Effects Of Different Feeding Levels Research Articles

10 Effects of different feeding levels during gestation on gilt reproductive performance during the first lactation

Abstract Our objective was to determine the effects of different feeding levels for gilts during gestation on reproductive performance during the first lactation. A total of 1,187 PIC Camborough gilts were used. Gilts were randomly allotted in a randomized complete block design based on breeding week, body weight (BW), and age to one of four treatments differing in daily metabolizable energy (ME) intakes per day during gestation. Gilts were housed in stalls throughout the entire gestation and individually fed with a gestation diet containing 2.95 Mcal of ME/kg via feed boxes that were weekly calibrated. Treatments consisted of 1) 5.0 Mcal of ME/d (1.7 kg feed/d) throughout the entire gestation; 2) 5.9 Mcal of ME/d (2.0 kg feed/d) throughout the entire gestation; 3) 6.8 Mcal of ME/d (2.3 kg feed/d) throughout the entire gestation; and 4) 5.0 Mcal of ME/d (1.7 kg feed/d) from breeding until d 90 of gestation, and then 5.9 Mcal of ME/d (2.0 kg feed/d) from d 90 to d 112 of gestation. Gilt was the experimental unit and data were analyzed using generalized linear mixed models with the lmer and glmer functions of R. There was no evidence (P > 0.10) for treatment differences on gilt BW and age at breeding, with gilts averaging 156.7 kg at 210 d of age (Table 1). Gilts receiving 6.8 Mcal of ME/d during gestation were heavier (P < 0.05) at farrowing compared with all other treatments; however, these gilts lost (P < 0.05) more BW during lactation. Gilts receiving 5.0 Mcal ME/d throughout the entire gestation had less (P < 0.05) maternal net BW gain from breeding to weaning compared with gilts receiving 6.8 Mcal ME/d. Gilts receiving 6.8 Mcal of ME/d gained more (P < 0.05) caliper scores (CS) from breeding to d 90 of gestation compared with gilts receiving 5.0 Mcal ME/d. Regardless of feeding level, gilts lost an average of 0.85 CS from d 90 to d 112 of gestation. Overall, gilts receiving 6.8 Mcal of ME/d gained more CS during gestation, but lost more CS during lactation (P < 0.05). There was no evidence for differences in gilt backfat depth measurements (P > 0.10). Gilt feeding levels did not impact (P > 0.10) total piglets born, percentage sillborn, or percentage of mummified fetuses. Gilts receiving 5.0 Mcal of ME/d had greater (P < 0.05) percentage piglets born alive compared with gilts receiving 5.9 Mcal of ME/d, with other treatments intermediate. There was no evidence (P > 0.10) for treatment differences in average piglet BW, average piglet daily gain during lactation, piglet mortality from cross foster to weaning, or wean to estrus interval in the next cycle. In summary, increasing energy intake of gilts during the first gestation did not impact reproductive performance during the first lactation, but gilts receiving 5.0 Mcal of ME/d throughout the entire gestation had less maternal net BW gain.

Concentrate supplementation improves cold-season environmental fitness of grazing yaks: responsive changes in the rumen microbiota and metabolome.

Yak (Bos grunniens) is an important economic animal species on the Qinghai-Tibet Plateau. Yaks grazed in the cold season often suffer from nutritional stress, resulting in low production performance. This situation can be improved by properly feeding the grazing yaks in the cold season; however, there is still little information about the effect of different feeding levels on the intestinal microflora and metabolites of yaks. Therefore, this study aimed to explore the effect of feeding different doses of concentrate supplements on rumen bacterial communities and metabolites in grazing yaks during the cold season. Feed concentrate supplementation significantly improved the production performance and rumen fermentation status of grazing yaks during the cold season, and switched the type of ruminal fermentation from acetic acid fermentation to propionic acid fermentation. Ruminal fermentation parameters and ruminal bacterial abundance correlated strongly. At the phylum level, the abundance of Firmicutes increased with increasing concentrate supplementation, while the opposite was true for Bacteroidota. At the genus level, the abundance of Christensenellaceae_R-7_group, NK4A214_group, Ruminococcus, norank_f__Eubacterium_coprostanoligenes_group, norank_f__norank_o__ Clostridia_UCG-014, Lachnospiraceae_NK3A20_group, Acetitomaculum, and Family_XIII_AD3011_group increased with increasing concentrate supplementation, while the abundance of Rikenellaceae_RC9_gut_ group decreased. Dietary concentrate supplementation altered the concentration and metabolic mode of metabolites in the rumen, significantly affecting the concentration of metabolites involved in amino acid and derivative metabolism (e.g., L-aspartic acid, L-glutamate, and L-histidine), purine metabolism (e.g., guanine, guanosine, and hypoxanthine), and glycerophospholipid metabolism (e.g., phosphatidate, phosphatidylcholine, and phosphocholine), and other metabolic pathways. The strong correlation between yak rumen microorganisms and metabolites provided a more comprehensive understanding of microbial community composition and function. This study showed significant changes in the composition and abundance of bacteria and metabolites in the rumen of cool season grazing yaks fed with concentrate supplements. Changes in ruminal fermentation parameters and metabolite concentration also showed a strong correlation with ruminal bacterial communities. These findings will be helpful to formulate supplementary feeding strategies for grazing yaks in the cold season from the perspective of intestinal microorganisms.

PENGARUH TINGKAT PEMBERIAN PAKAN BERBEDA TERHADAP LAJU PERTUMBUHAN IKAN NILEM (Osteochilus hasselti) YANG DIPELIHARA PADA SISTEM BIOFLOK RASIO C/N 20

Biofloc technology is an alternative in overcoming the problem of feed waste in hard-lipped barb culture media. The decline in hard-lipped barb production was caused by limited knowledge and traditional aquaculture. This research was conducted with the aim of knowing the effect of different feeding levels on the ratio of C/N 20 on the growth of hard-lipped barb (Osteochilus hasselti). This research was conducted in May 2021-June 2022 with a trial period of May-June 2021. The design used was a Completely Randomized Design with 3 treatments (feeding rate 1%, feeding rate 3%, feeding rate 5%) and 4 replications. Parameters observed included specific length growth rate (SLGR), specific weight growth rate (SWGR), feed efficiency (FE), and survival rate (SR). Water quality parameters (DO, temperature, Ammonia, CO2, and pH) were analyzed descriptively. The results showed that the different levels of feeding with a C/N ratio of 20 had a significant effect on SLGR, SWGR, FE, and SR. SLGR in the treatment of FR 1% (0.17±0.03), FR 3% (0.28±0.03), and FR 5% (0.32±0.01). SWGR in treatment A (0.33±0.06), B(0.95±0.04), and C(1.53±0.11), FE at 1% FR treatment (16.85±1, 12%), FR 3% (25.04±0.73%), and FR 5% (30.95±1.87%). SR in the treatment of FR 1% (55.83%), FR 3% (59.16%), and FR 5% (68.33%). FR 5% treatment had the highest growth rate compared to FR 1% and FR 3% treatment. The water quality during the 40-day trial period was still within normal limits for Nilem fish cultivation in the biofloc system.

Effect of feeding level on growth, digestive and metabolic enzymes and antioxidant capacity in juvenile Yangtze sturgeon (Acipenser dabryanus)

This study was performed to evaluate the effects of different feeding levels on the growth performance, digestive enzymes, body composition, metabolic enzymes and antioxidant activities of juvenile Yangtze sturgeon (Acipenser dabryanus). A total number of 135 fish (average initial weight of 67.80 ± 0.19 g) were randomly distributed into nine round fibre-reinforced plastic tanks with 15 fish per tank and three tanks for treatment. Fish were fed with three feeding levels [1%, 3% and 5% body weight per day (BW day−1)] twice per day for 8 weeks. The weight gain rate (WGR) and specific growth rate (SGR) in 3% BW day−1 treatment were significantly higher and the feed conversion ratio (FCR) was significantly lower than those in the other treatments (P < 0.05). The activities of amylase and lipase were significantly increased with increasing feeding levels, and fish fed with 3% BW day−1 had significantly higher trypsin activities (P < 0.05). The hepatic glucogen contents significantly increased with increasing feeding levels, and the highest glucogen levels in the muscles were found in 3% BW day−1 treatment (P < 0.05). The enzymes activites of liver metabolism significantly differed among fish fed with different dietary levels. Fish fed with 1% BW day−1 had higher hepatic Na+/K + -ATPase (NKA) and glucose-6-phosphate dehydrogenase (G6PDH) activities than others, whereas fish fed with 3% BW day−1 had the highest muscle phospho-pyruvate kinase (PK) and G6PDH (P < 0.05). Fish reared with 5% BW day−1 had the highest total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity and the lowest malondialdehyde (MDA) contents in the liver. Fish fed with 3% BW day−1 had the highest antioxidant indices [T-AOC, SOD and glutathione peroxidase (GSH-PX)] and the lowest MDA contents in the muscles (P < 0.05). Based on WG, SGR, FCR, digestive enzyme activities, and nutrient absorption and utilisation, the recommended feeding level for juvenile Yangtze sturgeon (average initial weight of 67.80 ± 0.19 g) is 3% BW day−1 when they are kept at 20.3 ± 1.3 °C. These data reveal that fish would tend to balance metabolism and growth by optimising nutrient absorption and utilisation when fed at different dietary levels.

Effects of different feeding levels during a 14-week preweaning phase in dairy heifer calves on telomere length and mitochondrial DNA copy number in blood.

Telomeres cap the ends of eukaryotic chromosomes, and the telomere length (TL) is related to cellular age. The mitochondrial DNA copy number (mtDNAcn) reflects the abundance of mitochondria in a cell. In addition to generating energy, mitochondria are also the main producers of reactive oxygen species, which in turn can accelerate TL attrition and impair mitochondrial function. Nutrition in early life could influence mtDNAcn and TL in later life. In the present study, we investigated the effects of feeding different levels of milk replacer (MR) on TL shortening and energetic status by examining mtDNAcn of heifers during their first year of life. In this study, whole blood samples were obtained from German Holstein heifer calves 36 to 48 h after birth (wk 1) and at wk 12 and wk 16 of life (n = 37), as well as from 31 calves when reaching 1 yr of age. Calves were fed either a high level of MR (14% solids) at 10 L/d (1.4 kg of MR/d; n = 18) or a restrictive low level at 5.7 L/d (0.8 kg of MR/d; n = 19) until linear weaning in wk 13 to 14 of life. Additional whole blood samples were taken from their respective dams 36 to 48 h after calving. Relative TL (qT) and mtDNAcn in cells from whole blood were measured by multiplex quantitative PCR. The greatest qT values were observed in neonates (36-48 h after birth), with decreasing qT values thereafter. Delta qT values were calculated as ΔqT = qT (first year of life) - initial qT (36-48 h after birth). We found no effect of the feeding regimen on qT values, but qT decreased with age. The mtDNAcn was lowest in neonates, increased until wk 12 of life, and then remained at a constant level until after weaning (wk 16). After the first year of life, mtDNAcn was decreased and returned to levels comparable to those of the neonatal stage. No differences in mtDNAcn were detectable between feeding groups within each time point. When comparing the values of qT and mtDNAcn between the calves and their dams after calving (36-48 h after birth and after calving), greater values were observed in calves than in dams. Delta qT values were negative in all but 2 calves (on the restricted diet), indicating that the change in TL with age was not uniform among individual animals, whereas no difference in mean ΔqT values occurred between the feeding groups. Additional analyses of the correlation between qT, mtDNAcn, and various indicators of oxidative status from birth until wk 16 of life did not indicate major interactions between oxidative status, qT and mtDNAcn. The results of this study support an age-dependent decrease of TL in calves independent of the MR feeding level and show the dynamic changes of mtDNAcn in early life.

The effect of dietary energy levels on the sexual puberty of ram lambs

Aim of study: To evaluate the effect of different feeding levels on body weight changes, sexual behavior activities, and spermatogenesis characteristics of testis tissue in immature Iranian breed lambs.&#x0D; Area of study: University of Tabriz, Iran.&#x0D; Material and methods: A total of 40 (start of experiment, 4; after 6 months, 12; 9 months, 12; sexual behavior, 12) two-month-old immature ram lambs were divided into three equal groups and were fed for eight months with three different concentrate mixtures formulated using conventional ingredients based on barley grain. Lambs received the same amount of crude protein with three levels of energy. The diet of the low-energy (LE) group had an energy of 10% lower than the control group, which received a diet with optimum energy of 100% according to the NRC. Lambs in the high-energy (HE) group were fed diets with an energy of 10% higher than the optimum energy group. In each group, four lambs were castrated in three steps, including the ages of 2 (start of treatment), 6, and 9 months. Body weight and scrotal circumference were recorded monthly. Sexual behaviors toward estrus ewes were evaluated for 30 min, and the testes were analyzed histologically.&#x0D; Main results: The lambs in the LE group had lower body weight and smaller scrotal circumference than HE group (p&lt;0.05). Sexual behaviors in the HE group occurred at an earlier age, such as mount and mounts with ejaculation, as the external presentations of puberty (p&lt;0.05). &#x0D; Research highlights: Underfeeding of pre-pubertal animals delayed puberty, while high-plane feeding advanced puberty.

Calcium Propionate Supplementation Has Minor Effects on Major Ruminal Bacterial Community Composition of Early Lactation Dairy Cows.

Calcium propionate is one kind of good source for preventing and treating hypocalcemia and ketosis for dairy cows in early lactation. However, little is known about the effects of different feeding levels of calcium propionate on the ruminal bacterial community of early lactation dairy cows. This study aimed to explore the effects of different calcium propionate feeding levels on the ruminal fermentation and bacterial community composition of early lactation dairy cows. Twenty-four multiparous cows were randomly allocated into control (CON), low calcium propionate (LCaP), medium calcium propionate (MCaP), and high calcium propionate (HCaP) groups with six cows per group after calving. The CON group cows were fed the normal total mixed ration (TMR), and the cows of the LCaP, MCaP, and HCaP groups were fed TMR supplemented with 200, 350, and 500 g/day calcium propionate for 35 days after calving, respectively. The rumen fermentation parameters were measured every week, and the ruminal bacterial community composition of the last week was analyzed by 16S rRNA gene sequencing. Under the same diet, the rumen pH showed no difference among the four groups, but the content of microbial crude protein (MCP) and ammonia nitrogen quadratically decreased and linearly increased with calcium propionate supplementation, respectively. The feeding of calcium propionate linearly increased the concentrations of total volatile fatty acid (VFA), acetate, propionate, butyrate, iso-valerate, and valerate in the rumen. In all the treatment groups, Bacteroidetes, Firmicutes, and Proteobacteria were the dominant phyla, and Prevotella_1 and Succiniclasticum were the dominant genera in the rumen. Compared with the CON group, the addition of calcium propionate to the early lactation dairy cows quadratically improved the alpha diversity index of Chao1 estimator and observed species, but had little effect on the relative abundance of the major bacterial at phyla and genera level. These results suggested different levels of calcium propionate supplementation improved the rumen fermentation and the ruminal bacterial diversity but had little impact on the major ruminal bacterial community composition of dairy cows in early lactation.

Effects of different feeding levels and frequencies on growth performance, feed utilization, survival and body composition of the freshwater prawn, Macrobrachium rosenbergii (De Man, 1879).

Effects of different feeding levels and frequencies on growth performance, feed utilization, survival and body composition of the freshwater prawn, Macrobrachium rosenbergii (De Man, 1879).

Enteric methane emissions, energy partitioning, and energetic efficiency of zebu beef cattle fed total mixed ration silage.

ObjectiveThe main objective of this study was to evaluate the effect of different feeding levels of a total mixed ration silage-based diet on feed intake, total tract digestion, enteric methane emissions, and energy partitioning in two beef cattle genotypes.MethodsSix mature bulls (three Thai natives, and three Thai natives - Charolais crossbreeds) were assigned in a replicated 3×3 Latin square design, with cattle breed genotype in separate squares, three periods of 21 days, and three energy feeding above maintenance levels (1.1, 1.5, and 2.0 MEm, where MEm is metabolizable energy requirement for maintenance). Bulls were placed in a metabolic cage equipped with a ventilated head box respiration system to evaluate digestibility, record respiration gases, and determine energy balance.ResultsIncreasing the feeding level had no significant effect on digestibility but drastically reduced the enteric methane emission rate (p<0.05). Increasing the feeding level also significantly increased the energy retention and utilization efficiency (p<0.01). The Thai native cattle had greater enteric methane emission rate, digestibility, and energy utilization efficiency than the Charolais crossbred cattle (p<0.05). The daily metabolizable energy requirement for maintenance in Thai native cattle (388 kJ/kg BW0.75, where BW0.75 is metabolic body weight) was 15% less than that in Charolais crossbred cattle (444 kJ/kg BW0.75).ConclusionOur results suggested that the greater feeding level in zebu beef cattle fed above maintenance levels resulted in improved energy retention and utilization efficiency because of the reduction in enteric methane energy loss. The results also indicated higher efficiency of metabolisable energy utilization for growth and a lower energy requirement for maintenance in Bos indicus than in Bos taurus.

Proteome of the periovulatory oviduct and uterus of goats as related to nutritional balance.

This study was conducted to evaluate the effects of different feeding levels on the proteome of oviduct and uterus tissues of hormonally stimulated goats during the periovulatory period. Forty goats were separated into four different diet groups: Diet 1.0M (n=11), Diet 1.3M (n=10), Diet 1.6M (n=9), Diet 1.9M (n=10), fed with 1.0, 1.3, 1.6 and 1.9 times live weight maintenance, respectively. After four weeks of treatment, six hormonally stimulated females per treatment group were randomly selected for collection of uterine and the oviduct tissue samples. Samples were collected after animals were slaughtered in a commercial unit. Feeding goats with 1.3 to 1.9 times more nutrients than a control group directly influenced the proteome of the oviduct and uterus, altering the expression of proteins that participate in biological processes such as apoptosis, antioxidant, and immunological activities. These events are crucial for fertilization and early embryonic survival. Expression of oviduct proteins such as Tubulin Beta 2B, Transferrin and Disulphide-isomerase A3 increased in the 1.9M group in relation to the other feeding levels. Disulphide-isomerase A4 showed higher expression in the 1.0M group compared to diets with higher energetic levels. As energy intake increased in the diets, there was higher expression of Alpha-1-antitrypsin and downregulation of Profilin-1 in the uterus of the goats. In conclusion, this study showed that specific proteins of the goat oviduct and uterus expressed during the periovulatory period are modified as the result of nutritional balance.

Effect of Different Feeding Levels of Plant‐ingredient‐based Feed on Fillet Fatty Acid Profile, Carcass Trait, and Sensory Characteristics of Indian Major Carps in Earthen Pond Polyculture

AbstractThe objective of the present study was to evaluate the effect of plant‐ingredient‐based feeds on fillet fatty acid profiles, proximate composition, carcass traits, and sensory characteristics of three Indian major carps (IMCs), Catla catla, Labeo rohita, and Cirrhinus mrigala, when fed at different levels of their body weight. An experimental feed was prepared with only plant ingredients. The IMCs were fed twice daily at 1.0, 1.5, 2.0, and 2.5% of their body weight for 150 d in 0.06‐ha earthen pond polyculture systems. The maximum growth and best feed utilization was achieved with feeding at 2% of fish biomass in the ponds. Fillet yield and lipid recovery increased significantly (P &lt; 0.05), with increasing feeding level up to 2% of body weight and plateaued thereafter. In fillets, eicosapentaenoic acid (20:5n‐3) and docosahexaenoic acid (22:6n‐3) concentration increased with increasing feeding levels. Carcass traits, sensory characteristics, and consumer acceptance of IMC fillets were not influenced by feeding plant‐ingredient‐based feeds at different feeding rates.

Effects of different feeding levels during three short periods of gestation on gilt and litter performance, nutrient digestibility, and energy homeostasis in gilts.

The present study investigated the effects of different feeding levels during 3 short periods of gestation on gilt and litter performance, apparent total tract digestibility (ATTD) of energy and nutrients, and energy homeostasis in gilts. A total of 18 gilts were allotted to 1 of 3 dietary treatments using a completely randomized design. All gilts were fed 1 common corn-soybean meal-based diet with the amount of 1.0 × maintenance energy intake (100 × BW (BW) kcal ME/d) throughout gestation except 3 periods of 7 d when dietary treatments were imposed on d 27, d 55, and d 83 of gestation. During the 3 short periods, gilts were fed 1 of 3 different feeding levels: 0.5, 1.0, and 2.0 × maintenance energy level (0.5M, 1.0M, and 2.0M, respectively). Results showed that gilts on 2.0M feeding level had higher ( < 0.05) weight gain from d 27 to 109 of gestation (37.05 vs. 15.34 kg) and greater ( < 0.05) BW change, average daily gain, and gain to feed ratio during gestation periods 1 (d 27-34) and 3 (d 83-90) when compared with gilts on 0.5M feeding level. No differences ( > 0.10) in litter performance were observed among the 3 feeding levels. Additionally, the slopes of BW change in response to feeding levels in period 1 were 4.32 kg/0.5M change from 0.5M to 1.0M feeding level and 3.72 kg/0.5M change from 1.0M to 2.0M feeding level, respectively. There were quadratic ( < 0.05) effects of feeding levels on ATTD of dry matter and gross energy during periods 1 and 2 (d 55-62). Furthermore, fasting plasma concentrations of acyl ghrelin and nonesterified fatty acid (NEFA) in period 1 were greater ( < 0.01) in gilts on 0.5M feeding level than those on 2.0M feeding level. In conclusion, increasing feeding levels during 3 short periods increased primiparous sow performance during these short periods but did not affect litter performance. ATTD of energy and nutrients, and BW change efficiency were maximized for gilts on 1.0 M feeding level. The data also indicated that sows on the lowest feeding level were exposed to negative energy balance as evidenced by the higher plasma acyl ghrelin and NEFA concentrations.

164 Effects of different feeding levels during three short periods of gestation on gilt and litter performance, nutrient digestibility, and energy homeostasis

164 Effects of different feeding levels during three short periods of gestation on gilt and litter performance, nutrient digestibility, and energy homeostasis

Effects of different feeding levels during three short periods of gestation on gilt and litter performance, nutrient digestibility, and energy homeostasis in gilts

Effects of different feeding levels during three short periods of gestation on gilt and litter performance, nutrient digestibility, and energy homeostasis in gilts

Effect of different feeding levels during three short periods of gestation on sow and litter performance over two reproductive cycles

The present study investigated the effects of different feeding levels during 3 short periods of gestation on sow and litter performance and its impact on subsequent reproductive performance. A total of 160 multiparous sows were allotted to 1 of 4 dietary treatments using a randomized complete block design with initial body weight (BW) and backfat (BF) as the blocking criteria. All sows were fed one common corn-soybean meal-based diet with the amount of 1.0×maintenance energy intake (100×BW0.75kcalME/d) throughout gestation except 3 periods of 7 d when dietary treatments were imposed on d 27, d 55 and d 83 of gestation. During the 3 short periods, sows were fed 1 of 4 different feeding levels: 0.5, 1.0, 1.5 and 2.0×maintenance energy level (0.5M, 1.0M, 1.5M and 2.0M, respectively). Results showed that both BW gain (16.12, 24.74, 30.62 and 36.71kg, respectively) and BF change (−0.27, 0.99, 1.49 and 2.45mm, respectively) from d 27 to 109 of gestation increased linearly (P<0.01) with the increase of gestation feeding levels. In contrast, with the rise of gestation feeding levels, lactation BW gain (14.31, 9.84, 7.09 and 3.50kg, respectively) decreased linearly (P<0.01), while BF loss during lactation (−0.79, −0.92, −1.12 and −1.57mm, respectively) increased linearly (P=0.05). Additionally, average daily feed intake during lactation (7.05, 7.00, 6.91 and 6.52kg, respectively) tended to decrease linearly (P=0.09) in response to the increase of gestation feeding levels. Furthermore, piglet birth weights increased linearly (P<0.01) with the increase of gestation feeding levels, while piglet weaning weights were similar (P>0.10) among treatments. Subsequent reproductive performance was not affected (P>0.10) by feeding levels during the previous reproductive cycle. In conclusion, increasing feeding levels during 3 short periods of gestation increased BW and BF gains during gestation and caused less BW gain and more BF loss during lactation due to the reduction of lactation feed intake in response to increasing gestation feeding levels. Increasing feeding levels during 3 short periods of gestation increased piglet birth weight, but did not affect piglet weaning weight. The feeding strategies in the current reproductive cycle did not impact subsequent reproductive performance. It was estimated that requirements of 1.20M, 0.66M and 0.65M feeding levels were needed to maintain a constant BW during d 27–34, d 55–62 and d 83–90 of gestation, respectively, indicating current maintenance energy requirement may underestimate the actual maintenance energy requirement in the early gestation, but overestimate the actual maintenance energy requirement in the mid and late gestation.

EFFECT OF DIFFERENT FEEDING REGIMES ON: 2- PRODUCTIVE AND REPRODUCTIVE PERFORMANCE OF GROWING BUFFALO HEIFERS

This study was conducted to investigate the effect of different feeding levels on productive and reproductive performance and some body measurements of growing buffalo heifers during the period from first services up to ninetieth days of pregnancy. Eighteen buffalo heifers at the first services were divided into three treated groups (6 heifers each) and received their feeding allowance according to Kearl, (1982) in which animals in group one (R1) fed 100% of their allowances up to the end of the experiment (control) and those in group two (R2) fed 80% of the allowances until heifers grow up to 300 kg, and then fed 100% of the allowances up to the end of the experiment, while those in the third group (R3) fed 80% of the allowances during the whole experimental period. Average age of heifers at first service was 517.3, 571.7 and 594.7 days old and live body weight were 347.8, 339.3 and 349.0 kg for R1, R2 and R3, respectively. Results indicated that heifers fed 80% of the allowance (R3) recorded the lowest values in most of nutrient digestion coefficients and feeding values (TDN and CP%) in comparison with the other experimental groups, while CF digestibility had the inverse trend. Also, animals in R3 recorded the lowest (P<0.05) blood constituents and oldest ages at first service and conception than those in other experimental groups. Heifers fed 100% of the allowance (R1) recorded the higher body condition score than those in the experimental groups. There were significant differences between heifers in both R1and R2 in comparison with those in R3 respecting the most of growth performance parameters and animals in both groups (R1 and R2) were significantly better than those in R2. However, Heifers fed 80% of the allowance (R3) had a better (P<0.05) feed conversion ratio expressed as the amount of intake of DM, TDN or CP than those in R1 and R2 groups. Interval from puberty to the first service or to conception was significantly shorter for heifers in R2 than those in R1 and R3 groups. Number of oestrous cycles from Puberty to the first service or to the conception was significantly the lowest with heifers in R1 followed by those in R2 then the highest values were recorded with those in R3 group. It could be concluded that feeding growing buffalo heifers at first service on (R2) had more beneficial effect on heifers’ reproductive performance, indicating positive reflection on the subsequent first lactation season of primiparous cows under Egyptian condition.

EFFECT OF DIFFERENT FEEDING REGIMES ON: 1- DIGESTIBILITY AND PERFORMANCE OF GROWING BUFFALO HEIFERS

This study aimed to evaluate the effect of different feeding levels on productive performance of growing buffalo heifers. Eighteen growing buffalo heifers (156 ±… days old and 110 ±… kg live body weight) were allocated randomly and equally to one of three treatments of 6 heads per each. Animals received their feeding allowance according to Kearl (1982) and the experiment was ended when the heifers reached to the first services: R1, 100% of the feeding allowances during the whole experimental period (control); R2, 80% of the feeding allowances to 300 kg body weight, then followed by 100% till the end of the experiment; and R3, 80% of the feeding allowances during the whole experimental period. Digestibility trials were conducted to determine the feeding values of the experimental rations. Results indicated that treatments (R2 and R3) during the first phase recorded the lowest values of digestibility coefficients, feeding values, total body weight gain and daily gain than those fed on control diet. When the heifers in (R2) received 100% during the second phase, an improvement in heifers performance were observed in comparison with those in R3 treatment that recorded the longest periods (P<0.05) of age at puberty and 1st service compared to those in other treatments. Increasing the feeding level was significantly (P<0.05) affected of the all blood serum parameters. Total feed cost and return economic efficiency indicted that the animals fed R2 ration had the superior economic efficiency, followed by those in R3 and then R1 was ranked the last. It could be concluded that feeding the weaned buffalo heifers on 80% of their feeding allowances until 300 kg body weight, followed by 100% of the allowances was more beneficial for the productive and reproductive performance and economical efficiency of growing buffalo heifers under Egyptian condition.

Carcass and non-carcass component yields of crossbred Boer and Brazilian semiarid indigenous goats subjected to different feeding levels

The effect of different feeding levels (ad libitum, 25 and 50 % restriction) and genotypes (½ Boer × ½ nondescript breed goats, Canindé, and Moxotó) on carcass quantitative characteristics and non-carcass components (NCC) were evaluated. Forty-five intact male goats were distributed in a 3 × 3 factorial design with five replicates. There was no effect of genotype on carcass weights and yields and retail cuts weights and yields (P > 0.05). Compared to Moxotó, ½ Boer presented better carcass conformation and higher weights (P < 0.01) and yields of viscera from gastrointestinal tract (P < 0.05), and compared to the other genotypes (P < 0.01), ½ Boer presented larger carcass compactness. Carcass weights and yields, retail cuts weights and NCC, and soft tissues yields were higher (P < 0.01) in goats fed ad libitum. The two restriction levels did not differ (P > 0.05) for these variables. There were interactions of genotype and feeding level. At ad libitum feeding, ½ Boer had higher weights of breast and shank, leg, soft tissues, and gastrointestinal viscera compared to the Moxotó (P < 0.05). The crossing of nondescript breed goats with Boer may be a strategy for increasing the efficiency of goat meat production in the Brazilian semiarid. Moreover, in times of feed scarcity, farmers may use higher feed restriction levels to keep animals, since for most of the parameters evaluated, there were no differences between the restriction levels.

The effect of long term under- and over-feeding of sheep on milk and plasma fatty acid profiles and on insulin and leptin concentrations

Since sheep's milk is mainly used for cheese making and milk chemical composition and fatty acids (FA) profile affect cheese yield and quality, the objective of this study was to determine the effects of different feeding levels on milk chemical composition and FA profile, as well as on plasma FA profile, and on insulin and leptin concentrations. Twenty-four sheep were assigned to three homogeneous sub-groups. Throughout the experimental period each group was fed the same diet but in quantities which met 70% (under-feeding), 100% (control) and 130% (over-feeding) of their respective energy and crude protein requirements. The results showed that the underfed sheep had higher milk fat content compared with overfed. In blood plasma the concentrations of C18:0 and C18:1 in the underfed sheep were significantly higher compared with control and overfed sheep. The concentrations of leptin and insulin were significantly higher in overfed compared with underfed sheep. Underfeeding reduced the concentrations of short chain FA (SCFA) and medium chain FA (MCFA) and increased that of C18:0 and mono unsaturated FA (MUFA) in sheep milk fat compared with controls and overfed. The concentrations of C18:0, long chain FA (LCFA) and monounsaturated FA (MUFA) in milk were significantly higher and those of SCFA, MCFA and saturated FA (SFA) significantly lower in the underfed compared with the overfed sheep. In conclusion, long term under- and over-feeding affected the sheep milk chemical composition and FA profile which consequently has an impact on milk products yield (cheese and yogurt) and quality (human health).

말에서 사료 급여 수준이 분 젖산 생산 박테리아 및 pH 변화에 미치는 영향

본 연구는 말의 다양한 사양체계가 분 젖산 생산 박테리아 및 pH 변화에 미치는 영향을 구명하기 위해 수행되었다. 시험 1에서는 농후사료 체중 2% 또는 건초(오챠드그라스) 2%를 30일 동안 급여한 후 분 중 Lactobacillus와 Streptococcus 균 수를 측정했다. 시험 2에서는 사양형태 또는 사료급여 수준에 따른 분 중 pH 변화를 측정했다. 시험 3에서는 알팔파 건초 급여 수준에 의한 분 pH 변화를 측정했다. 고－농후사료의 급여는 분 중 젖산 생산 박테리아인 lactobacillus와 streptococcus의 균 수를 크게 증가시켰다(P<0.05). 농후사료의 급여량을 증가시킴에 따라 분 pH는 유의적으로 감소했다(P<0.01). 알팔파 건초 단독 급여에서는 분 pH가 저하되지 않았으나, 알팔파 건초+농후사료 사양형태에서는 분 pH가 감소되었다(P<0.01). 본 연구 결과, 말에게 농후사료의 다량급여는 장내 젖산생산 박테리아의 활성을 증가시키며, 농후사료 급여량이 증가함에 따라 분 pH를 저하시키고 있음을 알 수 있다. 따라서 말에게 적절한 조사료/농후사료 비율을 유지하고 급여량을 조절하는 것이 필요하다. 또한 분 pH 측정으로 인해 대장 내 상태를 가늠할 수 있고, 분 pH 값을 이용해 사양관리의 지표로 활용할 수 있을 것으로 사료된다. This study was conducted to determine the effects of different feeding levels on the number of fecal lactic acid-producing bacteria and fecal pH in horses. In Exp. 1, 6 female cross-bred horses (<TEX>$332.4{\pm}50.4\;kg$</TEX>, 5 year old) were fed 2% hay or 2% concentrates of BW for 30 d, and the number of fecal Lactobacilli and Streptococci was measured. For Exp. 2, 5 castrated Thoroughbred (<TEX>$474.5{\pm}64.6kg$</TEX>, 4 year old) and 5 female cross-bred horses (<TEX>$343.6{\pm}56.3\;kg$</TEX>, 5 year old) were allotted to high- or low-concentrates diets (5 levels) for 30 d in a <TEX>$5{\times}5$</TEX> Latin square design, and the fecal pH was assessed. In Exp. 3, 3 castrated Thoroughbred (<TEX>$482.6{\pm}53.3\;kg$</TEX>, 4 year old) were fed high- or low-alfalfa hay diets (3 levels) for 30 d in a <TEX>$3{\times}3$</TEX> Latin square design, and the fecal pH was measured. Feeding high-concentrates diets increased (P<0.05) the number of fecal lactic acid-producing bacteria (Lactobacilli and Streptococci) and decreased (P<0.01) the fecal pH. Feeding alfalfa hay with high-concentrates diet (2% alfalfa hay + 1% concentrates of BW) decreased (P<0.01) the fecal pH. These results showed that feeding high-concentrates diets increased lactic acid-producing bacteria in the large intestine and decreased the intestinal or fecal pH causing colic or laminitis, indicating that the proper fiber/concentrates (1:1) should be maintained in horses.