Fatty acid-balanced oil improved nutrient digestibility, altered milk composition in lactating sows and fecal microbial composition in piglets

OBJECTIVE

This study aimed to investigate the effects of dietary supplementation of a fatty acid-balanced oil, instead of soybean oil, on reproductive performance, nutrient digestibility, blood indexes, milk composition in lactating sows, and fecal microbial composition in piglets.

METHODS

Twenty-four sows (Landrace×Yorkshire, mean parity 4.96) were randomly allotted to two treatments with twelve pens per treatment and one sow per pen based on their backfat thickness and parity. The experiment began on day 107 of gestation and continued until weaning on day 21 of lactation, lasting for 28 days. The control group (CG) was fed a basal diet supplemented with 2% soybean oil and the experimental group (EG) was fed the basal diet supplemented with 2% fatty acid-balanced oil.

RESULTS

The fatty acid-balanced oil supplementation increased (p<0.05) the apparent total tract digestibility of dry matter, crude protein, and gross energy in sows. The lower (p<0.05) serum high-density lipoprotein cholesterol and albumin levels of sows were observed in the EG on day 21 of lactation. Dietary supplementation with the fatty acid-balanced oil decreased the fat content, increased the immunoglobulin G level, and changed (p<0.05) some fatty acid content in milk. Moreover, the fatty acid-balanced oil supplementation changed (p<0.05) the fecal microbial composition of piglets, where the average relative abundance of Spirochaetota was decreased (p<0.05) by 0.55% at the phylum level, and the average relative abundance of some potentially pathogenic fecal microorganism was decreased (p<0.05) at the species level.

CONCLUSION

The fatty acid-balanced oil improved nutrient digestibility, changed the serum biochemical indices and milk composition of sows, and ameliorated the fecal microbial composition of piglets.

Short-term effects of dietary selenium on lactating sows to improve litter performance, milk composition and tissue selenium retention in piglets

Objective

This study was conducted to evaluate the short-term effects of dietary selenium supplementation on lactating sows on the physiological response, litter performance, milk composition, and tissue selenium retention in piglets when selenium was provided by different sources and at different levels in a lactation diet.

Methods

A total of 48 multiparous sows (Yorkshire × Landrace) with average body weight (BW), backfat thickness (BF), and parity were assigned to one of the four treatments with 12 sows per treatment using a 2 × 2 factorial arrangement in a completely randomized design (CRD). Inorganic or organic Se sources were added to the diet at 0.30 ppm and 0.50 ppm Se. Treatments were as follows: 1) IS30: basal diet + inorganic Se 0.30 ppm, 2) IS50: basal diet + inorganic Se 0.50 ppm, 3) OS30: basal diet + organic Se 0.30 ppm, and 4) OS50: basal diet + organic Se 0.50 ppm.

Results

At Day 21 of lactation, a high tendency of litter weight (p=0.08) and litter weight gain (p=0.09) were observed when sows were fed an organic Se source. The milk Se concentration in the organic Se treatment was higher than that in the inorganic Se treatment at Day 21 of lactation (p<0.05). The serum Se concentrations of sows and piglets at Day 21 of lactation were significantly higher when lactating sows were fed organic Se instead of inorganic Se (p<0.01). During the suckling period, the kidney and muscle Se concentrations of piglets at Day 21 of lactation were significantly higher when the sow dietary Se source was organic (p<0.05). Liver Se concentrations were affected by Se source and level (p<0.05). This also resulted in an interaction response at 21 days of lactation (p<0.05).

Conclusion

The supplementation of dietary organic Se in a lactating diet could improve sow feed consumption, piglet performance, milk Se level, and the Se status of sows and piglets.

The effect of seasonal thermal stress on milk production and milk compositions of Korean Holstein and Jersey cows

Objective

In this study we investigated the effect of seasonal thermal stress on milk production and milk compositions between Holstein and Jersey dairy cows under the temperate-climate in Korea.

Methods

A total of 9 Holstein lactating dairy cows (2.0±0.11 parity) which had a daily milk yield of 29.77±0.45 kg, and days in milk of 111.2±10.29 were selected similarly at the beginning of the experiments in each season. Also, a total of 9 Jersey lactating dairy cows (1.7±0.12 parity) which had a daily milk yield of 20.01±0.43 kg, and days in milk of 114.0± 9.74 were selected similarly at the beginning of the experiments.

Results

Results showed that the average ambient temperature (°C) and temperature-humidity index (THI) were higher in summer, and were lower in winter (p<0.05). The average relative humidity (RH, %) was higher in autumn than that of other seasons (p<0.05). Milk production was significantly decreased (Holstein 29.02 kg/d and Jersey 19.75 kg/d) in autumn than in other seasons (Holstein 30.14 kg/d and Jersey 20.96 kg/d). However, the milk production was negatively correlated in Holstein cows, and positively correlated in Jersey cows with THI values increased from 16 to 80. In addition, milk yield was increased by 15% in Holstein cows and decreased by 11% in Jersey cows with the THI values increased from 16 to 20. The fat and protein content percentage was significantly higher in Jersey milk than in Holstein milk, furthermore the fat and protein content yield was higher in Jersey cow milk than that of Holstein cow’s milk with all THIs.

Conclusion

From the study results, we concluded that Jersey cows might be less adaptable to low temperature of the winter, and this would have a negative impact on dairy farmer income since Korea’s milk price estimation system places a higher value on milk yield than on milk compositions or sanitary grades.

Effect of fermented spent instant coffee grounds on milk productivity and blood profiles of lactating dairy cows

Objective

This study was conducted to evaluate the fermentation characteristics under low mesophilic temperature of spent instant coffee ground (SICG) and to estimate the effect of fermented SICG (FSICG) as alternative feed ingredient on milk productivity of dairy cows.

Methods

In the fermentation trial, fermentation of SICG was performed to investigate changes in characteristics using the microbial mixture (Lactobacillus plantarum, Saccharomyces cerevisiae, and Bacillus subtilis = 1:1:1) for 21 days at 20°C under anaerobic conditions. Molasses was added at 5% of dry mass. In the animal trial, eighteen Holstein Friesian cows were used to evaluate the nutritive value of the FSICG which was fermented for 14 days under the same condition as the fermentation trial.

Results

In the fermentation trial, the dry matter (DM) and organic matter content linearly decreased with fermentation time (p<0.001 and p = 0.008, respectively). The acid detergent insoluble nitrogen content linearly decreased with fermentation time (p = 0.037). The microorganism counts linearly increased for Lactobacillus plantarum, Saccharomyces cerevisiae, and Bacillus subtilis across fermentation time (p<0.001). In the animal trial, the DM intake of the control and FSICG treatment were not significantly different, as were milk yield, 4% fat corrected milk, fat-protein corrected milk, and feed to milk conversion content. Fat, protein, lactose, non-fat solids, milk urea nitrogen, and somatic cell counts were also not significantly different in milk composition between treatments.

Conclusion

FSICG should be considered a sufficient substitute for cottonseed as a feed component, and 5% DM of a dietary FSICG level was appropriate for dairy cow diets.

A large-scale study of indicators of sub-clinical mastitis in dairy cattle by attribute weighting analysis of milk composition features: highlighting the predictive power of lactose and electrical conductivity

Sub-clinical mastitis (SCM) affects milk composition. In this study, we hypothesise that large-scale mining of milk composition features by pattern recognition models can identify the best predictors of SCM within the milk composition features. To this end, using data mining algorithms, we conducted a large-scale and longitudinal study to evaluate the ability of various milk production parameters as indicators of SCM. SCM is the most prevalent disease of dairy cattle, causing substantial economic loss for the dairy industry. Developing new techniques to diagnose SCM in its early stages improves herd health and is of great importance. Test-day Somatic Cell Count (SCC) is the most common indicator of SCM and the primary mastitis surveillance approach worldwide. However, test-day SCC fluctuates widely between days, causing major concerns for its reliability. Consequently, there would be great benefit to identifying additional efficient indicators from large-scale and longitudinal studies. With this intent, data was collected at every milking (twice per day) for a period of 2 months from a single farm using in-line electronic equipment (346 248 records in total). The following data were analysed: milk volume, protein concentration, lactose concentration, electrical conductivity (EC), milking time and peak flow. Three SCC cut-offs were used to estimate the prevalence of SCM: Australian ≥ 250 000 cells/ml, European ≥200 000 cells/ml and New Zealand ≥ 150 000 cells/ml. At first, 10 different Attribute Weighting Algorithms (AWM) were applied to the data. In the absence of SCC, lactose concentration featured as the most important variable, followed by EC. For the first time, using attribute weighted modelling, we showed that the concentration of lactose in milk can be used as a strong indicator of SCM. The development of machine-learning expert systems using two or more milk variables (such as lactose concentration and EC) may produce a predictive pattern for early SCM detection.

Effect of supplementary glycerin on milk composition and heat stability in dairy goats

Objective

This experiment was studied the effects of various levels of crude glycerin (CG) in dairy goat diet on daily intake, milk yield, milk composition, some physical properties and some quality changes of goat milk after sterilization.

Methods

Twelve 75% Saanen dairy goats (body weight = 49±3 kg; days in milk = 60±12 d) were randomly assigned in a completely randomized design to evaluate the effects of three experimental diets consisting of 0%, 5%, and 10% CG (dry matter basis) which were formulated to meet or exceed the nutrient requirements of goats. Experimental dairy goats were evaluated for feed and milk yield. Milk samples were analyzed for their composition, including fatty acids, casein profile, fat globule size, and color, and were sterilized to evaluate milk heat stability.

Results

There were no significant differences between 0% and 5% CG treatments infeed. Increasing CG supplementation from 0% to 5% increased milk yield from 2.38±0.12 to 2.64±0.23 kg/goat/d. In addition, milk samples from 5% CG treatment had the highest total solids, fat content and lactose content, and largest fat globule size. Increasing CG to 10% resulted in a decrease in milk fat. After sterilizing at 116°C, F₀ = 3 min, goat milk samples from 5% CG treatment had slightly higher sediment content and comparatively higher degree of browning.

Conclusion

Considering milk yield, milk fat content and quality of sterilized milk, 5% CG supplementation in a total mixed ration has a potential for implementation in dairy goats.

Genetic Parameters of Milk β-Hydroxybutyric Acid and Acetone and Their Genetic Association with Milk Production Traits of Holstein Cattle

This study was conducted to estimate the genetic parameters of β-hydroxybutyrate (BHBA) and acetone concentration in milk by Fourier transform infrared spectroscopy along with test-day milk production traits including fat %, protein % and milk yield based on monthly samples of milk obtained as part of a routine milk recording program in Korea. Additionally, the feasibility of using such data in the official dairy cattle breeding system for selection of cows with low susceptibility of ketosis was evaluated. A total of 57,190 monthly test-day records for parities 1, 2, and 3 of 7,895 cows with pedigree information were collected from April 2012 to August 2014 from herds enrolled in the Korea Animal Improvement Association. Multi-trait random regression models were separately applied to estimate genetic parameters of test-day records for each parity. The model included fixed herd test-day effects, calving age and season effects, and random regressions for additive genetic and permanent environmental effects. Abundance of variation of acetone may provide a more sensitive indication of ketosis than many zero observations in concentration of milk BHBA. Heritabilities of milk BHBA levels ranged from 0.04 to 0.17 with a mean of 0.09 for the interval between 4 and 305 days in milk during three lactations. The average heritabilities for milk acetone concentration were 0.29, 0.29, and 0.22 for parities 1, 2, and 3, respectively. There was no clear genetic association of the concentration of two ketone bodies with three test-day milk production traits, even if some correlations among breeding values of the test-day records in this study were observed. These results suggest that genetic selection for low susceptibility of ketosis in early lactation is possible. Further, it is desirable for the breeding scheme of dairy cattle to include the records of milk acetone rather than the records of milk BHBA.

Impact of Seasonal Conditions on Quality and Pathogens Content of Milk in Friesian Cows

Heat stress negatively affects milk quality altering its nutritive value and cheese making properties. This study aimed at assessing the impact of seasonal microclimatic conditions on milk quality of Friesian cows. The study was carried out in a dairy farm from June 2013 to May 2014 at Beni-Suef province, Egypt. Inside the barn daily ambient temperature and relative humidity were recorded and used to calculate the daily maximum temperature-humidity index (mxTHI), which was used as indicator of the degree of heat stress. The study was carried out in three periods according to the temperature-humidity index (THI) recorded: from June 2013 to September 2013 (mxTHI>78), from October 2013 to November 2013 (mxTHI 72–78) and from December 2013 to April 2014 (mxTHI<72). Eighty Friesian lactating dairy cows were monitored in each period. The three groups of cows were balanced for days in milk and parity. Milk quality data referred to somatic cell count, total coliform count (TCC), faecal coliform count (FCC), Escherichia coli count, percentage of E. coli, and Staphylococcus aureus, percentage of fat, protein, lactose, total solid and solid non-fat. Increasing THI was associated with a significant decrease in all milk main components. An increase of TCC, FCC, and E. coli count from mxTHI<72 to mxTHI>78 was observed. In addition, the isolation rate of both S. aureus and E. coli increased when the mxTHI increased. The results of this study show the seriousness of the negative effects of hot conditions on milk composition and mammary gland pathogens. These facts warrant the importance of adopting mitigation strategies to alleviate negative consequences of heat stress in dairy cows and for limiting related economic losses.

Variance Components and Genetic Parameters Estimated for Fat and Protein Content in Individual Months of Lactation: The Case of Tsigai Sheep

The objective of this study was to assess variance components and genetic parameters for fat and protein content in Tsigai sheep using multivariate animal models in which fat and protein content in individual months of lactation were treated as different traits, and univariate models in which fat and protein content were treated as repeated measures of the same traits. Test day measurements were taken between the second and the seventh month of lactation. The fixed effects were lactation number, litter size and days in milk. The random effects were animal genetic effect and permanent environmental effect of ewe. The effect of flock-year-month of test day measurement was fitted either as a fixed (FYM) or random (fym) effect. Heritabilities for fat content were estimated between 0.06 and 0.17 (FYM fitted) and between 0.06 and 0.11 (fym fitted). Heritabilities for protein content were estimated between 0.15 and 0.23 (FYM fitted) and between 0.10 and 0.18 (fym fitted). For fat content, variance ratios of permanent environmental effect of ewe were estimated between 0.04 and 0.11 (FYM fitted) and between 0.02 and 0.06 (fym fitted). For protein content, variance ratios of permanent environmental effect of ewe were estimated between 0.13 and 0.20 (FYM fitted) and between 0.08 and 0.12 (fym fitted). The proportion of phenotypic variance explained by fym effect ranged from 0.39 to 0.43 for fat content and from 0.25 to 0.36 for protein content. Genetic correlations between individual months of lactation ranged from 0.74 to 0.99 (fat content) and from 0.64 to 0.99 (protein content). Fat content heritabilities estimated with univariate animal models roughly corresponded with heritability estimates from multivariate models: 0.13 (FYM fitted) and 0.07 (fym fitted). Protein content heritabilities estimated with univariate animal models also corresponded with heritability estimates from multivariate models: 0.18 (FYM fitted) and 0.13 (fym fitted).

Chemical Composition, Nitrogen Fractions and Amino Acids Profile of Milk from Different Animal Species

Milk composition is an imperative aspect which influences the quality of dairy products. The objective of study was to compare the chemical composition, nitrogen fractions and amino acids profile of milk from buffalo, cow, sheep, goat, and camel. Sheep milk was found to be highest in fat (6.82%±0.04%), solid-not-fat (11.24%±0.02%), total solids (18.05%±0.05%), protein (5.15%±0.06%) and casein (3.87%±0.04%) contents followed by buffalo milk. Maximum whey proteins were observed in camel milk (0.80%±0.03%), buffalo (0.68%±0.02%) and sheep (0.66%±0.02%) milk. The non-protein-nitrogen contents varied from 0.33% to 0.62% among different milk species. The highest r-values were recorded for correlations between crude protein and casein in buffalo (r = 0.82), cow (r = 0.88), sheep (r = 0.86) and goat milk (r = 0.98). The caseins and whey proteins were also positively correlated with true proteins in all milk species. A favorable balance of branched-chain amino acids; leucine, isoleucine, and valine were found both in casein and whey proteins. Leucine content was highest in cow (108±2.3 mg/g), camel (96±2.2 mg/g) and buffalo (90±2.4 mg/g) milk caseins. Maximum concentrations of isoleucine, phenylalanine, and histidine were noticed in goat milk caseins. Glutamic acid and proline were dominant among non-essential amino acids. Conclusively, current exploration is important for milk processors to design nutritious and consistent quality end products.

Effects of Replacement of Concentrate Mixture by Broccoli Byproducts on Lactating Performance in Dairy Cows

The objective of the present study was to determine the effects of feeding pelletized broccoli byproducts (PBB) on milk yield and milk composition in dairy cows. In Trial 1, an in vitro gas test determined the optimal replacement level of PBB in a concentrate mixture in a mixed substrate with Chinese wild ryegrass hay (50:50, w/w) at levels of 0, 10%, 20%, 30%, or 40% (dry matter basis). When the concentrate was replaced by PBB at a level of 20%, no adverse effects were found on the gas volume or its rate constant during ruminal fermentation. In trial 2, 24 lactating cows (days in milk = 170.4±35; milk yield = 30±3 kg/d; body weight = 580 ±13 kg) were divided into 12 blocks based on day in milk and milk yield and randomly allocated to two dietary treatments: a basic diet with or without PBB replacing 20% of the concentrate mixture. The feeding trial lasted for 56 days; the first week allowed for adaptation to the diet. The milk composition was analyzed once a week. No significant difference in milk yield was observed between the two groups (23.5 vs 24.2 kg). A significant increase was found in milk fat content in the PBB group (p<0.05). Inclusion of PBB did not affect milk protein, lactose, total solids or solids-not-fat (p>0.05). These results indicated that PBB could be included in dairy cattle diets at a suitable level to replace concentrate mixture without any adverse effects on dairy performance.

Influence of Sunflower Whole Seeds or Oil on Ruminal Fermentation, Milk Production, Composition, and Fatty Acid Profile in Lactating Goats

This study aimed to investigate the effect of sunflower seeds, either as whole or as oil, on rumen fermentation, milk production, milk composition and fatty acids profile in dairy goats. Fifteen lactating Damascus goats were divided randomly into three groups (n = 5) fed a basal diet of concentrate feed mixture and fresh Trifolium alexandrinum at 50:50 on dry matter basis (Control) in addition to 50 g/head/d sunflower seeds whole (SS) or 20 mL/head/d sunflower seeds oil (SO) in a complete randomized design. Milk was sampled every two weeks during 90 days of experimental period for chemical analysis and rumen was sampled at 30, 60, and 90 days of the experiment for ruminal pH, volatile fatty acids (tVFA), and ammonia-N determination. Addition of SO decreased (p = 0.017) ruminal pH, whereas SO and SS increased tVFA (p<0.001) and acetate (p = 0.034) concentrations. Serum glucose increased (p = 0.013) in SO and SS goats vs Control. The SO and SS treated goats had improved milk yield (p = 0.007) and milk fat content (p = 0.002). Moreover, SO increased milk lactose content (p = 0.048) and feed efficiency (p = 0.046) compared to Control. Both of SS and SO increased (p<0.05) milk unsaturated fatty acids content specially conjugated linolenic acid (CLA) vs Control. Addition of SS and SO increased (p = 0. 021) C18:3N3 fatty acid compared to Control diet. Data suggested that addition of either SS or SO to lactating goats ration had beneficial effects on milk yield and milk composition with enhancing milk content of healthy fatty acids (CLA and omega 3), without detrimental effects on animal performance.

Dietary Supplementation of Magnesium Sulfate during Late Gestation and Lactation Affects the Milk Composition and Immunoglobulin Levels in Sows

This experiment was conducted to investigate the effects of dietary supplementation of magnesium sulfate (MgSO₄) during late gestation and lactation on sow and litter performance, fecal moisture, blood biochemistry parameters, immunoglobulin levels and milk composition in sows. Forty-eight sows (Yorkshire×Landrace, 4th to 5th parity) were randomly allocated to 1 of 4 dietary treatments supplemented with 0, 200, 400, or 600 mg/kg MgSO₄ (n = 12). The experiment started on day 90 of gestation and continued through day 21 of lactation. Blood samples were collected on day 107 of gestation, day 0 (farrowing) and 21 (weaning) of lactation for the analyses of the blood biochemistry parameters and immunoglobulin levels. The colostrum and milk samples were obtained on day 0 and 14 of lactation, respectively. Fecal samples were collected from the sows on day 107 of gestation as well as day 7 and 20 of lactation to determine fecal moisture content. The results showed that the survival percentage of piglets and the litter weight at weaning were decreased linearly (p<0.05) and other parameters of the sow or litter performance were not influenced (p>0.05) by MgSO₄ supplementation. The fecal moisture content of the sows were increased (p<0.05) linearly as dietary MgSO₄ increased on day 7 and 20 of lactation. Supplementation with MgSO₄ increased the plasma magnesium (Mg) level linearly (p<0.05) and had a trend to increase total protein level (p>0.05 and p<0.10). However, an increase in the dietary MgSO₄ level resulted in a linear decrease in the colostrum fat content (p<0.05). Dietary MgSO₄ supplementation enhanced the immunoglobulin G (IgG) level (linear, p<0.05) in plasma on day of farrowing and immunoglobulin A (IgA) level in colostrum (quadratic, p<0.05) and milk (linear, p<0.05) of the sows. These results indicated that supplementation with MgSO₄ during late gestation and lactation may have the potential to prevent sow constipation, but may also result in some negative effects.

Effects of linseed oil or whole linseed supplementation on performance and milk Fatty Acid composition of lactating dairy cows

The objective of this study was to determine the effects of linseed oil or whole linseed supplementation on performance and milk fatty acid composition of lactating dairy cows. Thirty six Holstein Friesian crossbred lactating dairy cows were blocked by milking days first and then stratified random balanced for milk yields and body weight into three groups of 12 cows each. The treatments consisted of basal ration (53:47; forage:concentrate ratio, on a dry matter [DM] basis, respectively) supplemented with 300 g/d of palm oil as a positive control diet (PO), or supplemented with 300 g/d of linseed oil (LSO), or supplemented with 688 g/d of top-dressed whole linseed (WLS). All cows were received ad libitum grass silage and individually fed according to the treatments. The experiment lasted for 10 weeks including the first 2 weeks as the adjustment period, followed by 8 weeks of measurement period. The results showed that LSO and WLS supplementation had no effects on total dry matter intake, milk yield, milk composition, and live weight change; however, the animals fed WLS had higher crude protein (CP) intake than those fed PO and LSO (p<0.05). To compare with the control diet, dairy cow’s diets supplemented with LSO and WLS significantly increased milk concentrations of cis-9, trans-11-conjugated linoleic acid (CLA) (p<0.05) and n-3 fatty acids (FA) (p<0.01), particularly, cis-9,12,15-C18:3, C20:5n-3 and C22:6n-3. Supplementing LSO and WLS induced a reduction of medium chain FA, especially, C12:0-C16:0 FA (p<0.05) while increasing the concentration of milk unsaturated fatty acids (UFA) (p<0.05). Milk FA proportions of n-3 FA remarkably increased whereas the ratio of n-6 to n-3 decreased in the cows supplemented with WLS as compared with those fed the control diet and LSO (p<0.01). In conclusion, supplementing dairy cows’ diet based on grass silage with WLS had no effect on milk yield and milk composition; however, trans-9- C18:1, cis-9, trans-11-CLA, n-3 FA and UFA were increased while saturated FA were decreased by WLS supplementation. Therefore, it is recommended that the addition 300 g/d of oil from whole linseed should be used to lactating dairy cows’ diets.

Effects of dietary protein levels for gestating gilts on reproductive performance, blood metabolites and milk composition

This experiment was conducted to evaluate the effects of dietary CP levels in gestation under equal lysine content on reproductive performance, blood metabolites and milk composition of gilts. A total of 25 gilts (F1, Yorkshire×Landrace) were allotted to 4 dietary treatments at breeding in a completely randomized design, and fed 1 of 4 experimental diets containing different CP levels (11%, 13%, 15%, or 17%) at 2.0 kg/d throughout the gestation. Body weight of gilts at 24 h postpartum tended to increase linearly (p = 0.09) as dietary CP level increased. In lactation, backfat thickness, ADFI, litter size and weaning to estrus interval (WEI) did not differ among dietary treatments. There were linear increases in litter and piglet weight at 21 d of lactation (p<0.05) and weight gain of litter (p<0.01) and piglet (p<0.05) throughout the lactation as dietary CP level increased. Plasma urea nitrogen levels of gilts in gestation and at 24 h postpartum were linearly elevated as dietary CP level increased (p<0.05). Free fatty acid (FFA) levels in plasma of gestating gilts increased as dietary CP level increased up to 15%, and then decreased with quadratic effects (15 d, p<0.01; 90 d, p<0.05), and a quadratic trend (70 d, p = 0.06). There were no differences in plasma FFA, glucose levels and milk composition in lactation. These results indicate that increasing dietary CP level under equal lysine content in gestation increases BW of gilts and litter performance but does not affect litter size and milk composition. Feeding over 13% CP diet for gestating gilts could be recommended to improve litter growth.

Milk production, milk composition, live weight change and milk Fatty Acid composition in lactating dairy cows in response to whole linseed supplementation

The objective of this study was to determine the effects of whole linseed supplementation on performances and milk fatty acid composition of dairy cows. Thirty six Holstein Friesian crossbred lactating dairy cows were blocked by milking days first and then stratified random balanced for milk yields and body weight into three groups of 12 cows each. The control group received 300 g of palm oil. The second group was supplemented with 344 g/d of top-dressed whole linseed plus 150 g of palm oil and the third group was supplemented with 688 g/d of top-dressed whole linseed. All cows also received ad libitum grass silage (Brachiaria ruziziensis), had free access to clean water and were individually housed in a free-stall unit and individually fed according to treatments. Residual feeds were collected on 2 consecutive days weekly and at the end of the experiment. Feed samples were pooled to make representative samples for proximate and detergent analyses. Daily milk yields were recorded. Milk samples were collected on 2 consecutive days weekly. Live weights were recorded at the start and at the end of the experiment. Milk samples were taken on d 56 of the experiment and subjected to milk fatty acid composition. The results showed no statistical significant differences in intakes, live weight change, milk yields and milk compositions, however, C18:1, C18:3 and unsaturated FAs were increased while saturated FAs were reduced by whole linseed supplementation. It is recommended that the addition of 300 g/d oil from whole linseed could be beneficial to lactating dairy cows in early lactation.