Milk Replacer Group Research Articles

Long-term effects of transition milk feeding on feed intake, growth performance, feeding behavior, and oxidative status of Holstein calves

This study investigated the long-term effects of feeding 5-d transition milk (TRANS) compared with milk replacer (MR) on parameters, including intake, growth, feeding behavior and oxidative stress. Fifty Holstein calves (30 females and 20 males) were fed either 12 L/day TRANS or MR for the first 5 d after an initial colostrum feeding of 3.5 L. Thereafter, all calves were fed with 12 L of MR/d (140 g/L) and were gradually weaned starting in wk 8 until wk 14. Throughout the 14 wk the calves had unrestricted access to concentrate (up to 9.8 kg/calf/day), hay, and water. After weaning all heifers were fed a total mixed ration for young cows. Oxidative status was assessed in blood samples from birth to first insemination. Parameters assessed included the ferric reducing ability of plasma (FRAP) for antioxidant capacity and the concentration of reactive oxygen metabolites by the dROM (detection of reactive oxygen metabolites) assay. In addition, the activity of glutathione peroxidase (GSH-Px), oxidative damage in the form of lipid peroxidation as thiobarbituric acid reactive substances (TBARS) and as advanced oxidation protein products (AOPP) were measured. An oxidative stress index (OSi) was calculated: dROM/FRAP x 100. Total protein (TP) concentration was also quantified via the Bradford assay. The only significant difference in feeding behavior between the 2 treatment groups was a higher concentrate intake by the TRANS calves during the weaning phase. Body weight and ADG did not differ significantly between the TRANS and MR groups. TRANS calves showed a trend for fewer cases of health disorders. Markers of oxidative status, including TBARS, AOPP, GSHPx, FRAP and ROM, showed no treatment effects but varied significantly over time. Of note, the oxidative stress index as ratio between pro- and antioxidants in both groups peaked during weaning and then returned to baseline, suggesting an effective response to this transition phase Overall, the results indicate that feeding TRANS during the first 5 d of life had no long-term effect on the parameters studied as compared with MR feeding under the present rearing conditions. These results provide insight into the changes of oxidative status with age and confirm that the relatively high milk feeding level, slow and late weaning enables calves to adapt well to solely solid feed.

Early-life milk replacer feeding mediates lipid metabolism disorders induced by colonic microbiota and bile acid profiles to reduce body weight in goat model

BackgroundDysregulation of lipid metabolism and its consequences on growth performance in young ruminants have attracted attention, especially in the context of alternative feeding strategies. This study aims to elucidate the effects of milk replacer (MR) feeding on growth, lipid metabolism, colonic epithelial gene expression, colonic microbiota composition and systemic metabolism in goat kids compared to breast milk (BM) feeding, addressing a critical knowledge gap in early life nutrition.MethodsTen female goat kids were divided into 2 groups: those fed breast milk (BM group) and those fed a milk replacer (MR group). Over a period of 28 d, body weight was monitored and blood and tissue samples were collected for biochemical, transcriptomic and metabolomic analyses. Profiling of the colonial microbiota was performed using 16S rRNA gene sequencing. Intestinal microbiota transplantation (IMT) experiments in gnotobiotic mice were performed to validate causality.ResultsMR-fed pups exhibited reduced daily body-weight gain due to impaired lipid metabolism as evidenced by lower serum and liver total cholesterol (TC) and non-esterified fatty acid (NEFA) concentrations. Transcriptomic analysis of the colonic epithelium revealed upregulated genes involved in negative regulation of lipid metabolism, concomitant with microbiota shifts characterized by a decrease in Firmicutes and an increase in Actinobacteria. Specifically, genera such as Bifidobacterium and Prevotella were enriched in the MR group, while Clostridium and Faecalibacterium were depleted. Metabolomics analyses confirmed alterations in bile acid and fatty acid metabolic pathways. IMT experiments in mice recapitulated the metabolic phenotype observed in MR-fed goats, confirming the role of the microbiota in modulating host lipid metabolism.ConclusionsMilk replacer feeding in goat kids disrupts lipid metabolism and gut microbiota dynamics, resulting in reduced growth rates and metabolic alterations. These findings highlight the importance of early nutritional intervention on metabolic programming and suggest that modulation of the gut microbiota may be a target for improving growth and metabolic health in ruminants. This study contributes to the understanding of nutritional management strategies in livestock and their impact on animal health and productivity.

Interactions between rumen epithelium-associated microbiota and host immunological and metabolic adaptations in response to different milk replacer feeding intensities in dairy calves

The milk replacer feeding regime in dairy calves has a great impact on metabolic and immunological functioning and affects animal welfare and lifetime performance. The feeding regime influences the rumen microbial composition, and epithelium-associated microbes may interact with the immune system of the host. We examined the correlations between blood leukocyte counts and the rumen epithelium-associated microbiome in dairy calves fed 2 different milk replacer feeding intensities and if these factors related to metabolic traits. Fourteen newborn female dairy calves were allocated to a group receiving either 10% (n = 7) or 20% (n = 7) milk replacer of their body weight (on average 41 kg) and provided ad libitum access to grass hay and concentrate pellets. At 3 weeks of life, all calves were fitted with a rumen cannula. Calves were weaned at 12 weeks of life and received a total mixed ration for ad libitum intake. Pre- (8 to 10 weeks of life) and post-weaning (21 to 23 weeks of life), methane production was measured in respiration chambers, and rumen epithelium and blood were sampled for 16S rRNA sequencing and leukocyte analyses, respectively. Pre-weaning, the reduced milk replacer feeding intensity was accompanied with higher concentrate intake but lower growth performance (P < 0.001), a higher abundance of amylolytic and lower abundance of cellulolytic epimural microbes. The group fed a low milk replacer intensity had also greater portions of monocytes (P = 0.031), CD8+ (P < 0.001), and CD14+ (P = 0.044) leukocytes, suggesting elevated inflammatory conditions. Correlations between CD8+ T cells and rumen methanogens, Ruminococcaceae, and Lachnospiraceae were recorded, but these were not consistent throughout maturation. Post-weaning, differences in feed intake and rumen microbial composition converged among milk replacer groups, while differences in growth performance (P = 0.040) and CD8+ cells (P < 0.001) were still present. In conclusion, a reduced milk replacer feeding intensity in dairy calves compromised growth performance and immunity and this effect persisted in the long-term. Significant correlations between the proportion of leukocytes and distinct epimural microbe taxa indicated an interplay between rumen epimural colonization and immune functioning of the host. However, further research is required addressing this interplay between rumen epimural microbes and immune functioning in dairy calves.

Effects of probiotic-supplemented milk replacer on growth, blood biochemistry, fermentation, digestibility, and carcass traits in lambs

The objective of this study was to investigate the effects of feeding cow's milk replacer and probiotic supplementation on growth performance, blood metabolites, ruminal fermentation parameters, and nutrient digestibility in male lambs, with ewe's milk serving as the control treatment. Eighteen male lambs with an average initial body weight of 5.0 ± 1.2 kg and age of 15 ± 4 days were randomly assigned to three experimental groups: ewe's milk, cow's milk replacer, and cow's milk replacer with probiotic supplementation. The experiment was conducted using a completely randomized design. Lambs fed ewe's milk showed significantly higher average daily gain (218.4 g/day) compared to those fed cow's milk replacer (183.7 g/day) or cow's milk replacer with probiotic (209.1 g/day). Similarly, dry matter intake was highest in the ewe's milk group (585.6 g/day) compared to the cow's milk replacer (435.9 g/day) and cow's milk replacer with probiotic (510.5 g/day) groups. Blood glucose levels were higher in the ewe's milk group (75.3 mg/dL) compared to the cow's milk replacer (70.3 mg/dL) and cow's milk replacer with probiotic (72.1 mg/dL) groups. Probiotic supplementation resulted in increased blood urea nitrogen (15.6 mg/dL) and total protein (7.3 g/dL) levels compared to the other groups. Furthermore, the ewe's milk group showed higher apparent dry matter (76.1%) and crude protein (68.5%) digestibility compared to the other treatments. The fecal score on day 30 was higher in the cow's milk replacer group (2.34) compared to the ewe's milk (1.24) and cow's milk replacer with probiotic (1.45) groups. There were no significant differences in the carcass traits of the experimental lambs. In conclusion, based on the results of this study, it seems that feeding cow's milk + probiotic as a replacement for ewe's milk did not significantly affect the performance, carcass traits, and blood and fermentation parameters in infant lambs.

Comparison of Growth Performance, Immunity, Antioxidant Capacity, and Liver Transcriptome of Calves between Whole Milk and Plant Protein-Based Milk Replacer under the Same Energy and Protein Levels.

High-cost milk proteins necessitate cheaper, effective milk replacer alternatives, such as plant proteins. To examine plant protein-based milk replacer’s impact on growth performance, serum immune and antioxidant indicators, and liver transcriptome profiles in suckling calves. We assigned 28 newborn Holstein calves (41.60 ± 3.67 kg of body weight at birth) to milk (M) or milk replacer (MR) and starter diets pre-weaning (0–70 d of age) but with the same starter diet post-weaning (71–98 d of age). During the pre-weaning period, compared with the M group, MR group had significantly lower body weight, withers height, heart girth, average daily gain, feed efficiency, serum immunoglobulin (Ig) M concentration, superoxide dismutase concentration, and total antioxidant capacity; whereas they had significantly higher serum aspartate aminotransferase concentration. During the post-weaning period, MR group presented significantly higher average daily gain, alanine transaminase, aspartate aminotransferase, and malonaldehyde concentrations; whereas they had significantly lower serum IgA and IgM concentrations than the M group. Transcriptome analysis revealed 1, 120 and 293 differentially expressed genes (DEGs; MR vs. M group) in the calves from pre- and post-weaning periods, respectively. The DEGs related to xenobiotic and lipid metabolism and those related to energy metabolism, immune function, and mineral metabolism were up- and downregulated, respectively, during the pre-weaning period; during the post-weaning period, the DEGs related to osteoclast differentiation and metabolic pathways showed difference. In this study, compared with M group, MR group had the same growth performance during the overall experimental period; however, MR affected the hepatic metabolism, immune, and antioxidant function of calves. These observations can facilitate future studies on milk replacers.

Retinol and α-Tocopherol Contents, Fat Color, and Lipid Oxidation as Traceability Tools of the Feeding System in Suckling Payoya Kids.

Simple SummaryIn Spain, goat farms are mainly oriented to milk production, although kid meat contributes to their sustainability, particularly in autochthonous breeds such as Payoya. Usually, kids are fed artificial milk until slaughter, allowing the use of goat milk for the commercialization of cheese, but several studies indicate that feeding kids natural milk improve the quality of their meat. The aim of the present study was to find traceability markers to discriminate between kids that are fed natural milk (with different goat management systems) and those fed a milk replacer. For this purpose, we proposed the quantification of retinol and α-tocopherol contents in plasma and fat, the amount of kidney fat, lipid oxidation, and some fat color parameters as potential markers. The results showed that plasma retinol concentrations were higher in kids fed feeding systems with synthetic vitamins. The plasma α-tocopherol concentrations were higher in kids fed grass-based feeding systems (which contain the natural forms of these vitamins). A dilution effect was shown for the retinol concentration in fat. Collectively, the analyzed variables allowed a discriminant analysis to correctly classify kids according to their feeding system and could ensure traceability to consumers.The effects of Payoya kid feeding systems on the fat-soluble vitamin (retinol/α-tocopherol) contents, fat content, fat color, and the oxidation index were evaluated to determine their potential for use as feeding system traceability tools. Four groups of Payoya kids (55 animals in total) fed milk exclusively were studied: a group fed a milk replacer (MR) and three groups fed natural milk from dams reared with different management systems (mountain grazing (MG), cultivated meadow (CM) and total mixed ration (TMR)). Kids were slaughtered around one month of age and 8 kg of live weight. Kids from the MG and CM groups presented lower retinol (5.56 and 3.72 µg/mL) and higher α-tocopherol plasma (11.43 and 8.85 µg/mL) concentrations than those from the TMR and MR groups (14.98 and 22.47 µg/mL of retinol; 2.49 and 0.52 µg/mL of α-tocopherol, respectively) (p < 0.001). With respect to fat, kids with a higher intramuscular fat percentage (CM and TMR groups) had lower retinol contents (16.52 and 15.99 µg/mL, respectively) than kids from the MG and MR groups (26.81 and 22.63 µg/mL, respectively) (p < 0.001). A dilution effect of vitamins on fat was shown: the higher the amount of fat, the lower the vitamin concentrations, the higher the lipid oxidation index (MDA), and the lower the SUM (absolute value of the integral of the translated spectra between 450 and 510 nm). A discriminant analysis that included all studied variables showed that 94.4% of the kids were classified correctly according to their feeding system and could allow traceability to the consumer.

Drenching Bovine Colostrum, Quercetin or Fructo-Oligosaccharides Has No Effect on Health or Survival of Low Birth Weight Piglets.

Simple SummaryOver the past three decades, the litter size of sows has been increased to improve productivity. This has not only led to more piglets per sow, but also an increased proportion of low birth weight piglets, and consequently, higher pre-weaning mortality. In an attempt to improve the resilience of small piglets, an oral supplementation (drenching) with a bioactive compound can be applied. In this study, low birth weight piglets were drenched with bovine colostrum, short-chain fructo-oligosaccharides or quercetin (each dissolved in a plain milk replacer) during the first seven days after birth. The animals’ body weight, mortality, skin lesions, and different blood parameters were evaluated between birth and 2 weeks post-weaning. None of the supplemented compounds had a positive effect on any of the parameters, and thus, on the resilience of low birth weight piglets. Moreover, a negative effect on survival was observed in piglets that were drenched with short-chain fructo-oligosaccharides. These results showed that the evaluated bioactive compounds, in their given dosages, were unable to improve the low birth weight piglets’ survival and emphasized the complex, multifactorial origin of pre-weaning mortality.The introduction of hyperprolific sows has resulted in more low birth weight (LBW) piglets, accompanied by higher mortality. A possible strategy to enhance the resilience and survival of LBW piglets is oral supplementation (drenching) of bioactive substances. This study evaluated the supplementation of bovine colostrum, short-chain fructo-oligosaccharides (scFOS) or quercetin that were dissolved separately in a milk replacer. The study was divided into two sub-experiments. First, the milk replacer was compared with a sham drenched group. Secondly, each dissolved compound was compared with the milk replacer. The LBW piglets, defined as weighing between (mean litter birth weight −1*SD) and (mean litter birth weight −2.5*SD), were randomly allocated to the different treatments and drenched once a day for seven days. On day 1, 3, 9, 24 and 38, piglets were weighed and scored for skin lesions. Blood samples were collected on day 9 and 38 and analyzed to determine glucose, non-esterified fatty acids, urea, immunoglobulin G, insulin-like growth factor 1, and a standard blood panel test. There was no difference between sham drenched piglets and piglets that were drenched with milk replacer regarding any of the parameters. No effect was observed between the milk replacer group and any of the bioactive compounds either, except a higher mortality within the scFOS group. In conclusion, this study showed that drenching the evaluated bioactive compounds, in the used dosages, did not improve LBW piglets’ resilience or survival and more research is required to determine the effect of scFOS on small piglets.

Early Feeding Regime of Waste Milk, Milk, and Milk Replacer for Calves Has Different Effects on Rumen Fermentation and the Bacterial Community.

Simple SummaryThe postnatal period may be the most critical window for rumen manipulation, and the early feeding regime may lead to permanent changes in the rumen microbial composition. The objective of this research was to investigate the effects of the most common liquid feeds (whole milk, waste milk, and milk replacer) on growth performance, rumen development, and the ruminal bacterial community during the weaning period, and to then follow calves to up to six months of age to determine the persistence of any ruminal imprinting effects. The results demonstrate that the early feeding regime impacts rumen development not only by dry matter intake, but also the type of liquid feed. Calves fed waste milk had a distinctly structured bacterial community at two months of age, but this difference diminished at six months of age. Calves fed milk replacer had a different rumen fermentation pattern at two months of age, which may induce a long-lasting effect on the rumen environment. We investigated the effects of different types of early feeding on rumen fermentation parameters and the bacterial community in calves. Fifty-four Holstein calves were assigned to three treatments and fed whole milk (M), pasteurized waste milk (WM), or milk replacer (MR). Male calves were slaughtered at the age of two months to measure the stomach masses. The female calves were followed for six months to determine the body weight, blood indices, rumen fermentation, and ruminal bacterial community. At the age of two months, the average daily gain was lower, but the concentration of total volatile fatty acids was greater in the MR group. Starter intake and stomach mass were lower, but the isovalerate molar proportion was greater in the WM group. The blood indices and ruminal bacterial community of the WM group differed from those of the other groups. At the age of six months, the ruminal propionate molar proportion was lower, but the ruminal pH and acetate/propionate ratio were greater in the MR group. In conclusion, calves fed WM had different rumen fermentation and bacterial community during the weaning period, whereas feeding MR produced a long-lasting effect on the rumen environment.

Effects of milk replacer and starter diet provided as creep feed for suckling pigs on pre- and post-weaning growth.

This study was aimed at investigating the long-term effects of provision of liquid milk replacer (MR) and solid starter diet (SD) during lactation on post-weaning (PW) growth of pigs. In experiment 1, 33 cross-bred litters were allotted to four treatments: no supplement (CON), MR ad libitum, SD ad libitum and 100 g SD/litter/day from lactation day 4 through weaning at day 21 during late fall. In experiment 2, 40 litters received MR or none in July. PW pigs received commercial diets to marketing. In experiment 1, weaning weight (WW), pre-weaning average daily gain (ADG) and mortality (2.4%) were not influenced by creep-feeding MR or SD. ADG was greater (P < 0.05) in the MR group versus CON during days 21-54, but did not differ across the treatments during days 54-162. In experiment 2, ADG during lactation and WW were greater in the MR group versus CON, with mortality lower in the former (5.6 vs. 10.3%). However, PW ADG to day 175 did not differ between the two groups. Results suggest that creep-feeding MR or SD has no effect on PW growth. However, it remains possible that MR reduces PW mortality during the hot season.

Health performance of crossbred Indian dairy calves reared on whey-based commercial milk replacer

Newly born crossbred calves (24) of either sex were selected and equally distributed into control, Treatment- 1(T-1) and Treatment-2 (T-2) groups for evaluating the effect of feeding milk replacer on their health performances. Control group received whole milk and skim milk as per the institute feeding schedule, whereas the T-1 and T-2 groups were fed on whole milk and milk replacer, respectively at the constant rate 1/10th of their body weight for first three months of age. The overall average daily gain in T-1 showed significantly higher average daily gain than control and T-2. Health of calves was evaluated in terms of number of calves days in diarrhoea and their fecal consistency scores (FCS). The values of FCS were significantly higher in T-2 than T-1 and control indicating that calves in milk replacer group had higher incidences of diarrhoea than other 2 groups fed on whole milk. No any major health problems or mortality were observed during the study in any of the groups. From the present study it was concluded that in spite of slightly higher incidences of digestive problems in calves during the winter months, milk replacer feeding could be a better option for commercial dairy producers and resource poor farmers in order to save the whole milk for human consumption.

Probiotics in milk replacer influence lamb immune function and meat quality

This study was undertaken to assess the effect of milk replacer (MR) containing Lactobacillus acidophilus and a mix of Bifidobacterium animalis subsp. lactis and Bifidobacterium longum subsp. longum on lamb immune response and on lamb meat quality. A 6-week-trial was conducted on 40 male Comisana lambs, divided into four groups, fed maternal milk (MM), MR, MR with L. acidophilus supplementation (MRL) and MR with a mix (1 : 1) of B. animalis subsp. lactis and B. longum subsp. longum supplementations (MRB). Lambs fed MR containing a mix of bifidobacteria showed the highest in vivo cellular immune response to phytohemagglutinin, whereas MM and MRB showed the highest antibody response to ovalbumin. At day 11 of the trial, MRL displayed the highest value of Interleukin-10; differences disappeared among groups subsequently. Blood cholesterol levels in lambs fed MR containing L. acidophilus was almost halved compared with that found in MM and MR groups. Meat from artificially reared lambs was characterized by trans-11 18:1 and total conjugated 18:2n-6, whereas meat from the dam-suckled lambs was characterized by 14:0, cis-9 14:1 and 16:0. Polyunsaturated to saturated fatty acid ratio was higher in meat of MR, MRL and MRB than in MM lambs. Meat from artificially reared lamb fed MR containing probiotics showed an improved fatty acid profile for human diet.

The effect of frequent milk feeding on abomasal curd formation of Holstein calves

In order to understand the effects of the automatic milk replacer feeding system on calf health, we examined the effect of frequent milk feeding on curd formation in the abomasum using ultrasonographic imaging. Eight male Holstein calves were divided into a milk-replacer group and a fresh milk group. Calves were fed twice a day to 12 days after birth (Period A). From 13 days, calves were fed six times a day (Period B). The abomasal fluid was taken by paracentesis. In both periods A and B, the fresh milk group formed bigger curds faster than the milk replacer group. The curd score of the milk replacer group in period B at 2 h was significant lower than those of both groups in period A. The pH in the abomasum was lower in period B than in period A. We could not identify the location of the abomasum in the milk replacer group during period B at almost time points. Our experiment suggests the possibility that frequent feeding of milk replacer causes incomplete hydrolysis of kappa-casein as well as curd formation, thus reducing the digestibility compared to the feeding of the milk replacer twice per day or frequent feeding of fresh milk.

Effect of rearing system on some meat quality traits and volatile compounds of suckling lamb meat

Twenty Churra-breed suckling lamb carcasses from two groups of animals were used in this study. One group had been reared on maternal milk (MM), and the other had been reared on milk replacer (MR) until slaughter at 25–35 days old. The effects of the type of milk on several meat quality traits were studied. These effects included pH, colour, WHC, texture, retinol and tocopherol concentrations, colour and lipid oxidation stability, and the volatile compounds that formed during boiling of the meat. Furthermore, a sensory analysis (triangle test) was carried out. The colour of M. longissimus dorsi of MM samples showed higher L*, lower a*, and higher b* values than those of MR samples ( P < 0.05). Retinol, α-, δ- and γ-tocopherol levels were all higher in the meat of lambs reared on MM ( P < 0.001). Rancimat tests and TBARS analysis revealed more lipid-oxidative stability for the meat of the MR group, and the colour of meat from this group was also more stable. Likewise, volatile compounds derived from lipid oxidation were more abundant in the MM samples than in the MR group samples. The presence of volatiles attributed to non-oxidative lipid thermal degradation also differed between the two rearing systems, with concentrations of volatiles derived from dodecanoic acid being clearly higher for the MR meat samples. Residues of butylated hidroxytoluene (BHT) were detected in MR samples but not in the samples of the MM treatment. In the triangle test, an untrained panel could not detect a significant difference between MM and MR meat samples. The present study has demonstrated that variation in the composition of milk sources (MM vs. EM) used in rearing suckling lambs may be responsible for a significant effect in oxidative stability of fresh suckling lamb meat during storage and display and in the volatile composition of cooked suckling lamb meat. Thus, meat from MR-fed suckling lambs may become more stable to oxidation compared to meat from MM-fed suckling lambs. MR-reared meat may, however, have a different flavour from what is expected from the more traditional MM-fed suckling lamb meat.

Efeitos do uso de sucedâneo do leite e milho processado no desempenho de bezerros da raça holandesa até o desmame

Seventy-two Holstein calves, 15 days old, were used to evaluate the substitution of whole milk by a milk replacer, and the effects of processed corn in starters. Animals were distributed in blocks by date of birth and sex, in a 2x3 factorial arrangement of treatments. Factors consisted of whole milk or milk replacer and steam flaked corn at densities 283, 360 and 437 g/L. During the pre-weaning period, the processed corn at different densities did not affect the performance of calves. Replacement of whole milk by milk replacer reduced daily body gain (milk = 0.56 vs. milk replacer = 0.30 kg/day), body weight at weaning (63.3 vs. 51.9 kg/day) and total dry matter intake (0.83 vs. 0.68 kg/day). Food conversion (1.61 vs. 2.60) became worse. Animals from milk replacer group were weaned earlier than the whole milk group (56.4 vs. 48.9 days).

Short Communication: Addition of Milk Replacer to Colostrum Whey: Effect on Immunoglobulin G Passive Transfer in Majorera Kids

Forty-two Majorera kids (21 males and 21 females) were assigned to 3 groups, a colostrum group (C), a colostrum whey group (CW), and a colostrum whey plus milk replacer group (CWMR). All kids were fed twice on the first day and received 4g of IgG/kg of body weight. No differences were found in serum IgG among the different treatments. Kid serum IgG concentrations on d 2 were 14.57, 17.25, and 13.32mg/mL in the C, CW, and CWMR group, respectively. Labor time per animal was higher in the C and CW treatments than in the CWMR group (24.2±2.3, 20.9±3.4, and 16.1±1.5min, respectively). This new management system may decrease labor costs during the colostrum feeding period.

Effect of type of suckling and polyunsaturated fatty acid use on lamb production.1. Productive performances and quanti-qualitative characteristics of the carcass

The aim of the study was to estimate the influence of artificial rearing and of the addition of polyunsaturated fatty acids (PUFA) to an acidified milk replacer on the productive performances and on the quanti-qualitative characteristics of the carcass. Fifty one twin-born Gentile di Puglia lambs were subdivided into three homogenous groups (9 females and 8 males) assigned the following feeding treatments: maternal milk (MM); acidified milk replacer (MR); acidified milk replacer + 10 ml/l of a mixture of linseed and fish oil rich in PUFA (MR+PUFA).Milk consumptions and live weights were recorded weekly. Seven males from each group were slaughtered at 45 days of age and the net warm dressing percentage, the composition of the carcass and the colorimetric characteristics of the Longissimus lumborum muscle were estimated. Artificial rearing improved the daily weight gain (0.182-0.172 vs 0.128 Kg; P<0.01) of lambs, provided fatter carcasses and meat with a better red index (6.16-6.43 vs 8.03; P<0.01).The addition of omega-3 fatty acids to the diet did not influence the weight gain, the feed conversion index, the net warm dressing percentage and the incidence of the different meat cuts of the half carcass. However, it significantly increased the half carcass length (37.86 vs 35.0 cm; P<0.05), the thoracic depth (19.71 vs 16.50 cm; P<0.01) while, it compared to the MR group reduced the proportion of lean (63.21 vs 53.98 %; P<0.01) in favour of bone (20.94 vs 29.40 %; P<0.01) in the lumbar region.

Development of Intestinal Immunoglobulin Absorption and Enzyme Activities in Neonatal Pigs Is Diet Dependent

Uptake of colostrum just after birth is essential to stimulate intestinal growth and function, and in many species, including pigs, colostrum also provides immunological protection via the absorption of immunoglobulin G (IgG). In this study, intestinal growth, IgG absorptive capacity and enzyme activities were investigated in newborn pigs in response to different diets. Newborn piglets were bottle-fed porcine colostrum (PC), bovine colostrum (BC), porcine plasma (PP), porcine milk (PM), bovine colostrum containing porcine plasma (BCP) or a milk replacer (MR) every 3 h (15 mL/kg) for up to 2 d. Bovine serum albumin (BSA) was added to the diets as a macromolecule marker. The percentage of absorbed BSA just after birth was highest for piglets fed the PC diet (30-50%), lower for those fed the BC and BCP diets (23-30%) and lowest for the PP, PM and MR diet-fed piglets (7-20%, P < 0.05 relative to those fed colostrum). Porcine IgG was absorbed more efficiently than bovine IgG. Intestinal closure occurred earlier in MR and BCP piglets (within 12 h after birth) than in PC pigs. At 2 d of age, intestinal mucosal weight (+120% increase from birth) and villus morphology were similar in the PC, BCP and MR groups. All 3 groups also had increased aminopeptidase A activity compared with values at birth (+100% increase). Compared with PC pigs, the BCP group had higher sucrase and maltase activities (+50% and +200%, respectively) and lower aminopeptidase N activity (-50%, P < 0.05). Similarly, MR pigs showed elevated sucrase activity (+40%) and lowered maltase, lactase and aminopeptidase N activities (-20% to -50%, P < 0.05) compared with PC pigs. We conclude that porcine and bovine colostrum contain factors that stimulate the intestinal endocytotic and enzymatic capacity in newborn pigs. A milk replacer can produce normal gut growth, but may be inefficient in mediating normal macromolecule transport and disaccharidase activity. Bovine colostrum mixed with porcine plasma proteins may be a useful substitute for porcine colostrum in artificial rearing of newborn pigs.

Production Performance and Physiological Responses of Angora Goat Kids Fed Acidified Milk Replacer

Angora kids were blocked by birth weight and sex and assigned randomly to goat milk or acidified milk replacer. Daily milk intake, weekly BW, and heart girth measurements, and blood parameters (packed cell volume, total protein, glucose, and NEFA) were monitored at 3 d (initial) and at 4, 6, 8, and 9 wk of age. Both groups were fed their respective milks for ad libitum intake for 6 wk and then reduced to 75, 50, 25, and 0% of wk-6 intake during wk 7, 8, 9, and 10, respectively. Solid feed (20% CP and 3.1 Mcal of metabolizable energy/kg of DM) was provided for ad libitum intake starting on wk 3. Pretreatment BW (average 2.4kg) and blood parameters were similar for milk and replacer groups. Packed cell volume (21.8 and 34.2%), total protein (50.3 and 46.6g/L), and NEFA (.52 and .69 meq/L) for goat milk and acidified milk replacer groups, respectively, were affected by dietary treatment. Final BW (average 10.5kg) and mean plasma glucose concentration (84 to 88 mg/dl) were similar between treatments; however, kids fed goat milk produced more mohair (13.8%) than those fed acidified milk replacer. Despite physiological differences, acidified milk replacer can be used successfully to raise Angora kids.

Utilization of raw or heat-treated starch fed in liquid diet to preruminants 2. Lambs

Eighteen Assaf lambs, 10±2 days old, weighing 6.3±0.33 kg were fed during 14 days milk replacer (MR) or MR in which 20% was substituted by heat-treated corn starch-soy mixture (20ES) or 20% untreated corn starch-soy mixture (20US). During the following 8 days, the amount of starch-soy mixtures was increased to 40% (40ES and 40US), after which lambs were weaned gradually. During the first suckling period (14 days) total weight gain was 2.5±0.30, 3.0±0.22, and 2.3±0.28 kg for the MR, 20ES and 20US groups, respectively (NS). However, feed utilization in the 20US was inferior to the MR and 20ES groups by 20% ( P<0.05). When starch-soy mixture substituted 40% of the milk replacer, feed consumption (kg/7 days) and daily body weight gain (g) were significantly lower ( P<0.05) in the 40ES (1.54±0.07 and 102±5.8) than in the MR (1.70±0.05 and 156±6.0) or 40US (1.65±0.05 and 131±9.7) groups. Daily gains of 40US group were significantly lower than those of MR lambs. The apparent digestibility of dry matter, ash and protein of liquid diets was higher in the MR group than in the other groups by 2–6% when fed 20US and 20ES, and by 3–12% when fed 40US and 40ES ( P<0.05). the pH of rumen liquor after the meal was slightly lower (NS) in 20ES and 20US groups than in the MR group. The 40ES lambs were less active before meals compared with the other groups.

Utilization of raw or heat-treated starch fed in liquid diet to preruminants 1. Kids

Twenty Saanen kids at average age of 7±1.5 days were fed 19 days a commercial milk replacer (MR) or a milk replacer in which 20% or 40% was substituted by heat-treated, expanded starch-soy mixture (20ES, 40ES), or 40% untreated starch-soy mixture (40US). Soy concentrate contained 65% protein and was toasted to inactivate trypsin and chymotrypsin inhibitors. Weight gain and food utilization of kids fed 20ES diet were the highest but did not differ significantly from kids fed MR. Substituting 40% of the milk replacer by expanded or untreated starch-soy mixtures reduced food consumption, body weight gain and food utilization 40%–50%. During weaning period, differences in body weight gain between the groups were smaller and non-significant, but performance of the 20ES group was still the best in comparison with the other groups. Apparent digestibility of dry matter, ash and protein was higher in the MR group than in the other groups. Heat treatment did not affect apparent digestibility of starch. Blood glucose levels were higher before and after feeding in the MR and 20ES groups than in the 40ES and 40US. Peaks of blood glucose were lower and delayed in groups fed starch compared with the MR group. The pH of rumen liquor dropped after meals more in the 40US and 40ES than in the MR and 20ES kids. The drop was accompanied by concurrent increase in concentration of total volatile fatty acids. During the suckling period, kids fed MR, 20ES and 40US were more active before than after meals. They stood more, none of them was sleeping, and only a few were sitting before meals. These differences were minor in the 40ES group. Differences in behaviour before and after meals were much smaller in all groups during the weaning period; 40ES and 40US groups spent more time in eating concentrate before and after the liquid meal than MR and 20ES kids.