Effect of grazing and homeopathy on milk production and immunity of Merino derived ewes

The effect of grazing and homeopathic therapy on sheep immune response and milk production was investigated on 40 multiparous Merino derived ewes. Twenty animals were housed in an indoor-bedded pen (P), whereas 20 others were allowed to graze on pasture for 9 h/d (G). P and G animals were fed an equivalent diet in terms of dry matter intake, crude protein percentage and energy concentration. In each group, 10 animals were subjected to unicistic homeopathic treatments (H), while 10 ewes were kept as a control and treated with conventional medicine when necessary (C). The grazing rearing system had a marked positive effect on in vivo cellular immune response (delayed-type hypersensivity to PHA, P < 0.001). Grazing animals produced more milk than the penned ones (1048.00 ± 75.61 kg versus 853.04 ± 67.78 kg, P < 0.05), with increased content of milk fat (7.69 ± 0.15% versus 7.25 ± 0.14%, P < 0.05). Accordingly, blood levels of triglycerides (P < 0.01), urea (P < 0.001) and alanine aminotransferase (ALT) (P < 0.001) were significantly higher in group G. The homeopathic treatments produced limited effects on the milk production and immune response. However, such treatments reduced the risk of contamination of the products with medicinal traces, as H group received no allopathic treatment.     

Effects of dietary conjugated linoleic acid on metabolic status,BW and expression of genes related to lipid metabolism in adipose tissue of dairy cows during peripartum

Conjugated linoleic acid (CLA) dietary supplementation reduces milk fat content and yield, but its effects on lipid metabolism and energy status remain controversial. The objective of this study was to investigate the effects of dietary CLA on adipose tissue (AT) mRNA abundance of genes related to lipid metabolism, plasma indicators of metabolic status, body condition score (BCS) and BW changes in dairy cows. Sixteen multiparous Holstein cows (3.2 ± 1.4 lactations, 615 ± 15 kg BW) were randomly assigned to treatments: 1) CLA; rumen-protected CLA (75 g/d) or 2) Control; equivalent amount of rumen inert fatty acid (FA) as the previous diet (78 g/d), from − 20.2 ± 3.2 (mean ± SEM) to 21 d relative to calving (d 0). Subcutaneous AT was biopsied from the tail-head region at d 21 to determine the mRNA abundance of genes related to lipid metabolism. Blood samples were collected at − 20.2 ± 3.2, 0, 7, 14 and 21 d relative to calving to determine plasma non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), insulin and glucose. Conjugated linoleic acid decreased milk fat yield and milk fat content by 15 and 16%, respectively. Cows fed CLA had lower plasma NEFA and BHBA and greater glucose and insulin concentrations (P < 0.05). Mean BCS at 21 d postpartum was greater (P < 0.01; 2.89 vs 2.25), and BCS loss from the day of enrollment to 21 d postpartum was reduced (P < 0.01; − 0.13 vs − 0.64) in the CLA group. The expression of acylcoenzyme A oxidase, carnitine palmitoyltransferase 1A, hormone-sensitive lipase, β2 adrenergic receptor and acetyl-CoA carboxylase was downregulated by CLA supplementation, whereas the expression of sterol regulatory element binding protein, lipoprotein lipase and peroxisome proliferator-activated receptor gamma was upregulated (P < 0.01). In summary, CLA-supplemented cows showed signs of better metabolic status and less severe fat mobilization. Moreover, CLA increased mRNA abundance of genes related to lipogenesis and decreased mRNA abundance of genes related to FA oxidation and lipolysis in the AT of dairy cows during early lactation.     

Reproductive performance and milk yield in Awassi ewes following crossbreeding

The objective of this study was to evaluate the effect of crossbreeding Awassi ewes with either Charollais or Romanov sires, on pre-weaning lamb production as reflected by reproductive performance and milk production in the ewes. Two hundred and five, 3- to 6-year-old multiparous ewes of three breeds were allocated to three groups [Awassi (A; n = 56), F₁ Romanov × Awassi (RA; n = 78) and F₁ Charollais × Awassi (CA; n = 71)]. Upon lambing, ewes and their offspring were placed in a large pen in which they remained until the end of the trial. Body weight (BW) and body condition score (BCS) of the ewes and the BW of the lambs were recorded weekly from birth to weaning at 70 days of age. Milk production was recorded weekly from parturition to weaning. Pregnancy rates were not influenced by breed-type. Multiple births and the fecundity of ewes were greater (P < 0.05) in the RA group, compared to the A and CA groups—while the weaning percentage was similar between the breeds. Lamb birth and weaning weights were similar, while the kg lamb born per kg ewe lambed was greater (P < 0.05) in the RA group, compared to the CA group. The CA ewes recorded a higher BW (P < 0.01) and BCS (P < 0.01) than the other breed groups. Awassi ewes produced more milk (P < 0.01) throughout the observation period. Milk ash percentage was higher (P < 0.05) in the CA group, while the percentage of crude protein and dry matter was similar for the different groups. Results of the present study indicate that crossbreeding of Awassi ewes with Charollais and Romanov breeds decreased milk production in the progeny, without affecting lamb growth. The crossbreeding of Awassi with Charollais resulted in improved BW and BCS, while the crossbreeding of Awassi ewes with Romanov resulted in improved reproductive performance of the crossbreds. Crossbreeding Awassi ewes with exotic rams can thus be conducted to increase the number of lambs produced per ewe.     

Fatty acid profiles,growth, and immune responses of neonatal lambs fed milk replacer and supplemented with fish oil or safflower oil

Diets supplemented with long chain, n − 3 polyunsaturated fatty acids (PUFA) have improved the health and performance of neonatal and growing animals. This study was conducted with lambs that were orphaned at approximately 1 day of age to determine whether supplementing milk replacer fed lambs with oils rich in long chain n − 3 or n − 6 PUFA would alter plasma lipid profiles and affect growth characteristics and immune functions. From days 1 to 28 of age, lambs had ad libitum access to commercial milk replacer. From days 7 to 28 of age, lambs received twice daily either 1 g of soybean oil, 1 g of fish oil, or 1 g of safflower oil per os in a gelatin capsule (n = 60 pens; 20 pens/treatment; one ewe and one ram with similar initial body weights/pen). On days 7, 14, 21, and 28 of age, lambs were weighed, and jugular blood was collected from ram lambs. Lymphocyte proliferation in vitro, differential white blood cell (WBC) counts, and weight gains were quantified. Plasma from days 7 and 28 was used for fatty acid analyses. Fish oil increased (P < 0.001) plasma total n − 3 fatty acid concentration and total n − 3:total n − 6 fatty acid ratio. Pen body weight (i.e., total lamb weight per pen) increased (P < 0.001) with day (day 7, 11.9 kg; day 14, 15.1 kg; day 21, 18.2 kg; and day 28, 21.2 kg), but oil treatment did not affect pen body weight. Neither oil treatment, day, nor oil treatment × day interaction were significant for pen body weight gains (3.5 kg), pen average daily gains (0.5 kg), pen milk intakes (19.0 kg), or pen gain:feed ratio (0.18) measured during three intervals: days 7–14; days 14–21; and days 21–28. Day, but not oil treatment, affected (P < 0.001) unstimulated, concanavalin A stimulated, and lipopolysaccharides stimulated lymphocyte proliferation: days 14, 21, and 28 proliferation > day 7 proliferation. For neutrophils per 100 WBC, the treatment × day interaction was significant (P < 0.05). Oil treatment and day affected (P < 0.01 and <0.05, respectively) lymphocyte numbers per 100 WBC. For monocytes, eosinophils, and basophils, neither oil treatment, day, nor the oil treatment × day interaction were significant. Fish oil altered plasma fatty acid profiles, but it did not seem to improve measures of the performance or immune function of healthy, milk replacer fed lambs.     

Influence of organic systems on milk fatty acid profile and CLA in goats

The effect of organic system on the fatty acid profile of milk and CLA content was evaluated using 30 pregnant pluriparous goats, divided into two homogeneous groups (S and O) of 15 goats each. Group S was housed in a stable and received alfalfa hay as forage, while group O was raised according EC Regulation 834/2007 and led to pasture. After the kids weaning, goats were milked twice a day for 5 months. Daily milk yield was recorded and, monthly, representative milk samples from the two daily milkings were analysed for chemical and fatty acid profile. Average milk yield did not differ statistically between the groups. The goats of the O group had significantly higher fat content in milk than those of group S (65.9 g/day vs. 54.3 g/day, P < 0.01). Among milk fatty acids, organic system significantly affected the percentages of C18:1 c9, C18:1 t11, linoleic acid, alpha-linolenic acid, monounsaturated fatty acid and polyunsaturated fatty acid. Organic system highly influenced the c9 t11 conjugated linoleic acid (CLA) (0.810 g/100 g of fat vs. 0.542 g/100 g of fat, for groups O and S, respectively, P < 0.01), t10 c12 CLA (0.041 g/100 g of fat vs. 0.024 g/100 g of fat, for groups O and S, respectively, P < 0.01) and ∑CLA (0.87 g/100 g of fat vs. 0.58 g/100 g of fat for groups O and S, respectively, P < 0.01) concentrations of milk.     

Plasma prolactin,blood metabolites and milk production in bromocryptine-treated crossbred goats

To determine the effect of bromocryptine on plasma prolactin, metabolites and milk production, six healthy crossbred goats in their second or third lactation were selected from the institute’s goat herd. The goats were injected with bromocryptine @ 5 mg per day intramuscularly for a period of 5 days during 55–60 days of lactation (period I) and treatment was repeated after 14 days for an additional 5 days (period II). Blood samples were collected for 5 consecutive days before, during and after administration of bromocryptine during both periods of the study. Milk samples were collected on days coinciding with the days of blood sampling. During period I, bromocryptine administration decreased (P < 0.01) milk yields by 27.4%. After withdrawal of bromocryptine the yields increased (P < 0.01); however, during period II, bromocryptine treatment did not decrease milk yields. During period I bromocryptine treatment suppressed prolactin level (P < 0.01) which coincided with decrease in milk yield, but in period II such decreases in prolactin did not coincide with changes in milk yields. Fat content increased (P < 0.01) after bromocryptine administration in both periods. A decrease (P < 0.01) in protein and lactose content indicated a possible role of prolactin in the synthesis of these constituents by the mammary gland cell in goats. Blood glucose and NEFA were not affected by bromocryptine in period I but in period II an increase in blood glucose with a simultaneous decrease in NEFA was observed (P < 0.01).From this study it is concluded that prolactin has a role in the maintenance of milk secretion through protein synthesis by the mammary gland. However, it does not seem to have any direct role on milk fat synthesis.     

Fluctuations in energy-related metabolites during the peri-parturition period in Lori-Bakhtiari ewes

This study describes the fluctuations in serum energy-related metabolites during a period of 2 weeks before, to 2 weeks after parturition in Lori-Bakhtiari ewes. The effect of parity was also studied. Blood profiles were determined in 60 healthy pregnant ewes with single (n = 30) and twin (n = 30) lambings. Blood was collected from each ewe on days 14 and 7 prepartum, and days 7 and 14 postpartum to determine the serum non-esterified fatty acid (NEFA), β-hydroxybutyrate (BHBA), glucose, cholesterol, blood urea nitrogen (BUN) and calcium (Ca) levels. The age of the ewes had no significant effect on the energy metabolism indicators. Serum NEFA, BHBA, glucose, BUN and calcium concentrations recorded peak levels 7 days before parturition. However, NEFA and BHBA recorded significant changes (P < 0.05) during the peri-parturition period. All metabolites changed significantly in ewes carrying twin-bearing ewes, compared to single-bearing ewes. Serum BHBA concentrations recorded positive correlations with the serum NEFA (P < 0.01) and cholesterol (P < 0.05), while blood glucose had negative correlations (P < 0.01) with NEFA, BHBA and Ca. Blood NEFA and BHBA recorded positive correlations (P < 0.05) with the BUN levels and negative correlations (P < 0.05) with Ca. The results showed that blood NEFA and BHBA levels are sensitive indicators of the energy balance during the peri-parturition period in ewes.     

Effect of group size on feed intake,aggressive behaviour and growth rate in goat kids and lambs

The effects of different group sizes on feed intake, growth and behaviour in penned kids and lambs were studied in an experiment (Exp. 1) with 30 kids and 30 lambs used in 3 periods. In each period, animals were divided into five group sizes. The group sizes were one, two, three, four or five animals per pen. In a second experiment (Exp. 2) 36 kids and 36 lambs were allotted to two groups of one and five animals per group. The diet consisted of Jackfruit (Artocarpus heterophyllus) and Acacia (Acacia mangium) foliages, sugar-cane (Saccharum officinarum) and concentrate. The foliages were given ad libitum, equal to 130% of intake of fresh matter of the group the previous day, and concentrate and sugar-cane were given at a level of 10 g dry matter (DM)/kg initial body weight. The time for each period in Exp. 1 was 21 days, with the last 7 days for data collection. The behaviour observations were done during the last 4 days of each data collection period. The time for Exp. 2 was 84 days.In Exp. 1, the kids had a higher total DM intake (DMI) (P = 0.011) and DMI of Jackfruit (P < 0.001) than the lambs. Total intake increased linearly as group size increased (P = 0.03). When feeding Jackfruit or sugar-cane aggressive behaviours recorded per pen or per animal increased linearly with group size. In Exp. 2, there was no difference in total DMI between kids and lambs, but kids had a significantly higher DMI of Jackfruit and a lower DMI of sugar-cane. Total DMI and DMI of Jackfruit and sugar-cane were similar for the group sizes of five animals and one animal, but kids showed a higher total intake and intake of Jackfruit in the group sizes of five animals, while a higher intake was obtained in single pens for lambs. The weight gain was higher (P < 0.05) for the lambs compared to the kids, but similar for the animals in the group size of one or five animals. The feed conversion ratio (FCR) was significantly lower for the lambs compared to the kids, but not different between group sizes. The water intake of the lambs was higher (P < 0.05) than that of the kids in both experiments and the animals in the pens with high density drank more water than the animals in individual pens only in Exp. 2. In conclusion, increasing the number of animals in the pens increased feed and water intake and also aggressive behaviours and did not improve growth rate or feed conversion ratio.     

Variation in blood leucocytes,somatic cell count,yield and composition of milk of crossbred goats

Ten multiparous crossbred goats, five each of alpine × beetal (AB) and saanen × beetal (SB) were selected from the National Dairy Research Institute goat herd immediately after parturition. These were managed as per the practices followed in the institute’s goatherd. Blood and milk samples were collected at biweekly intervals from day 14 post-kidding for 22 weeks (154 days). Somatic cell count, electrical conductivity, fat, protein and lactose contents of milk were determined using standard methods. In the blood samples total leucocytes and differential leucocytes were also determined. Somatic cell counts were high immediately after parturition on day 14 of lactation and declined gradually with advanced lactation. There were individual variations (P < 0.01) in somatic cell counts between different lactation periods. Somatic cell count of milk was negatively correlated with neutrophils only (P < 0.05) and was neither correlated with milk yield, or with fat, protein, lactose content of milk. Electrical conductivity of milk was low up to four weeks of lactation and thereafter increased as the lactation advanced. Lactose content of milk declined gradually with the advancement of lactation. Fat content of milk was stable up to the eighth week and thereafter increased with advancement of lactation while the protein content of milk did not change significantly during lactation.     

Effect of artificial vs. natural rearing on milk yield,kid growth and cost in Payoya autochthonous dairy goats

Seventy full lactations of Payoya dairy goats were used to study the effect of two different kid-rearing systems, natural or artificial, on milk yield, composition, hygiene-sanitary quality, kid growth and rearing cost. Two animal groups were established, one with goats under natural rearing (NS) and the other under artificial rearing (AR). In the NS group, the kids had free access to goat milk 18–20 h a day and were suckled up to 5 weeks of age and then the dams were milked twice daily. Dams in the AR were separated from their kids at 48 h post-partum; then, kids were reared artificially, and the dams were milked twice daily. The number of animals used in each type of rearing system was 35 (23 goats giving birth to twins and 12 goats giving birth to a single kid). Each week during suckling phase the volume of milk produced was measured, and individual samples were taken. From 5th week and until 210 days lactation, test-day yields recorded at intervals of 30 ± 3 days were obtained. The chemical composition of the milk, the bacteriology, and the somatic cell count was analyzed. The kids of both sexes were assigned to two groups, natural suckling (NS, n = 58) and ad libitum artificial rearing (AR, n = 58). Within each treatment, two groups of kids were formed depending on prolificacy: first group with kids from single birth (n = 12) and the second with twin kids (n = 46). Birth weight and weight every week upto the 4th week of life were recorded. During the 5 weeks of lactation the total milk yield per goat was higher for the NS group (140.2 L vs. 95.4 L; P < 0.001), although the total amount of marketable milk was greater for the AR group, with a difference of some 21 L (P < 0.05). Throughout the entire lactation the milk yield was higher in the group of natural rearing (total yield of 508 L vs. 400 L; P < 0.05). Although a significant effect of prolificacy was found during suckling phase (P < 0.001), during 30 weeks of lactation this factor did not affect milk yield (P > 0.05). For the milk composition and hygiene-sanitary quality there were no effects on the type of rearing system or the type of birth (P > 0.05). No significant effect was observed either for the feeding system or the sex or the prolificacy on the live weight of the kids at 28 days and the postnatal growth rate from birth to 28 days (P > 0.05). Natural rearing system had higher cost per kid comparing with artificial rearing system (€18.63/kid vs. €14.70/kid, respectively). However, when comparing total incomes during a full lactation, goats with natural rearing system had a higher income because of increment of total milk production (€29.95/kid).     

Characteristics of Korean-Saanen goat milk caseins and somatic cell counts in comparison with Holstein cow milk counterparts

Characteristics of α- and β-casein fractions in the milk of Korean-Saanen goats were compared with those of Holstein cow milk using capillary electrophoresis (CE) analysis. The αs₁-CN content of the Saanen goat milk samples varied from 2.4% to 9.3% of total proteins. Total αs-CN content of the goat milk varied from 10.1% to 17.0%. Total β-CN content containing β₁-CN and the β₂-CN varied from 49.6% to 61.0% of total proteins. Average αs-CN to β-CN ratio of the Saanen goat milk from different farms was 0.24 ± 0.04, ranging from 0.17 to 0.33. The αs-CN (αs₁-CN + αs₀-CN) to β-CN (β_A1-CN + β_A2-CN) ratio of Holstein cow milk was 0.81, which was much higher than that of Korean-Saanen goat milk. The goat milk samples having more than 1.5 million cells/ml somatic cell counts (SCC) contained higher αs-CNs (P < 0.01) and lower β-CNs (P < 0.05) contents than milks with <1.5 million SCC. This resulted in a higher αs-CN to β-CN ratio (P < 0.01) in the milk with >1.5 million SCC.     

Proliferation and apoptosis in subcutaneous adipose tissue of lactating cows with different genetic merit for milk yield

The aim of this study was to investigate the adipocyte size and fate in subcutaneous fat (scAT) of cows diverging for genetic merit at mid lactation stage, when anabolic activity increases and animals are in a state of positive energy balance. Twenty mid lactation cows (180 ± 20 days in milk) grouped according to the Estimated Breeding Values (EBV) for milk yield in plus (EBVp) and minus (EBVm) variants were selected. Average of adipocytes area, proliferation and apoptotic labelling index as well as DLK-1 expression, a marker of pre-adipocytes, were immunohistochemically evaluated in scAT biopsies. In EBVp cows, the BCS was lower (P < 0.01) whereas milk yield, protein, fat yield (P < 0.001) and plasma free fatty acid concentration (P < 0.05) were higher. The scAT of EBVp cows showed a significantly (P < 0.001) higher frequency between 500 and 3000 μm² classes in comparison to EBVm cows, that showed a significantly (P < 0.01) higher apoptotic labeling index. The immunohistochemical reaction showed DLK-1 positivity in scAT of EBVp cows. Taking together, the data indicate a link between milk yield genetic merit of cows, scAT morphology and function, suggesting greater dynamics and metabolic flexibility in EBVp cows.     

Presence of Mycoplasma species and somatic cell counts in bulk-tank goat milk

This cross-sectional study performed on dairy goat herds was designed to establish the relationship between the presence of Mycoplasma species in bulk-tank milk samples from different farms and the bulk-tank milk somatic cell count (BTMSCC) in an area where contagious agalactia (CA) is endemic. Three BTMSCC thresholds, used in payment schemes or as legal requirements for milk quality in Europe and the USA, were considered: (1) 2,000,000 cells/ml; (2) 1,500,000 cells/ml and (3) 1,000,000 cells/ml. Of the 1068 milk samples tested, 7.9% (n = 84) showed the presence of Mycoplasma spp. (Mycoplasma agalactiae 82% and Mycoplasma mycoides subsp. mycoides large colony 17%). Somatic cell counts for bulk-tank samples containing mycoplasmas were higher than those recorded for negative samples (1,176,000 cells/ml vs. 875,000 cells/ml; P < 0.001). Two-by-two table analyses revealed that the presence of mycoplasmas in bulk-tank milk increased the risk of surpassing all SCC thresholds considered, with the highest risk for Mycoplasma positive bulk-tank milk samples exceeding the threshold of 1500 × 10³ cells/ml (odds ratio = 2.42 (1.49 < OR < 3.91). Our results indicate that the presence of mycoplasmas in goat milk had yet another economic consequence and a further incentive to encourage the implementation of specific programs for disease control.     

Effects of feeding method,diet nutritive value and physical form and genotype on feed intake,feeding behavior and growth performance by meat goats

Thirty-two F1 Boer × Spanish (28.7 ± 0.49 kg) and 40 3/4 Boer–1/4 Spanish (31.9 ± 0.47 kg) wethers, approximately 5 months of age, were used to compare feeding systems with different dietary treatments. Feeding systems were Calan gates and automated feeding units allowing one animal to consume feed at a time. Two diets included concentrate (C) and two were dehydrated alfalfa (A), fed pelletized (P) or loose (L). The main effect of feeding method was not significant for any variable. There was an interaction in DM intake (DMI) involving feeding method, diet, and genotype, which indicated that with a concentrate diet, regardless of physical form, DMI was not influenced by feeding method. Main effect dietary treatment means (1.78, 1.67, 2.04, and 1.70 kg for C-P, C-L, A-P, and A-L, respectively; S.E. = 0.030) indicated that pelletizing had a slightly greater effect on DMI with A versus C. ADG was lowest among treatments for A-L (212, 205, 190, and 157 g for C-P, C-L, A-P, and A-L, respectively; S.E. = 8.9), and ADG:DMI was greater for C versus A (127, 120, 94, and 94 g/kg for C-P, C-L, A-P, and A-L, respectively; S.E. = 7.8). Both ADG and ADG:DMI were similar between genotypes. For wethers subjected to automated feeding units, the number of feeder visits was lowest among diets (P < 0.05) for C-P (23.1, 31.2, 35.7, and 35.7 per day; S.E. = 2.00); total feeder occupancy time per animal ranked (P < 0.05) C-P < A-P < C-L and A-L (74, 130, 105, and 122 min/day; S.E. = 6.8), and rate of DMI was greater for P than for L diets (24.6, 12.9, 22.0, and 13.7 g/min for C-P, C-L, A-P, and A-L, respectively; S.E. = 3.89). In summary, meat goats can markedly vary feeding behaviors in response to different diet types and forms; however, there appear limits to such changes, as exemplified by lowest ADG for A-L. Calan gates and automated feeding systems appear similar in the ability to compare growth performance with treatments such as the concentrate-containing diets and genotypes of this experiment. Pelletizing does not seem to affect growth performance with diets consisting of appreciable concentrate. Effects of pelletizing on growth performance of meat goats consuming forage diets may be attributable to change in level of feed intake, without impact on efficiency of feed utilization.     

Combined effect of probiotics and specific immunoglobulin Y directed against Escherichia coli on growth performance,diarrhea incidence,and immune system in calves

Enterotoxigenic Escherichia coli (ETEC) K99 is one of the major pathogens associated with calf diarrhea. The induction of passive immunity in animals by immunoglobulin Y and using probiotics are inexpensive alternatives to antibiotics for the prevention and treatment of a number of bacterial infections, including diarrhea. Hence, the aim of this research was to evaluate the impact of dietary probiotics and ETEC K99-specific egg yolk antibody supplements, alone and in combination with each other, on health and growth parameters, diarrhea incidence and immune stimulation in newborn Holstein calves. One hundred and twenty neonatal calves were allocated randomly into 4 dietary groups (n = 30 per group) received colostrum/milk without any additives (control group), or supplemented with egg yolk powder contained E. coli K99-specific antibody (Ab group; 1 g/day), a commercial probiotic, Hypro-calves (Pro group; 3 g/day), and their combination (Ab + Pro group), from day (d) 1 to d28 of age. Analyses of the growth parameters, feed efficiency, fecal score, and microbiota and immune function were carried out on d0, 14, 21, and 28 of the experiment. Calves in Ab or Ab + Pro group had higher (P < 0.05) average daily gain compared to control and Pro groups during 0–14d. Feed efficiency of calves in Ab and Ab + Pro groups was significantly higher than that in control group during the period of 0–14d; however, no significant differences were observed in 0–28d period. Diarrhea prevalence and fecal score in Ab + Pro group were lower than control group (P < 0.05). Calves in Ab + Pro group had the lowest number of fecal E. coli in comparison to other groups on d28 (P < 0.05). Feeding Ab + Pro supplement increased (P < 0.05) concentrations of blood IgA and serum CD4 compared to the control group. Likewise, calves in Pro group had higher CD4 levels as compared to the control calves (P < 0.05). Serum concentration of interferon-gamma in control group was lower than other groups (P < 0.05). Overall, these data suggest that feeding a combination of probiotic and specific antibody against ETEC to neonate Holstein calves enhances feed efficiency, boosts immunity, and reduces diarrhea prevalence.     

Seasonal variations in fatty acid composition of pasture forage plants and CLA content in ewe milk fat

The relations between fatty acids (FAs) composition of pasture forage plants and the content of conjugated linoleic acid (CLA) as a total content of cis-9, trans-11 + trans-7, cis-9 + trans-8, cis-10 CLA isomers in ewes’ milk fat during natural pasture season (April–September) were investigated. The extracts of ewes’ milk fat samples as well as the pasture samples were analyzed for fatty acid composition by capillary gas chromatography with flame ionization and mass spectrometric detection. α-Linolenic, linoleic, and palmitic acids were predominant in pasture plants, and their contents varied during pasture season. The most abundant and most varied fatty acid compound in pasture plants was α-linolenic acid. Its content significantly decreased from 62% to 39% (of total FA) (P < 0.001) from May to August, and subsequently it slightly (57%) increased from August to September (P < 0.05), compared with the beginning of pasture season. Similarly, the content of CLA in ewes’ milk fat decreased from 2.4% in May to 1.3% in August (P < 0.001), and subsequently it rose to 2.6% in September (P < 0.001). The α-linolenic/linoleic acid ratio in the pasture sample decreased from 4.36 in May to 1.97 in August (P < 0.001), and subsequently it increased to 3.14 in September (P < 0.001); thus, it reached the level approaching to that at the beginning of pasture season. The pasture seasonal variations in the ratio were directly proportional to the corresponding content of CLA and indirectly proportional to the ratio in ewes’ milk fat. The results suggest that the seasonal variations in CLA content in ewes’ milk fat are related primarily to the seasonal variation in α-linolenic acid content in grass lipids.     

Pre-weaning growth response of lambs fed creep mixtures with varying levels of energy and protein

The pre-weaning nutrient requirements for growth of lambs were assessed by feeding them on ad libitum creep mixtures with free suckling and free choice of Pala (Z. nummularia) leaves. Thirty six lambs (15 days old) were divided into three equal groups and fed creep mixtures containing high (HEHP), medium (MEMP) and low (LELP) levels of digestible energy and protein. A cafeteria system of feeding management was used. The ratio of creep mixture, pala leaf and milk in the total DMI of HEHP lambs was 74.9:11.4:13.7. The corresponding ratios in DMI were 73.8:14.3:11.8 and 90.3:2.1:7.6 in MEMP and LELP regimens. Digestibility of DM, OM and CP was higher (P<0.01) in HEHP than MEMP and LELP. Digestibility of NDF and ADF was also significantly (P<0.01) higher in HEHP than MEMP and LELP. However, digestibility of cellulose and hemicellulose were higher (P<0.01) in LELP than other two groups. The lambs in all the three groups were in positive N balance while per cent N retention was lower (P<0.01) in LELP (52.6%) compared to MEMP (61.5%) and HEHP (70.4%). The lambs in HEHP, MEMP and LELP consumed 58.2, 51.6 and 83.5 g DM, 10.4, 7.4 and 8.0 g DCP and 250.4, 163.2 and 228.9 kcal DE/kg W^0.75/day amounting to an average of 43 g DCP/Mcal DE consumed/day and had 124, 108 and 124 g ADG, respectively. It is concluded from the study that ad libitum LELP creep mixture with free suckling and free choice pala (Z. nummularia) leaves was adequate to meet the growth requirement for 124 g pre-weaning average daily gain.     

Responses of milk protein,arterial AA concentration,and mammary AA metabolism to graded abomasal casein infusion in lactating goats

It has been generally assumed in postruminal protein or AA infusion studies that casein or AA mixtures mimicking the essential AA (EAA) composition of milk approach ‘ideal protein’ status, but the differences in postabsorptive metabolism of individual EAA may bring the assumption into question. Graded amounts of caseinate sodium were abomasally infused into lactating goats, and concentrations in the plasma of carotid, mammary uptakes and utilization efficiencies of amino acids were monitored in the present study. The results indicated that arterial concentrations of all the amino acids, except for Arg were increased with the increase of caseinate sodium infused (P < 0.05). The increments in plasma concentration differed with individual EAA. Concentrations of Ile, Leu, and Lys increased about two-folds, and that of Met, Thr, Phe, and His increased 58.33, 32.5, 29.87, and 61.66%, respectively, when data of the 99 g/day and the control treatment was compared. Mammary extraction efficiencies of Arg, Thr, Lys, Leu, and Phe increased with graded casein infusion (P < 0.05), while those of the other EAA were not significantly changed (P > 0.05). Mammary extraction efficiencies of individual non-essential amino acids (NEAA) varied greatly, and ranged from 9.18 to 33.89% in the control treatment. Except for Pro, mammary extraction efficiency of NEAA increased with graded casein infusion. Mammary uptake to milk output ratios (U/O) of sequestered AA was generally increased with the increase of casein infused, but that of Thr, His, and Ala was not insignificantly changed (P > 0.05). Compared with the data of previous researchers, the U/O of Thr recorded in the present study was much lower (<0.42). We speculate that Thr may be extracted in forms other than FAA (such as peptide bond AA) by the mammary under conditions of the present study. Consistent with the results of other authors, mammary uptake of Arg was two times more than milk output even in the control treatment, which suggests that there may be a requirement of Arg other than milk protein synthesis in the mammary.     

Effect of partial replacement of concentrates with jackfruit (Artocarpus heterophyllus) leaves on growth performance of kids grazing on native pasture of Tripura,India

Fifteen Black Bengal kids of about 3 months of age and body weight ranging from 3.8 to 4.9 kg were randomly distributed into three groups of five. Kids grazed native pasture 8 h/d. The kids in group I received supplementary concentrate (maize 35%, mustard cake 32%, rice bran 30%, mineral mixture 2% and common salt 1%) at approximately 2% of BW. However, 25 and 50% of the concentrate was replaced with jackfruit leaves for groups II and III, respectively. Total dry matter intake (DMI) was significantly higher in groups II and III than for group I due to greater forage consumption. Digestibility of CP (P < 0.05) decreased and that of NDF increased (P < 0.01) with increasing level of jackfruit leaves in the diet. Digestibility of ADF (P < 0.01), hemi cellulose (P < 0.05) and cellulose (P < 0.01) was higher in groups II and III in comparison to group I. Ruminal pH and TVFA concentration were not significantly different among the groups; however, rumen ammonia-N concentration decreased (P < 0.01) with increased level of jackfruit leaves in the diet. Similarly, plasma urea nitrogen and blood glucose levels were also reduced (P < 0.05) with increasing level of jackfruit leaves in the diet Average daily gain (ADG) was 47.33, 45.11 and 35.56 g/d in groups I, II and III, respectively. ADG and DMI/kg gain were not adversely affected when the level of replacement was restricted to 25%; however, at the 50% of replacement both parameters were adversely affected (P < 0.05). From the results of this experiment, it was concluded that jackfruit leaves might replace 25% of the supplemental concentrate for growing kids grazing in native pasture of northeast India.     

Effect of different level of roughage availability and contrast levels of concentrate supplementation on flavour of goat milk

Rancid and tart flavours are the most common off-flavours in Norwegian goat milk. In a feeding trial, we examined the effects of different levels of concentrate and of supplementary hay feeding on the occurrence of these off-flavours. Forty-eight experimental goats grazed cultivated pasture in the lowland during spring and autumn, and mountain pasture in summer. Twenty-four of the goats were fed 0.2 kg/day of concentrate (low concentrate, LC) and the remaining 24 goats 0.7 kg/day (high concentrate, HC). Twelve animals in LC and HC groups grazed freely, while the remaining goats in the two groups were given feeding challenges (limited periods of roughage restriction and ad libitum hay feeding). This was done to examine the effect of differing roughage availability on milk flavour. The animals fed low level of concentrate and with free grazing represented the control group. During the challenge periods, the goats were kept indoors and fed 0.2 kg hay/day for 2 days (roughage restriction) or hay according to appetite for 2 days (ad libitum feeding). At least 10 days of uninterrupted grazing were allowed between the challenges. Milk samples for sensory and chemical analysis were taken at the end of the challenge periods.The level of concentrate feeding did not influence the flavour of the milk when the goats were on lush spring pasture. However, the low level of concentrate feeding (LC) increased the frequency of off-flavour during the mountain and autumn experimental periods (P < 0.05).In the end of the mountain experimental period when the frequency of rancid/tart flavour increased in all groups, the sensory quality of milk produced by goats fed hay ad libitum (S1) had better taste ratings (P < 0.001) than milk from goats that were grazing. When the goats were given restricted amounts of hay, they adapted to the treatment by reducing their milk yield. In the spring and mountain experimental periods, restricted roughage feeding resulted in higher fat content and better taste ratings, especially in the group fed low level of concentrate (LC/S1). However, this connection was not clear in the autumn.Probably, the goats are able to handle a negative energy balance as long as mobilizable body reserves exist, but start to produce milk with lower dry matter content and higher frequencies of rancid/tart flavour when the body reserves are empty and the energy deficit is still pronounced.It is concluded that increasing the level of concentrate and feeding hay supplements will reduce the frequency of flavour defects at times when grazing is suboptimal or the pasture is of medium or low quality.