Diet change from a system combining total mixed ration and pasture to confinement system (total mixed ration) on milk production and composition, blood biochemistry and behavior of dairy cows

Pasture access and eye temperature in dairy cows

Pasture access can benefit dairy cows' behavior, health, and welfare, but herds are increasingly housed indoors full-time. Recent infrared thermal-imaging (thermography) studies suggest that higher eye temperatures may be a physiological indicator of chronic stress. We, therefore, hypothesized that, compared to cows with pasture access, cows housed indoors full-time would have higher eye temperatures. In a two-phase crossover experiment, 29 Holstein-Friesian dairy cows experienced 18 days of overnight pasture access and 18 days of full-time indoor housing. We measured each animal's eye temperature 16 times (eight/phase). During Phase One, cows with pasture access had higher eye temperatures than cows housed indoors full-time (contrary to our hypothesis). However, during Phase Two, cows with pasture access had lower eye temperatures than cows housed indoors full-time. It is, therefore, unclear whether eye temperature reflected disparities in dairy cow welfare between different housing treatments.

Different Conditions during Confinement in Pasture-Based Systems and Feeding Systems Affect the Fatty Acid Profile in the Milk and Cheese of Holstein Dairy Cows

The diet of dairy cows influences the fatty acid (FA) profiles of their milk and cheese, but how these are affected by different conditions during confinement in a mixed system (MS:grazing + total mixed ration:TMR) is not known. The aim of this study was to compare the FAs of the milk and cheese from MS in a compost-bedded pack barns (CB-GRZ) versus an outdoor soil-bedded pen (OD-GRZ) during confinement, and with a confinement system (100%TMR) in a compost-bedded pack barns (CB-TMR). Individual milk samples (n = 12 cows/group), cheese, and pooled milk (MilkP) samples were collected. The saturated FA percentages in the milk and the omega 6/omega 3 ratio in the MilkP and cheese were greater for the CB-TMR (p < 0.0001), while the unsaturated and monounsaturated FA percentages in the milk were lower for the CB-TMR than the MS (p < 0.001). The milk n-3, C18:3, and conjugated linoleic acid percentages were lower for the CB-TMR than the MS (p < 0.001). The milk n-3 and C18:3 were higher for the CB-GRZ than the OD-GRZ (p < 0.01), but no differences were observed between the MS in the MilkP and cheese. In conclusion, CB-GRZ cows during confinement produced better quality milk compared to OD-GRZ cows. However, the FA profiles of the milk, MilkP, and cheese were affected to a greater extent by the feeding management than by the conditions during confinement.

Short Communication: The effects of heat stress on milk production and the grazing behavior of dairy Holstein cows milked by an automatic milking system

The objective of the present study was to evaluate the productive performance and grazing behavior of 25 primiparous and 44 multiparous Holstein cows in a pasture-based automatic milking system (AMS) while experiencing heat stress (defined as a temperature-humidity index-THI ≥ 68). Productive traits were analyzed according to the THI from days 0, -1, -2, and -3 in relation to the milking day, and grazing behaviors (expressed as the % of daily observation time) were related to the average THI only on the day of observation. Milk yield was not associated with the THI on day 0, but a significant linear relationship was found with the THI on the three previous days, decreasing approximately 0.18 kg (primiparous) and 0.40 kg (multiparous) per THI unit increment. In contrast, for multiparous cows only, the milking frequency was positively associated with the THI on the day of evaluation but not on the previous days, increasing 0.01 milking/THI unit increments. Additionally, for each unit of THI increment, cows spent 0.14% more time standing, whereas they exhibited a decrease in grazing, lying, and ruminating behaviors time by 0.30%, 0.04%, and 0.70%, respectively, for both parities. In conclusion, milk loss was related to heat stress conditions from the previous days, but not milking frequency, which increased with the THI of the same milking day. Lower grazing, lying, and ruminating activities and greater standing behavior were observed due to heat stress.

Milk Fatty Acid Profile of Holstein Cows When Changed from a Mixed System to a Confinement System or Mixed System with Overnight Grazing

This study is aimed at comparing the milk fatty acid profile (FAP) of cows that changed from a mixed system (MS) of double grazing plus total mixed ration (TMR) to a total confinement system (TCS, 100% TMR) with cows that changed to another MS with one overnight grazing plus TMR and compare with cows that were kept unchanged in TCS. The diet change was made in the second month of lactation. The milk samples were collected at one (M1-spring) and three months of lactation (M3-summer). Three treatments are as follows (each n = 10): confined cows fed with TMR throughout the period (GTMR), cows that changed from MS with double grazing plus TMR in M1 to TCS in M3 (GCHD), and cows that changed from a MS with double grazing plus TMR in M1 to a MS with overnight grazing plus TMR in M3 (GTMR+P). Unlike GTMR+P, GCHD improved milk production after change (increased 14% from M1 to M3), but milk FAP was impaired. In M3, conjugated linoleic acid (C18 : 2-CLA) in GTMR and GCHD was lower than GTMR+P (p < 0.05), and linolenic (C18 : 3-n-3) was lower in GCHD than GTMR+P. Maintaining grazing in summer overnight sustained milk fat quality, evidenced by higher C18 : 3 (n-3); C18 : 2 (CLA); and n-6/n-3 ratio than cows that changed to TCS.

Effects of probiotic administration on the digestibility characteristics and growth performance of finishing beef cattle fed a total mixed ration containing different levels of corn stover

In this study, we aimed to assess the effects of probiotic administration on the digestibility characteristics and growth performance of finishing beef cattle fed a total mixed ration (TMR) containing different levels of corn stover. One hundred and sixty Simmental × Continental crossbred bulls were randomly allocated to two animal houses (80 bulls each) and randomly assigned four TMR differing in the level of corn stover-high (HCT) and low (LCT)-with or without probiotics in each animal house. Feeding HCT supplemented with probiotics increased (P < 0.05) the apparent digestibility of crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), and acid detergent fiber (ADF). Regardless of probiotic supplementation, the nitrogen intake and fecal nitrogen levels of animals fed HCT were lower than those fed LCT (P < 0.05). Additionally, feeding probiotics increased (P < 0.05) the efficiency of ruminal fermentation, final body weight, and average daily gain (ADG) of animals, with this effect being stronger in animals fed HCT. In conclusion, supplementing probiotics with HCT has a positive effect on the growth of finishing beef cattle, thereby providing economic benefits.

Growth of foetal bones and metabolic profile during gestation in primiparous ewes and multiparous ewes

Primiparous ewes and multiparous ewes show physiological differences during pregnancy, which can have an impact on the development of their offspring. The objective of this study was to compare the changes in the metabolic profile and in the size of some foetal bones throughout gestation between primiparous and multiparous ewes. Twelve primiparous (PM) ewes and 14 multiparous (MT) ewes were used. According to the dates of lambing, two groups of ewes were formed: Group 1 (G1, n = 6 PM and n = 7 MT) and Group 2 (G2, n = 6 PM and n = 7 MT). The body weight, body condition score, metabolic and foetal morphometric parameters were determined from before conception until the end of gestation. After lambing, the body weight and survival rate during the first 72 hr of life of lambs, as well as the maternal behaviour score were recorded. The PM ewes were lighter (p < .01) and had a greater mobilization of body reserves during gestation, mainly evidenced by a greater serum concentration of NEFAs and lower serum concentration of total proteins (p < .05) compared with the MT ewes. The parity did not affect the foetal morphometric variables. The lambs of MT ewes were heavier at parturition (p = .002) and tended to have a greater survival rate than those lambs of PM ewes (p = .09). In conclusion, PM ewes and MT ewes differ in their metabolic profile throughout the gestation. However, in the present study, we did not find parity differences in the dimensions of foetal bones during growth in gestation.