Impact of Climate Change and Heat Stress on Milk Production in Korean Holstein Cows: A Large-Scale Data Analysis.

This study investigated the effects of heat stress on milk production in Korean Holstein cows using large-scale data. Heat stress was assessed using the temperature-humidity index (THI). Weather records (2016 to 2020) were collected from 70 regional weather stations using an installed automated surface observing system (ASOS). A dataset of 2,094,436 milk production records from 215,276 Holstein cows obtained from the Dairy Cattle Genetic Improvement Center was analyzed. Stepwise selection was used to select the input variables, including the daily maximum THI (THI_max). Least-squares means were calculated for milk yield, fat and protein corrected milk (FPCM), fat and protein yield, fat-to-protein ratio, solids not fat, and lactation persistency. Segmented linear regression analysis determined the break points (BPs) of the THI_max. Over the five years, heat stress exposure increased, particularly from May to September. This study identified BPs around THI_max of 80-82 for milk yield and FPCM. Similar patterns for other milk traits were observed, which significantly decreased beyond their respective BPs. These findings indicate that THI variations adversely affect milk yield and composition in dairy cows, highlighting the importance of appropriate feeding management strategies to ensure the optimal productivity of Holstein cows under varying climatic conditions.

Helix-loop-helix protein ID4 expressed in bovine Sertoli cells.

Stage- and cell type-specific biomarkers are important for understanding spermatogenesis in mammalian testis. The present study identified several testicular cell marker proteins in 6- and 24-month old bovine testes. In 6-month old bovine testes, spermatogonia and spermatocytes were detected but complete spermatogenesis occurred in 24-month old testes. The diameters of the seminiferous tubules increased significantly in the 24-month old testes compared with those in the 6-month old testes. Protein Gene Product 9.5 (PGP9.5), also known as the undifferentiated spermatogonium marker, and GATA4 (GATA binding protein 4), vimentin, and SOX9 (SRY-Box Transcription Factor 9) were detected in the basement membrane region. Interestingly, ID4 (inhibitor of DNA binding protein 4; previously known as the undifferentiated cell marker) proteins were located in the basement membrane region but their expression patterns were different from those of PGP9.5. Co-immunohistochemistry results showed that ID4 was detected in the Sertoli cells expressing vimentin and SOX9 in 6- and 24-month old bovine testes. This result indicated that ID4 is a putative biomarker of Sertoli cell in the bovine system, which is different from the rodent models. Thus, these results will contribute in understanding the process of spermatogenesis that is different in bovines compared to other species.

Analysis of seasonal effect on Korean native cattle (Hanwoo) birth weight.

Recently, summer temperatures have frequently been abnormal in Korea owing to global warming. In summer, a decrease in feed intake rate and biological activity were observed in Hanwoo (Korean Native Cattle), leading to lower production rates in the industry. However, the precise scale of damage was not reported as with other animals of economic value. This study was conducted to investigate the effects of birth season on birth weight in Hanwoo. Data were collected from 100 local breeding farms from 2016 to 2019. A total of 41,081 Hanwoo calves were classified and analyzed by sex, year, month, and season (March-May, spring; June-August, summer; September-November, fall; and December-February, winter) of birth. The birth weight of Hanwoo calves differed according to birth month. The average birth weight of male calves was 30.47 kg and that of female calves was 28.16 kg. Hanwoo birth weight was the highest in March-born calves and the lowest in July-born calves. The birth weights of calves born in February, March, April, November, and December were significantly larger than those of calves born in July. In addition, the birth weight of Hanwoo calves from the summer was significantly lower than that of calves born in other seasons. Furthermore, Hanwoo steer slaughter age showed a negative correlation, whereas carcass weight had a positive correlation with birth weight. In the beef cattle industry, birth weight is a very important economic characteristic that is related to growth rate. These data will contribute toward planning the reproduction of Hanwoo and analysis of changes in characteristics of economic value owing to high temperatures.

Effects of supplementing limiting amino acids on milk production in dairy cows consuming a corn grain and soybean meal-based diet.

Limiting amino acids (AAs) for milk production in dairy cows fed on a concentrate diet of corn grain and soybean meal was evaluated in this study. Four lactating and multiparous Holstein cows (in third or fourth parities, with an average body weight of 633 ± 49.2 kg), 8 to 9 weeks into their lactation period, were used in a 4 × 4 Latin square design. The experiment comprised four dietary treatments: (1) no intravenous infusion (control); (2) control plus intravenous infusion of an AA mixture of 6 g/d methionine, 19.1 g/d lysine, 13.8 g/d isoleucine, and 15.4 g/d valine (4AA); (3) control plus intravenous infusion of the AA mixture without methionine (no-Met); and (4) control plus intravenous infusion of the AA mixture without lysine (no-Lys). All animals were fed on a controlled diet (1 kg/d alfalfa hay, 10 kg/d silage, 14 kg/d concentrate mixture, ad libitum timothy hay). The AA composition of the diet and blood were determined using an automatic AA analyzer. Milk composition (protein, fat, lactose, urea nitrogen, and somatic cell counts) was determined using a MilkoScan. The results showed that feed intake for milk production did not differ from that of intravenous infusion using a limiting AA mixture. The 4AA treatment numerically had the highest milk yield (32.4 kg/d), although there was no difference when compared with the control (31.2 kg/d), no-Met (31.3 kg/d), and no-Lys (31.7 kg/d) treatments. The concentration of AAs in blood plasma of cows in all treatments, mainly isoleucine and valine, increased significantly compared with that of control. The no-Met treatment increased (p < 0.05) the concentration of lysine in the blood relative to the control and no-Lys treatments, whereas the no-Lys treatment increased (p < 0.05) the concentration of methionine relative to the control and no-Met treatments. In conclusion, milk production increased when feeding 10 g/d methionine to the cows, together with their concentrate diet of corn grain and soybean meal.

Supplementing Rhodobacter sphaeroides in the diet of lactating Holstein cows may naturally produce coenzyme Q10-enriched milk.

OBJECTIVE: To examine the effects of Rhodobacter sphaeroides (R. sphaeroides) supplementation as a direct-fed microbial (DFM) on rumen fermentation in dairy cows and on coenzyme Q10 (CoQ10) transition into milk, an in vitro rumen simulation batch culture and an in vivo dairy cow experiment were conducted. METHODS: The characteristics of in vitro ruminal fermentation were investigated using rumen fluids from six cannulated Holstein dairy cows at 2 h post-afternoon feeding. A control treatment was included in the experiments based on a typified total mixed ration (TMR) for lactating dairy cows, which was identical to the one used in the in vivo study, plus R. sphaeroides at 0.1%, 0.3%, and 0.5% TMR dry matter. The in vivo study employed six ruminally cannulated lactating Holstein cows randomly allotted to either the control TMR (C-TMR) treatment or to a diet supplemented with a 0.5% R. sphaeroides culture (S-TMR, dry matter basis) ad libitum. The presence of R. sphaeroides was verified using denaturing gradient gel electrophoresis (DGGE) applied to the bacterial samples obtained from the in vivo study. The concentration of CoQ10 in milk and in the supernatant from the in vitro study was determined using high performance liquid chromatography. RESULTS: The results of the in vitro batch culture and DGGE showed that the concentration of CoQ10 significantly increased after 2 h of R. sphaeroides supplementation above 0.1%. When supplemented to the diet of lactating cows at the level of 0.5%, R. sphaeroides did not present any adverse effect on dry matter intake and milk yield. However, the concentration of CoQ10 in milk dramatically increased, with treated cows producing 70.9% more CoQ10 than control cows. CONCLUSION: The CoQ10 concentration in milk increased via the use of a novel DFM, and R. sphaeroides might be used for producing value-added milk and dairy products in the future.

Rumen fermentation and digestibility of spent mushroom ( Pleurotus ostreatus ) substrate inoculated with Lactobacillus brevis for Hanwoo steers / Fermentación ruminal y digestibilidad de la cama de champiñón (Pleurotus ostreatus) desechada inoculada con Lactobacillus brevis en novillos Hanwoo / Fermentação ruminal e digestibilidade de resíduo de substrato de cogumelo (Pleurotus ostreatus) inoculado com Lactobacillus brevis en novilhos Hanwoo

Abstract Background: Ensiling spent mushroom substrate (SMS) generally increases its nutrient digestibility and quality. Objective: To determine the feed quality and digestibility of SMS from Pleurotus ostreatus (SMSP) inoculated with lactic acid bacteria (LAB: Lactobacillus brevis) in Hanwoo steers. Methods: Ruminal disappearance of SMSP and inoculated SMSP (ISMSP) were evaluated in three rumen-fistulated Hanwoo steers (408 ± 13.0 Kg body weight). Further, three healthy Hanwoo steers (336 ± 69.0 Kg body weight) were randomly allotted to one of three dietary treatments (control: 25% straw, 75% concentrates; treatments: 25% straw, 60% concentrates, and 15% of either SMSP or ISMSP) in a 3×3 Latin square design. Results: The chemical composition of the ISMSP diet did not differ from that of the control or the SMSP diets. In the ISMSP diet, the rate of decrease of pH of ruminal fluid and the increase in storage period was greater than with the SMSP diet. Ruminal disappearance of dry matter, crude protein, neutral detergent fiber, and acid detergent fiber were slightly higher in steers fed ISMSP than those fed SMSP. Furthermore, the degradation rate and effective degradability of crude protein was greater in the ISMSP diet than in the SMSP diet. Effective ruminal fermentation characteristics and total nutrients digestibility were not affected by SMSP nor ISMSP diet. Conclusion: The SMSP and ISMSP diets could replace formulated concentrate without adverse effects and be a cost-effective feed for Hanwoo steers. Furthermore, LAB inoculation improved the SMSP preservation.

Resumen Antecedentes: El ensilado de cama de champiñón desechada (SMS) generalmente aumenta la digestibilidad y la calidad de sus nutrientes. Objetivo: Determinar la calidad del alimento y digestibilidad del SMS a partir de Pleurotus ostreatus (SMSP) inoculado con bacterias ácido-lácticas (LAB: Lactobacillus brevis) en bueyes Hanwoo. Métodos: La desaparición ruminal del SMSP y ISMSP (SMSP inoculado) fue evaluada en tres bueyes Hanwoo fistulados en el rumen (408 ± 13,0 Kg peso corporal). Igualmente, tres bueyes Hanwoo sanos (336 ± 69,0 Kg peso corporal) fueron asignados al azar a uno de los tres tratamientos dietéticos (control: 25% de heno, 75% de concentrados; tratamientos: 25% de heno, 60% de concentrados y 15% de SMSPo ISMSP) en un diseño cuadrado latino 3×3. Resultados: La composición química de la dieta ISMSP no difirió de la del control o de la dieta SMSP. En la dieta ISMSP, la tasa de disminución del pH del fluido ruminal y el incremento del tiempo de almacenamiento fueron mayores que los de la dieta SMSP. La desaparición ruminal de la materia seca, proteína cruda, fibra detergente neutra y la fibra detergente ácida fue ligeramente superior en los bueyes alimentados con el ISMSPque en aquellos alimentados con SMSP. Además, la tasa de degradación y la degradabilidad efectiva de la proteína cruda fueron mayores en la dieta ISMSPque en la dieta SMSP. Las características de la fermentación ruminal efectiva y la digestibilidad total de nutrientes no fueron afectadas por la dieta SMSP ni por la de ISMSP. Conclusión: Las dietas SMSPe ISMSP podrían reemplazar el concentrado formulado sin efectos adversos y ser una alimentación económica para los bueyes Hanwoo. Además, la inoculación con LAB mejoró la conservación del SMSP.

Resumo Antecedentes: Ensilagem de resíduo de substrato de cogumelo (SMS) geralmente aumenta a digestibilidade e a qualidade dos nutrientes. Objetivo: Determinar a qualidade da alimentação e digestibilidade do RSC apartir do Pleurotus ostreatus (SMSP) inoculado com bactérias de ácido láctico (LAB: Lactobacillus brevis) nos novilhos Hanwoo. Métodos: Desaparecimento ruminal do SMSP e ISMSP (SMSP inoculado) foram avaliados em três novilhos Hanwoo fistulados no rúmen (408 ± 13.0 Kg peso corporal). Além disso, três novilhos Hanwoo (336 ± 69.0 Kg peso corporal) foram aleatoriamente distribuídos para um dos três tratamentos dietéticos (controle: 25% palha, 75% concentrado; tratamentos: 25% palha, 60% concentrado, e 15% ambos SMSP e ISMSP) em um quadrado Latino de 3×3. Resultados: A composição química da dieta ISMSP não diferiu do controle ou das dietas SMSP. Na dieta ISMSP, a taxa de diminuição do pH do fluido ruminal e o aumento no período de armazenamento foram melhores do que com a dieta SMSP. O desaparecimento ruminal de matéria seca, proteína bruta, fibra em detergente neutro, e fibra detergente ácido foi ligeiramente superior em novilhos alimentados com ISMSP, do que aqueles alimentados com SMSP. Além disso, a taxa de degradação e degradabilidade da proteína bruta foi maior na dieta ISMSP, do que na dieta SMSP. As características efetivas de fermentação ruminal e a digestibilidade total de nutrientes não foram afetadas pela dieta SMSP, nem pela dieta ISMSP. Conclusão: Dietas com SMSP e ISMSP podem ser utilizados em substituição ao concentrado formulado sem causar efeitos adversos e ser um alimento rentável em novilhos Hanwoo. Além disso, a inoculação com LAB melhorou a qualidade conservante da SMSP.

Dietary Conjugated Linoleic Acid (CLA) increases milk yield without losing body weight in lactating sows.

This study was conducted to evaluate the effects of dietary conjugated linoleic acid (CLA) on the performance of lactating sows and piglets as well as the immunity of piglets suckling from sows fed CLA. Eighteen multiparous Duroc sows with an average body weight (BW) of 232.0 ± 6.38 kg were randomly selected and assigned to two dietary treatments (n = 9 for each treatment), control (no CLA addition) and 1% CLA supplementation. For the control diet, CLA was replaced with soybean oil. Experimental diets were fed to sows during a 28-day lactation period. Litter size for each sow was standardized to nine piglets by cross-fostering within 24 hours after birth. Sow milk and blood samples were taken from sows and piglets after 21 and 27 days of lactation, respectively. Loss of BW was significantly (p < 0.05) higher in sows fed control diet compared to sows fed CLA diet. Piglet weights at weaning and weight gain during suckling were significantly (p < 0.05) higher in sows fed CLA compared to sows fed control diet. Serum non-esterified fatty acid (NEFA) and urea nitrogen concentrations were significantly (p < 0.05) lower in sows fed CLA than in sows fed soybean oil. IgG concentrations of the groups supplemented with CLA increased by 49% in sow serum (p < 0.0001), 23% in milk (p < 0.05), and 35% in piglet serum (p < 0.05) compared with the control group. Sows fed CLA showed an increase of 10% in milk yield compared with sows fed soybean oil (p < 0.05), even though there was no difference in daily feed intake between the treatments. Milk fat content was significantly (p < 0.05) lower in sows fed CLA than in sows fed soybean oil. Solid-not-fat yield was significantly (p < 0.05) higher in sows supplemented with CLA than in sows fed control diet and also protein-to-fat ratio in milk was significantly (p < 0.05) higher in sows fed CLA compared with the control group. The results show that CLA supplementation to sows increased milk yield without losing BW during lactation, whereas soybean oil supplementation resulted in severe BW loss.