Milk Composition In Dairy Goats Research Articles

Evaluation of the health status of mammary glands and compositional changes in udder-half milk obtained from dairy goats for milk quality management.

This study evaluated the health status of the mammary glands and milk composition of dairy goats. The California mastitis test (CMT) score, somatic cell counts (SCCs), somatic cell type, electrical conductivity (EC), N-acetyl-β-d-glucosaminidase (NAGase) activity, mastitis-causing pathogens, and milk composition in 121 udder-half milk samples from 62 crossbreed goats (1-3years old) at 23-45 days postpartum were compared in four categories with SCCs of <200 × 103 , <300 × 103 , 301-1000 × 103 , and >1010 × 103 cells/ml. The SCC, CMT score, EC, and NAGase activity were significantly lower (p < 0.05) in udder-half milk with SCCs of <200 × 103 and <300 × 103 cells/ml than those in milk with SCCs of 301-1000 × 103 and >1010 × 103 cells/ml. The protein, lactose/ash, and solids-not-fat (SNF) in milk with an SCC of <300 × 103 cells/ml were similar to the previously reported values. The proportion of polymorphonuclear neutrophils was significantly higher (p < 0.05) in milk with SCCs of 301-1000 and >1010 × 103 cells/ml than in milk with an SCC of <300 × 103 cells/ml. Assessing mammary gland health and milk composition based on categorization of udder-half milk by SCC may be useful for milk quality control on goat farms.

Effects of condensed tannin-amended cassava silage blend diets on feeding behavior, digestibility, nitrogen balance, milk yield and milk composition in dairy goats

Condensed tannins (CTs) are phenolic compounds derived from secondary plant metabolism that act as part of the plant's chemical defense system against pathogen invasion and herbivorous attack. This study aimed to evaluate the intake, digestibility, nitrogen (N) balance, production and composition of milk from goats fed cassava silage with added levels of CTs. Eight Anglo-Nubian goats with a mean BW of 40 ± 2.0 kg were distributed in a double Latin square design with four levels of CTs (0, 25, 50 and 75 g/kg DM) with four 20-day periods with 15 days of adaptation and five evaluation days for each period. No differences were observed in DM, NDF, CP intake and feed conversion (grams of DM intake (DMI) per gram of milk produced); however, when expressed as percent of BW, DMI showed a quadratic increase to 29.1 g/kg. As the level of supplemented CTs increased in the diet, the CP digestibility (P = 0.023), NDF (P = 0.044), non-fiber carbohydrates (NFC; P = 0.032) and total digestible nutrients (P = 0.033) exhibited a linear decrease. Furthermore, the addition of CTs to cassava silage induced a linear increase in N-fecal excretion (P = 0.014) and a positive quadratic effect on N-retained (P = 0.014) and N-balance (P = 0.024) as well as a positive quadratic trend in N-digested (P = 0.092). Milk urea N (P = 0.023) decreased linearly. The addition of CTs to cassava silage had a positive quadratic effect on ruminating time (P = 0.011). In addition, comparing the use or non-use from the orthogonal contrast test, the inclusion of CTs in goat diet increased water and N-intake, CP and NDF digestibility, spent time eating and ruminating and N-balance and decreased milk production corrected3.5%, fat milk content, milk urea N and dry defatted extract of milk. Thus, adding CTs to cassava silage at 25 g/kg total DM promoted goats' greater use of the diet without impairing feed conversion and the quality of goat milk produced. Dietary levels of 50 and 75 g/kg total DM are not recommended because under the conditions of this study, they reduced the productive efficiency of dairy goats.

Effects of Calcium Soaps from Palm, Canola and Safflower Oils on Dry Matter Intake, Nutrient Digestibility, Milk Production, and Milk Composition in Dairy Goats.

Simple SummaryDietary fats can increase energy density in dairy goat diets. However, dietary fats are subject to changes in rumen that affect nutrient intake and digestibility and milk production. In order to by-pass rumen degradation, one strategy is to protect those fats by saponification, which results in calcium soaps of fatty acids. Thus, this study determined the effect of calcium soaps of either palm (PO), canola (CO) or safflower (SO) oils on dry matter intake, digestibility and milk production in dairy goats. Compared with PO and CO, milk production increased with SO, while CO was more digestible. Compared to calcium soaps from PO, SO resulted in increased milk yield without negative effects on digestibility and nutrient intake. Overall, compared with the traditional use of calcium soaps manufactured from PO, at an inclusion of 2.7% dry matter, calcium soaps of SO can be used in goat diets to increase milk production, milk protein and milk fat yields without negative effects on nutrient intake and digestibility.This study determined the effect of protected dietary oils on dry matter intake (DMI), digestibility and milk production in dairy goats. Nine Saanen goats were used in a 3 × 3 Latin square design with three periods of 25 days. A basal diet based on barley hay and corn silage was supplemented with 2.7% DM of calcium soaps of either palm (PO), canola (CO) or safflower (SO) oils. Data for dry matter intake, nutrient digestibility and milk production was analyzed using the general linear model (GLM) procedure of SAS. Gas production data was analyzed using the procedure of non-linear regression analysis (PROC NLIN) from SAS. Nutrient intakes were not affected by treatments. However, compared with CO, the digestibility of dry matter (653 vs. 552 and 588 g/kg), organic matter (663 vs. 559 and 606 g/kg) and neutral detergent fiber (616 vs. 460 and 510 g/kg) were lowered (p < 0.001) by SO and PO. Compared with CO, in vitro gas production increased (p < 0.001) in PO and SO (174 vs. 201 and 206 mL gas/g incubated DM). Compared with PO and CO, milk production increased (p < 0.001) with SO (0.88 and 0.95 vs. 1.10 kg/d, respectively). With regard to PO and SO, CO decreased fat (34 and 35 vs. 32 g/d) and protein (35 and 38 vs. 30 g/d) in milk. In conclusion, compared to the traditional use of calcium soaps manufactured from PO, protected SO resulted in increased milk yield without negative effects on digestibility and nutrient intake.

Variation in Milk Composition of Dairy Goats due to N-3 Unsaturated Fatty Acids Supplementation

The objective of this research was to determine the effect of addition of n-3 unsaturated fatty acids (α-linoleic, eicosapentaenoic and docosahexaenoic) in dairy goats’ ration on milk composition (fat and protein content). Also, the persistence of the effect after supplementation was analysed. The research was conducted on dairy goats (Alpine and Saanen) bred at an indoor farm. Regarding the experimental period, the milk sampling at milking (morning and evening) was performed in the period before supplementation (BS), during supplementation (S), and after supplementation (AS). According to the added supplement, animals were randomly allocated into a group (G-4) with no added supplement and three test groups (G-1; G-2; G-3) where a supplement containing n-3 unsaturated fatty acid was added over a period of five days. The results of this research indicate that the addition of PUFA in goats’ ration changes the milk composition. The supplementation of α-linoleic resulted in increase of both milk fat and protein content. Furthermore, the addition of eicosapentaenoic and docosahexaenoic resulted in decrease of fat but increase of protein content in milk. The observed trends also persisted after the supplementation period.

PSXV-24 Dietary strategies to reduce the impact of high-concentrate diet on performance, ruminal fermentation and milk composition of dairy goats.

PSXV-24 Dietary strategies to reduce the impact of high-concentrate diet on performance, ruminal fermentation and milk composition of dairy goats.

The Relationship between Body Condition and Milk Composition in Dairy Goats

Abstract A total of 46 Swiss alpine does were examined. We analysed the composition of the milk and evaluated the body condition of the animals (BCS: 0.5 to 4.5 scale) on the same day in the last third of lactation. Goats were grouped according to their body condition for statistical calculations. We found that there was a statistically detectable relationship between body condition and milk composition of the goats. Together with the increase of BCS, the fat, protein and mineral contents in the milk increased as well. Significantly more fat, protein and mineral contents were found in the milk (6.01%;3.55%; 0,98%) in case of the well-conditioned (BCS 3.5) animals than in the thin ones (BCS 1.5-2) (4.56%, 3.11%, 0.77%) (P&lt;5%). The concentration of milk sugar was similar between thin and better conditioned groups of animals, so the body condition did not affect these values. The importance of our study is that, the high fat and protein content of milk increases the yield of dairy products. If the animals can produce milk that has higher fat and protein content, than we can produce more dairy products that will bring more economic benefits. The aim of our study was to evaluate the effects of body condition on milk yield and quality (milk composition) in dairy goats.

Effect of mid-line or low-line milking systems on lipolysis and milk composition in dairy goats

AbstractTwo experiments were carried out to investigate how milking in mid-line (ML) affects the lipolysis level and milk composition in goat livestock, in comparison with low-line (LL) milking. The first experiment took place, in triplicate, on an experimental farm. For each replicate, a crossover design (62 goats, two treatments, ML and LL, in two periods each lasting 4 days) was used. Milk samples were taken daily at 0 and 24 h after milking. In the first experimental replicate, some enzymatic coagulation cheeses were made, which were assessed by a panel of tasters at 50 and 100 days of maturation. In the second experiment, the lipolysis level and composition of tank milk from 55 commercial dairy goat farms (25 ML and 30 LL) were analysed, in milk samples taken in three different weeks. The results of the first experiment showed that ML milking increased free fatty acid (FFA) concentration in raw goat's milk significantly (0.71 v. 0.40 mmol/l, respectively). However, in the milk samples taken from commercial farms the FFA concentration remained unaffected by the milking pipeline height (0.59 v. 0.58 mmol/l for ML and LL, respectively). No significant differences were found in the milk composition, nor in the sensory characteristics in the cured cheeses, which suggests that factors other than the milkline height are able to influence the level of lipolysis under commercial conditions. Therefore, ML milking should not be discouraged, provided that the correct functioning and management of the milking operation and milk storage on the farm is guaranteed.

Composição do leite e diagnóstico de mastite em caprinos

Background: Milk is one of the most used foodstuffs by humans in their diet. The quality of goat milk is already regulated by Law, which takes into consideration its physical-chemical and microbiological composition parameters. Several factors contribute for the alteration of the physical-chemical and microbiological parameters of caprine milk. These include breed, age, lactation phase and diet, among others. The health status of animals may interfere in the quality of the milk produced, both regarding food safety and milk processing and, for that reason, the identification of mastitis-causing agents is important, so that prevention and control measures can be implemented. The present study aimed at analyzing the occurrence of mastitis and the milk composition of dairy goats in a semi-intensive production system. Materials, Methods & Results : In a private goat farm with a flock composed of 32 female animals of breeds such as Saanen and Anglo-Nubian, raised on a semi-confined system, the diagnosis of mastitis was made through methods such as California Mastitis Test (CMT), Somatic Cells Count (SCC) and bacterial isolation. A total of 136 milk samples were analyzed, which were individualized per teat. Additionally, the study determined the volume of milk produced individually and the chemical composition of milk samples (fat, raw protein, lactose and total solids). In 37 (27.2%) samples, subclinical mastitis caused by CNS was identified. A negative response to CMT was observed in 125 (91.92%) samples. Only four samples presented a coincidence (OR=1.239) between CMT and bacterial isolation (P=0.7470). It was observed that the daily milk production ranged between 207.90 mL and 2.68 L. Moreover, it became clear that the milk production in half of the teats with subclinical mastitis was smaller (P=0.0026). A tendency to a significant reduction (p -1 ) during the sampling months. A significant concordance (P Discussion : Mastitis is an inflammation of the mammary gland and, in the majority of cases, it is manifested in its subclinical form, having CNS as its main agent, both in Brazil and in other countries. Methods such as bacterial isolation, SCC and CMT are used for the diagnosis of mastitis. In the present study, no relation among these diagnostic methods has been found. This fact had already been reported in Brazilian literature. The herd configuration may have contributed for the occurrence of mastitis, since this disease is influenced by genetic factors and age. Moreover, its occurrence was higher in Anglo-Nubian females which, in addition to being older and consequently having undergone a higher number of lactations, presented an udder conformation with fragile ligaments and pending teats. Such conformation of the mammary glands may collaborate to the occurrence of infection. Mastitis is responsible for damages in the dairy production system, due to economical losses and reduction in the quality and volume of milk. However, the present study did not observe a variation in milk production due to bacterial contamination or an increase of SCC. A reduction in solid and fat contents did coincide with the beginning of the lactation period in Saanen goats; animals belonging to this breed tend to produce a higher volume of milk and, consequently, a smaller proportion of its components is observed. Based on the results obtained, the study concluded that the herd composition with regard to breed and lactation phase has an influence in the occurrence of subclinical mastitis, as well as in milk composition. Methods such as the CMT and SCC should be used carefully in the diagnosis of mastitis in goats.

Performance and milk composition of dairy goats as affected by the dietary level of stoned olive cake silages.

ObjectiveThe current study compared the effects of dietary levels of two phase stoned olive cake (OC) in form of silage (OCS) on milk production and quality of Saanen goats.MethodsThe OCS included in total mixed ration (TMR) at dry matter proportions of 0.0 (OC0), 0.10 (OC10), and 0.20 (OC20). The TMR were fed to a total of 18 goats in a completely randomized design for a period of 5 weeks.ResultsDietary treatments had no effect on the milk yield of Saanen goats, but the daily milk fat production was greater (p<0.05) at feeding OC20. The total phenolic (TP) compounds contents increased (p<0.01) in each increment of OCS in TMR and this was also reflected in the TP contents of milk. The C8:0, C10:0, C12:0, and C14:0 saturated fatty acids (FAs) in milk fat decreased (p<0.01) with increasing dietary level of OCS, but the decrease (p<0.001) in C16:0 and the increase (p<0.01) in C18:0 in milk fat occurred similarly at each inclusion level of OCS. Only OC20 reduced (p<0.05) the total saturated FA, yet the reduction (p<0.01) in n6/n3 ratio and atherogenicity index occurred in both OC10 and OC20.ConclusionTwo phase stoned OCS increases milk quality not only through modifying the milk FA composition, but also by increasing the milk TP content. These favorable changes in milk quality are closely associated with the dietary level of OCS.

Effect of estrus synchronization on dairy goat milk composition.

This study was aimed to observe the effects of progesterone impregnated sponge insertion on milk yield and milk composition in dairy goats. For this reason milk samples were collected before insertion and during the treatment. Sixty four Turkish Saanen goats were used in the research. Animals were milked twice daily. Reduce in milk yield was observed. Fat content of milk decreased, while lactose content, solids-non-fat, density and pH value increased during the sponge application. Protein content was not influenced by the treatment. New experiment under controlled conditions might be planned to characterize the hormonal status of animal and their effects on milk yield and composition.

Short communication: Effect of αS1-casein (CSN1S1) and κ-casein (CSN3) genotypes on milk composition in Murciano-Granadina goats

The effects of the caprine αS1-casein (CSN1S1) polymorphisms on milk quality have been widely demonstrated. However, much less is known about the consequences of the κ-casein (CSN3) genotype on milk composition in goats. Moreover, the occurrence of interactions between CSN3 and CSN1S1 genotypes has not been investigated. In this study, an association analysis between CSN1S1 and CSN3 genotypes and milk quality traits was performed in 89 Murciano-Granadina goats. Total milk yield as well as total protein, fat, solids-not-fat, lactose, αS1-casein (CSN1S1), and αS2-casein (CSN1S2) contents were recorded every other month during a whole lactation (316 observations). Data analysis using a linear mixed model for repeated observations revealed no interaction between the CSN1S1 and CSN3 genotypes. With regard to the effect of the CSN3 locus, AB and BB genotypes were significantly associated with higher levels of total casein and protein content compared with the AA CSN3 genotype. In strong contrast with French breeds, the CSN1S1 genotype did not affect protein, casein, and fat concentrations in Murciano-Granadina goats. These results highlight the importance of taking into consideration the CSN3 genotype when performing selection for milk composition in dairy goats.

Factors of variation influencing production level, SCC and basic milk composition in dairy goats

Factors of variation influencing production level, SCC and basic milk composition in dairy goats

Effects of Once Versus Twice Daily Milking Throughout Lactation on Milk Yield and Milk Composition in Dairy Goats

The effects of once (1X) vs. twice (2X) daily milking throughout lactation on milk yield, milk composition, somatic cell count (SCC), and udder health were studied in 32 Murciano-Granadina dairy goats. Goats were assigned at wk 2 of lactation to two treatment groups; once daily milking at 0900 (1X, n = 17), or twice daily milking at 0900 and 1700 (2X, n = 15). Milk yield was recorded weekly until wk 28, and milk composition and SCC were evaluated for each individual udder half at each milking at wk 2 and 4 of lactation and then, monthly until the end of the experiment. Once daily milking resulted in an 18% reduction in the yield of 4% fat-corrected milk compared to twice daily milking (1.61 vs. 1.95 L/d, respectively). This reduction was more marked from wk 2 to 12 than in mid and late lactation. Response to milking frequency also varied according to parity number where goats of less than four parities suffered more milk yield losses during 1X than older goats. Milk of 1X goats contained higher percentages of total solids (13.6 vs. 12.9%), fat (5.10 vs. 4.62%) and casein (2.57 vs. 2.35%) than milk of 2X goats, but milk protein percentage did not differ between treatments (3.28 vs. 3.20%). Yields of total solids, fat, protein and casein tended to be higher for 2X than 1X. Milk SCC did not differ between treatments. We conclude that application of once daily milking in Murciano-Granadina dairy goats moderately reduced milk yield without negative effects on milk composition and udder health. Losses in milk yield would be reduced if 1X is practiced during mid- or late lactation and in older goats. An increase in labor productivity and a higher farmer's standard of living is also expected.

Interactions between Nutrition, Blood Metabolic Profile and Milk Composition in Dairy Goats

Khaled N. F., J. Illek, S. GajdU‰ek: Interactions between Nutrition, Blood Metabolic Profile and Milk Composition in Dairy Goats. Acta Vet. Brno 1999, 68: 253–258. The aim of this study was to investigate changes in the concentrations of blood and milk constituents of dairy goats under the effects of stable diet and grazing during lactation from April to June. The experiment was carried out on 10 dairy goats fed a ration composed of concentrate mixture, sugar beet silage and grass hay during winter season (stable diet), and pasture season. Jugular blood and milk samples were taken from all goats during lactation months of April through June at one-month intervals. The blood concentration of total protein (TPP), urea, glucose, triacylglycerols, total ketones, serum non-esterified fattty acids (NEFA), Na, K, Ca, inorganic phosphorus (Pi), Cu, Zn, aspartic amino transferase (AST), γ-glutamyl transferase (GGT), creatine kinase (CK), lactate dehydrogenase (LDH), pH and haemoglobin (Hb) were determined. The measurements of milk contents of fat, protein, casein, urea, lactose, citric acid, total ketones, pH and titratable acidity were performed, too. The results showed variations in serum NEFA, plasma triacylglycerols, Pi , plasma CK and plasma urea during the first months of lactation. In addition to milk levels of total ketones, citric acid, fat and urea were changed. Highest correlation coefficients were found between plasma and milk urea (r = 0.88; p � 0.001). However, there were correlations between milk fat, plasma urea, blood haemoglobin, plasma glucose, plasma triacylglycerols, blood total ketones and plasma Mg. Citric acid in milk was positively correlated with plasma glucose (r= 0.46; p � 0.01) and negatively with plasma total protein (r = - 0.31; p � 0.05). In conclusion, high concentration of serum NEFA, blood total ketones and plasma urea in addition to the decline in the milk concentrations of citric acid and protein, along with increase in milk concentrations of ketone bodies and urea during the first lactation months were observed and may be associated with corresponding energy deficit and induce considerable metabolic changes in dairy goats.