Rice straw is a readily available, practical, and cheap source of fodder for feeding ruminants such as buffaloes, cattle, goats, and sheep. Livestock producers commonly haul and stack rice straw from their rice farm, which then forms reserved feed for their animals during lean months or when good-quality roughages are scarce. The feeding of pure rice straw to ruminants during the stages of fast growth and early lactation has been shown to affect both body condition score and animal performance. This is due to lower dry matter intake and protein content (from 4.0% to 4.7% crude protein) of the straw. The high silica and lignin contents of straw also contribute to poor nutrient (dry matter and protein) digestibility (<50%). So, pretreatment of straw is necessary to enhance its contribution to improving meat and milk production. Science- and technology-based farm strategies to optimize the nutritive and feeding values of rice straw had been developed with significant improvement on intake, nutrient digestibility, and animal performance. These technologies were also proven effective in contributing additional income to livestock producers from the sales of milk or live animals. This chapter presents and discusses current innovations and developed technologies on how the nutritive (nutrient composition and fiber fraction) and feeding values of rice straw can be improved. Specifically, this focuses on pretreatment (optimization process), enrichment, and recycling of rice straw by physical, chemical, and biological processes. Also covered are practical feeding protocols when rice straw—or its combination with other feed ingredients—is used in formulating a ration. The authors also share secondary information on the effect of rice straw as animal fodder on the improvement in animal performance and production efficiencies; as well as its impact on food production (meat and milk), increasing farmers’ income, and on the protection of the environment.

Smallholder dairy farms (SDFs) are distributed widely across lowland and highland regions in Vietnam, but data on the productivity and welfare status of these cows remains limited. This cross-sectional study was conducted to describe and compare the productivity and welfare status of SDF cows across contrasting regions. It was conducted in autumn 2017 on 32 SDFs randomly selected from four typical but contrasting dairy regions (eight SDFs per region); a south lowland, a south highland, a north lowland, and a north highland region. Each farm was visited over a 24-h period (an afternoon followed by a morning milking and adjacent husbandry activities) to collect data of individual lactating cows (n = 345) and dry cows (n = 123), which included: milk yield and concentrations, body weight (BW), body condition score (BCS, 5-point scale, 5 = very fat), inseminations per conception, and level of heat stress experienced (panting score, 4.5-point scale, 0 = no stress). The high level of heat stress (96% of lactating cows were moderate to highly heat-stressed in the afternoon), low energy corrected milk yield (15.7 kg/cow/d), low percentage of lactating cows (37.3% herd), low BW (498 and 521 kg in lactating and dry cows, respectively), and low BCS of lactating cows (2.8) were the most important productivity and welfare concerns determined and these were most serious in the south lowland. By contrast, cows in the north lowland, a relatively hot but new dairying region, performed similarly to those in the south highland; a region historically considered to be one of the most suitable for dairy cows in Vietnam due to its cool environment. This indicates the potential to mitigate heat stress through new husbandry strategies. Cows in the north highland had the highest BW (535 and 569 kg in lactating and dry cows, respectively) and the highest energy corrected milk yield (19.2 kg/cow/d). Cows in all regions were heat-stressed during the daytime, although less so in the highlands compared to the lowlands. Opportunities for research into improving the productivity and welfare of Vietnamese SDF cows are discussed.

A limited literature suggests relatively simple feeding regimes and diet formulation strategies for dairy cows in Vietnamese smallholder dairy farms (SDFs). This study aimed to classify and compare feeding regimes and nutrient balance for lactating cows between four typical dairy regions (south lowland, south highland, north lowland, and north highland) in Vietnam and evaluate the possibility of systematic dietary imbalance. Eight SDFs from each of the four regions were visited for two adjacent milking periods per farm. For each visit, frequency and methods of feed and water supply to the lactating cows were recorded, and individual fat corrected milk yield (ECM) of lactating cows were calculated from milk yield and fat concentration. The amount of each diet ingredient offered and refused by each lactating group was weighed and sampled for calculation of dry matter intake per cow (DMI) and analysis of nutrient composition in the component offered. PCDairy, a diet formulation computer model, was used to calculate actual and recommended dietary nutrient concentrations and predict potential milk production. Factor analysis, cluster analysis, and ANOVA were applied to determine grouping effects across as well as between regions. Feeding regimes and diets were grouped into three and nine clusters, respectively. Farmers in the same region tended to apply similar diets and feeding regimes. Across regions, only 47% of all SDFs supplied water ad libitum to the cows. The most used roughages including Napier grass, corn silage, fresh corn with cob, and rice straw were all relatively high in neutral detergent fibre (NDF), acid detergent fibre (ADF), and acid detergent lignin (ADL). The diets in all regions were excessive in crude protein, NDF, ADF, ADL, and most minerals (Ca, P, Mg, K, Na, S, Fe, Zn, Cu, and Mn) but insufficient in net energy and non-fibre carbohydrate. Feed efficiency (1.06 kg FCM/kg DMI) of the diets were sub-optimal. Feeding regimes and dietary nutrient balance of the south lowland SDFs were most problematic. Increasing dietary net energy concentration by increasing the use of starch and fat and decreasing dietary fibre concentration by decreasing the use of Napier grass or rice straw to balance the diets might help improve the milk production and thereby increase feed efficiency.

Up to now, the definitive conclusion of the positive effects of rapid transient thawing at higher temperatures for shorter durations has not been obtained yet and is still under discussion due to some contradictory findings and limited assessment of post-thawed parameters. The purpose of the current study was to evaluate the effectiveness of rapid thawing in water at 70 °C by using various post-thawed parameters of frozen bull spermatozoa. Experiment 1, monitoring the change of temperature inside frozen bull straw thawed in water at different temperatures. Experiment 2, evaluation of various post-thawed characteristics of frozen bull spermatozoa thawed in water at different temperatures by using a computer-assisted sperm analysis, flow cytometry and immunocytochemistry. The time it took for the temperature inside the straw to warm up to 15 °C was nearly twice as faster when the straw was thawed in 70 °C water compared with 39 °C. Although there were differences among bulls, viability, motility, and mitochondrial membrane potential of spermatozoa thawed at 70 °C for 8 seconds and stabilized at 39 °C for 52 seconds were significantly higher than those of controls (thawed at 39 °C for 60 seconds) at 0 and 3 h after thawing. Just after thawing, however, there were no differences in acrosome integrity and distribution of phospholipase C zeta1, whereas mitochondrial reactive oxygen species production was significantly lower in spermatozoa thawed at 70 °C. From these results, we conclude that rapid thawing at 70 °C and then stabilization at 39 °C significantly improves viability, motility and mitochondrial health of bull spermatozoa rather than conventional thawing at 39 °C. The beneficial effect of rapid transient thawing could be due to shorter exposure to temperatures outside the physiological range, consequently maintaining mitochondrial health.

The objective of this study was to evaluate effects of dietary supplementation of a seaweed-originated product (SOP) on milk productivity, milk quality and health of milking cows under Vietnam weather conditions at the dairy farm of One Member Dairy and Beef Joint Stock Company HCMC, Vietnam from October 2019 to February 2020. A total of 40 Holstein Friesian crossbred cows were randomly allotted into 2 treatments in a randomized complete block design. The 2 dietary treatments included (1) cows fed a basal ration without SOP supplementation (control) and (2) control plus 70 g SOP/cow per day (about 0.35% dry matter intake/day). Parity, days in milk, body weight, and milk yield of cows in both treatments were almost equal (P > 0.05). The results showed that the average milk yield of cows over the experimental period was not different between the two treatments (P > 0.05), but the lactation stability curve was better in SOP group. The SOP supplementation also did not improve milk quality indicators (fat, protein, solids not fat, lactose, somatic cell count) as compared with the control (P > 0.05). The blood ketone level of cows in the control group was higher than that of cows in the SOP group (P < 0.05), although there were no differences in the blood levels of AST, ALT, protein, glucose, cholesterol, cortisol (P > 0.05). The SOP supplementation did not affect BW, body condition score, and locomotion score as well as the prevalences of lameness and digestive diseases (P > 0.05). Briefly, these results suggest that the dietary SOP addition of 70 g/cow per day appears not to improve milk productivity, milk quality and health of milking cows.

The objective of this study was to evaluate the efficacy of propylene glycol (PG) on prevention and treatment of ketosis in dairy cows from 09/2018 to 03/2019. The study consisted of 2 experiments using a total of 126 multiparous dairy cows in a HF crossbred herd. Cows in both experiments were randomly assigned to treatments in a randomized complete block design. In Exp. 1, 96 cows without ketosis disease (BHBA < 1.4 mmol/L) were assigned to 2 groups (48 cows/group), including (1) untreated control group (no PG) and (2) treatment group (oral PG for 3 consecutive days after parturition). In Exp. 2, 30 ketotic cows (BHBA ≥ 1.4 mmol/L) were divided into 3 groups (10 cows/group), including (1) cows provided with glucose + vitamin B12 + dexamethasone (TT1), (2) cows treated with PG for 3 days (TT2), and (3) combination of TT1 and TT2 (TT3). The results of the Exp. 1 showed that the proportion of ketotic cows was lower (P < 0.01) in the PG-treated group (18.75%) than in the control group (47.92%). The PG treatment also reduced (P < 0.01) the blood ketone concentration of cows as compared with the control without PG use (0.89 vs. 1.22 mmol/L). In the Exp. 2, after treatment the reduction of blood ketone concentration was much greater (P < 0.01) in TT3 cows (1.97 mmol/L) than in TT2 cows (1.30 mmol/L) and TT1 cows (1.23 mmol/L). The percentage of cows recovered from ketosis was greatest in TT3 (90%), followed by TT2 (60%), and then TT1 (50%) (P > 0.05).