respond when challenged with a defined concentration of VFA. The objective of this study was to assess the effects of 2 different feeding programs on VFA absorption in preweaned calves. Neonatal Holstein bull calves were individually housed and randomly assigned to 1 of 2 diets. The diets were milk replacer only (MRO; n = 5) or milk replacer with starter (MRS; n = 6). Diets were isoenergetic (3.87 ± 0.06 Mcal of metabolizable energy per day) and isonitrogenous (0.17 ± 0.003 kg/d of apparent digestible protein). Milk replacer was 22% crude protein, 21.5% fat (dry matter basis). The textured calf starter was 21.5% crude protein (dry matter basis). Feed and ad libitum water intakes were recorded daily. Calves were exposed to a defined concentration of VFA buffer (acetate 143 mM, propionate 100 mM, butyrate 40.5 mM) 6 h before euthanasia on d 43 ± 1. Rumen fluid samples were obtained every 15 to 30 min for 6 h to measure the rate of VFA absorption. Rumen tissues were obtained from the ventral sac region and processed for morphological and immunohistochemical analyses of the VFA transporters monocarboxylate transporter 1 (MCT1) and 4 (MCT4). Body growth did not differ between diets, but empty reticulorumens were heavier in MRS than MRO calves (0.67 vs. 0.39 ± 0.04 kg) and MRS calves had larger papillae areas (0.76 vs. 15 ± 0.08 mm2). We observed no differences between diets in terms of the abundance of MCT1 and MCT4 per unit area. These results indicate that the extrapolated increase in total abundance of MCT1 or MCT4 in MRS calves was not due to increased transporter density per unit area. Modeled VFA absorption metrics (flux, mmol/h, or 6 h absorbed VFA in mmol) were not different across diets. These results demonstrate that the form of calfhood diet, whether solely MR or MR and starter, does not alter VFA absorption capacity when the rumen is exposed to a defined concentration of VFA at 6 wk of age.

Form of calf diet and the rumen. I: Impact on growth and development

Preweaning diet is known to affect rumen tissue appearance at the gross level. The objectives of this experiment were to investigate effects of different preweaning diets on the growth and development of the rumen epithelium and on putative rumen epithelial stem and progenitor cell measurements at the gene and cell levels. Neonatal Holstein bull calves (n = 11) were individually housed and randomly assigned to 1 of 2 diets. The diets were milk replacer only (MRO; n = 5) or milk replacer with starter (MRS; n = 6). Diets were isoenergetic (3.87 ± 0.06 Mcal of metabolizable energy per day) and isonitrogenous (0.17 ± 0.003 kg/d of apparent digestible protein). Milk replacer was 22% crude protein, 21.5% fat (dry matter basis). The textured calf starter was 21.5% crude protein (dry matter basis). Water was available ad libitum and feed and water intake were recorded daily. Putative stem and progenitor cells were labeled by administering a thymidine analog (5-bromo-2'-deoxyuridine, BrdU; 5 mg/kg of body weight in sterile saline) for 5 consecutive days and allowed a 25-d washout period. Calves were killed at 43 ± 1 d after a 6 h exposure to a defined concentration of volatile fatty acids. We obtained rumen tissue from the ventral sac and used it for immunohistochemical analyses of BrdU (putative stem and progenitor cells) and Ki67 (cell proliferation), gene expression analysis, and morphological measurements via hematoxylin and eosin staining. Epithelial stem and progenitor cell gene markers of interest, analyzed by real-time quantitative PCR, were β1-integrin, keratin-14, notch-1, tumor protein p63, and leucine-rich repeat-containing G protein-coupled receptor 5. Body growth did not differ by diet, but empty reticulorumens were heavier in MRS calves (MRS: 0.67 ± 0.04 kg; MRO: 0.39 ± 0.04 kg). The percentage of label-retaining BrdU basale cells was higher in MRO calves than in MRS calves (2.0 ± 0.3% vs. 0.3 ± 0.2%, respectively). We observed a higher percentage of basale cells undergoing proliferation in MRS calves than in MRO calves (18.4 ± 2.6% vs. 10.8 ± 2.8%, respectively). Rumen epithelial gene expression was not affected by diet, but the submucosa was thicker in MRO calves and the epithelium and corneum/keratin layers were thicker in MRS calves. Presumptive stem and progenitor cells in the rumen epithelium were identifiable by their ability to retain labeled DNA in the long term, changed proliferative status in response to diet, and likely contributed to observed treatment differences in rumen tissue thickness.

English

Body weight, testes development and serum testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels were determined and compared in two groups of peri-pubertal male dromedaries. Daily maximum and minimum ambient temperatures and dry and wet-bulb temperatures were recorded. Temperature-humidity index was calculated. The camels were divided into two equal groups of nine camels each, of comparable body weight: Group (A) received a diet of 13% crude protein and 2.9 MCal metabolizable energy (ME) with added premix, while Group (B) received a non-pelleted diet of alfa-alfa and wheat straw at the ratio of 1:3 giving 12.4% CP and 2.7 MCal ME. Individual feed intake was calculated after 14 days of adaptation. Feed offered and orts were recorded daily throughout the experimental period (24 months). Animals were fed diets containing 1:3 alfa alfa:wheat straw. Blood samples were collected from 5 camels in each group at 15-day intervals during the experimental period. None significant difference in total body weight was found between groups A and B throughout the entire experimental period (p &gt;0.05). Group averages of daily feed intake for the entire period were 5.82 kg in group A and 7.08 kg in group B, respectively (p&lt;0.05). The latter group had significantly larger testicular size than group A (p&lt;0.05), seasonal difference&nbsp; in testicular size was also significant (p&lt;0.05); serum FSH level was significantly higher in group B than group A (p&lt;0.05), whereas serum testosterone and LH levels were comparable in the two groups.&nbsp; &nbsp; Key words: Camelus dromedaries, body weight gain, testicular size, testosterone, follicle stimulating hormone (FSH), luteinizing hormone (LH).

Seasonal variation of fibre follicle activity and wool growth in fat-tailed Sanjabi sheep in west Iran.

This experiment was conducted to investigate the seasonal pattern of hair follicle activity, wool growth and fibre diameter (FD) in Sanjabi sheep in west Iran, Kermanshah (34° 18' N and 47° 3' E, elevation 1420 m). Ten male and 10 female Sanjabi sheep with an initial live weight of 32.1 ± 1.3 and 32.7 ± 1.5 (means ± SD), respectively, were used in a 365-day study. A diet was offered with an estimated concentration of 2.18 Mcal metabolizable energy and 130.0 g/kg DM crude protein. Body weight, average daily gain (ADG) and dry matter intake (DMI) were recorded weekly. The percentages of active primary and secondary wool follicles (PAP and PAS), follicle density and the ratio of secondary to primary follicles (S/P) were determined from skin biopsies, taken from the right mid-side of the sheep at monthly intervals. Raw and clean fibre growth rates and FD were measured from left mid-side patches (10 × 10 cm) harvested at the end of every month. There was a gradual increase in live weight throughout the experiment, while ADG and DMI changed in concert with day length. The greatest values for PAP and PAS were observed in summer, whereas lowest were obtained in winter (p < 0.001). Clean wool growth rate and FD were greatest (p < 0.001) in summer and lowest (p < 0.001) in winter. It is concluded that a seasonal cycle of feed intake, body growth, fibre follicle activity, wool growth and FD occur in fat-tailed Sanjabi sheep.

Effect of nutritional state on semen characteristics, testicular size and serum testosterone concentration in Sanjabi ram lambs during the natural breeding season

This experiment was conducted to investigate the effect of plane of nutrition on body weight, average daily gain, dry mater intake, semen characteristics, serum testosterone concentration and testicular circumference of Sanjabi ram lambs during the natural breeding season. Sanjabi ram lambs (n=20) that were 8 months of age were penned under natural photoperiod at latitude 34°18′N for a period of 9 months. The control group (C, n=10) received a diet consisting of 80% alfalfa and 20% concentrate, providing 2.18Mcal metabolizable energy and 130.0g/kg DM crude protein, whereas, treatment group (T, n=10) was fed with 65% alfalfa and 35% concentrate, providing 2.34Mcal metabolizable energy and 160.0g/kg DM crude protein. Body weight, additive daily gain and feed intake in T group were significantly greater than those obtained in C group. Body weight and testicular circumference increased at a steady rate throughout the experiment. All semen variables (except percentage of abnormal sperm and semen pH), serum testosterone concentration and testicular circumference were positively influenced by nutritional state (P<0.05). Interaction of nutritional state with season was found for semen volume, sperm concentration and abnormal sperm, but there was no interaction on the total sperm, progressive motility, live sperm, semen pH and semen index. It is concluded that the reproductive activity of growing Sanjabi ram lambs is affected by nutritional state. These results also demonstrated a monthly pattern in reproductive characteristics of Sanjabi ram lambs, independent of the nutritional state.

Intake, performance, and efficiency of nutrient utilization in Saanen goat kids fed diets containing calcium salts of fatty acids.

The objective of this study was to evaluate the effect of feeding Saanen goat kids with calcium salts of fatty acids (CSFA) in diet, on intake, performance, digestibility of nutrients, and blood parameters. Twenty-eight uncastrated male goat kids, with round average age to 112.86 ± 4.81days and an average body weight (BW) of 19.54 ± 2.76kg, were distributed in a completely randomized design distributed into four groups with seven animals per group: one control group fed a diet containing 2.5Mcal metabolizable energy (ME)/kg dry matter (DM) and three groups fed a diet containing 2.6, 2.7, or 2.8Mcal ME/kg DM, with CSFA added to increase the energy levels. The animals were fed the diets until they reached an average BW of 28kg. There was hardly any apparent effect of dietary CSFA on intake of DM and organic matter (OM). The digestibility of DM and OM showed an improvement with 2.64 and 2.65Mcal ME/kg DM in the diet. The diets containing CSFA improved average daily gain and reduced the time on the feedlot to 30days fed diet with 2.8Mcal ME/kg DM. However, lipid supplementation increased serum cholesterol levels. Thus, CSFA can be used to increase the energy density of the diet in finisher Saanen goat kids and improve performance by reducing days on feedlot.

Lactation curves and economic results of Saanen goats fed increasing dietary energy levels obtained by the addition of calcium salts of fatty acids

The objective of this study was to evaluate the use of calcium salts of fatty acids (CSFA) to increase the dietary energy levels for Saanen goats and their effects on the lactation curve, dry matter intake, body weight, and economic results of the goats. Twenty multiparous goats, weighing an average of 63.5±10.3 kg, were randomly assigned to one of four treatment groups, each receiving one of the following dietary energy levels: a control diet consisting of 2.6 Mcal of metabolizable energy per kg of dry matter (Mcal ME/kg DM) or a test diet supplemented with CSFA (Lactoplus®) to obtain 2.7, 2.8, or 2.9 Mcal ME/kg DM. Goats were housed in individual stalls and were fed and milked twice daily. The animals were evaluated until 180 days in milk by measuring dry matter intake and milk yield. These measurements were used to calculate feed efficiencies and the cost-benefit ratio of diet and lactation curves using Wood's nonlinear model. Increasing dietary energy levels showed no effect on body weight. Supplementation with CSFA did not limit dry matter intake; however, it changed the shape of the lactation curve by promoting a late peak lactation with a longer duration. Milk yields at 180 days in milk had a quadratic increase with a maximum energy level at 2.85 Mcal ME/kg DM. Increasing the dietary energy level for Saanen goats using CSFA changes their lactation curves, with the best milk production achieved with a 2.85 Mcal ME/kg DM diet; however, the greatest economic results were obtained with a 2.7 Mcal ME/kg DM diet.

Influence of pre and postnatal energy restriction on the productive performance of ewes and lambs

The objective of this study was to evaluate the influence of feeding energy levels during the last third of gestation and lactation on performance of ewes and lambs up to weaning. The experiment was carried out in the sheep raising sector of Universidade Estadual de Londrina (UEL), from August to December of 2007. Thirty-two adult lambs with 105 days of gestation, average live weight of 57.55 kg and average body condition scores of 3.42 were used in the beginning of the experiment. The animals were confined in collective pens, distributed randomly in three treatments: 2.4; 2.2 and 2.0 Mcal of metabolizable energy (ME)/kg of dry matter (DM). Feed supply was ad libitum during the last third of gestation and lactation. Weaning occurred at 70 days. Body weight, body condition score and milk production of ewes and body weight of the lambs were analyzed. There were no significant differences for body weight and body condition of ewes at lambing; however, the level of 2.4 Mcal enabled better results for those characteristics at weaning and higher gain in weight and body condition scoring during the experiment. Severe energetic restriction (2.0 Mcal ME/kg DM) determined lower average daily milk production. Lambs from levels 2.4 and 2.2 presented similar weights in all measurements and were superior to those in level 2.0. Lambs from level 2.4 presented higher average weight gain from birth to weaning. The energetic restriction upon lambs at the end of gestation and during lactation limits the performance of ewes and lambs up to weaning.

Effects of restricted feeding of prepubertal ewe lambs on reproduction and lactation performances over two breeding seasons

The aim of this study was to determine the effects of restricted feeding before puberty on reproduction, lactation and offspring growth performance in replacement ewe lambs over two breeding seasons. At weaning, 41 Dorset ewe lambs were assigned to one of three diets: an ad libitum control diet with medium-quality forage (MQF; 13.3% crude protein (CP), 1.81 Mcal metabolizable energy per kg, 42.8% ADF; diet A-MQF); a restricted diet with the same forage as A but less feed concentrate (diet R-MQF); or a high-quality forage (HQF) diet (14.8% CP, 2.15 Mcal ME/kg, 34.7% ADF; diet F-HQF). The quantity of concentrate offered to the group R-MQF and F-HQF ewe lambs was adjusted to obtain 70% of the control ewe lambs’ growth rate. The diets were offered for 75 days following weaning to cover the allometric phase of mammary gland development. Prepubertal restriction did not affect (P > 0.10) the gestation rate, number of lambs born or the body weight and body condition score of ewes at lambing or at the end of lactation. Ewes from groups R-MQF and F-HQF tended to produce more milk during their first lactation compared to those from group A-MQF (P = 0.07). During the second lactation, groups R-MQF and F-HQF had better standardized milk production than group A-MQF (P < 0.05), and group R-MQF produced more milk than group F-HQF (P < 0.05). Milk fat and protein content were not affected by treatments (P > 0.10) Fat and protein yield were affected by treatments only at the second lactation (P < 0.10 and P < 0.05, respectively). Lamb birth and weaning weights were not affected by prepubertal restriction of feeding in their mother (P > 0.10). However, the average daily gain of second breeding season lambs was higher for the R-MQF group than the F-HQF group (P < 0.05), and a similar trend was observed for total gain (P < 0.10). Restricted feeding before puberty does not impair future reproductive performance; however, it has a positive impact on lactation and on lambs’ growth performance.