Milk Production In Dairy Goats Research Articles

Total Replacement of Soybean Meal with Sundried Soymilk Residue in the Total Mixed Ration has a Negative Impact on Intake, Digestibility, and Milk Production in Dairy Goats.

This study aimed to evaluate whether total replacement of soybean meal (SBM) with sundried soymilk residue (SSR) in a total mixed ration (TMR) affects intake, digestibility, milk production, and blood metabolites in dairy goats. A total of 12 healthy Saanen dairy goats (40.12 ± 5.80 kg of BW) in midlactation (31.23 ± 10.12 days) were used in a randomized complete design (n = 4 goats/group). Dietary treatments were based on a TMR as follows: control TMR without SSR (CON) or SBM-based TMR with 50% or 100% of SSR replacing SBM (SSR-50 and SSR-100, respectively). All goats had ad libitum access to feed and clean water throughout the experiment. The dry matter (DM) intake decreased (p < 0.05) with the increasing replacement ratio of SBM and was lowest in the SSR-100 group. Similarly, organic matter (OM) digestibility was lowest (p < 0.05) in the SSR-100 group. However, the digestibility of DM, CP, NDF, and ADF did not change (p > 0.05) by dietary treatments. Compared with CON, the milk yield decreased significantly (p < 0.05) with increasing replacement ratio of SBM. In contrast, milk composition such as total solids, solids-not-fat, milk fat, lactose, protein, and pH were not influenced (p > 0.05) by feeding dietary SSR. Compared with other treatments, blood glucose concentration was lower (p < 0.05) in the SSR-100 group. In contrast, packed cell volume, glucose, and plasma urea nitrogen concentrations did not differ (p > 0.05). The results indicated that SSR could replace SBM in a TMR at less than 50%. Thus, the present study provides support for further investigation to enhance the utilization of soybean waste as an alternative protein source in the TMR for dairy goats and potentially other ruminants.

The Effect of Lameness on Milk Production of Dairy Goats.

Lameness on dairy goat farms is a welfare concern and could negatively affect milk production. This study's objective was to evaluate the effects of clinical lameness on the daily milk production of dairy goats. Between July 2019 and June 2020, 11,847 test-day records were collected from 3145 goats on three farms in New Zealand. Locomotion scoring of goats used a five-point scoring system (0 to 4). The dataset was split into two groups by lactation type, where goats were classified as being in seasonal lactation (≤305 days in milk) or extended lactation (>305 days in milk). A linear mixed model was used to analyze datasets using milk characteristics as the dependent variables. Severely lame goats (score 4) in seasonal and extended lactation produced 7.05% and 8.67% less milk than goats not lame, respectively. When the prevalence of severe lameness is between 5 and 20% of the herd, the estimated average daily milk income lost was between NZD 19.5 and 104 per day. This study established the negative impact of lameness on milk production and annual income in dairy goats on three farms.

Chi-miR-3880 mediates the regulatory role of interferon gamma in goat mammary gland

A healthy mammary gland is a necessity for milk production of dairy goats. The role of chi-miR-3880 in goat lactation is illustrated in our previous study. Among the differentially expressed genes regulated by chi-miR-3880, one seventh were interferon stimulated genes, including MX1, MX2, IFIT3, IFI44L, and DDX58. As the inflammatory cytokine interferon gamma (IFNγ) has been identified as a potential marker of caseous lymphadenitis in lactating sheep, the interaction between IFNγ and immune-related microRNAs was explored in this study. Chi-miR-3880 was found to be one of the microRNAs downregulated by IFNγ in goat mammary epithelial cells (GMECs). The study illustrated that IFNγ/chi-miR-3880/DDX58 axis modulates GMEC proliferation and lipid formation through PI3K/AKT/mTOR pathway, and regulates apoptosis through Caspase-3 and Bcl-2/Bax pathways. The role of the axis in mammary involution was reflected by the expression of p53 and NF-κB. In conclusion, IFNγ/chi-miR-3880/DDX58 axis plays an important part in lactation.

Pengaruh litter size dan bobot induk terhadap produksi susu kambing perah

This study aims to determine the effect of litter size and mother weight on dairy goat milk production. The research method uses the survey method, data collection is carried out by purposive sampling with the criteria of Kaligesing dairy goats that have been lactation as many as 100 tail. The variables analyzed were the identity of the farmer, litter size, milk production and mother weight. Data analysis was carried out with descriptive analysis and simple correlation analysis. The results showed that the average litter size was 2.04 heads, milk production was 896 ml or 0.9 liters and the parent weight was 44.77 kg. The results of the correlation analysis showed a value of 0.662 or there was a strong relationship between the litter size and the weight of the mother to goat milk production. It can be concluded that the litter size and mother weight have a strong influence on the milk yield of dairy goats. &#x0D;

Influence of Replacement Levels of Orange Waste Silage on Intake, Nutrient Digestion, Ruminal Fermentation and Milk Yield in Barki Goats

Abstract Exploring new alternative sources of feedstuffs can contribute to animal production sustainability in some Mediterranean regions in order to overcome the rising food demand. The influence of dietary replacement of wheat straw (WS) with orange waste silage (OWS) on nutrient intakes, apparent digestibility, ruminal fermentation and blood biochemical constituents and milk production of dairy goats were evaluated. Forty pregnant goats (46.30±1.6 kg BW) were housed in individual pens in a completely randomized design and fed (ad libitum) a TMR for 75 days period. Goats were assigned to four experimental diets with the forage amounts consisting of either WS as a control diet (1000 g WS/kg DM in the TMR), a 50:50 mixture of both WS and OWS (500 g WS and 500 g OWS/kg DM in the TMR), an orange waste silage (1000 g OWS/kg DM in the TMR) or corn silage as a positive control (1000 g CS/kg DM in the TMR). The DMI increased linearly (P&lt;0.01), while fiber fractions intake decreased linearly (P&lt;0.01) with increasing of OWS in the diet. Ruminal pH was increased quadratically (P&lt;0.01), whereas NH3-N concentration and total protozoa abundance decreased quadratically (P&lt;0.01) with increasing OWS in the diet. Ruminal acetate content was increased linearly (P = 0.012) by diet; whereas linear effects were observed on propionate and butyrate proportions (P&lt;0.01) as OWS amount increased. Blood urea nitrogen (BUN), non-esterified free fatty acids (NEFA) and β-hydroxybutyrate (BHBA) levels decreased linearly (P&lt;0.01) with ascending amounts of OWS. Serum glucose, BUN, NEFA and BHBA levels were lower (P&lt;0.01) for goats fed the OWS diet than those fed the CS diet. Milk yield and milk nitrogen efficiency were linearly increased (P&lt;0.01), whereas quadratic effects (P = 0.049) were observed on milk urea nitrogen content with increasing dietary OWS. In conclusion, the replacement of WS with OWS enhanced rumen fermentation and milk yield of late pregnant and early lactation Barki goats.

Further Insights Into Caprine Arthritis Encephalitis (CAE): The Current Status of Seroprevalence Among Small Ruminants in Two Selected States of Peninsular Malaysia.

Caprine arthritis-encephalitis virus (CAEV) is a member of the genus lentivirus causing caprine arthritis-encephalitis (CAE), a chronic inflammatory condition affecting the lungs, joints, udder and central nervous system of small ruminants such as sheep and goats. CAE is distributed worldwide and is recognised as a significant cause of morbidity and decreased milk production in dairy goats. Earlier studies highlighted the clinicopathological features and supplied preliminary serological evidence for the existence of CAE among selected goat herds in Malaysia. Therefore, this study aims to provide further insights into the seroprevalence and contributing factors of CAE among sheep and goat herds in two states of Peninsular Malaysia. The blood samples and biodata were randomly collected from a total of 262 individual sheep (40) and goat (222) in seven smallholder farms. Blood sera were tested for specific anti-CAEV antibodies using Qayee-Bio CAEV sandwich-ELISA test kits according to standard procedures. Our results of the study revealed 21.4% (95% CI: 15.8–28.6) apparent and 20.6% (95% CI: 14.5–27.8) true seroprevalence with significant differences (p < 0.05) in seroconversion rates between the states, farms, production systems and breeds of small ruminants. The prevalence of CAE in the Malaysian Peninsular is a potential threat to the small ruminant industry and developing agricultural economy. Further studies are required to determine the genetic characteristics, distribution and risk factors of CAEV for effective prevention and control in Malaysia.

The role of diglyceride acyltransferase (DGAT) genes polymorphisms on milk production in dairy goats

Milk quantity, fat, and protein contents are important traits in dairy animals, particu-larly in dairy goats. However, little is known about the genetics and genomics in dairy goats that influence these traits. The diacylglycerol O-acyltransferase (DGAT) genes are considered the most important genes in dairy goats for milk quantity and fat con-tents. The DGAT genes have two isoforms as DGAT1 and DGAT2, that have similar re-actions but no sequence homology in-between. The DGAT1 gene in chromosome 14 is a functional and potential candidate gene for fat content in goats, while DGAT2 is associated with milk yield and fat percentage in goats. The phylogenetic analyses re-vealed similar topologies and evolutionary partitioning of DGAT family proteins into two major clades: DGAT1 and DGAT2. Moreover, DGAT1 proteins were found to play a significant role in the milk yield in dairy goats. In this review, the role of polymor-phisms in DGAT family genes on milk production in dairy goats is discussed

Native and introduced forage cacti in Saanen dairy goat diets

This study aimed to assess the nutrient intake and milk production of dairy goats fed with total mixed rations with different species of forage cacti. Five pluriparous Saanen goats (50 ± 4 kg) at nine weeks of lactation were allocated in a Latin square (5 x 5) with five diets and five periods. Each period was composed of 10 days for adaptation and seven days for collection. The treatments were composed of 473.0 to 501.0 g kg-1 of forage cacti: xiquexique (Pilosocereus gounellei), mandacaru (Cereus jamacaru), facheiro (Pilosocereus chrysostele), cactus cladodes cv. miúda (Nopalea cochenillifera Salm-Dyck) and cactus cladodes cv. orelha de elefante mexicana (Opuntia stricta); plus sabiá hay (Mimosa caesalpiniifolia) (188.0 to 198.0 g kg-1) and concentrate (311.0 to 329.0 g kg-1). The intake of dry matter, organic matter, ether extract, neutral detergent fiber, total carbohydrates, and water intake through diet components were unaffected by experimental diets. For milk production and feed efficiency, no difference was observed among the diets. All diets containing different species of forage cacti can be used for dairy goats feed.

Native and introduced forage cacti in Saanen dairy goat diets

ABSTRACT. This study aimed to assess the nutrient intake and milk production of dairy goats fed with total mixed rations with different species of forage cacti. Five pluriparous Saanen goats (50 ± 4 kg) at nine weeks of lactation were allocated in a Latin square (5 x 5) with five diets and five periods. Each period was composed of 10 days for adaptation and seven days for collection. The treatments were composed of 473.0 to 501.0 g kg-1 of forage cacti: xiquexique (Pilosocereus gounellei), mandacaru (Cereus jamacaru), facheiro (Pilosocereus chrysostele), cactus cladodes cv. miuda (Nopalea cochenillifera Salm-Dyck) and cactus cladodes cv. orelha de elefante mexicana (Opuntia stricta); plus sabia hay (Mimosa caesalpiniifolia) (188.0 to 198.0 g kg-1) and concentrate (311.0 to 329.0 g kg-1). The intake of dry matter, organic matter, ether extract, neutral detergent fiber, total carbohydrates, and water intake through diet components were unaffected by experimental diets. For milk production and feed efficiency, no difference was observed among the diets. All diets containing different species of forage cacti can be used for dairy goats feed.

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.

Oxytocin Hormone Induction on Milk Production in Relation to Dairy Kid Performance

The application of oxytocin induction to milk production in relation to the performance of kids in dairy goats had been carried out in the "PEGUMAS" dairy goat farmer group Gumelar District, Banyumas. This activity aimed to increase milk production and kid performance through the induction of the hormone oxytocin in dairy goats. The approach method was designed in two stages: the first stage carried out the socialization activities and demonstration of techniques for applying IPTEKS, and the second stage applied hormonal technology in the form of oxytocin hormone induction in dairy goats. The material used was dairy goat parity I aged 1.5 - 2 years allocated into 2 groups of 10 individuals each. Group I was dairy goat experiment not induced with the oxytocin hormone as the control. Group II was dairy goat experiment induced with the oxytocin hormone at a dose of 1 ml (10 IU) intramuscularly before milking. Milk production was measured morning and evening as daily milk production in milliliters (ml). Milk was given to the kid of each parent. The kid's performance was measured based on the daily weight gain of the kid during the study. Overall, the application of science and technology could be adopted by farmers, and oxytocin-induced dairy goat milk production (503.2 ml) was significantly higher (P&lt;0.05) than control (305.4 ml) with an increase of 64.77%, with a positive level of correlation (r = 0.45) and contributed 19.83% to the kids daily body weight gain.

The Effects of Substituting Dietary Soybean Meal with Maize Grain on Milk Production in Dairy Goats.

Simple SummaryToday the environmental sustainability of livestock has become increasingly important. Nitrogen excretion from livestock can lead to air and groundwater pollution, causing acid rain, fine air particulates, and greenhouse gas emissions that lead to climate change, groundwater nitrate poisoning, and surface water eutrophication. Often, livestock are fed diets with a protein content that is much higher than what they require. In this experiment, a herd of dairy goats of the Alpine breed, reared on a farm in the hills near Genoa, Italy, was used to study the impacts of being fed a low- or a high-protein diet. The high-protein diet did not improve milk yield and quality; on the contrary, it lowered the efficiency of dietary-nitrogen utilization, increased feeding cost, and, above all, increased nitrogen excretion and the associated environmental risks. In conclusion, a high-protein diet is not advisable, both economically and environmentally, and a precision feeding approach (i.e., supplying the nutrients required for a given body mass and level of production, and no more) is highly recommended.In view of better environmental sustainability, livestock diets must not exceed protein requirements, as often happens with lactating goats reared in semi-intensive systems. The aim of this experiment was to verify in real-breeding conditions the influence of two diets with different protein contents (% crude protein (CP) on dry matter (DM)): 16.0 (high-protein diet; HP) vs 12.2 (low-protein diet; LP) on milk production in dairy goats. The diets differed only in the replacement—in the LP diet—of 250 g soybean meal with 250 g maize grain meal. Twenty-three Alpine goats were divided into two groups and used in a cross-over feeding trial for 2 months. Animals were weighed at the beginning of each month of the trial, and feed intake and milk yield and composition were recorded weekly. HP and LP did not differ statistically for milk yield and composition (3.32 vs 3.42 kg milk/d, 3.21% vs 3.27% fat, 3.31% vs 3.27% protein for HP and LP, respectively), but the HP diet determined a higher milk urea content (51.2 vs 36.6 mg/dL, p < 0.001) and a worse efficiency of nitrogen utilization (28.0% vs 37.2%). In conclusion, the LP diet resulted in a reduction of urinary nitrogen excretion by 28% and of the feed cost by about 10%.

Management options to reduce the environmental impact of dairy goat milk production

Although numbers are still low compared to cattle rearing, intensive dairy goat farms have been widely spreading in the Italian livestock systems. Since goats are quite rustic, they can easily adapt to different management practices; however, improving the efficiency can make the difference, both in productivity and on the environmental impact attributed to goat milk production.In the present study, the Life Cycle Assessment (LCA) approach was used to quantify the potential environmental impact of goat milk production system in 17 farms in Lombardy (Northern Italy). Together with the environmental assessment, statistical analysis was carried out in order to determine whether it was possible to identify any relation among the variables that characterise this farming system.From an environmental point of view, it has been shown that the lower the individual milk production, the more it affects the environmental impact: specifically, the carbon footprint appears higher than the one emitted by cattle milk production. Climate Change resulted, on average, equal to 2.67 kg CO2 eq/kg Fat and Protein Corrected Milk (FPCM) with a wide variability (min: 1.12 kg CO2 eq/kg FPCM; max: 5.05 kg CO2 eq/kg FPCM). Purchased feed was the main hotspot for several environmental impact categories (such as freshwater eutrophication, land use and mineral, fossil and renewable resources depletion). Enteric emissions and emissions from manure storage were hotspots for climate change, particulate matter and terrestrial acidification. The C sequestration during crop cultivation was not considered. As shown by the statistical analysis, the main driver which influenced the 6 main impact categories was, in fact, individual milk production. The environmental assessment was also performed considering a second Functional Unit (FU) (i.e. 1 ha of land) and the statistical analysis conducted on this FU showed the relevance of livestock intensity. In addition to this, the statistical analysis also showed how a restricted land availability can negatively affect the environmental outcome. This study represents one of the first studies on the environmental impact assessment of dairy goat milk production. Additionally, studying two FUs and using a statistical analysis approach helped to identify the main management options to which farmers should pay attention to improve goat milk production from an environmental point of view.

Effects of commercial fatty acids, organic acids and mineral supplementation on milk yield and blood characteristics of dairy goats in selected farms in Kelantan, Malaysia.

Milk production of dairy goats raised by smallholders in Malaysia are usually very low with which are mainly attributed to poor nutrition. This study was aimed at evaluating the benefits of supplementing commercial fatty acids, organic acids and chelated minerals for enhancing milk production. Eighty Saanen dairy goats in the stage of mid-lactation were selected from 8 smallholder farms in Kelantan, Malaysia to evaluate their blood profile and mineral status in relation to their daily rations. Based on estimated dry matter intake (DMI), 50% of the animals were found not adequately fed, with deficit of 6% - 12% from the targeted DMI. Initial screening of the blood revealed that red blood cell (RBC), haemoglobin (HGB), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) values were marginally low while sodium (Na) was deficient. Based on these findings, 6 groups of 10 Saanen dairy goats from 6 farms were selected from the above 8 farms for the second trial. Five animals in each group were supplemented with either commercial fatty acids, organic acids and chelated minerals, while another 5 were not supplemented and fed only on routine rations. A formulated feed mixture, which comprised of PKC, NaCl, CaCO3, zeolite and mineral-vitamin premix at the rate of 100, 15, 15, 5 and10 g/day respectively were provided to the supplemented groups on top of routine rations. Supplementation of fatty acids (Extima 100, Extima 300, Extima Star and Extima 100 + Extima Star at the rate of 100, 100, 100 and 50+50 g/day), chelated mineral (POWERMIN 4COW/CATTLE+P, 400g/day) and organic acid (ORGACID, 100 g/day) to the respective supplemented groups resulted in improvement in certain blood characteristics and enhanced Na level. The improvement in milk yield associated with supplementation was between 12 – 16%. However, body condition score (BCS) of the supplemented groups were improved as compared to those non-supplemented. The findings revealed that supplementation of the above supplements, even with limited amount of a formulated feed mixture were less effective in enhancing milk yield of the dairy goats raised under the smallholders feeding condition.

Milk production and hormonal profile as affected by Fenugreek supplementation in lactating goats of Kashmir valley

ABSTRACT A decline in the milk production in dairy goats during the winter can be overcome by nutritional manipulation by the provision of galactogogues in their feed. The study was conducted on lactating goats in Mountain Research Centre for Sheep and Goat (MRCSG), SKUAST-Kashmir during the winter season. The lactating Bakarwal goats with uniform body weight and milk production were divided into two groups, namely, control and treatment. The goats in the treatment group were offered 30 g of fenugreek daily in addition to the normal feed ingredients. The blood and milk samples were collected weekly up to 6 weeks, and the data were presented as an average. There was a significant (p < 0.05) decrease in plasma cortisol concentration in treatment (18.64 ± 1.72 ng/ml) as compared to control (22.58 ± 1.25 ng/ml) group. Thyroid stimulating hormone (TSH) showed a nonsignificant increase in the treatment group (0.45 ± 0.03 μIU/ml) as compared to the control group (0.39 ± 0.05 μIU/ml). Prolactin was significantly (p < 0.05) higher in the supplemented group (3.94 ± 0.03 ng/ml) than the control group (2.72 ± 0.02 ng/ml). Blood glucose was significantly (p < 0.05) higher in control (57.30 ± 3.40 mg/dl) than the treatment (53.52 ± 2.79 mg/dl) group. Milk components like fat, protein, lactose, solids not fat (SNF) and total solids showed a nonsignificant change after fenugreek supplementation. Finally, there was a drastic increase in the milk production of the supplemented group (559.00 ± 17.29 ml/day) than their counterparts (407.00 ± 23.59 ml/day). From the study, it could be concluded that fenugreek supplementation alters the hormone profile, enhances feed intake and thereby increases the milk production in lactating goats.

Effects of chronic heat stress on lactational performance and the transcriptomic profile of blood cells in lactating dairy goats.

High temperature is a major stress that negatively affects welfare, health, and productivity of dairy animals. Heat-stressed animals are more prone to disease, suggesting that their immunity is hindered. Although productive and physiologic responses of dairy animals to heat stress are well known, there is still limited information on the response at the transcriptome level. Our objective was to evaluate the changes in performance and blood transcriptomics of dairy goats under heat stress. Eight multiparous Murciano-Granadina dairy goats in mid-lactation were assigned to 1 of 2 climatic treatments for 35 d. Treatments and temperature-humidity index (THI) were: (1) thermal neutral (TN: n = 4; 15-20 °C, 40-45%, THI = 59-65), and (2) heat stress (HS: n = 4; 12 h at 37 °C-40%, THI = 86; 12 h at 30 °C-40%, THI = 77). Rectal temperature, respiratory rate, feed intake and milk yield were recorded daily. Additionally, milk composition was evaluated weekly. Blood samples were collected at d 35 and RNA was extracted for microarray analyses (Affymetrix GeneChip Bovine Genome Array). Differences in rectal temperature and respiratory rate between HS and TN goats were maximal during the first 3 d of the experiment, reduced thereafter, but remained significant throughout the 35-d experimental period. Heat stress reduced feed intake, milk yield, milk protein and milk fat contents by 29, 8, 12, and 13%, respectively. Microarray analysis of blood revealed that 55 genes were up-regulated, whereas 88 were down-regulated by HS. Bioinformatics analysis using the Dynamic Impact Approach revealed that 31 biological pathways were impacted by HS. Pathways associated with leukocyte transendothelial migration, cell adhesion, hematopoietic cell lineage, calcium signaling, and PPAR signaling were negatively impacted by HS, whereas nucleotide metabolism was activated. In conclusion, heat stress not only negatively affected milk production in dairy goats, but also resulted in alterations in the functionality of immune cells, which would make the immune system of heat-stressed goats less capable of fending-off diseases.

Pseudopregnancy and aseasonal breeding in dairy goats: genetic basis of fertility and impact on lifetime productivity

Until recently, the main selection focus in UK dairy goats has been on milk yield. To develop a selection index suitably weighted for a variety of traits, it is important to understand the genetic relationships between production, health and fertility traits. This study focussed on three aspects of reproduction that are of interest to goat breeders. (1) Out of season (OOS) kidding ability: goats are highly seasonal breeders so achieving consistent, year-round dairy production presents a challenge. It may be possible to select for extended or shifted breeding cycles, however, there are no published studies on the genetic basis of seasonal kidding ability, and a genetic correlation with milk production in dairy goats; (2) age at first kidding (AFK): a reduced AFK offers the opportunity for more rapid genetic improvement, as well as reducing the amount of time and resources required to raise the animals to producing age; (3) pseudopregnancy (PPG): as it is difficult to diagnose pregnancy within 30 days of mating, high herd levels of PPG could add a significant delay in breeding replacement animals, or commencing a new lactation. Using records from 9546 goats, the objective of this study was to investigate the genetic relationships between the reproductive traits described above, and the production traits 520-day milk yield (MY520), lifetime milk yield (MYLife) and lifetime number of days in milk (DIMLife). The ‘out of season’ phenotype was defined as week of kidding relative to the 4 weeks of the year where the highest average number of births occur. Incidences of PPG that occurred during the first lactation were used as cases, while goats with none were assigned as controls. Relevant fixed and random effects were fitted in the models. In line with other reproduction traits, heritability estimates were low ranging from 0.08 to 0.11. A negative genetic correlation was found between AFK and MY520 (−0.22±0.10), whereas a positive genetic correlation was found between PPG and DIMLife (0.58±0.11). Pseudopregnancy and OOS were positively genetically correlated (0.36±0.15). All other genetic correlations were very low. The results of this study indicate that selection for the reproductive traits analysed is feasible, without adversely affecting MYLife.

Milk production in dairy goats supplemented with different levels of ruminally protected methionine.

The objective of the study reported in this Research Communication was to evaluate graded levels of ruminally protected methionine (RPM) in dairy goat rations on milk production and live weight changes during 155 d of lactation. Twenty-five primiparous dairy goats (crosses of Toggenburg, French Alpine and Saanen; 45·4 ± 1·0 kg BW) were fed a basal diet (10·10% CP, 6·13 DP and 2·34 Mcal/kg ME) of corn silage, oat hay, alfalfa hay and concentrate (80% forage, 20% concentrate). After kidding, the treatments, which consisted of four oral doses of ruminally protected methionine (RPM) at 0, 1, 2 and 3 g/d, were randomly assigned to the goats. The experiment was conducted for 110 d with measurements of milk production and composition, body weight and dry matter intake. No treatment effects were detected in milk production and composition. However, goats with RPM showed a positive live weight changes during lactation which were improved as dose was increased (linear P < 0·01) whereas goats without RPM showed weight loss during the experiment.

Carbon footprint of dairy goat milk production in New Zealand

The aim of this study was to assess the cradle-to-farm gate carbon footprint of indoor and outdoor dairy goat farming systems in New Zealand, identifying hotspots and discussing variability and methodology. Our study was based on the International Organization for Standardization standards for life cycle assessment, although only results for greenhouse gas emissions are presented. Two functional units were included: tonnes of CO2-equivalents (CO2e) per hectare (ha) and kilograms of CO2e per kilogram of fat- and protein-corrected milk (FPCM). The study covered 5 farms, 2 farming systems, and 3yr. Two methods for the calculation of enteric methane emissions were assessed. The Lassey method, as used in the New Zealand greenhouse gas inventory, provided a more robust estimate of emissions from enteric fermentation and was used in the final calculations. The alternative dry matter intake method was shown to overestimate emissions due to use of anecdotal assumptions around actual consumption of feed. Economic allocation was applied to milk and co-products. Scenario analysis was performed on the allocation method, nitrogen content of manure, manure management, and supplementary feed choice. The average carbon footprint for the indoor farms (n=3) was 11.05 t of CO2e/ha and 0.81kg of CO2e/kg of FPCM. For the outdoor farms (n=2), the average was 5.38 t of CO2e/ha and 1.03kg of CO2e/kg of FPCM. The average for all 5 farms was 8.78 t of CO2e/ha and 0.90kg of CO2e/kg of FPCM. The results showed relatively high variability due to differences in management practices between farms. The 5 farms covered 10% of the total dairy goat farms but may not be representative of an average farm. Methane from enteric fermentation was a major emission source. The use of supplementary feed was highly variable but an important contributor to the carbon footprint. Nitrous oxide can contribute up to 18% of emissions. Indoor goat farming systems produced milk with a significantly higher carbon footprint per area of land farmed compared with outdoor farming systems, although the 2 systems were not significantly different when results were expressed per kilogram of FPCM, at 0.81kg CO2e and 1.03kg CO2e per kg of FPCM, respectively. Both systems had footprints less than other reported dairy goat carbon footprints and on par with those for New Zealand dairy cows. The methodology used to determine enteric methane is important for an accurate and meaningful assessment. The choice of manure management system and supplementary feed can substantially affect the carbon footprint.

Transcriptome analysis of the mammary gland from GH transgenic goats during involution

Mammary glands are organs for milk production in female mammals. Growth hormone (GH) is known to affect the growth and development of the mammary gland, as well as to increase milk production in dairy goats. This study performed a comprehensive expression profiling of genes expressed in the mammary gland of early involution GH transgenic (n=4) and non-transgenic goats (n=4) by RNA sequencing. RNA was extracted from mammary gland tissues collected at day 3 of involution. Gene expression analysis was conducted by Illumina RNA sequencing and sequence reads were assembled and analyzed using TopHat. FPKM (fragments per kilobase of exon per million) values were analyzed for differentially expressed genes using the Cufflinks package. Gene ontology analysis of differentially expressed genes was categorized using agriGO, while KEGG pathway analysis was performed with the online KEGG automatic annotation server. Our results revealed that 75% of NCBI goat annotated genes were expressed during early involution. A total of 18,323 genes were expressed during early involution in GH transgenic goats, compared with 18,196 expressed genes during early involution of non-transgenic goats. In these expressed genes, the majority (17,589) were ubiquitously expressed in GH transgenic and non-transgenic goats. However, there were 745 differentially expressed genes, 421 of which were upregulated and 324 were downregulated in GH transgenic goats. GO and KEGG pathway analysis showed that these genes were involved in mammary gland physiology, including cell adhesion molecules, ECM-receptor interaction, Jak-STAT signaling pathway, and fat metabolism. Our results demonstrated that the GH receptor was strongly affected in GH transgenic goats, which may activate the IGF-1/Stat3 signaling pathway. Overall, our study provided a global view of the transcriptome during involution of GH transgenic and non-transgenic goats, which increases our understanding of the biology of involution in the goat.